阅读说明：本技术 从氮化钛表面去除氧化物 (Removal of oxides from titanium nitride surfaces ) 是由 J·J·王 仲華 于 2019-08-07 设计创作，主要内容包括：提供了用于从氮化钛表面去除氧化物的系统和工艺。在一个示例实施中,方法包括将工件放置在处理腔室中的工件支撑件上。工件可具有氮化钛层。方法可包括对氮化钛层进行基于等离子体的氧化物去除工艺。基于等离子体的氧化物去除工艺可包括：使用等离子体源在工艺气体中通过诱导等离子体生成一种或多种物质；和将工件暴露于等离子体中生成的物质。工艺气体可包括第一气体和第二气体的混合物。第一气体可包括含氢气体和含氮气体的一种或多种。第二气体可包括含氟气体。(Systems and processes for removing oxide from a titanium nitride surface are provided. In one example implementation, a method includes placing a workpiece on a workpiece support in a processing chamber. The workpiece may have a titanium nitride layer. The method may include subjecting the titanium nitride layer to a plasma-based oxide removal process. The plasma-based oxide removal process may include: generating one or more species in the process gas by inducing a plasma using a plasma source; and exposing the workpiece to species generated in the plasma. The process gas may comprise a mixture of a first gas and a second gas. The first gas may include one or more of a hydrogen-containing gas and a nitrogen-containing gas. The second gas may comprise a fluorine-containing gas.)

1. A method for processing a workpiece in a plasma processing apparatus, the method comprising:

placing a workpiece on a workpiece support in a processing chamber, the workpiece having a titanium nitride layer;

subjecting the titanium nitride layer to a plasma-based oxide removal process, the plasma-based oxide removal process comprising:

inducing a plasma in a process gas by using a plasma source to generate one or more species;

exposing the workpiece to species generated in the plasma;

wherein the process gas comprises a mixture of a first gas comprising one or more of a hydrogen-containing gas and a nitrogen-containing gas and a second gas comprising a fluorine-containing gas.

2. The method of claim 1, wherein the first gas comprises H₂Gas and N₂A gas.

3. The method of claim 1, wherein the first gas comprises NH₃A gas.

4. The method of claim 1, wherein the first gas comprises H₂Gas, N₂Gas and NH₃A gas.

5. The method of claim 1, wherein the second gas comprises CF₄A gas.

6. The method of claim 1, wherein the second gas comprises NF₃A gas.

7. The method of claim 1, wherein the process gas comprises H₂Gas, N₂Gas and CF₄Gas, H₂The flow rate of the gas is in the range of about 1000SCCM to about 8000SCCM, N₂The flow rate of the gas is in the range of about 1000SCCM to about 8000SCCM, CF₄The flow rate of the gas is in the range of about 0.1SCCM to about 220 SCCM.

8. A method according to claim 7, wherein the total flow rate of the process gas is in the range of about 2000SCCM to about 15000 SCCM.

9. The method of claim 1, wherein a pressure in the processing chamber during a plasma-based oxide removal process is in a range of about 200mTorr to about 1500 mTorr.

10. The method of claim 1, wherein the temperature of the workpiece is in a range of about 90 ℃ to about 400 ℃ during the plasma-based oxide removal process.

11. The method of claim 1, wherein the plasma source comprises an inductively coupled plasma source.

12. The method of claim 1, wherein the plasma is generated in a plasma chamber separated from the processing chamber by a baffle.

13. The method of claim 1, wherein the method comprises performing a plasma-based process on the workpiece in the processing chamber without removing the workpiece.

14. The method of claim 12, wherein the plasma-based process comprises one or more of a plasma etch process, a plasma strip process, or a plasma surface treatment process.

15. A method for processing a workpiece, comprising:

placing a workpiece on a workpiece support in a processing chamber, the workpiece comprising a titanium nitride layer;

generating one or more species by inducing a plasma in a process gas in a plasma chamber;

filtering one or more ions from one or more substances using a barrier separating the plasma chamber from the process chamber;

injecting a fluorine-containing gas downstream of the plasma chamber into the one or more species to generate a second mixture;

the workpiece is exposed to the second mixture in the processing chamber to remove the oxide from the titanium nitride layer.

16. The method of claim 15, wherein the fluorine-containing gas comprises NF₃。

17. The method of claim 15, wherein the fluorine-containing gas comprises CF₄。

18. The method of claim 15, wherein the process gas comprises hydrogen.

19. A method for processing, the method comprising:

placing a workpiece on a workpiece support in a processing chamber, the workpiece having a titanium nitride layer;

subjecting the titanium nitride layer to a plasma-based oxide removal process in a plasma chamber using a first plasma generated with a first process gas, the plasma-based oxide removal process comprising:

generating one or more species in the plasma chamber by inducing a plasma in the process gas using the plasma source;

filtering ions generated using the plasma through a barrier separating the plasma chamber from the process chamber; and

exposing the workpiece to neutral species generated in the plasma in the processing chamber;

performing a plasma-based process on the workpiece in a plasma chamber using a second plasma generated with a second process gas;

removing the workpiece from the processing chamber;

wherein the first process gas comprises H₂Gas, N₂Gas and fluorine-containing gas, H₂The flow rate of the gas is in the range of about 1000SCCM to about 8000SCCM, N₂The flow rate of the gas is in the range of about 1000SCCM to about 8000SCCM, CF₄The flow rate of the gas is in the range of about 0.1SCCM to about 220 SCCM.

