Method for processing workpiece, plasma apparatus and semiconductor workpiece

Abstract

The invention provides a method for processing a workpiece, plasma equipment and a semiconductor workpiece, and relates to the technical field of semiconductor equipment. The method for processing the workpiece comprises the following steps: placing the workpiece to be processed on a tray of a reaction chamber; heating the surface of the workpiece to a target temperature; gas is conveyed to the reaction chamber, the gas is excited to form plasma, the plasma is conveyed to the surface of the workpiece, and free radical substances in the plasma make contact with the metal layer of the heated workpiece; the metal layer comprises at least one of a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer and a cobalt layer. Residual impurities or oxides of the metal layer can be reduced, the resistivity of the metal layer of the workpiece can be reduced, and the purpose of workpiece surface treatment is achieved.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor equipment technology, and more particularly to a method for processing workpieces, a plasma device, and a semiconductor workpiece. Background Technology

[0002] Among related technologies, ICP (Inductively Coupled Plasma Etcher) equipment is an important process equipment in semiconductor chip manufacturing, and remote plasma technology has been widely used on such equipment. The purpose of remote plasma technology is to generate plasma in a region far from the wafer, and then process the wafer after the plasma reaches the wafer area. Summary of the Invention

[0003] This disclosure provides a method for processing workpieces, a plasma device, and a semiconductor workpiece.

[0004] According to one aspect of this disclosure, a method for processing a workpiece is provided, comprising: placing the workpiece to be processed on a tray in a reaction chamber; heating the surface of the workpiece to a target temperature; supplying a gas to the reaction chamber, exciting the gas to form a plasma, and supplying the plasma to the surface of the workpiece such that free radicals in the plasma come into contact with a metal layer of the heated workpiece; the metal layer comprising at least one of the following: a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer, and a cobalt layer.

[0005] In some embodiments, when the metal layer includes a tungsten layer, the free radical material in the plasma comes into contact with the heated metal layer of the workpiece, including: the hydrogen free radical in the plasma comes into contact with the tungsten layer, causing the oxide film on the surface of the tungsten layer to be reduced.

[0006] In some embodiments, the step of supplying gas to the reaction chamber and exciting the gas to form plasma includes: supplying oxygen and hydrogen to the reaction chamber and exciting the oxygen and hydrogen and their mixture to form plasma; wherein the proportion V1 of hydrogen in the mixture of oxygen and hydrogen satisfies: 65 vol% ≤ V1 ≤ 95 vol.

[0007] In some embodiments, the oxygen flow rate F1 satisfies: 100sccm≤F1≤3000sccm.

[0008] In some embodiments, the hydrogen flow rate F2 satisfies: 400sccm ≤ F2 ≤ 8000sccm.

[0009] In some embodiments, the free radical material in the plasma comes into contact with the metal layer of the heated workpiece, including: the hydrogen free radical treatment in the plasma comes into contact with the titanium nitride layer to reduce the impurity content in the titanium nitride layer; correspondingly, the gas delivery to the reaction chamber includes: delivering hydrogen to the reaction chamber; wherein the flow rate F3 of the hydrogen satisfies: 100sccm≤F3≤2000sccm.

[0010] In some embodiments, the free radical material in the plasma comes into contact with the heated metal layer of the workpiece, including: the hydrogen free radical in the plasma is used to treat the contact with the metal layer, thereby reducing the oxide film on the surface of the metal layer; wherein the metal layer includes at least one of a copper layer, a molybdenum layer, and a cobalt layer; correspondingly, the gas delivery to the reaction chamber includes: the gas delivered to the reaction chamber includes hydrogen; wherein the flow rate F4 of the hydrogen satisfies: 100 sccm ≤ F4 ≤ 2000 sccm.

[0011] In some embodiments, the target temperature T1 satisfies: 70℃≤T1≤650℃.

[0012] In some embodiments, the target temperature T1 satisfies: 200℃≤T1≤600℃.

