阅读说明：本技术 通过脉冲式rf等离子体的膜形成 (Film formation by pulsed RF plasma ) 是由 K·尼塔拉 D·N·凯德拉亚 K·嘉纳基拉曼 Y·杨 于 2020-02-07 设计创作，主要内容包括：本文讨论了使用脉冲式RF等离子体来形成非晶膜和微晶膜的系统和方法。形成膜的方法可以包括：(a)由膜前驱物在处理腔室中形成等离子体以及(b)脉冲RF功率源以使由RF功率源产生的脉冲的工作循环的工作循环导通时间(TON)小于工作循环的总循环时间(TTOT)的约20％,以形成膜。方法可以进一步包括：(c)在处理腔室中的基板上沉积第一膜中间层；(d)在(c)之后,净化处理腔室；以及(e)在(d)之后,将氢等离子体引入处理腔室。此外,在方法中,重复(b)-(e)以形成膜。膜可具有小于约10％的膜内氢含量。(Systems and methods for forming amorphous and microcrystalline films using pulsed RF plasma are discussed herein. The method of forming a film may include: (a) forming a plasma from a film precursor in a processing chamber and (b) pulsing an RF power source such that a duty cycle on Time (TON) of a duty cycle of pulses generated by the RF power source is less than about 20% of a total cycle time (TTOT) of the duty cycle to form a film. The method may further comprise: (c) depositing a first film intermediate layer on a substrate in a processing chamber; (d) after (c), purging the processing chamber; and (e) introducing a hydrogen plasma into the processing chamber after (d). Further, in the method, the (b) to (e) are repeated to form a film. The membrane may have an intra-membrane hydrogen content of less than about 10%.)

1. A method of forming a film comprising:

ionizing a precursor gas to form a plasma in a processing volume of a processing chamber;

a pulsed RF power source coupled to the process chamber; and

depositing a film on a substrate positioned on a substrate support within the processing volume during the pulsing of the RF power source in response to the pulsing, wherein the film comprises a hydrogen content of less than about 10%.

2. The method of claim 1, wherein the substrate support is at a temperature of 350 ℃ to 450 ℃ during the depositing the film.

3. The method of claim 1, wherein introducing the precursor gas comprises: introducing the precursor gas via a gas distribution assembly opposite the substrate support, the gas distribution assembly being at a temperature of about 200 ℃ to about 350 ℃ during the depositing the film.

4. The method of claim 1, further comprising: depositing the film at a deposition rate of 1A/s to 8A/s during the pulsing the RF power source.

5. The method of claim 1, wherein pulsing the RF power source comprises: making a duty cycle of the RF power source on for a time (T)_ON) Less than about 20%.

6. The method of claim 1, wherein the precursor gas comprises silicon (Si) or germanium (Ge).

7. The method of claim 1, wherein the precursor gas comprises hydrogen.

8. The method of claim 7, wherein the precursor gas comprises C₂H₆、C₂H₂Or GeH₄。

9. A method of forming a film comprising:

introducing a precursor gas into a processing volume of a processing chamber having a chamber lid, a chamber bottom, and a sidewall extending therebetween;

ionizing the precursor gas to form a plasma;

pulsing an RF power source to cause a duty cycle on time (T) of a duty cycle of pulses generated by the RF power source_ON) Less than the total cycle time (T) of the working cycle_TOT) About 20% of; and

depositing a film having a hydrogen content of less than about 10%.

10. The method of claim 9, wherein the first and second light sources are selected from the group consisting of a red light source, a green light source, and a blue light source,wherein the duty cycle on time (T) of a duty cycle of pulses generated by the RF power source_ON) Less than the total cycle time (T) of the working cycle_TOT) About 10% of the total.

11. The method of claim 9, wherein the film comprises a hydrogen content of less than about 5%.

12. The method of claim 9, wherein the film has a thickness variation of less than about 6%.

13. The method of claim 9, wherein the film is deposited on a substrate positioned on a substrate support in the processing chamber.

14. The method of claim 9, wherein the film is deposited on at least one of: the chamber lid, the chamber bottom, and the sidewall of the processing chamber.

15. The method of claim 9, wherein said depositing said film is performed to aboutTo aboutThe deposition rate of (3) occurs.

Technical Field

Embodiments of the present disclosure generally relate to thin film deposition on substrates such as semiconductor substrates and hardware components.

Description of the related Art

Plasma Enhanced Chemical Vapor Deposition (PECVD) can be used to form films including silicon and hydride films during semiconductor device fabrication. High hydrogen (H) content in PECVD formed films can lead to integration problems when subsequent films are formed on top of such films. Integration issues may include peeling and blistering of the film and migration of hydrogen in the film to other layers. The deposition temperature may be adjusted during PECVD deposition of thin films to vary the hydrogen content of the film, but high deposition temperatures utilize amounts of energy that may exceed the thermal budget of semiconductor manufacturing operations.