20. The method of claim 17, wherein the second process gas is different from the first process gas.

Technical Field

The present disclosure relates generally to semiconductor processing, and more particularly to removing oxide from a workpiece, such as a semiconductor workpiece.

Background

In semiconductor processing, titanium nitride surfaces can be used as conductive diffusion barriers in the fabrication of integrated circuits. For example, titanium nitride may be used as a conductive diffusion barrier between a semiconductor material (e.g., Si, SiGe, etc.) and a metal (such as aluminum, copper, or tungsten). As a diffusion layer, titanium nitride can reduce the diffusion of metals and other impurities (which can dramatically change device performance) into the semiconductor material. As a conductive layer, a titanium nitride layer can be used as a conductive contact layer between the metal and the semiconductor layer.

Disclosure of Invention

Aspects and advantages of embodiments of the present disclosure will be set forth in part in the description which follows, or may be learned by practice of the embodiments.

One example aspect of the present disclosure relates to a method for processing a workpiece in a plasma processing apparatus. The method includes placing a workpiece on a workpiece support in a processing chamber. The workpiece may have a titanium nitride layer. The method may include subjecting the titanium nitride layer to a plasma-based oxide removal process. The plasma-based oxide removal process may include: inducing a plasma in a process gas by using a plasma source to generate one or more species; and exposing the workpiece to species generated in the plasma. The process gas may comprise a mixture of a first gas and a second gas. The first gas may include one or more of a hydrogen-containing gas and a nitrogen-containing gas. The second gas may comprise a fluorine-containing gas.

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 relevant principles.

Drawings

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

fig. 1 depicts an example plasma processing apparatus according to an example embodiment of the present disclosure;

fig. 2 depicts a flowchart of an example method according to an example embodiment of the present disclosure;

FIG. 3 depicts a flowchart of an example method according to an example embodiment of the present disclosure;

FIG. 4 depicts example results associated with an example oxide removal process, according to example embodiments of the present disclosure;

FIG. 5 depicts an example post-plasma gas injection in accordance with an example embodiment of the present disclosure;

FIG. 6 depicts an example plasma processing apparatus according to an example embodiment of the present disclosure; and

fig. 7 depicts an example plasma processing apparatus according to an example embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to implementations of one or more embodiments of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of various embodiments, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments without departing from the scope or spirit of the disclosure. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. It is therefore intended that aspects of the present disclosure cover such modifications and variations.

Example aspects of the present disclosure relate to methods for processing a workpiece having a titanium nitride layer. In semiconductor processing, a titanium nitride layer may be used as a conductive diffusion barrier layer in the fabrication of integrated circuits. For example, titanium nitride may be used as a conductive diffusion barrier between a semiconductor material (e.g., Si, SiGe, etc.) and a metal (such as aluminum, copper, or tungsten). As a diffusion layer, titanium nitride can reduce the diffusion of metals and other impurities (which can dramatically change device performance) into the semiconductor material. As a conductive layer, a titanium nitride layer can be used as a conductive contact layer between the metal and the semiconductor layer.

The titanium nitride layer can be easily oxidized when exposed to the atmosphere or an oxygen-containing environment. Oxidation of the titanium nitride layer can result in the undesirable effects of increasing the film resistivity of the titanium nitride, reducing its efficacy as a conductive layer, and ultimately degrading device (e.g., transistor) performance. The oxidation of the titanium nitride layer may vary from sample to sample depending on storage conditions and circumstances. This variability can lead to unpredictability in the performance and/or fabrication of the integrated circuit.

The removal of oxygen from the titanium nitride film may result in more controlled and reproducible etching, stripping, surface cleaning, and modification processes. Many etching, stripping, surface cleaning, and other modification processes are plasma-based processes that are performed in vacuum and can be affected by oxygen-containing environments. In this regard, it would be advantageous if the oxide removal process for the titanium nitride layer could be performed within the same process chamber as these plasma-based processes. In plasma-based processes, materials such as tungsten, silicon dioxide, silicon nitride, and other materials may be exposed simultaneously with the titanium nitride layer. It is important that these other materials are not damaged during processing of the workpiece.