[0013] In some embodiments, the method further includes: supplying oxygen to the reaction chamber, exciting the oxygen to form plasma, and delivering the plasma to the surface of the workpiece, such that oxygen free radicals in the plasma contact the heated silicon layer of the workpiece to form a silicon oxide film.

[0014] In some embodiments, the method further includes processing the silicon oxide film based on flow chemical vapor deposition.

[0015] In some embodiments, the method further includes: supplying oxygen to the reaction chamber, exciting the oxygen to form plasma, and delivering the plasma to the surface of the workpiece, such that oxygen free radicals in the plasma treat the silicon oxide film; wherein the oxygen flow rate F5 satisfies: 500 sccm ≤ F5 ≤ 3000 sccm; supplying hydrogen to the reaction chamber, exciting the hydrogen to form plasma, and delivering the plasma to the surface of the workpiece, such that hydrogen free radicals in the plasma treat the silicon oxide film to reduce the wet etching reaction rate; wherein the hydrogen flow rate F6 satisfies: 25 sccm ≤ F6 ≤ 200 sccm.

[0016] According to another aspect of this disclosure, a plasma device is provided for implementing the method described in any of the preceding claims, the plasma device comprising: a reaction chamber including a plasma generation space and a workpiece surface treatment space; the plasma generation space being used to excite gas to generate plasma; the workpiece surface treatment space being used to allow free radical substances in the plasma to contact a metal layer of a heated workpiece, the metal layer including at least one of the following: a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer, and a cobalt layer; a grid located at the connection between the plasma generation space and the workpiece surface treatment space, for filtering and / or homogenizing the plasma flowing from the plasma generation space to the workpiece surface treatment space; a tray installed in the workpiece surface treatment space for supporting the workpiece; a first gas inlet pipe connected to the plasma generation space for supplying gas to the plasma generation space; and a heating element installed in the workpiece surface treatment space for heating the surface of the workpiece to a target temperature.

[0017] In some embodiments, the heating element includes a heating wire mounted to the tray; or, the heating element includes a heating lamp mounted to the inner wall of the reaction chamber.

[0018] In some embodiments, the plasma device further includes a second gas inlet pipe, which is connected to the workpiece surface treatment space and is used to replenish the workpiece surface treatment space with gas.

[0019] According to another aspect of this disclosure, a semiconductor workpiece is provided, comprising: a workpiece made using the method described in any of the foregoing embodiments.

[0020] The technology disclosed herein can reduce residual impurities or oxides in the metal layer, thereby reducing the resistivity of the metal layer of the workpiece and achieving the purpose of surface treatment of the workpiece.

[0021] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0022] The accompanying drawings are provided to better understand this solution and do not constitute a limitation of this disclosure. Wherein: Figure 1 This is a schematic flowchart of a method for processing a workpiece according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a plasma device according to an embodiment of the present disclosure; Figure 3This is a schematic diagram of the structure of a plasma device according to an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the structure of a plasma device provided according to an embodiment of the present disclosure.

[0023] Explanation of reference numerals: 100-Plasma generation space; 110-Dielectric cylinder; 120-Inductor coil; 200-Workpiece surface treatment space; 210-Tray; 220-Heating element; 300-Grate; 410-First air inlet pipe; 420-Second air inlet pipe; 500-Workpiece. Detailed Implementation

[0024] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0025] Please refer to Figure 1 The method for processing a workpiece provided in this embodiment includes the following steps S110 to S130: Step S110: Place the workpiece to be processed onto the tray in the reaction chamber; Step S120: Heat the surface of the workpiece to the target temperature; Step S130: Gas is supplied to the reaction chamber and excited to form plasma. The plasma is then delivered to the surface of the workpiece so that the free radicals in the plasma come into contact with the metal layer of the heated workpiece. The metal layer includes at least one of the following: tungsten layer, titanium nitride layer, copper layer, molybdenum layer, and cobalt layer.

[0026] Please refer to Figure 2 and Figure 3 In step S110, the plasma device used to implement the method for processing the workpiece is provided with a tray 210, on which the workpiece 500 is typically supported. The workpiece 500 can be placed directly on the tray 210, or it can be suspended above the tray 210.