Accordingly, there remains a need in the art for improved methods of forming thin films on semiconductor substrates and hardware components.

Background

Disclosure of Invention

Methods and systems for forming films using RF pulsed plasma are discussed herein. In one aspect, a method of forming a film includes: the method includes ionizing a precursor to form a plasma in a processing volume of a processing chamber, and pulsing an RF power source coupled to the processing chamber. Depositing a film on a substrate positioned on a substrate support within the processing volume during the pulsing of the RF power source in response to the pulsing of the RF power, wherein the film comprises a hydrogen content of less than about 10%.

Implementations may include one or more of the following. During deposition of the film, the substrate support may be at a temperature between 350 ℃ and 450 ℃. Introducing the precursor gas may include: the precursor gases are introduced through a gas distribution assembly opposite the substrate support, the gas distribution assembly being at a temperature of about 200 ℃ to about 350 ℃ during deposition of the film. During the pulse of the RF power source, the RF power source can be controlled to reduce the power consumptionToThe deposition rate of (3) deposits a film. The pulsed RF power source may include: make the work cycle of the RF power source conducting for a time (T)_ON) Less than about 20%. The precursor gas may include silicon (Si) or germanium (Ge). The precursor gas may include hydrogen. The precursor gas may include C₂H₆、C₂H₂Or GeH₄。

In another aspect, a method of forming a film includes: the method includes introducing a precursor into a processing volume of a processing chamber having a chamber lid, a chamber bottom, and a sidewall extending therebetween, and ionizing the precursor gas to form a plasma. Pulsing an RF power source to cause a duty cycle on time (T) of a duty cycle of pulses generated by the RF power source_ON) Less than the total cycle time (T) of the working cycle_TOT) About 20% of the total hydrogen content, and depositing a film having a hydrogen content of less than about 10%.

Implementations may include one or more of the following. Duty cycle on time (T) of a duty cycle of pulses generated by an RF power source_ON) Less than the total cycle time (T) of the working cycle_TOT) About 10% of the total. The membrane may include a hydrogen content of less than about 5%. The film may have a thickness variation that may be less than about 6%. A film may be deposited on a substrate positioned on a substrate support in a process chamber. The film may be deposited on at least one of: toChamber lid, chamber bottom and side wall of the processing chamber. The deposited film may be deposited at aboutTo aboutThe deposition rate of (3) occurs.

In another aspect, a method of forming a film includes: (a) forming a plasma in the processing chamber from the film precursor and (b) pulsing the RF power source such that a duty cycle on time (T) of a duty cycle of a pulse generated by the RF power source_ON) Less than the total cycle time (T) of the working cycle_TOT) About 20% of the total. The method further comprises the following steps: (c) depositing a first film intermediate layer on a substrate in a processing chamber; (d) after (c), purging the processing chamber; and (e) introducing a hydrogen plasma into the processing chamber after (d). Further, in the method, the (b) to (e) are repeated to form a film.

Implementations may include one or more of the following. The substrate may comprise at least one of: a lid surface of a process chamber, a bottom surface of a process chamber, a sidewall of a process chamber, or a substrate positioned on a substrate support in a process chamber. The film deposition rate at (c) may be about To aboutThe thickness of the first film intermediate layer may be aboutTo aboutThe thickness of the film may be aboutTo about

In another aspect, a non-transitory computer readable medium has instructions stored thereon, which when executed by a processor, cause processes to perform the operations of the above-described apparatus and/or method.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

Fig. 1 is a schematic view of a substrate processing system according to an embodiment of the present disclosure.

Fig. 2 is a flow chart of a method of forming a film using a pulsed RF plasma according to an embodiment of the present disclosure.

Fig. 3 is a flow diagram of another method of forming a film using a pulsed RF plasma according to an embodiment of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially utilized on other embodiments without further recitation.

Detailed Description

The following disclosure relates generally to substrate processing systems and, more particularly, to apparatus and methods for depositing films using pulsed RF plasma. Certain details are set forth in the following description and in figures 1-3 to provide a thorough understanding of various embodiments of the disclosure. Additional details describing well-known structures and systems typically associated with optical detection and substrate positioning are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

Many of the details, dimensions, angles and other features shown in the drawings are merely illustrative of particular embodiments. Accordingly, other embodiments may have other details, components, dimensions, angles, and features without departing from the spirit or scope of the disclosure. Other embodiments of the disclosure may be practiced without several of the details described below. Furthermore, the device descriptions described herein are illustrative and should not be understood or interpreted as limiting the scope of the embodiments described herein.

