阅读说明：本技术 等离子体处理设备中具有成角度的喷嘴的气体供给装置 (Gas supply device with angled nozzle in plasma processing apparatus ) 是由 T·F·王 Y·马 楊雲 马绍铭 M-H·基姆 P·J·伦贝西斯 瑞安·M·帕库尔斯基 于 2020-02-05 设计创作，主要内容包括：提供了等离子体处理设备和相关的方法。在一个示例实施方式中,所述等离子体处理设备可包括位于等离子体处理设备的处理腔室中的气体供给装置,例如感应耦合等离子体处理设备。该气体供给装置可包括一个或多个喷嘴。所述一个或多个喷嘴中的每一个可相对于与工件半径平行的方向成角度,以产生与所述工件中心垂直方向的旋转气流。这样的气体供给装置可改善工艺均匀性、工件边缘关键尺寸调节、气体离子化效率和/或所述处理腔室中的对称流,以减少工件上的颗粒沉积,并且还可以降低来自停滞流的热积聚。(Plasma processing apparatus and associated methods are provided. In one example embodiment, the plasma processing apparatus may include a gas supply located in a process chamber of the plasma processing apparatus, such as an inductively coupled plasma processing apparatus. The gas supply means may comprise one or more nozzles. Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow in a direction perpendicular to a center of the workpiece. Such gas supplies may improve process uniformity, workpiece edge critical dimension tuning, gas ionization efficiency, and/or symmetric flow in the processing chamber to reduce particle deposition on the workpiece, and may also reduce heat accumulation from stagnant flow.)

1. A plasma processing apparatus, comprising:

a process chamber having a workpiece support configured to support a workpiece during plasma processing;

an inductively coupled plasma source configured to induce a plasma in a process gas in the processing chamber;

a gas supply configured to deliver the process gas to the processing chamber, wherein the gas supply comprises one or more nozzles, wherein each of the one or more nozzles is angled with respect to a direction parallel to a radius of a workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

2. The plasma processing apparatus of claim 1, wherein the gas supply is located in a ceiling of the process chamber such that the gas supply delivers the process gas into the process chamber from a top of the process chamber.

3. The plasma processing apparatus of claim 1, wherein the gas supply is integrated with a sidewall of the process chamber.

4. The plasma processing apparatus of claim 3, wherein at least one of the one or more nozzles delivers the process gas to a location downstream of the inductively coupled plasma source.

5. The plasma processing apparatus of claim 1, wherein at least one of the one or more nozzles is angled upward relative to the workpiece.

6. The plasma processing apparatus of claim 1, wherein the gas supply comprises at least one gas manifold comprising the one or more nozzles.

7. The plasma processing apparatus of claim 1, wherein the one or more nozzles are angled in a clockwise direction to generate a clockwise gas flow relative to a direction perpendicular to a center of the workpiece.

8. The plasma processing apparatus of claim 7, wherein an angle between each of the one or more nozzles and a direction parallel to a radius of the workpiece is no more than about 60 degrees.

9. The plasma processing apparatus of claim 1, wherein the one or more nozzles are angled in a counterclockwise direction to generate a counterclockwise gas flow relative to a direction perpendicular to the center of the workpiece.

10. The plasma processing apparatus of claim 9, wherein an angle between each of the one or more nozzles and the workpiece radius parallel direction is no more than about 60 degrees.

11. A method of processing a workpiece, comprising:

disposing the workpiece on a workpiece support in a processing chamber;

admitting a process gas into the process chamber through a gas supply;

generating a plasma in the process gas in the process chamber;

exposing the workpiece to the plasma-generated one or more species;

wherein the gas supply comprises one or more nozzles, each of the one or more nozzles being angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

12. The method of claim 11, wherein the gas supply is integrated with a ceiling of the processing chamber such that the gas supply delivers the process gas into the processing chamber from a top of the processing chamber.

13. The method of claim 11, wherein the gas supply is integrated with a sidewall of the process chamber.

14. The method of claim 13, wherein at least one of the one or more nozzles delivers the process gas from a plasma source to a downstream location to induce plasma.

15. The method of claim 11, wherein at least one of the one or more nozzles is angled upward relative to the workpiece.

16. The method of claim 11, wherein the gas supply comprises at least one gas manifold comprising the one or more nozzles.

17. The method of claim 11, wherein the one or more nozzles are angled in a clockwise direction to generate a clockwise airflow relative to a direction perpendicular to the workpiece center.

18. The method of claim 11, wherein an angle between each of the one or more nozzles and the parallel to the radius of the workpiece is no more than about 60 degrees.

19. The method of claim 11, wherein the one or more nozzles are angled in a counterclockwise direction to generate a counterclockwise airflow relative to a direction perpendicular to the center of the workpiece.

20. The method of claim 11, wherein an angle between each of the one or more nozzles and the parallel to the radius of the workpiece is no more than about 60 degrees.

Technical Field

The present disclosure relates generally to gas supplies for plasma processing apparatuses and systems.

Background

Plasma processing tools can be used in the manufacture of devices such as integrated circuits, micromechanical devices, flat panel displays, and other devices. Plasma processing tools used in modern plasma etch and/or photoresist removal applications are required to provide high plasma uniformity and multiple plasma controls, including individual plasma profile, plasma density, and ion energy control. In some cases, plasma processing tools may be required to provide good and uniform coverage against the wafer and good control of critical dimension adjustment at the wafer edge.