[0027] In step S120, a heating element 220 is provided in the plasma device. The heating element 220 is installed in the workpiece surface treatment space 200 and is used to heat the surface of the workpiece 500 to a target temperature. The target temperature is the process temperature required for the workpiece 500, such as a wafer, to react with free radical substances in the plasma.

[0028] In some examples, heating element 220 includes a heating wire mounted to tray 210; for example, the heating wire is mounted in tray 210. In other examples, heating element 220 includes a heating lamp mounted to the inner wall of the reaction chamber; for example, at least a portion of the heating lamp is mounted below tray 210.

[0029] In step S130, the reaction chamber of the plasma device includes a plasma generation space 100 and a workpiece surface treatment space 200. A grid 300 is provided at the connection between the plasma generation space 100 and the workpiece surface treatment space 200. The grid 300 is used to filter and / or homogenize the plasma flowing from the plasma generation space 100 to the workpiece surface treatment space 200.

[0030] Gas is supplied to the plasma generation space 100 in the reaction chamber via the pipeline of the plasma equipment. The pressure of the plasma generation space 100 is adjusted to a pressure range where the gas can be easily excited to a plasma state. Radio frequency energy is fed into the inductor coil 120 of the plasma equipment, thereby exciting the gas in the plasma generation space to generate inductively coupled plasma. The radio frequency (RF) power of the inductor coil 120 is approximately 1 kW to 5 kW. The generated plasma includes at least one free radical substance: oxygen, nitrogen, hydrogen, ammonia, or helium. After passing through the grid 300, most of the ions are filtered out, and the remaining free radical substances reach the workpiece surface treatment space 200.

[0031] Please refer to Figure 4 Optionally, the plasma device's piping may include a first inlet pipe 410 and a second inlet pipe 420, with each pipe supplying gas independently. The first inlet pipe 410 is connected to the plasma generation space 100 and is used to supply gas to the plasma generation space 100. In some examples, the second inlet pipe 420 may be connected to the workpiece surface treatment space 200 and is used to supplement the workpiece surface treatment space 200 with gas to dilute the plasma concentration in the workpiece surface treatment space 200. In other examples, the second inlet pipe 420 may be connected to the plasma generation space 100 and is used to supplement the plasma generation space 100 with gas. In some other examples, the second air inlet pipe 420 can be connected to the plasma generation space 100 and the workpiece surface treatment space 200 to supplement the gas required for plasma generation or to dilute the generated plasma, thereby controlling the degree of reaction; wherein, the outlet end of the second air inlet pipe 420 can be located adjacent to the grille 300 and above the grille 300; in the case of a multi-layer grille 300, the outlet end of the second air inlet pipe 420 is at least above the bottom layer of the grille 300.

[0032] After the workpiece 500 is adjusted to a suitable height and heated to the target temperature, at least one free radical substance in the plasma can come into contact with the metal layer of the workpiece 500. For example, the metal layer of the workpiece 500 can chemically react with at least one free radical substance in the plasma to reduce residual impurities or oxides in the metal layer, thereby reducing the resistivity of the metal layer and achieving the purpose of surface treatment.

[0033] The metal layer of workpiece 500 includes at least one of the following: a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer, and a cobalt layer. It is understood that when the metal layer of workpiece 500 includes at least two of these, the two metal layers can be located in different layer structures or in different regions of the same layer, depending on actual needs.

[0034] It is understandable that workpiece 500 can be heated at atmospheric pressure; however, workpiece 500 needs to be processed at process pressure, which is usually less than 20 Torr; Torr stands for Torr, a unit of pressure.