Example aspects of the present disclosure relate to plasma-based processes for selectively removing titanium oxide and oxynitride from a titanium nitride film on a workpiece while leaving other materials on the workpiece undamaged. Removal of the titanium oxide and oxynitride may result in a decrease in the resistivity of the titanium nitride film. In some embodiments, plasma-based processes according to example aspects of the present disclosure may remove titanium oxide and/or oxynitride in situ within the same processing chamber before, during, and/or after other plasma-based processes (e.g., photoresist stripping, etching, surface cleaning, surface modification, etc.). By suitable surface treatment after oxide removal, oxygen, oxides and oxynitrides on and in the titanium nitride film can be maintained at reduced levels even after exposure to air.

According to example aspects of the present disclosure, a plasma-based oxide removal process for a titanium nitride film on a workpiece may remove oxides, oxynitrides, and oxygen in the titanium nitride film using a plasma comprising a hydrogen-containing species, a nitrogen-containing species, and a fluorine-containing species. This can lead to the removal of native oxides (and nitrogen oxides) and a reduction in membrane resistivity. In addition, the plasma-based oxide removal process according to example aspects of the present disclosure may result in the oxygen content in the titanium nitride layer remaining reduced even after several days of exposure to air. Plasma-based oxide removal processes according to example aspects of the present disclosure may be combined with one or more other surface modification processes (e.g., nitridation, sulfidation, etc.) to further inhibit oxidation of the titanium nitride film upon exposure to air.

In some example embodiments, a method may include placing a workpiece on a workpiece support in a processing chamber. The method may include generating a plasma (e.g., a direct plasma and/or a remote plasma) from a process gas in a plasma chamber. The process gas may comprise hydrogen (H)₂) Nitrogen-containing gas (e.g. N)₂) And a fluorine (F) -containing gas. In some embodiments, the process gasThe body may include a carrier gas, such as an inert gas, such as helium, argon, and/or xenon. The fluorine-containing gas may be, for example, CF₄And/or NF₃. In some embodiments, NH may be used in addition to hydrogen and/or nitrogen₃Or NH may be used₃Instead of hydrogen and/or nitrogen. The method may include exposing the workpiece having the titanium nitride layer to a hydrogen-containing species, a nitrogen-containing species, and/or a fluorine-containing species generated in a plasma.

Example process parameters for one example embodiment of the present disclosure are provided below:

process gas:

H₂flow rate: about 1000 to about 8000SCCM

N₂Flow rate: about 1000 to about 8000SCCM

CF₄Flow rate: about 0.1 to about 220SCCM

Total process gas flow rate: about 2000SCCM to about 15000SCCM

The process pressure is as follows: about 200mTorr to about 1500mTorr

Workpiece temperature: from about 90 ℃ to about 400 ℃.

In some embodiments, an additional plasma-based surface treatment process may be performed after the oxide removal. Such plasma-based surface treatment processes may include, but are not limited to, plasma nitridation, surface functionalization, polymer deposition, sulfur passivation. The plasma-based surface treatment process may be performed on a workpiece in the same processing chamber as the oxide removal process.

In some embodiments, oxide removal may be accomplished using post plasma gas injection (post plasma gas injection). For example, a plasma may be induced in a process gas in a plasma chamber using a plasma source. The process gas may include, for example, hydrogen and/or an inert gas, such as helium. The plasma chamber may be separate from the process chamber containing the workpiece. For example, a barrier that filters ions and allows neutral species to pass through may be disposed between the plasma chamber and the process chamber. The fluorine-containing gas may be injected into the neutral species downstream of the plasma chamber (e.g., at and/or below the louvers). The resulting mixture may be exposed to the workpiece for oxide removal in the titanium nitride layer.

For purposes of illustration and discussion, aspects of the present disclosure are discussed with reference to a "workpiece," "wafer," or semiconductor wafer. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that example aspects of the disclosure may be used in conjunction with any semiconductor substrate or other suitable workpiece. In addition, the use of the term "about" in conjunction with a numerical value is intended to mean within ten percent (10%) of the numerical value recited. "susceptor" refers to any structure that can be used to support a workpiece.

Fig. 1 depicts an example plasma processing apparatus 100 that may be used to perform an oxide removal process according to example embodiments of the present disclosure. FIG. 1 depicts one example processing apparatus that may be used to implement an oxide removal process in accordance with example aspects of the present disclosure. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that other processing devices may be used without departing from the scope of the present disclosure.

As illustrated, the plasma processing apparatus 100 includes a process chamber 110 and a plasma chamber 120 spaced apart from the process chamber 110. The processing chamber 110 includes a workpiece support or pedestal 112 operable to support a workpiece 114, such as a semiconductor wafer, to be processed. In this example illustration, a plasma is generated in the plasma chamber 120 (i.e., the plasma generation region) by the inductively coupled plasma source 135, and the desired species are directed from the plasma chamber 120 to the surface of the substrate 114 through the barrier assembly 200.

For purposes of illustration and discussion, aspects of the present disclosure are discussed with reference to an inductively coupled plasma source. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that any plasma source (e.g., inductively coupled plasma source, capacitively coupled plasma source, etc.) may be used without departing from the scope of the present disclosure.