The semiconductor device may include a silicon-containing, nitride-containing, and hydride-containing film. The same type of film may also be used to coat and protect the process chamber components in which the semiconductor devices are fabricated. The process chamber may be configured to perform operations comprising: chemical Vapor Deposition (CVD)), plasma enhanced CVD (pecvd), Atomic Layer Deposition (ALD), or Physical Vapor Deposition (PVD). The quality of the film on the substrate or on chamber components may be negatively affected by impurities within the film, such as high hydrogen content, e.g., 10% or more of the hydrogen content within the film. If the process chamber components are coated with a thin film, the poor film quality of the protective coating may cause the protective coating to flake off and contaminate substrates located in the process chamber. In another example, when forming thin films on substrates of semiconductor devices, poor film quality can pose challenges for downstream operations, generate waste, or degrade device performance. High intra-film hydrogen content can negatively impact film quality and overall device quality. For example, subsequently formed film layers on film layers of poor quality may experience sticking or other quality problems, including migration of hydrogen content within the film. In other examples, the underlying layer on which the film is formed may also experience quality issues, including migration of hydrogen content within the film to the underlying layer.

Using the systems and methods discussed herein, the RF power source is pulsed during a plasma enhanced chemical vapor deposition Process (PECVD) during film formation on a substrate or chamber component. The film formed may comprise amorphous silicon, amorphous carbon, or microcrystalline films of silicon or other materials. In one example, the RF power source is pulsed during film deposition to form a thin film with pre-chargeAnd (3) fixing the hydrogen content in the membrane. In one example, the hydrogen content within the membrane is less than 10%, for example, in the range of about 1% to about 9%. In another example, the hydrogen content within the membrane is less than 5%, such as in the range of about 1% to about 4%. In yet another example, the hydrogen content within the membrane is less than 2%, for example, in the range of about 0.1% to about 1%. Each pulse of the RF power source includes a total time (T)_TOT) Total time (T)_TOT) Is the "on time" (T) when the RF power source is on_ON) And "off time" (T) when the power source is off_OFF) The sum of (a) and (b). T is_ONAnd T_OFFMay be defined as T per pulse_ONAnd T_OFFThe sum of (a) is the percentage of the duty cycle for 100% of cases. During PECVD film formation, the duty cycle of the pulse of RF power can be adjusted such that T of the duty cycle_ONThe fraction is less than 20%, 15%, 10% or 5%. In one example, during PECVD film formation, the duty cycle of the pulse of RF power may be adjusted such that T of the duty cycle_ONThe fraction is less than 20%, for example, about 1% to about 19%. In another example, during PECVD film formation, the duty cycle of the pulse of RF power may be adjusted such that T of the duty cycle_ONThe fraction is less than 15%, for example, about 1% to about 14%. In yet another example, during PECVD film formation, the duty cycle of the pulse of RF power may be adjusted such that T of the duty cycle_ONThe fraction is less than 10%, for example, about 1% to about 9%. In yet another example, during PECVD film formation, the duty cycle of the pulse of RF power may be adjusted such that T of the duty cycle_ONThe fraction is less than 5%, for example, about 1% to about 4%. Without being bound by theory, it is believed that the hydrogen content in the film can be further reduced by replacing the helium diluent gas with a hydrogen diluent gas.

In some examples, the substrate can be heated prior to and/or during the pulsed RF plasma film deposition. The substrate may be heated using heating lamps disposed around a substrate support on which the substrate is positioned. In another example, the substrate may be heated using a heating element included in the substrate support. In one example, pulsed RF plasma film deposition occurs when the substrate is at a temperature of 300 ℃ to 500 ℃ (e.g., 350 ℃ to 450 ℃). In one example, which can be combined with other examples, the pressure in the chamber during film deposition is at least 8Torr, e.g., about 8Torr to about 20Torr, such as about 8Torr to about 15 Torr. In addition, film properties such as refractive index (n), stress, and extinction coefficient (k) can be adjusted by varying the duty cycle of the pulsed RF plasma PECVD operation discussed herein.

In another example, the film is deposited in a cyclic process, where a plasma, such as a silane plasma, is pulsed at a low deposition rate. The low deposition rate may be about 1 a/min to about 5 a/min. The film may be deposited to 20 angstroms in the presence of helium, hydrogen, or a combination of gases Or aboutTo aboutSuch as aboutTo aboutIs measured. Subsequently, the membrane is exposed to a hydrogen plasma for a predetermined period of time. The deposition and hydrogen plasma exposure are repeated for one or more iterations to form a film having a hydrogen content or refractive index (n), stress, and/or extinction coefficient (k) within the target film.

Fig. 1 is a schematic diagram of a substrate processing system including a system 100 according to an embodiment of the present disclosure. The system 100 may be configured as a CVD system, including as a plasma enhanced CVD (pecvd) system. The system 100 includes a process chamber 102, the process chamber 102 having a substrate support 104, the substrate support 104 disposed within a processing volume 146 formed within the process chamber 102. The process chamber 102 includes a chamber sidewall 122, a chamber bottom 124, and a chamber lid 140, the chamber sidewall 122, the chamber bottom 124, and the chamber lid 140 defining a process volume 146. The chamber lid 140 includes a gas distribution assembly 116 to facilitate distribution of process gases and/or plasma.