[0035] The method for processing a workpiece provided in this embodiment involves placing the workpiece 500 to be processed on a tray 210 of a reaction chamber, supplying gas to the reaction chamber, exciting the gas to form plasma, supplying the plasma to the surface of the workpiece 500, and heating the surface of the workpiece 500 to a target temperature. This allows free radical substances in the plasma to come into contact with the metal layer of the heated workpiece 500. The metal layer includes at least one of the following: a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer, and a cobalt layer. This reduces residual impurities or oxides in the metal layer, thereby reducing the resistivity of the metal layer of the workpiece 500 and achieving the purpose of surface treatment of the workpiece 500.

[0036] In some embodiments, in order to drive the processing of the metal layer of workpiece 500 and to save energy, the target temperature T1 satisfies 70℃≤T1≤650℃. Here, ℃ represents degrees Celsius. For example, T1 can be 70℃, 100℃, 150℃, 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, or 650℃, or any value between two of the above.

[0037] Optionally, the target temperature T1 satisfies: 200℃≤T1≤600℃. For example, T1 can be 200℃ or 250℃ or 300℃ or 350℃ or 400℃ or 450℃ or 500℃ or 550℃ or 600℃, or any value between any two of the above.

[0038] In some embodiments, step S130, contacting the free radical material in the plasma with the metal layer of the heated workpiece 500, includes: hydrogen free radical treatment in the plasma contacting the tungsten layer, causing the oxide film on the surface of the tungsten layer to be reduced, thereby reducing the thickness of the oxide film in the tungsten layer and achieving the purpose of reducing the resistivity of the tungsten layer.

[0039] The gas supplied to the reaction chamber includes hydrogen. The free radical substances entering the workpiece surface treatment space 200 include hydrogen free radicals.

[0040] In some examples, step S130, supplying gas to the reaction chamber and exciting the gas to form plasma, includes: supplying oxygen and hydrogen to the reaction chamber and exciting the oxygen and hydrogen and their mixture to form plasma; wherein the proportion V1 of hydrogen in the mixture of oxygen and hydrogen satisfies: 65 vol% ≤ V1 ≤ 95 vol.

[0041] Where vol% represents the gas volume percentage. For example, V1 can be 65 vol%, 70 vol%, 75 vol%, 80 vol%, 85 vol%, 90 vol%, or 95 vol%, or a ratio between any two of the above.

[0042] Oxygen is supplied to the plasma generation space 100 to generate oxygen free radicals. To minimize the oxide film of the tungsten layer, a large amount of hydrogen is supplied to the plasma generation space 100 to generate a large amount of hydrogen free radicals. The volume of hydrogen in the gas supplied to the plasma generation space 100 is approximately 65% ​​to approximately 95% of the total volume of hydrogen and oxygen. The specific volume percentage of hydrogen can be selected according to actual needs. A hydrogen volume percentage below 65% will limit the selectivity of the oxidation process. A hydrogen volume percentage above 65% will reduce the impact on subsequent processing, for example, it will reduce silicon oxidation. It is understood that within the above gas volume percentage range, a higher hydrogen volume percentage results in better treatment of the tungsten layer.

[0043] In some examples, to meet the requirements of tungsten layer processing and subsequent silicon oxidation, the oxygen flow rate F1 satisfies: 100 sccm ≤ F1 ≤ 3000 sccm. sccm represents standard cubic centimeters per minute. For example, F1 can be 100 sccm, 500 sccm, 1000 sccm, 1500 sccm, 2000 sccm, 2500 sccm, or 3000 sccm, or any value between two of these.

[0044] In some examples, to meet the requirements of tungsten layer processing, the hydrogen flow rate F2 satisfies: 400 sccm ≤ F2 ≤ 8000 sccm. For example, F2 can be 400 sccm, 500 sccm, 1000 sccm, 1500 sccm, 2000 sccm, 2500 sccm, 3000 sccm, 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm, 6000 sccm, 6500 sccm, 7000 sccm, 7500 sccm, or 8000 sccm, or any value between two of the above.

[0045] In this embodiment, the resistivity of the tungsten layer can be reduced by about 10%; the reduction in the resistivity of the tungsten layer is specifically related to the oxide thickness of the tungsten layer before treatment, as well as the treatment time, the concentration of hydrogen free radicals, etc.