The plasma chamber 120 includes dielectric sidewalls 122 and a ceiling 124. The dielectric sidewall 122, ceiling 124, and barrier 200 define a plasma chamber interior 125. The dielectric sidewalls 122 can be formed of a dielectric material, such as quartz and/or a ceramic (e.g., alumina). The inductively coupled plasma source 135 may include an induction coil 130 disposed about the plasma chamber 120 adjacent the dielectric sidewall 122. The inductive coil 130 is coupled to an RF power generator 134 through a suitable matching network 132. Process gases (e.g., hydrogen and carrier gases) may be provided to the chamber interior from a gas supply 150 and an annular gas distribution channel 151 or other suitable gas introduction mechanism. When the inductive coil 130 is energized with RF power from the RF power generator 134, a plasma may be generated in the plasma chamber 120. In particular embodiments, the plasma processing apparatus 100 can include an optional grounded Faraday cage 128 to reduce capacitive coupling of the inductive coil 130 to the plasma.

As shown in fig. 1, a barrier 200 separates the plasma chamber 120 from the processing chamber 110. The louvers 200 may be used to perform ion filtration from the mixture generated by the plasma in the plasma chamber 120 to generate a filtered mixture. In the process chamber, the filtered mixture may be exposed to the workpiece 114.

In some embodiments, the grill 200 may be a multi-panel grill. For example, the louvres 200 may include a first louver 210 and a second louver 220 spaced apart in parallel relationship to each other. The first louver 210 and the second louver 220 may be separated by a certain distance.

The first louver 210 may have a first louver pattern having a plurality of holes. The second louver 220 may have a second louver pattern having a plurality of holes. The first gate pattern may be the same as or different from the second gate pattern. The charged particles may recombine on the walls in their path through the holes of each of the louvers 210, 220 in the barrier. Neutral species (e.g., radicals) may flow relatively freely through the pores in the first and second louvers 210 and 220. The pore size and thickness of each baffle 210 and 220 may affect the permeability of both charged and neutral particles.

In some embodiments, the first louver 210 may be made of metal (e.g., aluminum) or other conductive material, and/or the second louver 220 may be made of conductive or dielectric material (e.g., quartz, ceramic, etc.). In some embodiments, the first louver 210 and/or the second louver 220 may be made of other materials, such as silicon or silicon carbide. If the louvers are made of metal or other conductive material, the louvers may be grounded. In some embodiments, the grid assembly may include a single grid having one grid plate.

Fig. 2 depicts a flowchart of an example method (250) in accordance with example aspects of the present disclosure. The method (250) will be discussed by way of example with reference to the plasma processing apparatus 100 of fig. 1. The method (250) may be implemented in any suitable plasma processing apparatus. For purposes of illustration and discussion, fig. 2 depicts steps performed in a particular order. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that various steps of any of the methods described herein can be omitted, expanded, performed simultaneously, rearranged and/or modified in various ways without departing from the scope of the present disclosure. Additionally, various steps (not illustrated) may be performed without departing from the scope of the present disclosure.

At (252), the method may include placing a workpiece in a process chamber of a plasma processing apparatus. For example, the method may include placing the workpiece 114 on the workpiece support 112 in the processing chamber 110. The workpiece may include a titanium nitride layer. The titanium nitride layer can be, for example, a diffusion barrier between the semiconductor material and the metal on the workpiece.

At (254), the method may optionally include performing a plasma-based process using a plasma processing apparatus prior to the oxide removal process. Plasma-based processes may expose a workpiece to species generated using a plasma source. Exemplary plasma-based processes include plasma etching, plasma stripping, plasma-based surface modification, and other processes.

In the example plasma processing apparatus of fig. 1, the plasma-based process may include inducing a plasma from a process gas in a plasma chamber using an inductively coupled plasma source 135. The louvres 200 may be used for ion filtering from a mixture to produce a filtered mixture. In the processing chamber, the filtered mixture may be exposed to the workpiece 114 for a plasma etch process, a photoresist strip process, a surface modification process, or other processes. Other plasma-based processes may be implemented without departing from the scope of the present disclosure.

At (256), the method may include performing a plasma-based oxide removal process on the titanium nitride layer on the workpiece. The plasma-based oxide removal process may be any of the oxide removal processes disclosed herein. For example, the oxide removal process may include one or more of the oxide removal processes discussed with reference to fig. 3-5. The plasma-based oxide removal process may use a plasma comprising a hydrogen-containing species, a nitrogen-containing species, and a fluorine-containing species to remove oxides, oxynitrides, and oxygen in the titanium nitride film.

At (258), the method may optionally include performing a plasma-based process after the oxide removal process. Plasma-based processes may expose a workpiece to species generated using a plasma source. Exemplary plasma-based processes include plasma etching, plasma stripping, plasma surface treatment, plasma-based surface modification, and other processes.