Disclosure of Invention

Aspects and advantages of the present disclosure will be set forth in part in the following description, or may be learned from the description, or may be learned through practice of the embodiments.

One exemplary aspect of the present disclosure is directed to a plasma processing apparatus. The plasma processing apparatus may include a process chamber having a workpiece support. The workpiece support may support a workpiece during plasma processing. The plasma processing apparatus may include an inductively coupled plasma source to induce a plasma in a process gas in a processing chamber. The plasma processing apparatus may include a gas supply for delivering a process gas to the processing chamber. The gas supply means may comprise one or more nozzles. Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

Another exemplary aspect of the present disclosure is directed to a method of processing a workpiece. The method may include placing a workpiece on a process support in a process chamber. The method may include admitting a process gas into the processing chamber through a gas supply. The method may include generating a plasma in a process gas in a processing chamber. The method may include exposing the workpiece to one or more species generated by the plasma. The gas supply means may comprise one or more nozzles. Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

Variations and modifications may be made to the embodiments of the present disclosure.

These and other features, aspects, and advantages of various embodiments will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles involved.

Drawings

A detailed discussion of embodiments directed to one of ordinary skill in the art is set forth in detail in the specification, which makes reference to the appended drawings, in which:

FIG. 1 depicts an exemplary plasma processing apparatus according to an exemplary embodiment of the present disclosure;

FIG. 2 depicts one example gas supply apparatus according to an example embodiment of the present disclosure;

FIG. 3 depicts an exemplary gas supply apparatus according to an exemplary embodiment of the present disclosure;

FIG. 4 depicts an exemplary plasma processing apparatus according to an exemplary embodiment of the present disclosure;

FIG. 5 depicts an exemplary gas supply apparatus according to an exemplary embodiment of the present disclosure;

FIG. 6 depicts one exemplary cross-sectional view of an edge gas nozzle according to an exemplary embodiment of the present disclosure;

FIG. 7 depicts one exemplary cross-sectional view of an edge gas nozzle according to an exemplary embodiment of the present disclosure;

FIG. 8 depicts an exemplary plasma processing apparatus according to an exemplary embodiment of the present disclosure;

FIG. 9 depicts a flowchart of one exemplary method according to an exemplary embodiment of the present disclosure;

FIG. 10 depicts an example gas supply velocity comparison between a gas supply and one example gas supply in accordance with an example embodiment of the present disclosure;

FIG. 11 depicts an example mass fraction comparison between a gas supply and an example gas supply in accordance with example embodiments of the present disclosure; and

fig. 12 depicts a comparison of gas mass fraction distribution over an exemplary workpiece surface between a gas supply and an exemplary gas supply in accordance with exemplary embodiments of the present disclosure.

Detailed Description

Reference now will be made in detail to embodiments, one or more examples of which are illustrated in the drawings. Each example is provided as an explanation of the embodiment, and does not limit the present disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, aspects of the present disclosure are intended to cover such modifications and variations.

Exemplary aspects of the present disclosure are directed to a plasma processing apparatus and associated methods. The plasma processing apparatus may include a gas supply, such as an inductively coupled plasma processing apparatus, located in a process chamber of the plasma processing apparatus. The gas supply means may comprise one or more nozzles (e.g. gas nozzles). Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece. Because the nozzles of the gas supply are not orthogonal to the edge of the workpiece, and the nozzles are not arranged in a symmetrical gas injection pattern, such gas supplies can improve process uniformity (e.g., uniformity between different workpieces, azimuthal etch uniformity at the edge of the workpiece, etchant mass fraction uniformity at the surface of the workpiece, and/or flow velocity uniformity at the surface of the workpiece), workpiece edge critical dimension tuning, gas ionization efficiency, and/or symmetrical flow within the processing chamber reduces particle deposition on the workpiece, and can also reduce heat buildup from stagnant flow.

According to an exemplary aspect of the present disclosure, the gas supply apparatus may be integrated with a sidewall of the plasma processing chamber. The gas supply may have nozzles arranged in azimuthally symmetric gas injection for critical dimension and/or uniformity adjustment of the edge of the workpiece. In some embodiments, the gas supply may include one or more gas manifolds. Each gas manifold may be integrated with the plasma processing chamber housing and/or the liner. Each gas manifold may be parallel to the plane of the workpiece. The distance between the gas manifold and the workpiece plane can be determined by calculation and/or various process test results. Each gas manifold may include one or more gas nozzles for delivering a flow of gas around or toward the periphery of the workpiece. Each nozzle in each gas manifold may be angled relative to a direction parallel to a radius of the workpiece to generate a rotating gas flow relative to a direction perpendicular to a center of the workpiece. As one example, the nozzles may be angled in a clockwise or counterclockwise direction to produce a clockwise or counterclockwise airflow relative to a direction perpendicular to the center of the workpiece. The angle between each nozzle and the direction parallel to the radius of the workpiece may be no more than about 60 degrees, for example in the range of 15 degrees to about 45 degrees. In some embodiments, at least one nozzle of the gas manifold may be angled upward or downward toward the workpiece. In some embodiments, the nozzles of the gas manifold may be oriented diagonally toward the plane of the workpiece.

In some embodiments, the plasma processing chamber liner may have a gas manifold. The gas manifold may include a set of nozzles (e.g., about 4 to about 30 individual nozzles). The nozzles may be arranged to target the edge of the workpiece and may be angled with respect to a direction parallel to the radius of the workpiece. The nozzles may also be angled downwardly from the plane of the workpiece to generate a rotating gas flow relative to a direction perpendicular to the center of the workpiece. This can become a way to adjust or fine-tune the gas flow concentration near the edge of the workpiece. It may also combine top and edge flow injection to change chamber flow conditions.