[0046] In some embodiments, step S130, contacting the free radical material in the plasma with the metal layer of the heated workpiece 500, includes: contacting the titanium nitride layer with hydrogen free radical treatment in the plasma to reduce the impurity content in the titanium nitride layer.

[0047] Accordingly, the gas is supplied to the reaction chamber, including hydrogen, and the flow rate F3 of the hydrogen satisfies: 100sccm≤F3≤2000sccm.

[0048] For example, the hydrogen flow rate F3 can be 100 sccm, 500 sccm, 1000 sccm, 1500 sccm, or 2000 sccm, or any two of these values. The surface temperature of workpiece 500 is approximately 550°C.

[0049] In this embodiment, the above-described settings effectively reduce oxygen, chlorine, and carbon impurities in the titanium nitride layer, thereby reducing its resistivity. The impurity content of the titanium nitride layer is reduced by approximately 2% to 5%, which is specifically related to the film state of the untreated titanium nitride layer, as well as the treatment time and the concentration of hydrogen free radicals.

[0050] In some embodiments, step S130, contacting the free radical material in the plasma with the metal layer of the heated workpiece 500, includes: hydrogen free radical treatment in the plasma contacting the metal layer to reduce the oxide film on the surface of the metal layer; wherein the metal layer includes at least one of a copper layer, a molybdenum layer, and a cobalt layer.

[0051] Accordingly, the gas is supplied to the reaction chamber, including hydrogen, with the hydrogen flow rate F4 satisfying: 100sccm≤F4≤2000sccm.

[0052] For example, the hydrogen flow rate F3 can be 100 sccm, 500 sccm, 1000 sccm, 1500 sccm, or 2000 sccm, or any two of the above.

[0053] When surface treating the copper layer, the surface temperature of workpiece 500 is approximately 70°C to 350°C. Compared to heat treatment alone, the contact between hydrogen free radicals and the copper layer at a lower temperature results in fewer grains and a lower grain boundary density, thereby reducing the resistivity of the copper layer. For example, with a surface temperature of 70°C for workpiece 500, the proportion of small-sized grains (area <0.15 μm²) in the copper layer can be reduced from 98% to 77%, and the number of grains in the same sampling area can be reduced from 726 to 107. At the same time, a reduction of approximately 20% in sheet resistivity (Rs) is achieved at 70°C.

[0054] When surface-treating the molybdenum layer, the surface temperature of workpiece 500 is approximately 250°C to 600°C. Compared to heat treatment alone, the contact between hydrogen free radicals and the molybdenum layer reduces the oxide film on the surface of the molybdenum layer at a lower temperature, reducing its thickness and oxygen content, thereby lowering the resistivity of the molybdenum layer. For example, with a surface temperature of approximately 250°C for workpiece 500, the film resistivity (Rs) of the molybdenum layer can be reduced by about 35%. The specific reduction depends on the film state of the molybdenum layer before treatment, as well as the treatment time and the concentration of hydrogen free radicals.

[0055] During surface treatment of the cobalt layer, the surface temperature of workpiece 500 is approximately 250°C to 600°C. Compared to heat treatment alone, the contact between hydrogen free radicals and the cobalt layer reduces the oxide film on the surface of the cobalt layer at a lower temperature, resulting in a thinner film, fewer grains, and lower grain boundary density, thereby reducing the resistivity of the cobalt layer. For example, with a surface temperature of approximately 250°C for workpiece 500, the film resistivity (Rs) of the cobalt layer can be reduced by about 10%. The specific reduction depends on the film state of the cobalt layer before treatment, as well as the treatment time and the concentration of hydrogen free radicals.

[0056] In this embodiment, the resistivity of the copper layer, molybdenum layer and cobalt layer can be effectively reduced by the above settings.

[0057] In some embodiments, the method for processing a workpiece further includes oxidizing the silicon layer. Specifically, oxygen is supplied to a reaction chamber, the oxygen is excited to form a plasma, and the plasma is delivered to the surface of the workpiece 500, so that oxygen free radicals in the plasma come into contact with the heated silicon layer of the workpiece 500 to form a silicon oxide film. The surface temperature of the heated workpiece 500 reaches a target temperature to promote the bonding of oxygen free radicals with silicon atoms.