In the example plasma processing apparatus of fig. 1, the plasma-based process may include inducing a plasma from a process gas in a plasma chamber using an inductively coupled plasma source 135. The louvres 200 may be used to perform filtration of ions from a mixture to produce a filtered mixture. In the processing chamber, the filtered mixture may be exposed to the workpiece 114 for a plasma etch process, a photoresist strip process, a surface modification process, or other processes. Other plasma-based processes may be implemented without departing from the scope of the present disclosure.

In some embodiments, after performing the plasma-based oxide removal process according to example aspects of the present disclosure, the method may include performing a plasma-based surface treatment process to further reduce oxidation of the titanium nitride layer. For example, plasma-based surface treatment processes may include, but are not limited to, plasma nitridation, surface functionalization, polymer deposition, sulfur passivation. The plasma-based surface treatment process may be performed on the workpiece in the same processing chamber as the oxide removal process.

In some embodiments, a method may include exposing a titanium nitride layer to organic radicals (e.g., methyl radicals) in a processing chamber. The organic radicals may, for example, dissociate the hydrocarbon gas by using a plasma and/or inject the hydrocarbon gas (e.g., CH) by using a post-plasma gas injection₄) Mixed with a substance (e.g., excited H radicals, excited noble gas molecules, etc.). The methyl radicals can reduce the formation of oxides in the titanium nitride layer.

At (210), the method may include removing the workpiece from the processing chamber. For example, the workpiece 114 may be removed from the workpiece support 112 in the processing chamber 110. The plasma processing apparatus may then be adjusted for future processing of other workpieces. In this way, the oxide removal process (206) and the one or more optional plasma-based processes (204), (208) may be performed using the same processing apparatus with the workpiece in the same processing chamber without removing the workpiece. This may reduce processing latencies caused by moving workpieces between different processing chambers, as well as exposing the workpieces to the atmosphere.

Fig. 3 depicts a flow diagram of an example oxide removal process (300) according to an example aspect of the present disclosure. The process 300 may be performed using the plasma processing apparatus 100. However, as will be discussed in detail below, methods according to example aspects of the present disclosure may be implemented using other approaches without departing from the scope of the present disclosure. Fig. 3 depicts steps performed in a particular order for purposes of illustration and discussion. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that various steps of any of the methods described herein can be omitted, expanded, performed simultaneously, rearranged and/or modified in various ways without departing from the scope of the present disclosure. Additionally, various additional steps (not illustrated) may be performed without departing from the scope of the present disclosure.

At (302), the oxide removal process may include heating the workpiece. For example, the workpiece 114 may be heated to a process temperature in a process chamber. The workpiece 114 may be heated using one or more heating systems associated with the pedestal 112. In some embodiments, the workpiece may be heated to a process temperature in the range of about 90 ℃ to about 400 ℃.

At 304, the oxide removal process may include allowing a process gas to enter the plasma chamber. For example, process gases may be allowed to enter the plasma chamber interior 125 from the gas source 150 via the annular gas distribution channel 151 or other suitable gas introduction mechanism.

In some embodiments, the process gas may be a mixture of a first gas and a second gas. In some embodiments, the first gas may be a mixture of a hydrogen-containing gas and a nitrogen-containing gas. For example, in some embodiments, the first gas can be H₂And N₂A mixture of (a). In some embodiments, the first gas may be NH₃. In some embodiments, the first gas can be H₂、N₂And NH₃Mixture of

In some embodiments, the second gas may be a fluorine-containing gas. For example, the second gas may be CF₄. In some embodiments, the second gas may be NF₃。

In some embodiments, the process gas comprises H₂Gas, N₂Gas and CF₄Gas, H₂The flow rate of the gas is in the range of about 1000 standard cubic centimeters per minute (SCCM) to about 8000SCCM, N₂The flow rate of the gas is in the range of about 1000SCCM to about 8000SCCM, CF₄The flow rate of the gas is in the range of about 0.1SCCM to about 220 SCCM. The total flow rate of the process gas may range from about 2000SCCM to about 15000 SCCM.

At (306), the oxide removal process may include energizing an inductively coupled plasma source to generate a plasma in the plasma chamber. For example, the inductive coil 130 can be powered with RF energy from an RF power generator 134 to generate a plasma within the plasma chamber interior 125. In some embodiments, an inductively coupled plasma source may be powered with pulsed power to obtain the desired plasma energy reduced radicals. At (308), the plasma may be used to generate one or more species.

At (310), the oxide removal process may include filtering one or more plasma-generated ions to form a filtered mixture. The filtered mixture may include neutral radicals. In some embodiments, one or more ions may be filtered using a barrier assembly that separates the plasma chamber from a process chamber in which the workpiece is located. For example, the barrier assembly 200 may be used to filter ions generated by a plasma. The grill 200 may have a plurality of holes. Charged particles (e.g., ions) may recombine on the walls in their path through the plurality of pores. Neutral species (e.g., free radicals) can pass through these pores.