In some embodiments, at least one gas inlet may be used for a circular gas manifold. For example, two gas inlets may be used to flow gas into a gas manifold. The two gas inlets may be configured close to each other so that each nozzle 220/fitting may be used to deliver gas from a single delivery line. Within the gas manifold, gas particles from each gas inlet may collide with or push away from each other. Thus, a two port design may provide better gas distribution for the nozzle than a single gas port design.

According to an exemplary aspect of the present disclosure, the gas supply may be located in a ceiling of the plasma processing chamber (e.g., on a top dome of the processing chamber). The nozzles may be located at the center and/or at one or more edges of the gas supply. The nozzles may be arranged in an azimuthally symmetric gas injection pattern with respect to a direction perpendicular to the center of the workpiece. For example, each nozzle may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to the center of the workpiece. As one example, the nozzles may be angled in a clockwise or counterclockwise direction to produce a clockwise or counterclockwise airflow relative to a direction perpendicular to the center of the workpiece. The angle between each nozzle and the direction parallel to the radius of the workpiece may be no more than about 60 degrees, for example in the range of 15 degrees to about 45 degrees. In some embodiments, at least one nozzle is angled upwardly or downwardly toward the workpiece.

One exemplary aspect of the present disclosure is directed to a plasma processing apparatus. The processing chamber may include a workpiece support for supporting a workpiece during plasma processing. The processing chamber may include an inductively coupled plasma source to induce a plasma in the process gas in the processing chamber. The process chamber may include a gas supply for delivering a process gas to the process chamber. The gas supply means may comprise one or more nozzles. Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

In some embodiments, the gas supply may be integrated with a sidewall of the process chamber. In some embodiments, the gas supply may comprise at least one gas manifold, which may comprise one or more nozzles. In some embodiments, at least one nozzle may deliver the process gas at a location downstream of the inductively coupled plasma source. In some embodiments, the nozzles may be angled in a clockwise or counterclockwise direction to generate a clockwise or counterclockwise airflow relative to a direction perpendicular to the center of the workpiece. The angle between each nozzle and the direction parallel to the radius of the workpiece may be no more than about 60 degrees, for example about 15 degrees to about 45 degrees. In some embodiments, at least one nozzle of the gas manifold is angled upwardly or downwardly toward the workpiece.

One exemplary aspect of the present disclosure is directed to a method of processing a workpiece. The method may include placing a workpiece on a process support in a process chamber. The method may include admitting a process gas into the processing chamber through a gas supply. The method may include generating a plasma in a process gas in a processing chamber. The method may include exposing the workpiece to one or more species generated by the plasma. The gas supply means may comprise one or more nozzles. Each of the one or more nozzles may be angled with respect to a direction parallel to a radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to a center of the workpiece.

Exemplary aspects of the present disclosure may provide some technical effects and benefits. For example, the nozzles of a gas supply in plasma processing may be angled with respect to a direction parallel to the radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to the center of the workpiece. Thus, such gas supplies may have a larger process window to improve etch throughput and critical dimension azimuthal symmetry. The gas supply also improves workpiece edge critical dimension adjustability, uniformity from workpiece to workpiece, and chamber wall plasma dry cleaning efficiency. The gas may also reduce particle deposition on the workpiece and gas purge time during workpiece transfer or step transitions.

For purposes of example and discussion, exemplary aspects of the present disclosure are discussed with reference to an inductive plasma source. Using the disclosure provided herein, one skilled in the art will appreciate that other plasma sources may be used without departing from the scope of the disclosure. For example, a plasma processing apparatus may include an inductively coupled plasma source having an electrostatic shield. The plasma processing apparatus may include an inductively coupled plasma source without an electrostatic shield. The plasma processing apparatus may include a capacitively coupled plasma source (e.g., using a bias disposed in, for example, a pedestal or a workpiece support).

For purposes of example and discussion, aspects of the present disclosure are discussed with reference to a "workpiece" being a "semiconductor wafer". Using the disclosure provided herein, one of ordinary skill in the art will appreciate that the exemplary aspects of the disclosure may be used in association with any semiconductor substrate or other suitable substrate. Also, the term "about" used in connection with a numerical value means within ten percent (10%) of the stated numerical value. "susceptor" refers to any structure that can be used to support a workpiece.

Fig. 1 depicts an exemplary plasma processing apparatus 100 according to an exemplary embodiment of the present disclosure. The plasma processing apparatus 100 includes a process chamber defining an interior space 102. A pedestal or workpiece support 104 is provided for supporting a workpiece 106, such as a semiconductor wafer, within the interior space 102. A dielectric window 110 is located above the workpiece holder 104. The dielectric window 110 includes a relatively flat central portion 112 and an angled peripheral portion 114. The dielectric window 110 includes a space in the central portion 112 for a showerhead 120 for supplying process gas into the interior space 102.

The apparatus 100 further includes a plurality of inductive elements, such as a primary inductive element 130 and a secondary inductive element 140, for generating an inductive plasma in the interior space 102. The inductive elements 130, 140 may include coils or antenna elements that induce a plasma in the process gas in the interior space 102 of the plasma processing apparatus 100 when supplied with RF power. For example, the first RF motor 160 may be configured to provide electromagnetic energy to the primary inductive element 130 through the matching network 162. The second RF motor 170 may be configured to provide electromagnetic energy to the secondary inductive element 140 through the matching network 172.