[0058] In some examples, since the silicon oxide film formed above may be loose and porous and contain unsaturated bonds, flowable chemical vapor deposition (FCVD) can be used to form flowable silicon oxide in the trench to achieve seamless filling and optimize the performance of the silicon oxide film.

[0059] In some examples, the method for processing the workpiece further includes: supplying oxygen and hydrogen to a reaction chamber, exciting the oxygen and hydrogen and their mixture to form a plasma, and delivering the plasma to the surface of the workpiece 500, such that oxygen radicals and hydrogen radicals in the plasma perform stepwise processing on the silicon oxide film to reduce the wet etching reaction rate.

[0060] Specifically, the optimized silicon oxide film is subjected to oxygen free radical treatment to enhance the crosslinking density of silicon oxide, fill pores, reduce oxygen vacancy defects, and improve the compactness of the silicon oxide film. Optionally, when oxygen is supplied to the plasma generation space 100 of the process chamber, the oxygen flow rate F5 satisfies: 500 sccm ≤ F5 ≤ 3000 sccm. For example, the oxygen flow rate F5 can be 500 sccm, 1000 sccm, 1500 sccm, 2000 sccm, 2500 sccm, or 3000 sccm, or any value between two of the above.

[0061] The optimized silicon oxide film is subjected to hydrogen radical treatment to passivate the surface of the workpiece 500, converting residual active sites (such as Si⁻) into stable Si-H bonds, reducing chemical activity, and decreasing the penetration channels of the wet etching solution. Optionally, the hydrogen flow rate F6 satisfies: 25 sccm ≤ F6 ≤ 200 sccm. For example, the hydrogen flow rate F6 can be 25 sccm, 50 sccm, 100 sccm, 150 sccm, or 200 sccm, or any two of the above.

[0062] In this example, the bulk phase of the silicon oxide film is first densified by oxygen free radicals, and then the surface is passivated by hydrogen free radicals. The dual effect significantly reduces the wet etch reaction rate (WERR).

[0063] It should be noted that in the description of the method for processing the workpiece, the combined use of the term "about" with the numerical value is intended to be within ten percent (20%) of the value being referred to.

[0064] This embodiment also provides a plasma device for implementing the method in any of the foregoing embodiments. The similarities between this embodiment and the foregoing embodiments will not be repeated here.

[0065] Please refer to Figure 2 and Figure 3 The plasma device of this embodiment includes: a reaction chamber, which includes a plasma generation space 100 and a workpiece surface treatment space 200; the workpiece surface treatment space 200 is used for contacting the free radical substances in the plasma with the metal layer of the heated workpiece 500, the metal layer including at least one of the following: a tungsten layer, a titanium nitride layer, a copper layer, a molybdenum layer, and a cobalt layer; a grid 300, located at the connection between the plasma generation space 100 and the workpiece surface treatment space 200, for filtering and / or homogenizing the plasma flowing from the plasma generation space 100 to the workpiece surface treatment space 200; a tray 210, installed in the workpiece surface treatment space 200, for supporting the workpiece 500; a first air inlet pipe 410, connected to the plasma generation space 100, for supplying gas to the plasma generation space 100; and a heating element 220, installed in the workpiece surface treatment space 200, for heating the surface of the workpiece 500 to a target temperature.

[0066] For example, the plasma generation space 100 and the workpiece surface treatment space 200 are distributed vertically, with the plasma generation space 100 located above the workpiece surface treatment space 200. The plasma generation space 100 is equipped with a dielectric cylinder 110, the upper end of which is sealed to the dielectric cylinder 110. The lower end of the dielectric cylinder 110 communicates with the workpiece surface treatment space 200. An inductor coil 120 is disposed outside the dielectric cylinder 110. The portion of the first air inlet pipe 410 near the air outlet can be inserted into the upper end cover.