The system further includes a system controller 118, the system controller 118 operable to control an automated aspect of the process chamber 102. The system controller 118 facilitates control and automation of the overall process chamber 100, and may include a Central Processing Unit (CPU), memory, and support circuits (or I/O). The software instructions and data may be encoded and stored in a memory for instructing the CPU. The system controller 118 may communicate with one or more of the components of the process chamber 102 via, for example, a system bus. A program (or computer instructions) readable by the system controller 118 determines which tasks are executable on the substrate. In some embodiments, the program is software readable by the system controller 118, which may include code for controlling the pulsing of the plasma source, the gas flow, the sequence of movement of the various controlled components, and any combination thereof.

Although shown as a single system controller 118, it should be understood that multiple system controllers may be used with the embodiments described herein. For example, in one embodiment, a first controller controls the plasma source and a second controller controls chamber automation.

In some examples, the substrate support 104 is a substrate support pedestal. The substrate support 104 may include a mechanism to hold or support the substrate 106 on the top surface of the substrate support 104. Substrate 106 may be a semiconductor substrate including silicon and/or germanium. In some examples, the substrate 106 may have one or more layers formed thereon, including metal layers or dielectric layers. Examples of the holding mechanism may include an electrostatic chuck, a vacuum chuck, a substrate holding jig, and the like. The substrate support 104 may include mechanisms for controlling the temperature of the substrate (such as heating and/or cooling devices) and/or mechanisms for controlling the flux of species and/or ion energy near the substrate surface. The substrate support 104 includes one or more substrate support heating elements 108 disposed therein or otherwise thermally coupled to the substrate support 104. One or more power sources 126 are coupled to the one or more substrate support heating elements 108 to heat the substrate support 104 to a predetermined temperature, for example, when the substrate 106 is at a temperature of 300 ℃ to 500 ℃ (such as 350 ℃ to 450 ℃). In one embodiment, the one or more power sources 126 are configured to provide at least 5kW of energy. In alternative examples, the process chamber 102 may have one or more radiant heat lamps (not shown) positioned to illuminate the substrate 106 and/or the substrate support 104.

A gas distribution assembly 116 is disposed in the process chamber 102 opposite the substrate support 104. The gas distribution assembly 116 may be heated to a temperature of about 200 ℃ to about 350 ℃ before and/or during one or more operations in the process chamber 102, such as film deposition operations. The temperature of the gas distribution assembly 116 may be established prior to placing the substrate 106 in the process chamber 102. The temperature of the gas distribution assembly 116 may be maintained within or modified to be within a predetermined temperature range during the formation of one or more films in the process chamber 102. The elevated temperature of the gas distribution assembly 116 facilitates the flow of gases into the process chamber 102, in part, by reducing the temperature differential between the gas distribution assembly 116 and the substrate support 104 on which the substrate 106 is positioned 104. In one example, the temperature of the gas distribution assembly 116 may be controlled by applying power from the power source 130 to the plurality of temperature control elements 110. In one example, the gas distribution assembly 116 may have a plurality of temperature control elements 110 disposed therein, the plurality of temperature control elements 110 configured to create a temperature gradient and/or temperature zone across the gas distribution assembly 116. The plurality of temperature control elements 110 may be used to raise, lower, or maintain the temperature of the gas distribution assembly 116. In some examples, the gas distribution assembly 116 may be coupled to an RF source (not shown) configured to provide power to the gas distribution assembly before, during, and/or after operation within the process chamber 102.

The gas distribution assembly 116 further includes a plurality of apertures 132 formed through the face plate of the gas distribution assembly 116. Gases introduced into the process chamber 102 from the gas manifold 114 are introduced into the process volume 146 via the plurality of apertures 132. As shown in fig. 1, the plurality of apertures 132 may be arranged in various configurations on the gas distribution assembly 116, the gas distribution assembly 116 including a chamber lid 140. In various examples, the plurality of apertures 132 may be arranged as concentric rings, ring clusters, randomly positioned clusters, or other geometric shapes. Although each of the plurality of holes 132 is shown herein as being approximately the same diameter, it is contemplated that in other examples, the diameter of the holes 132 may vary. In some examples, the gas distribution assembly 116 includes zone heating such that multiple temperature control elements 110 may be controlled individually or in groups to create zones of different temperatures on the chamber lid 140.