Although the present disclosure refers to primary and secondary sensing, those skilled in the art will appreciate that the terms "primary" and "secondary" are used for convenience only. The secondary coil may operate independently of the primary coil and vice versa.

Although the present disclosure refers to primary and secondary sensing, those skilled in the art will appreciate that the device need not include them entirely. The device may include one or more (e.g., one or two) primary and secondary inductive elements.

The apparatus 100 may include a metal barrier section 152 disposed around the secondary inductive element 140. The metal barrier section 152 separates the primary inductive element 130 and the secondary inductive element 140 to reduce cross-talk between the inductive elements 130, 140. The apparatus 100 can further include a faraday barrier 154 disposed between the primary inductive element 130 and the dielectric window 130. The faraday barrier 154 may be a slotted metal shield that reduces capacitive coupling between the primary inductive element 154 and the processing chamber 102. As shown, the faraday barrier 154 can fit over the angled portion of the dielectric barrier 110.

In one embodiment, the metal barrier 152 and the faraday barrier 154 may form a single body 150 for ease of manufacturing and other purposes. The multi-turn coil of the primary inductive element 130 can be located adjacent to the faraday barrier portion 154 of the single-piece metal barrier/faraday barrier 150. The secondary inductive element 140 can be located in close proximity to the metal barrier portion 152 of the unitary metal barrier/faraday barrier 150, such as between the metal barrier portion 152 and the dielectric window 110.

Arranging the primary and secondary inductive elements 130, 140 on opposite sides of the metal barrier 152 allows the primary and secondary inductive elements 130, 140 to have distinct structural configurations and perform different functions. For example, the primary inductive element 130 may include a multi-turn coil located adjacent to a peripheral portion of the process chamber. The primary inductive element 130 can be used for reliable starting during the basic plasma generation and inherent transient ignition phases. The primary inductive element 130 may be coupled to a powerful RF motor and expensive auto-tune matching network, and may operate at increased RF frequencies (e.g., at about 13.56 MHz).

The secondary inductive element 140 can be used for corrective and support functions and for improving the stability of the plasma during steady state operation. Since the secondary inductive element 140 may be used primarily for corrective and support functions and to improve the stability of the plasma during steady state operation, the secondary inductive element 140 does not need to be coupled to a powerful RF motor like the first inductive element 130, may be designed differently, and effectively overcomes the difficulties associated with previous designs. In some cases, the secondary inductive element 140 may also operate at lower frequencies (e.g., at about 2MHz), allowing the secondary inductive element 140 to be very compact and fit in a confined space on top of the dielectric window.

The primary inductive element 130 and the secondary inductive element 140 may operate at different frequencies. The frequencies may be completely different to reduce cross talk between the primary inductive element 130 and the secondary inductive element 140. Interference between the inductive elements 130, 140 is reduced due to the different frequencies that may be applied to the primary inductive element 130 and the secondary inductive element 140. More specifically, in a plasma, the only interaction between the inductive elements 130, 140 is through the plasma density. Accordingly, no phase synchronization is required between the RF motor 160 coupled to the primary inductive element 130 and the RF motor 170 coupled to the secondary inductive element 140. Power control between the inductive elements is independent. Moreover, since the inductive elements 130, 140 operate at significantly different frequencies, it is practical to use frequency adjustment of the RF motors 160, 170 to match the power delivered to the plasma, significantly simplifying the design and cost of any additional matching networks.

For example (not shown in fig. 1), the secondary inductive element 140 may include a planar coil and a flux concentrator. The flux concentrator may be made of a ferrite material. The use of a magnetic flux concentrator with appropriate coils provides high plasma coupling efficiency and good energy conversion efficiency of the secondary inductive element 140 and significantly reduces its coupling to the metal barrier 150. Using a lower frequency (e.g., about 2MHz) on the secondary inductive element 140 increases the skin, which also improves plasma heating efficiency.

In some embodiments, different inductive elements 130 and 140 may perform different functions. Specifically, only the primary inductive element 130 is required to perform the most important function of plasma generation during ignition and to provide sufficient activation for the secondary inductive element 140. The primary inductive element 130 may participate in the operation of an Inductively Coupled Plasma (ICP) tool and should be coupled to the plasma and the grounded barrier to stabilize the plasma potential. The faraday barrier 154 associated with the first inductive element 130 can avoid window sputtering and can be used to provide ground coupling.

As shown in fig. 1, a gas supply 190 delivers process gas into the process chamber 102 in accordance with an exemplary aspect of the present disclosure. The gas supply 190 is integrated with the sidewall of the process chamber 102.0. The gas supply 190 includes a plurality of gas nozzles 122 having supply gas ports. Each nozzle may be angled with respect to a direction parallel to a radius of the workpiece 106 to generate a rotating gas flow with respect to a direction perpendicular to the center of the workpiece 106. In some embodiments (not shown in fig. 1), the gas supply 190 may include one or more gas manifolds. Each gas manifold may be integrated with the process chamber barrier and/or liner 102. Each gas manifold may be parallel to the workpiece 106. The distance between the gas manifold and the workpiece 106 can be determined by calculation and/or various process test results. Each gas manifold may include one or more gas nozzles 122 that deliver a flow of gas around or toward the periphery of the workpiece 106. As one example, the nozzles 122 may be angled in a clockwise or counterclockwise direction to generate a clockwise or counterclockwise airflow relative to a direction perpendicular to the center of the workpiece 106. The angle between each nozzle and the direction parallel to the radius of the workpiece 106 may be no more than about 60 degrees, such as in the range of 15 degrees to about 45 degrees. In some embodiments, at least one nozzle of the gas manifold may be angled upward or downward toward the workpiece. In some embodiments, the nozzles 122 of the gas manifold may be oriented diagonally toward the plane of the workpiece. Examples are further illustrated in fig. 2 and 3.