In some embodiments, the louvers 200 may be configured to filter ions at an efficiency of greater than or equal to about 90%, such as greater than or equal to about 95%. The percentage efficiency for ion filtration refers to the amount of ions removed from the mixture relative to the total number of ions in the mixture. For example, an efficiency of about 90% indicates that about 90% of the ions are removed during filtration. An efficiency of about 95% indicates that about 95% of the ions are removed during filtration.

In some embodiments, the barrier may be a multi-panel barrier. The multi-plate grid may have a plurality of grid plates in parallel. The arrangement and arrangement of the apertures in the baffle plate may be selected to provide a desired efficiency for ion filtration, such as greater than or equal to about 95%.

For example, the grill 200 may have a first grill 210 and a second grill 220 that are in parallel relationship with each other. The first louver 210 may have a first louver pattern having a plurality of holes. The second louver 220 may have a second louver pattern having a plurality of holes. The first gate pattern may be the same as or different from the second gate pattern. Charged particles (e.g., ions) may recombine on the walls in their path through the apertures of each baffle plate 210, 220 in the baffle 200. Neutral species (e.g., radicals) may flow relatively freely through the pores in the first and second louvers 210 and 220.

At (312) of fig. 3, an oxide removal process may include exposing the workpiece to the species. More specifically, the workpiece may be exposed to species generated in the plasma and passing through the barrier assembly. By way of example, the hydrogen-containing species, the nitrogen-containing species, and the fluorine-containing species may pass through the louvers 200 and be exposed to the workpiece 114. Exposing the workpiece to fluorine-containing species can result in the removal of oxides, oxynitrides, and oxygen from the titanium nitride layer.

Fig. 4 depicts example results associated with an example oxide removal process according to example embodiments of the present disclosure. More specifically, fig. 4 depicts X-ray photoelectron spectroscopy (XPS) spectra of titanium 2p peaks showing a change in chemical bonding of titanium in the titanium nitride layer before and after the oxide removal process. Curve 410 is associated with a "control" sample, which is associated with the sample being deposited titanium nitride. Curves 412 and 414 correlate to two samples "9" and "10". Using H for oxide removal process₂/N₂/CF₄The induced plasma in the process gas treated samples 9 and 10 for one minute. Curve 416 correlates to sample "8". Ar/H for oxide removal process₂/CF₄The plasma induced in the process gas treated the sample for 8 minutes. All samples were exposed to air before and after the oxide removal process. Curves 410, 412, 414, and 416 indicate the removal of TiO after the plasma oxide removal process₂And TiON.

Table 1 below provides the elemental composition of the samples measured from XPS. Table 1 shows that the oxygen content is reduced after performing a plasma-based oxide removal process according to an exemplary aspect of the present disclosure.

Table 1:

sample ID	C 1s％	F 1s％	N 1s％	O 1s％	Si 2p％	Ti 2p％
							Control	8.4	1.2	30.6	26.7	1.2	31.9
10	6.1	2.2	32.6	24.0	1.8	33.4
							9	6.2	2.9	34.2	21.5	1.3	34.0
8	6.2	2.5	34.9	21.1	1.8	33.6

Table 2 below provides data relating to the sheet resistance of sample 10 before and after the oxide removal process. As shown, the resistance of the titanium nitride layer is reduced.

Table 2:

in some embodiments, the oxide removal process from the titanium nitride layer on the workpiece is performed using a post-plasma gas implantation. Post-plasma gas injection may include mixing a fluorine-containing gas into neutral species downstream of the plasma. In some embodiments, the fluorine-containing gas is mixed with neutral species at or downstream of a barrier separating the process chamber containing the workpiece from the plasma chamber in which the plasma is induced in the process gas. Post-plasma gas implantation according to example embodiments of the present disclosure may result in the generation of fluorine-containing radicals for exposure to a workpiece. Fluorine-containing radicals may be used for oxide removal of the titanium nitride layer on the workpiece.

Fig. 5 depicts the generation of fluorine-containing radicals using a post-plasma gas injection example in accordance with an example embodiment of the present disclosure. More specifically, fig. 5 depicts an example barrier 200 for post-plasma fluorine-containing gas injection in accordance with example embodiments of the present disclosure. The grill 200 includes a first grill panel 210 and a second grill panel 220 disposed in a parallel relationship. The first louver 210 and the second louver 220 may be provided for ion/UV filtering.

The first louver 210 and the second louver 220 may be in a parallel relationship with each other. The first louver 210 may have a first louver pattern having a plurality of holes. The second louver 220 may have a second louver pattern having a plurality of holes. The first gate pattern may be the same as or different from the second gate pattern. Species 215 from the plasma may be exposed to the barrier 200. Charged particles (e.g., ions) may recombine on the walls in their path through the apertures of each baffle plate 210, 220 in the baffle 200. Neutral species may flow relatively freely through the apertures in the first louver 210 and the second louver 220.