The gas distribution assembly 116 may be positioned adjacent to the optional chamber liner 120 such that the optional chamber liner 120 is flush with the gas distribution assembly 116 (either in direct contact or with an adhesive disposed therebetween). In examples employing the optional chamber liner 120, the liner sidewall 138 is exposed to the processing volume 146, the optional chamber liner thus protecting the chamber sidewall 122. In some embodiments, the optional chamber liner 120 may be further disposed along a chamber bottom 124 (e.g., bottom surface) of the process chamber 102. Thus, the chamber sidewall 122 of the process chamber 102 may be protected from the process volume 146 by the optional chamber liner 120. One or more exhaust systems (not shown) may be coupled to the process chamber 102 and used to remove excess process gases or byproducts from the processing volume 146 during processing or after processing.

In one example, the gas distribution assembly 116 may be further coupled to a cooler plate 148. In one example, when the cooler plates 148 are coupled to the gas distribution assembly 116, the cooler plates 148 facilitate control of the temperature or temperature gradient across the gas distribution assembly 116. In some embodiments, the cooler plates 148 include a plurality of channels (not shown) formed in the cooler plates 148. The plurality of channels allow the temperature control fluid provided by the temperature control fluid supply (cooler) 150 to flow through the cooler plates 148 to facilitate control of the temperature of the gas distribution assembly 116.

As discussed herein, the film deposition operation may include forming one or more films on the substrate 106 positioned on the substrate support 104, and forming one or more films on exposed surfaces of the process chamber 102. In one example, one or more films formed inside the processing volume 146 (e.g., when the optional chamber liner 120 is excluded) may be formed on the chamber sidewall 122. When the optional chamber liner 120 is used in the process chamber 102, one or more films formed as discussed herein may be formed on the liner sidewall 138 instead of the chamber sidewall 122 because the chamber sidewall 122 is protected from the processing volume 146 by the optional chamber liner 120.

One or more gas sources 112 are coupled to the process chamber 102 via a gas manifold 114. The gas manifold 114 is coupled to the gas distribution assembly 116 and is configured to deliver one or more gases from the one or more gas sources 112 to the process volume 146. Each gas source 112 of the one or more gas sources 112 may contain a carrier gas, an ionizable gas for plasma formation (such as hydrogen or He), or a precursor for film formation. The RF power source 136 can be electrically coupled to a chamber wall electrode 142 in the chamber sidewall 122. The RF power source 136 may be a 13.56MHz RF power source. The RF power source 136 may be further electrically coupled to a substrate support electrode 152 disposed in the substrate support 104. A plasma can be generated in process space 146 via RF power source 136. The RF power source 136 is a modulated power source configured to create an RF field using the chamber wall electrode 142 (which may be a positive electrode) and the substrate support electrode 152 (which may be a ground electrode). The RF power source 136 may be pulsed during various operations. In some examples, a remote plasma source 134 may be used to deliver plasma to the processing chamber 102 and may be coupled to the gas distribution assembly 116.

Fig. 2 is a flow diagram of a method 200 of forming a film using a pulsed RF plasma. The method 200 may be used to form one or more films on a substrate disposed on a substrate support in a process chamber 102, such as the process chamber 102 shown in figure 1. In this example of the method 200, a substrate (such as the substrate 106 in fig. 1) is positioned on a substrate support (such as the substrate support 104) at operation 202. In another example, the method 200 may be used to form one or more films inside a processing chamber 102 on a substrate (which includes the chamber sidewall 122, the chamber bottom 124, the chamber lid 140, and other exposed surfaces) (e.g., to age one or more surfaces within the processing chamber 102). As discussed above in fig. 1, when an optional chamber liner 120 is employed, one or more films may be formed on the optional chamber liner 120. In one example, the method 200 is performed without positioning a substrate in the process chamber 102. In other examples, the method 200 is employed to form one or more films on the substrate 106 positioned in the process chamber 102 and on one or more exposed surfaces of the process chamber 102.

At operation 204, one or more film precursor gases are introduced into the processing chamber 102. The one or more film precursor gases may include Silane (SiH)₄)、Si₂H₆Or other hydride or silicon based precursors. In other examples, the one or more film precursor gases may include compounds containing carbon and hydrogen. For example, the one or more film precursor gases may include C₂H₂Or C₃H₆. In another example, the one or more film precursor gases may include germanium, such as GeH₄. In another example, the one or more film precursor gases may include arsenic (As), such As AsH₃. In one example, one or more film precursor gases are introduced at a flow rate of about 100sccm to about 1000sccm at operation 204. In one example, one or more film precursor gases are introduced at a flow rate of about 300sccm to about 800sccm at operation 204.