In some embodiments (not shown in fig. 1), at least one gas inlet may be used for a circular gas manifold. For example, two gas inlets may be used to flow gas into a gas manifold. The two gas inlets may be configured close to each other so that each nozzle 220/fitting may be used to deliver gas from a single delivery line. Within the gas manifold, gas particles from each gas inlet may collide with or push away from each other. Thus, a two port design may provide better gas distribution for the nozzle than a single gas port design. Examples are further illustrated in fig. 2 and 3.

Fig. 2 depicts one example gas supply apparatus 200 according to an example embodiment of the present disclosure. The gas supply apparatus 200 may be one of the embodiments of the gas supply apparatus 190 shown in fig. 1. The gas supply 200 includes a gas manifold 210. The gas manifold 210 includes a set of gas nozzles 220 (e.g., about 15 gas nozzles). The nozzle 220 is arranged to be aimed at an edge of a workpiece (e.g., the workpiece 106 shown in fig. 1). Each nozzle 220 is angled relative to a direction 250 parallel to the radius of the workpiece. For example, the angle 255 between the nozzle 220 and the direction 250 parallel to the radius of the workpiece may be no more than about 60 degrees, such as in the range of 15 degrees to about 45 degrees. As shown in fig. 2, the nozzle 220 is angled in a counterclockwise direction to generate a counterclockwise gas flow 230 relative to a direction 260 perpendicular to the center of the workpiece. In some embodiments (not shown in fig. 2), one or more nozzles 220 may be angled upward or downward toward the workpiece to create a counter-clockwise airflow 230. In some embodiments (not shown in fig. 2), the nozzle 220 may be oriented diagonally toward the workpiece. This may become a way of adjusting or fine-tuning the gas flow concentration near the edge of the workpiece.

As shown in fig. 2, the gas manifold 210 includes two gas inlets 240. The two gas inlets 240 are used to flow gas into the gas manifold 210. The two gas inlets 240 are located close to each other so that a small size three-way adapter/fitting can be used to deliver gas from a single delivery line. Within the gas manifold, gas particles from each gas inlet may collide with or push away from each other. Thus, a two port design may provide better gas distribution for the nozzle 220.

Fig. 3 depicts one example gas supply apparatus 300 according to an example embodiment of the present disclosure. The gas supply apparatus 300 may be one of the embodiments of the gas supply apparatus 190 shown in fig. 1. The gas supply 300 includes a gas manifold 310. The gas manifold 310 includes a set of gas nozzles 320 (e.g., about 15 gas nozzles). The nozzle 320 is arranged to be aimed at an edge of a workpiece (e.g., the workpiece 106 shown in fig. 1). Each nozzle 320 is angled relative to a direction 350 parallel to the radius of the workpiece. For example, the angle 355 between the nozzle 320 and the direction 350 parallel to the radius of the workpiece may be no more than about 60 degrees, such as in the range of 15 degrees to about 45 degrees. As shown in fig. 3, the nozzle 320 is angled in a clockwise direction to generate a clockwise air flow 330 relative to a direction 360 perpendicular to the center of the workpiece. In some embodiments (not shown in fig. 3), one or more nozzles 320 may be angled upward or downward toward the workpiece to generate a clockwise airflow 330. In some embodiments (not shown in fig. 3), the nozzle 320 may be directed diagonally toward the workpiece. This may become a way of adjusting or fine-tuning the gas flow concentration near the edge of the workpiece.

As shown in fig. 3, the gas manifold 310 includes two gas inlets 340. The two gas inlets 340 are used to flow gas into the gas manifold 310. The two gas inlets 340 are located close to each other so that a small size three-way adapter/fitting can be used to deliver gas from a single delivery line. Within the gas manifold, gas particles from each gas inlet may collide with or push away from each other. Thus, a two port design may provide better gas distribution for the nozzle 320.

Fig. 4 depicts an exemplary plasma processing apparatus 400, according to an exemplary embodiment of the present disclosure. The plasma processing apparatus 400 is similar to the plasma processing apparatus 100 of fig. 1.

More specifically, the plasma processing apparatus 400 includes a process chamber defining an interior space 102. A pedestal or workpiece support 104 is provided for supporting a workpiece 106, such as a semiconductor wafer, within the interior space 102. A dielectric window 110 is located above the workpiece holder 104. The dielectric window 110 includes a relatively flat central portion 112 and an angled peripheral portion 114. The dielectric window 110 includes a space in the central portion 112 for a gas supply 410 for supplying a process gas into the interior space 102.

The apparatus 100 further includes a plurality of inductive elements, such as a primary inductive element 130 and a secondary inductive element 140, for generating an inductive plasma in the interior space 102. The inductive elements 130, 140 may include coils or antenna elements that induce a plasma in the process gas in the interior space 102 of the plasma processing apparatus 100 when supplied with RF power. For example, the first RF motor 160 may be configured to provide electromagnetic energy to the primary inductive element 130 through the matching network 162. The second RF motor 170 may be configured to provide electromagnetic energy to the secondary inductive element 140 through the matching network 172.