After the second baffle plate 220, a gas injection source 230 may be configured to mix a fluorine-containing gas 232 into the substance 237 passing through the baffle 200. In some embodiments, the fluorine-containing gas is CF₄. In some embodiments, the fluorine-containing gas is NF₄. A mixture 225 including fluorine-containing radicals produced from the implantation of the fluorine-containing gas may pass through a third baffle plate 235 for exposure to a workpiece in the processing chamber.

For exemplary purposes, the present example is discussed with reference to a barrier having three barrier panels. Using the disclosure provided herein, one of ordinary skill in the art will appreciate that more or fewer louvers may be used without departing from the scope of the present disclosure. Additionally, the fluorine-containing gas may be mixed with the species at any point in and/or after the barrier in the processing chamber. For example, the gas injection source 230 may be located between the first louver 210 and the second louver 220.

Other plasma processing apparatuses may be used to perform the oxide removal process and/or the plasma strip process without departing from the scope of the present disclosure.

Fig. 6 depicts an example plasma processing apparatus 500 that may be used to implement a process according to an example embodiment of the present disclosure. The plasma processing apparatus 500 is similar to the plasma processing apparatus 100 of fig. 1.

More specifically, the plasma processing apparatus 500 includes a process chamber 110 and a plasma chamber 120 spaced apart from the process chamber 110. The processing chamber 110 includes a substrate support or pedestal 112 operable to support a workpiece 114, such as a semiconductor wafer, to be processed. In this example illustration, a plasma is generated in the plasma chamber 120 (i.e., the plasma generation region) by the inductively coupled plasma source 135, and the desired species are directed from the plasma chamber 120 to the surface of the substrate 114 through the barrier assembly 200.

The plasma chamber 120 includes dielectric sidewalls 122 and a ceiling 124. The dielectric sidewall 122, ceiling 124, and barrier 200 define a plasma chamber interior 125. The dielectric sidewalls 122 may be formed of a dielectric material, such as quartz and/or alumina. The inductively coupled plasma source 135 may include an induction coil 130 disposed about the plasma chamber 120 adjacent the dielectric sidewall 122. The inductive coil 130 is coupled to an RF power generator 134 through a suitable matching network 132. Process gas (e.g., inert gas) may be provided to the chamber interior from a gas supply 150 and an annular gas distribution channel 151 or other suitable gas introduction mechanism. When the inductive coil 130 is energized with RF power from the RF power generator 134, a plasma may be generated in the plasma chamber 120. In particular embodiments, plasma processing apparatus 100 can include an optional grounded faraday cage 128 to reduce capacitive coupling of the inductive coil 130 to the plasma.

As shown in fig. 6, the barrier 200 separates the plasma chamber 120 from the process chamber 110. The louvers 200 may be used to perform ion filtration from the mixture generated by the plasma in the plasma chamber 120 to generate a filtered mixture. In the process chamber, the filtered mixture may be exposed to the workpiece 114.

In some embodiments, the grill 200 may be a multi-panel grill. For example, the louvres 200 may include a first louver 210 and a second louver 220 spaced apart in parallel relationship to each other. The first louver 210 and the second louver 220 may be separated by a certain distance.

The first louver 210 may have a first louver pattern having a plurality of holes. The second louver 220 may have a second louver pattern having a plurality of holes. The first gate pattern may be the same as or different from the second gate pattern. The charged particles may recombine on the walls in their path through the holes of each of the louvers 210, 220 in the barrier. Neutral species (e.g., radicals) may flow relatively freely through the pores in the first and second louvers 210 and 220. The pore size and thickness of each baffle 210 and 220 may affect the permeability of both charged and neutral particles.

In some embodiments, the first louver 210 may be made of metal (e.g., aluminum) or other conductive material and/or the second louver 220 may be made of conductive material or dielectric material (e.g., quartz, ceramic, etc.). In some embodiments, the first louver 210 and/or the second louver 220 may be made of other materials, such as silicon or silicon carbide. If the louvers are made of metal or other conductive material, the louvers may be grounded.

The example plasma processing apparatus 500 of fig. 6 is operable to generate a first plasma 502 (e.g., a remote plasma) in the plasma chamber 120 and a second plasma 504 (e.g., a direct plasma) in the processing chamber 110. As used herein, "remote plasma" refers to a plasma that is remote from the workpiece, such as generated in a plasma chamber separated from the workpiece by a barrier. As used herein, "direct plasma" refers to a plasma that is directly exposed to a workpiece, such as a plasma generated in a processing chamber having a pedestal that operably supports the workpiece.

More specifically, the plasma processing device 500 of fig. 6 includes a bias source having a bias electrode 510 in the pedestal 112. Bias electrode 510 may be coupled to an RF power generator 514 via a suitable matching network 512. When the bias electrode 510 is powered with RF energy, a second plasma 504 may be generated from the mixture in the process chamber 110 for direct exposure to the workpiece 114. The processing chamber 110 may include an exhaust port 516 for exhausting gases from the processing chamber 110. The species used in the oxide removal process according to example aspects of the present disclosure may be generated using the first plasma 502 and/or the second plasma 504.