Further, at operation 204, one or more process gases may be introduced into the process chamber 102. At operation 204, one or more film precursor gases and process gases may be introduced via the gas distribution assembly 116 of FIG. 1. The one or more process gases may include argon (Ar), hydrogen, and/or helium (He). In thatIn one example, helium and argon are introduced into the processing chamber 102 with at least one film precursor gas at operation 204. In another example, helium, hydrogen, and argon are introduced into the process chamber 102 at operation 204. In another example, at operation 204, hydrogen and argon are introduced into the process chamber 102. At operation 204, helium may be introduced into the process chamber 102 at a flow rate of about 6500sccm to about 8000 sccm. At operation 204, argon may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 10,000 sccm. In one example, hydrogen may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 1,000sccm at operation 204. In another example, hydrogen may be introduced into the process chamber 102 at a flow rate of about 6,500sccm to about 8,000sccm at operation 204. In one example, the ratio of the flow rate of helium to the flow rate of hydrogen is about 4:1 to about 9: 1. In another example, the ratio of the flow rate of helium to the flow rate of hydrogen is about 5:1 to about 8: 1. In some examples, there may be a target flow rate ratio between the one or more film precursor gases introduced at operation 204 and the one or more process gases introduced at operation 204. In one example, at least one film precursor gas (F)_PC) With process gas (F)_G) Of (2) is the ratio of the flow rates of (F)_PC:F_G) Greater than 1: 10.

In another example, at operation 204, hydrogen, argon, and helium are introduced into the process chamber 102. At operation 204, hydrogen may be introduced into the process chamber 102 at a flow rate of about 6,500sccm to about 8,000 sccm. At operation 204, argon may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 10,000 sccm. At operation 204, helium may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 1000 sccm. In one embodiment, the ratio of the flow rate of hydrogen to the flow rate of helium is from about 4:1 to about 9: 1. In another example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 5:1 to about 8: 1.

In yet another example, at operation 204, hydrogen and argon are introduced into the process chamber 102. At operation 204, hydrogen may be introduced into the process chamber 102 at a flow rate of about 6,500sccm to about 8,000 sccm. At operation 204, argon may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 10,000 sccm. In one embodiment, the ratio of the flow rate of hydrogen to the flow rate of helium is from about 4:1 to about 9: 1. In another example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 5:1 to about 8: 1.

At operation 206, one or more precursors and process gases are ionized to form a plasma. At operation 208, an RF power source (such as the RF power source 136 in fig. 1) is pulsed while introducing the one or more process gases and the one or more precursor gases into the processing chamber. At operation 208, each pulse has a total time T of the duty cycle_TOT。T_TOTIs T_ONAnd T_OFFThe sum of (a) and (b). In one example, T at operation 208_ONLess than T_TOT30%, e.g., about 20% to about 29%. In another example, T at operation 208_ONLess than T_TOT20% of (e.g. T)_TOTFrom about 15% to about 19%. In another example, T at operation 208_ONLess than T_TOT10% of (e.g. T)_TOTFrom about 5% to about 9%. In additional examples, T at operation 208_ONLess than T_TOT5% of (e.g. T)_TOTFrom about 1% to about 4%.

Further, in the method 200, at least at operations 204, 206, and 208, the pressure in the process chamber 102 may be about 1mTorr to about 50 Torr. In another example, the pressure in the process chamber 102 may be about 8Torr to about 50Torr, such as about 8Torr to about 20Torr, at least during operations 204, 206, and 208. Further, in the method 200, at least at operations 204, 206, and 208, the temperature in the process chamber 102 may be about 300 ℃ to about 500 ℃. In other examples, the temperature in the process chamber 102 may be about 350 ℃ to about 450 ℃ at operations 204, 206, and 208. The power density of a PECVD operation is the amount of power applied to the processing chamber per unit volume of the processing chamber. The peak power density is the highest value of the power density during operation of the process chamber. In one example, the peak power density during film deposition may be 0.03W/cm²To about 1.64W/cm². In another example, the peak power density during film deposition is about 0.06W/cm²Or about 0.12W/cm². In another example, the power density during the method 200 may be about 0.03W/cm²To about 1.64W/cm². In some examples, the power density during the method 200 is about 0.06W/cm²To about 0.3W/cm²。

At operation 210 of the method 200, a film is formed. When operation 202 is performed, the film formed at operation 210 may be formed on substrate 106. In other examples, the film formed at operation 210 may be formed on a lid, bottom, sidewall, or other exposed surface of the process chamber 102. The use of the RF power to the plasma pulse at operation 208 reduces the hydrogen concentration of the plasma in the processing volume 146 and increases the rate of hydrogen desorption (desorption) from the surface of the substrate 106 or the exposed surface of the process chamber 102. The reduced desorption reduces the hydrogen content of the film formed at operation 210. T in response to operation 208_ONPeriodically, film formation from the film precursor occurs at operation 210.