The apparatus 100 may include a metal barrier section 152 disposed around the secondary inductive element 140. The metal barrier section 152 separates the primary inductive element 130 and the secondary inductive element 140 to reduce cross-talk between the inductive elements 130, 140. The apparatus 100 can further include a faraday barrier 154 disposed between the primary inductive element 130 and the dielectric window 130. The faraday barrier 154 may be a slotted metal shield that reduces capacitive coupling between the primary inductive element 154 and the processing chamber 102. As shown, the faraday barrier 154 can fit over the angled portion of the dielectric barrier 110.

In one embodiment, the metal barrier 152 and the faraday barrier 154 may form a single body 150 for ease of manufacturing and other purposes. The multi-turn coil of the primary inductive element 130 can be located adjacent to the faraday barrier portion 154 of the single-piece metal barrier/faraday barrier 150. The secondary inductive element 140 can be located in close proximity to the metal barrier portion 152 of the unitary metal barrier/faraday barrier 150, such as between the metal barrier portion 152 and the dielectric window 110.

Arranging the primary and secondary inductive elements 130, 140 on opposite sides of the metal barrier 152 allows the primary and secondary inductive elements 130, 140 to have distinct structural configurations and perform different functions. For example, the primary inductive element 130 may include a multi-turn coil located adjacent to a peripheral portion of the process chamber. The primary inductive element 130 can be used for reliable starting during the basic plasma generation and inherent transient ignition phases. The primary inductive element 130 may be coupled to a powerful RF motor and expensive auto-tune matching network, and may operate at increased RF frequencies (e.g., at about 13.56 MHz).

The secondary inductive element 140 can be used for corrective and support functions and for improving the stability of the plasma during steady state operation. Since the secondary inductive element 140 may be used primarily for corrective and support functions and to improve the stability of the plasma during steady state operation, the secondary inductive element 140 does not need to be coupled to a powerful RF motor like the first inductive element 130, may be designed differently, and effectively overcomes the difficulties associated with previous designs. In some cases, the secondary inductive element 140 may also operate at lower frequencies (e.g., at about 2MHz), allowing the secondary inductive element 140 to be very compact and fit in a confined space on top of the dielectric window.

The primary inductive element 130 and the secondary inductive element 140 may operate at different frequencies. The frequencies may be completely different to reduce cross talk between the primary inductive element 130 and the secondary inductive element 140. Interference between the inductive elements 130, 140 is reduced due to the different frequencies that may be applied to the primary inductive element 130 and the secondary inductive element 140. More specifically, in a plasma, the only interaction between the inductive elements 130, 140 is through the plasma density. Accordingly, no phase synchronization is required between the RF motor 160 coupled to the primary inductive element 130 and the RF motor 170 coupled to the secondary inductive element 140. Power control between the inductive elements is independent. Moreover, since the inductive elements 130, 140 operate at significantly different frequencies, it is practical to use frequency adjustment of the RF motors 160, 170 to match the power delivered to the plasma, significantly simplifying the design and cost of any additional matching networks.

For example (not shown in fig. 4), the secondary inductive element 140 may include a planar coil and a flux concentrator. The flux concentrator may be made of a ferrite material. The use of a magnetic flux concentrator with appropriate coils provides high plasma coupling efficiency and good energy conversion efficiency of the secondary inductive element 140 and significantly reduces its coupling to the metal barrier 150. Using a lower frequency (e.g., about 2MHz) on the secondary inductive element 140 increases the skin, which also improves plasma heating efficiency.

In some embodiments, different inductive elements 130 and 140 may perform different functions. Specifically, only the primary inductive element 130 is required to perform the most important function of plasma generation during ignition and to provide sufficient activation for the secondary inductive element 140. The primary inductive element 130 may participate in the operation of an Inductively Coupled Plasma (ICP) tool and should be coupled to the plasma and the grounded barrier to stabilize the plasma potential. The faraday barrier 154 associated with the first inductive element 130 can avoid window sputtering and can be used to provide ground coupling.

As shown in fig. 4, according to an exemplary aspect of the present disclosure, the gas supply 410 is located in the ceiling of the plasma processing chamber 102 (e.g., on the top dome of the processing chamber 102). The gas supply 410 may include one or more nozzles (not shown in fig. 4). The nozzles may be located at the center and/or one or more edges of the gas supply 410. The nozzles may be arranged in an azimuthally symmetric gas injection pattern with respect to a direction 420 perpendicular to the center of the workpiece 106. For example, each nozzle may be angled relative to a direction parallel to a radius of the workpiece 106 to generate a rotating gas flow relative to the direction 420. As one example, the nozzles may be angled in a clockwise or counterclockwise direction to produce a clockwise or counterclockwise airflow relative to direction 420. The angle between each nozzle and the direction parallel to the radius of the workpiece may be no more than about 60 degrees, for example in the range of 15 degrees to about 45 degrees. In some embodiments, at least one nozzle may be angled upward or downward toward the workpiece 106.

Fig. 5 depicts an example gas supply 510 according to an example embodiment of the present disclosure. The gas supply 510 may be one of the embodiments of the gas supply 420 shown in fig. 4. Fig. 5 shows an axial cross-sectional view. As shown in this axial cross-sectional view, the gas supply 510 includes an edge gas nozzle 512, and center gas nozzles 514 and 516. The edge gas nozzles 512 may generate a rotating gas flow relative to a direction perpendicular to the center of the workpiece (e.g., the workpiece 106 shown in fig. 4). Center gas nozzles 514 and 516 may generate a gas flow toward the center of the workpiece. In some embodiments (not shown in fig. 5), the edge gas nozzles 512 may be arranged in a counter-clockwise direction. In some embodiments (not shown in fig. 5), the edge gas nozzles 512 may be arranged in a clockwise direction. In some embodiments (not shown in fig. 5), one or more nozzles 512 may be angled upward or downward toward the workpiece to generate a counter-clockwise airflow 528 or a clockwise airflow 538.