Fig. 7 depicts a process chamber 600 similar to that of fig. 2 and 7. More specifically, the plasma processing apparatus 600 includes a process chamber 110 and a plasma chamber 120 spaced apart from the process chamber 110. The processing chamber 110 includes a substrate support or pedestal 112 operable to support a workpiece 114, such as a semiconductor wafer, to be processed. In this example illustration, a plasma is generated in the plasma chamber 120 (i.e., the plasma generation region) by the inductively coupled plasma source 135, and the desired species are directed from the plasma chamber 120 to the surface of the substrate 114 through the barrier assembly 200.

The plasma chamber 120 includes dielectric sidewalls 122 and a ceiling 124. The dielectric sidewall 122, ceiling 124, and barrier 200 define a plasma chamber interior 125. The dielectric sidewalls 122 may be formed of a dielectric material, such as quartz and/or alumina. The inductively coupled plasma source 135 may include an induction coil 130 disposed about the plasma chamber 120 adjacent the dielectric sidewall 122. The inductive coil 130 is coupled to an RF power generator 134 through a suitable matching network 132. Process gas (e.g., inert gas) may be provided to the chamber interior from a gas supply 150 and an annular gas distribution channel 151 or other suitable gas introduction mechanism. When the inductive coil 130 is energized with RF power from the RF power generator 134, a plasma may be generated in the plasma chamber 120. In particular embodiments, plasma processing apparatus 100 can include an optional grounded faraday cage 128 to reduce capacitive coupling of the inductive coil 130 to the plasma.

As shown in fig. 7, the barrier 200 separates the plasma chamber 120 from the process chamber 110. The louvers 200 may be used to perform ion filtration from the mixture generated by the plasma in the plasma chamber 120 to generate a filtered mixture. In the process chamber, the filtered mixture may be exposed to the workpiece 114.

In some embodiments, the grill 200 may be a multi-panel grill. For example, the louvres 200 may include first and second louvers 210, 220 spaced in parallel relationship to one another. The first louver 210 and the second louver 220 may be separated by a certain distance.

The first louver 210 may have a first louver pattern having a plurality of holes. The second louver 220 may have a second louver pattern having a plurality of holes. The first gate pattern may be the same as or different from the second gate pattern. The charged particles may recombine on the walls in their path through the holes of each of the louvers 210, 220 in the barrier. Neutral species (e.g., radicals) may flow relatively freely through the pores in the first and second louvers 210 and 220. The pore size and thickness of each baffle 210 and 220 may affect the permeability of both charged and neutral particles.

In some embodiments, the first louver 210 may be made of metal (e.g., aluminum) or other conductive material and/or the second louver 220 may be made of conductive material or dielectric material (e.g., quartz, ceramic, etc.). In some embodiments, the first louver 210 and/or the second louver 220 may be made of other materials, such as silicon or silicon carbide. If the louvers are made of metal or other conductive material, the louvers may be grounded.

The example plasma processing apparatus 600 of fig. 7 is operable to generate a first plasma 602 (e.g., a remote plasma) in the plasma chamber 120 and a second plasma 604 (e.g., a direct plasma) in the processing chamber 110. As shown, the plasma processing device 600 can include an angled dielectric sidewall 622 extending from the vertical sidewall 122 associated with the remote plasma chamber 120. The angled dielectric sidewalls 622 may form a portion of the processing chamber 110.

A second inductive plasma source 635 may be placed proximate the dielectric sidewall 622. The second inductive plasma source 635 may include an inductive coil 610 coupled to an RF generator 614 via a suitable matching network 612. The inductive coil 610, when energized with RF energy, may induce a direct plasma 604 from the mixture in the processing chamber 110. A faraday cage 628 may be disposed between the induction coil 610 and the sidewall 622.

The base 112 is movable in a vertical direction V. For example, the base 112 may include a vertical riser 616 that may be configured to adjust the distance between the base 112 and the louvre assembly 200. As one example, the pedestal 112 may be placed in a first vertical position for processing using the remote plasma 602. The pedestal 112 may be in a second vertical position for processing using the direct plasma 604. The first vertical position may be closer to the grill assembly 200 than the second vertical position.

The plasma processing apparatus 600 of fig. 7 includes a bias source having a bias electrode 510 in the pedestal 112. Bias electrode 510 may be coupled to an RF power generator 514 via a suitable matching network 512. The processing chamber 110 may include an exhaust port 516 for exhausting gases from the processing chamber 110. The species used in the oxide removal process according to example aspects of the present disclosure may be generated using the first plasma 602 and/or the second plasma 604.

While the present subject matter has been described in detail with respect 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 illustrated but not limited, and the present 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.