[0067] The workpiece surface treatment space 200 is equipped with a box, the upper end of which has an opening to communicate with the medium cylinder 110. The box contains a tray 210 and a heating element 220, and the tray 210 may be equipped with a lifting structure and / or a rotating structure.

[0068] The grille 300 can be positioned at the top opening of the housing. For example, the grille 300 can be connected to the inner wall of the top of the housing, and the outer contour of the projection of the grille 300 onto the top wall of the housing can cover the outer contour of the projection of the top opening onto the top wall of the housing, ensuring the filtering and / or homogenizing effect of the grille 300 on the plasma flowing from the plasma generation space 100 to the workpiece surface treatment space 200. The specific dimensions of the grille 300, the specific dimensions of the grille 300 holes, and their arrangement can be set according to actual needs.

[0069] Optionally, the grid 300 may employ a double-layer structure to improve the filtration and / or homogenization effect of plasma flowing from the plasma generation space 100 to the workpiece surface treatment space 200. For example, the grid 300 may include two grid plates spaced vertically apart, the spacing between which can be set according to actual needs; the two grid plates are connected by a connector, which may be located near the edge of the grid plate and extend circumferentially along the grid plate, so that plasma flowing through the upper grid plate can flow again through the lower grid plate. The connector may be connected to the two grid plates by bonding, welding, or screwing, or the connector may be integrally formed with the two grid plates.

[0070] In some embodiments, the heating element 220 includes a heating wire mounted to the tray 210.

[0071] In some embodiments, the heating element 220 includes a heating lamp mounted to the inner wall of the reaction chamber.

[0072] Please refer to Figure 4 In some embodiments, the plasma device further includes a second air inlet pipe 420, which communicates with the workpiece surface treatment space 200 and is used to supply gas to the workpiece surface treatment space 200. The portion of the second air inlet pipe 420 near the outlet end can be inserted into the grid 300. When the grid 300 has a double-layer structure, the portion of the second air inlet pipe 420 near the outlet end can be inserted into the upper grid plate.

[0073] In some embodiments, the plasma apparatus may further include a pressure regulating line for regulating the pressure within the process chamber. The pressure regulating line may communicate with the workpiece surface treatment space; exemplaryly, a portion of the pressure regulating line near the outlet end may be inserted into the bottom wall of the chamber. The pressure regulating line may be equipped with a pressure switch PS and a hydraulic pump G. The pressure switch can be used to detect pressure changes, and the hydraulic pump provides the power source for delivering the fluid used to regulate the pressure.

[0074] here, Figures 2 to 4 The structure shown is merely exemplary. In practical applications, plasma devices may include other functional components based on actual needs, and this application does not impose any restrictions on this.

[0075] This application also provides a semiconductor workpiece manufactured by the method in any of the foregoing embodiments. This semiconductor workpiece can be used in devices such as logic processors and memories.

[0076] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0078] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for processing a workpiece, comprising: Place the workpiece to be processed onto the tray in the reaction chamber; The surface of the workpiece is heated to the target temperature; Gas is supplied to the reaction chamber, the gas is excited to form plasma, and the plasma is delivered to the surface of the workpiece, so that the free radical substances in the plasma come into contact with the metal layer of the heated workpiece; the metal layer includes at least one of the following: tungsten layer, titanium nitride layer, copper layer, molybdenum layer and cobalt layer.

2. The method according to claim 1, wherein when the metal layer comprises a tungsten layer, the free radical material in the plasma contacts the heated metal layer of the workpiece, comprising: The hydrogen free radicals in the plasma come into contact with the tungsten layer, causing the oxide film on the surface of the tungsten layer to be reduced.

3. The method according to claim 2, wherein, The process of supplying gas to the reaction chamber and exciting the gas to form plasma includes: Oxygen and hydrogen are supplied to the reaction chamber, and the oxygen and hydrogen gases, and their mixture, are excited to form plasma; wherein the proportion V1 of hydrogen in the oxygen and hydrogen mixture satisfies: 65vol%≤V1≤95vol%.