FIG. 6 depicts one exemplary cross-sectional view 520 of an edge gas nozzle according to an exemplary embodiment of the present disclosure. The edge gas nozzles 512 may be arranged in a counterclockwise direction. As shown in cross-sectional view 520, edge gas nozzle 522 may be an embodiment of edge gas nozzle 512. Each edge gas nozzle 512 is angled relative to a direction 524 parallel to the radius of the workpiece. For example, an angle 526 between the nozzle 522 and the direction 524 may be no more than about 60 degrees, such as in the range of 15 degrees to about 45 degrees. The edge gas nozzles 522 are angled in a counterclockwise direction to generate a counterclockwise gas flow 528 relative to the direction 518 perpendicular to the center of the workpiece (also shown in fig. 5).

FIG. 7 depicts one cross-sectional view 530 of an edge gas nozzle according to an exemplary embodiment of the present disclosure. The edge gas nozzles 512 may be arranged in a clockwise direction. As shown in the cross-sectional view 530, the edge gas nozzle 532 may be one embodiment of the edge gas nozzle 512. Each edge gas nozzle 532 is angled relative to a direction 524 parallel to the radius of the workpiece. For example, the angle 526 between the nozzle 532 and the direction 524 may be no more than about 60 degrees, such as in the range of 15 degrees to about 45 degrees. The edge gas nozzles 532 are angled in a clockwise direction to produce a clockwise gas flow 538 relative to the direction 518.

Fig. 8 depicts an exemplary plasma processing apparatus 600 according to an exemplary embodiment of the present disclosure. The plasma processing apparatus 600 is similar to the plasma processing apparatus 100 of fig. 1 and the apparatus 400 of fig. 4.

More specifically, the plasma processing apparatus 400 includes a process chamber defining an interior space 102. A pedestal or workpiece support 104 is provided for supporting a workpiece 106, such as a semiconductor wafer, within the interior space 102. A dielectric window 110 is located above the workpiece holder 104. The dielectric window 110 includes a relatively flat central portion 112 and an angled peripheral portion 114. The dielectric window 110 includes a space in the central portion 112 for a gas supply 410 for supplying a process gas into the interior space 102.

The apparatus 100 further includes a plurality of inductive elements, such as a primary inductive element 130 and a secondary inductive element 140, for generating an inductive plasma in the interior space 102. The inductive elements 130, 140 may include coils or antenna elements that induce a plasma in the process gas in the interior space 102 of the plasma processing apparatus 100 when supplied with RF power. For example, the first RF motor 160 may be configured to provide electromagnetic energy to the primary inductive element 130 through the matching network 162. The second RF motor 170 may be configured to provide electromagnetic energy to the secondary inductive element 140 through the matching network 172. The gas supply 190 is integrated with the sidewall of the process chamber 102.

The apparatus 100 may include a metal barrier section 152 disposed around the secondary inductive element 140. The metal barrier section 152 separates the primary inductive element 130 and the secondary inductive element 140 to reduce cross-talk between the inductive elements 130, 140. The apparatus 100 can further include a faraday barrier 154 disposed between the primary inductive element 130 and the dielectric window 130. The faraday barrier 154 may be a slotted metal shield that reduces capacitive coupling between the primary inductive element 154 and the processing chamber 102. As shown, the faraday barrier 154 can fit over the angled portion of the dielectric barrier 110.

In one embodiment, the metal barrier 152 and the faraday barrier 154 may form a single body 150 for ease of manufacturing and other purposes. The multi-turn coil of the primary inductive element 130 can be located adjacent to the faraday barrier portion 154 of the single-piece metal barrier/faraday barrier 150. The secondary inductive element 140 can be located in close proximity to the metal barrier portion 152 of the unitary metal barrier/faraday barrier 150, such as between the metal barrier portion 152 and the dielectric window 110.

Arranging the primary and secondary inductive elements 130, 140 on opposite sides of the metal barrier 152 allows the primary and secondary inductive elements 130, 140 to have distinct structural configurations and perform different functions. For example, the primary inductive element 130 may include a multi-turn coil located adjacent to a peripheral portion of the process chamber. The primary inductive element 130 can be used for reliable starting during the basic plasma generation and inherent transient ignition phases. The primary inductive element 130 may be coupled to a powerful RF motor and expensive auto-tune matching network, and may operate at increased RF frequencies (e.g., at about 13.56 MHz).

The secondary inductive element 140 can be used for corrective and support functions and for improving the stability of the plasma during steady state operation. Since the secondary inductive element 140 may be used primarily for corrective and support functions and to improve the stability of the plasma during steady state operation, the secondary inductive element 140 does not need to be coupled to a powerful RF motor like the first inductive element 130, may be designed differently, and effectively overcomes the difficulties associated with previous designs. In some cases, the secondary inductive element 140 may also operate at lower frequencies (e.g., at about 2MHz), allowing the secondary inductive element 140 to be very compact and fit in a confined space on top of the dielectric window.