The film formed at operation 210 may be formed to have a thickness of up to aboutIs measured. The film formed at operation 210 may include a hydrogen content of less than about 10%. In other examples, the film formed at operation 210 may include a hydrogen content of less than about 5%. In another example, the film formed at operation 210 may include a hydrogen content of less than about 3%. In another example, the film formed at operation 210 may include a hydrogen content of less than about 2%. In another example, the film formed at operation 210 may include a hydrogen content of less than about 1%. The film formed at operation 210 in response to the introduction of the precursor gas and the pulse of the plasma may be at aboutTo aboutIs deposited. In another example, the deposition rate may be aboutTo aboutThe film formed using method 200 may be an amorphous film (such as amorphous Si) or a polycrystalline film. The film formed using method 200 may have a refractive index at 633nm of about 4.25 to about 4.45. In another example that may be combined with other examples herein, the film formed using method 200 exhibits an extinction coefficient (k) of about 0.140 to about 0.180. In another example, which may be combined with other examples, the film formed using method 200 has a k of about 0.140 to about 0.160. In another example that may be combined with other examples herein, the film formed using method 200 exhibits an in-film stress of about-1100 MPa to about-300 MPa. Further, in examples of the method 200 that may be combined with other examples herein, the variation in film thickness (which may also be referred to as film uniformity) may be from less than about 1% to about 6%. In another example that may be combined with other examples herein, the film uniformity is less than about 4%.

Fig. 3 is a flow chart of a method 300 of forming a film using a pulsed RF plasma. The method 300 is similar to the method 200, but the method 300 forms a membrane in a cyclic process. The method 300 may be used to form one or more films on a substrate positioned on a substrate support in a process chamber, such as the process chamber 102 shown in figure 1. In this example of the method 300, a substrate (such as the substrate 106 in fig. 1) is positioned on a substrate support, e.g., the substrate support 104 in fig. 1, at operation 302. In another example, the method 300 may be used to form one or more films on the interior surfaces of the processing chamber 102, for example, an aging process. The method 300 is performed without positioning the substrate in the processing chamber 102 during the seasoning process. In other examples, the method 300 is used to form one or more films on both the substrate 106 positioned in the process chamber 102 and on the interior surfaces of the process chamber 102.

At operation 304, one or more film precursor gases are introduced into the processing chamber. The one or more film precursor gases may include silane(s) (iii)SiH₄)、Si₂H₆Or other carbon-containing or silicon-containing precursors. In other examples, the one or more film precursor gases may include C₂H₂Or C₃H₆. In another example, the one or more film precursor gases may include germanium, such as GeH₄. In another example, the one or more film precursor gases may include arsenic (As), such As AsH₃. In one example, one or more film precursor gases are introduced at a flow rate of about 100sccm to about 1,000sccm at operation 304.

Additionally, at operation 304, one or more process gases may be introduced into the processing chamber 102. At operation 304, one or more film precursor gases and process gases may be introduced via the gas distribution assembly 116 of FIG. 1. The one or more process gases may include argon (Ar), hydrogen, and/or helium (He). In one example, helium and argon are introduced into the processing chamber with at least one film precursor gas at operation 304. In another example, at operation 304, helium, hydrogen, and argon are all introduced into the processing chamber. In another example, at operation 304, hydrogen and argon are introduced into the processing chamber. Helium may be introduced into the processing chamber at an operating flow rate of about 6,500sccm to about 8,000sccm at an operating flow 304. At operation 304, argon may be introduced into the processing chamber at a flow rate of about 100sccm to about 10,000 sccm. At operation 304, hydrogen may be introduced into the processing chamber at a flow rate of about 100sccm to about 1,000 sccm. In another example, hydrogen may be introduced into the process chamber at a flow rate of about 6,500sccm to about 8,000sccm at operation 304. In one example, the ratio of the flow rate of helium to the flow rate of hydrogen is about 4:1 to about 9: 1. In another example, the ratio of the flow rate of helium to the flow rate of hydrogen is about 5:1 to about 8: 1. In some examples, there may be a target flow rate ratio between the one or more film precursor gases introduced at operation 304 and the one or more process gases introduced at operation 304. In one example, at least one film precursor gas (F)_PC) With process gas (F)_G) Of (2) is the ratio of the flow rates of (F)_PC:F_G) Greater than 1: 10.

In another example, at operation 304, hydrogen, argon, and helium are introduced into the process chamber 102. At operation 304, hydrogen may be introduced into the process chamber 102 at a flow rate of about 6,500sccm to about 8,000 sccm. At operation 304, argon may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 10,000 sccm. At operation 304, helium may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 1,000 sccm. In one example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 4:1 to about 9: 1. In another example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 5:1 to about 8: 1.

In yet another example, at operation 304, hydrogen and argon are introduced into the process chamber 102. At operation 304, hydrogen may be introduced into the process chamber 102 at a flow rate of about 6,500sccm to about 8,000 sccm. At operation 304, argon may be introduced into the process chamber 102 at a flow rate of about 100sccm to about 10,000 sccm. In one example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 4:1 to about 9: 1. In another example, the ratio of the flow rate of hydrogen to the flow rate of helium is about 5:1 to about 8: 1.