4. The method according to claim 3, wherein, The oxygen flow rate F1 satisfies: 100sccm≤F1≤3000sccm; And / or, the flow rate F2 of the hydrogen gas satisfies: 400sccm ≤ F2 ≤ 8000sccm.

5. The method according to claim 1, wherein, The free radical substances in the plasma come into contact with the heated metal layer of the workpiece, including: The hydrogen free radical treatment in the plasma comes into contact with the titanium nitride layer to reduce the impurity content in the titanium nitride layer; Accordingly, the gas delivery to the reaction chamber includes: Hydrogen gas is supplied to the reaction chamber; wherein the flow rate F3 of the hydrogen gas satisfies: 100sccm≤F3≤2000sccm.

6. The method according to claim 1, wherein, The free radical substances in the plasma come into contact with the heated metal layer of the workpiece, including: The hydrogen free radical treatment in the plasma comes into contact with the metal layer, reducing the oxide film on the surface of the metal layer; wherein the metal layer includes at least one of a copper layer, a molybdenum layer, and a cobalt layer; Accordingly, the gas delivery to the reaction chamber includes: The gas supplied to the reaction chamber includes hydrogen; wherein the flow rate F4 of the hydrogen satisfies: 100sccm≤F4≤2000sccm.

7. The method according to claim 1, wherein, The target temperature T1 satisfies the following condition: 70℃≤T1≤650℃.

8. The method according to claim 1, wherein, The target temperature T1 satisfies the following condition: 200℃≤T1≤600℃.

9. The method according to claim 1, further comprising: Oxygen is supplied to the reaction chamber and excited to form plasma. The plasma is then delivered to the surface of the workpiece, whereby oxygen free radicals in the plasma come into contact with the heated silicon layer of the workpiece to form a silicon oxide film.

10. The method of claim 9, further comprising: The silicon oxide film is processed using flow chemical vapor deposition.

11. The method of claim 9, further comprising: Oxygen is supplied to the reaction chamber, and the oxygen is excited to form plasma. The plasma is then delivered to the surface of the workpiece, whereby oxygen free radicals in the plasma treat the silicon oxide film. The oxygen flow rate F5 satisfies the following condition: 500 sccm ≤ F5 ≤ 3000 sccm. Hydrogen gas is supplied to the reaction chamber and excited to form plasma. The plasma is then delivered to the surface of the workpiece, whereby hydrogen free radicals in the plasma treat the silicon oxide film to reduce the wet etching reaction rate. The flow rate F6 of the hydrogen gas satisfies the following condition: 25 sccm ≤ F6 ≤ 200 sccm.

12. A plasma device for implementing the method of any one of claims 1 to 11, the plasma device comprising: The reaction chamber includes a plasma generation space and a workpiece surface treatment space. The plasma generation space is used to excite the gas to generate plasma; The workpiece surface treatment space is used to allow free radical substances in the plasma to contact the metal layer of the heated workpiece. The metal layer includes at least one of the following: tungsten layer, titanium nitride layer, copper layer, molybdenum layer, and cobalt layer. A grid, located at the junction of the plasma generation space and the workpiece surface treatment space, is used to filter and / or homogenize the plasma flowing from the plasma generation space to the workpiece surface treatment space. A tray, installed in the workpiece surface treatment space, is used to support the workpiece; The first air inlet pipe is connected to the plasma generation space and is used to deliver gas to the plasma generation space. A heating element is installed in the workpiece surface treatment space to heat the surface of the workpiece to a target temperature.

13. The plasma device according to claim 12, wherein, The heating element includes a heating wire, which is mounted to the tray; or, the heating element includes a heating lamp, which is mounted to the inner wall of the reaction chamber. The plasma device further includes a second gas inlet pipe, which is connected to the workpiece surface treatment space and is used to replenish the workpiece surface treatment space with gas.

14. A semiconductor workpiece, comprising: A workpiece made using the method described in any one of claims 1 to 11.

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