The primary inductive element 130 and the secondary inductive element 140 may operate at different frequencies. The frequencies may be completely different to reduce cross talk between the primary inductive element 130 and the secondary inductive element 140. Interference between the inductive elements 130, 140 is reduced due to the different frequencies that may be applied to the primary inductive element 130 and the secondary inductive element 140. More specifically, in a plasma, the only interaction between the inductive elements 130, 140 is through the plasma density. Accordingly, no phase synchronization is required between the RF motor 160 coupled to the primary inductive element 130 and the RF motor 170 coupled to the secondary inductive element 140. Power control between the inductive elements is independent. Moreover, since the inductive elements 130, 140 operate at significantly different frequencies, it is practical to use frequency adjustment of the RF motors 160, 170 to match the power delivered to the plasma, significantly simplifying the design and cost of any additional matching networks.

For example (not shown in fig. 8), the secondary inductive element 140 may include a planar coil and a flux concentrator. The flux concentrator may be made of a ferrite material. The use of a magnetic flux concentrator with appropriate coils provides high plasma coupling efficiency and good energy conversion efficiency of the secondary inductive element 140 and significantly reduces its coupling to the metal barrier 150. Using a lower frequency (e.g., about 2MHz) on the secondary inductive element 140 increases the skin, which also improves plasma heating efficiency.

In some embodiments, different inductive elements 130 and 140 may perform different functions. Specifically, only the primary inductive element 130 is required to perform the most important function of plasma generation during ignition and to provide sufficient activation for the secondary inductive element 140. The primary inductive element 130 may participate in the operation of an Inductively Coupled Plasma (ICP) tool and should be coupled to the plasma and the grounded barrier to stabilize the plasma potential. The faraday barrier 154 associated with the first inductive element 130 can avoid window sputtering and can be used to provide ground coupling.

Fig. 9 depicts a flowchart of one example method 700 in accordance with an example embodiment of the present disclosure. The method 700 will be discussed with reference to the plasma processing apparatus 100 of fig. 1 as an example. The method 700 may be implemented in any suitable plasma processing apparatus. For purposes of example and discussion, FIG. 9 depicts the steps performed in a particular order. Using the disclosure provided herein, those of skill in the art will understand that various steps in any of the methods described herein can be eliminated, expanded, performed simultaneously, rearranged, and/or modified in various ways without departing from the scope of the present disclosure. Moreover, various steps (not shown) may be performed without departing from the scope of the disclosure.

At 710, the method may include placing a workpiece on a process support in a process chamber. For example, the workpiece 106 may be placed in the workpiece support 104 in the process chamber 102.

At 720, the method may include admitting a process gas into the processing chamber through a gas supply. For example, a gas supply 190 integrated with a sidewall of the process chamber 102 and/or a gas supply 410 located on a ceiling of the process chamber 102 may allow process gases to enter the process chamber 102. The gas supply 190 or 410 may include one or more nozzles. Each nozzle may be angled relative to a direction parallel to a radius of the workpiece 106 (e.g., in a clockwise or counterclockwise direction). Such a nozzle arrangement may generate a rotating gas flow (e.g., a clockwise gas flow or a counterclockwise gas flow) relative to a direction perpendicular to the center of the workpiece 106.

At 730, the method may include generating a plasma in a process gas in a processing chamber. For example, the primary inductive element 130 and/or the secondary inductive element 140 may generate a plasma in the process gas in the processing chamber.

At 740, the method can include exposing the workpiece to one or more species generated by the plasma. For example, the workpiece 106 may be exposed to one or more species generated by the plasma.

Fig. 10 depicts an example gas velocity comparison between a gas supply 1010 and an example gas supply 1020 according to example embodiments of the present disclosure. As seen in fig. 10, the gas supply 1010 includes a center gas nozzle, an edge gas nozzle, and a side gas nozzle. The edge gas nozzles and/or the side gas nozzles are arranged in a direction parallel to the radius of the workpiece. An example gas supply 1020 according to an example embodiment of the present disclosure includes a center gas nozzle, an edge gas nozzle, and a side gas nozzle. The edge gas nozzles and/or the side gas nozzles are angled with respect to a direction parallel to the radius of the workpiece to generate a rotating gas flow with respect to a direction perpendicular to the center of the workpiece. As can be seen in fig. 10, the example gas supply 1020 may reduce stagnant gas flow areas.

Fig. 11 depicts an example mass fraction comparison between a gas supply 1110 and an example gas supply 1120 in accordance with example embodiments of the present disclosure. The gas supply 1110 includes a standard side gas nozzle directed toward the centerline of the workpiece. The example gas supply 1120 includes side gas nozzles angled relative to a direction parallel to the radius of the workpiece to generate a rotating gas flow relative to a direction perpendicular to the center of the workpiece. As can be seen in fig. 11, the example gas supply 1120 may reduce the mass fraction variation within the processing chamber.

Fig. 12 depicts an exemplary mass fraction distribution comparison over the surface of a workpiece between a gas supply and an exemplary gas supply in accordance with exemplary embodiments of the present disclosure. The gas supply associated with the workpiece 1210 includes a standard side gas nozzle directed toward the centerline of the workpiece. An exemplary gas supply associated with workpiece 1220 includes a side gas nozzle angled relative to a direction parallel to the radius of the workpiece to generate a rotating gas flow relative to a direction perpendicular to the center of the workpiece. As can be seen in fig. 12, an exemplary gas supply associated with workpiece 1220 can reduce mass fraction non-uniformities at the surface of workpiece 1210.

While the present subject matter has been described in detail with reference to specific exemplary embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.