At operation 306, one or more film precursor gases are ionized into a plasma. At operation 308, an RF power source (such as RF power source 136 in fig. 1) is pulsed to deposit a first film intermediate layer, e.g., a sub-portion of the film. At operation 308, a first film interlayer may be deposited on the substrate 106. In another example, at operation 308, a first film intermediate layer may be deposited on one or more interior surfaces of the process chamber 102. During operation 308, a process gas including argon (Ar) and helium (He) may be present in the process chamber and ionized into a plasma. In one example, during operation 308, no hydrogen is present in the process chamber 102. In other examples, during operation 308, a hydrogen plasma is present in the process chamber 102.

The first film intermediate layer formed at operation 308 may be at least aboutTo aboutAt a rate such as aboutTo aboutIs deposited. At operation 308, the use of the RF power to the plasma pulses reduces the hydrogen plasma concentration in the processing space and increases the rate of hydrogen desorption from the surface, thereby reducing the hydrogen content of each film intermediate layer to within a predetermined range or less than a predetermined maximum. As discussed above, each pulse of RF power at operation 308 has a total time T of the duty cycle_TOTTotal time T_TOTIs T_ONAnd T_OFFThe sum of (a) and (b). In one example, T at operation 308_ONLess than T_TOT30%, e.g., about 20% to about 29%. In one example, T at operation 308_ONLess than T_TOT20% of (e.g. T)_TOTFrom about 15% to about 19%. In one example, T at operation 308_ONLess than T_TOT10% of (e.g. T)_TOTFrom about 5% to about 9%. In yet another example, T at operation 308_ONLess than T_TOT5% of (e.g. T)_TOTFrom about 1% to about 4%. T at operation 308_ONDuring the time period, deposition of a film interlayer from the film precursor occurs.

Further, in the method 300, the pressure in the process chamber 102 may be about 1mTorr to about 50Torr during one or more of the operations 304, 306, and 308. In another example, the pressure in the process chamber 102 may be about 8Torr to about 50Torr, such as about 8Torr to about 20Torr, during one or more of the operations 304, 306, and 308. Further, in the method 300, the temperature in the process chamber 102 may be about 300 ℃ to about 500 ℃ during one or more of the operations 304, 306, and 208. In other examples, the temperature in the process chamber 102 may be about 300 ℃ to about 500 ℃ in one or more of operations 304, 306, and 308. In yet other examples, the process chamber is processed in one or more of operations 304, 306, and 308The temperature in 102 may be about 350 ℃ to about 450 ℃. The power density during the method 300 may be about 0.03W/cm²To about 1.64W/cm². In some examples, the power density during the method 300 is about 0.06W/cm²To about 0.3W/cm²。

At operation 310, the processing chamber 102 is optionally purged to remove the precursor plasma. In some examples, purging is not performed. In another example, the carrier gas and/or purge gas is continuously flowed such that the plasma remains ignited in the chamber and the flow of precursor gas is stopped to remove it from the chamber. In examples where purging is not performed, a hydrogen plasma may be present at least during operations 306 and 308. Further, in this example, method 300 may proceed from operation 308 to operation 312. At an operation 312, a hydrogen plasma is formed and/or maintained in the processing chamber 102, and the first film intermediate layer formed at operation 308 is exposed to the hydrogen plasma.

At operation 314 of the method 300, a film is formed from one or more intermediate layers deposited in one or more iterations of operations 304, 306, 308, 310, and 312. The total thickness of the intermediate layer formed by these iterations may be up to aboutThe thickness of each intermediate layer formed in each cycle may be aboutTo aboutThe film formed at operation 314 by one or more iterations of operations 304, 306, 308, 310, and 312 may include a hydrogen content of less than about 10%, such as less than about 5%, or less than about 3%, or less than about 2%, such as less than about 1%. The film formed at operation 314 may be formed on an interior surface of the process chamber. In another example, which may be combined with other examples, a film may be formed on a substrate 106 positioned in the process chamber 102. In one example, formed at operation 314The film may have a microcrystalline structure.

Thus, using the systems and methods discussed herein, pulsed RF plasma is used alone or in combination with H plasma exposure to deposit films. The films deposited herein may be formed on a substrate and/or on chamber components or other exposed surfaces. The pulsed RF plasma may include one or more semiconductor film precursors, and the plasma may be pulsed with RF power to have a plurality of pulses with a duty cycle having an on-time of less than about 20%.

Implementations may include one or more of the following advantages. Films formed according to the methods discussed herein may have a hydrogen content of less than 10%. The systems and methods discussed herein may form films that include predetermined film properties, such as extinction coefficient, film stress, and refractive index.

The embodiments and all functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural elements disclosed in this specification and their structural equivalents, or in combinations of them. The embodiments described herein may be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine-readable storage device for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.

The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

The term "data processing apparatus" encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks (e.g., internal hard disks or removable disks); magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.