Patent Application
20240355615
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-069426, filed on Apr. 20, 2023, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a method and apparatus for processing a substrate.
In a semiconductor device manufacturing process, there is a process in which a recess such as a via hole or a trench is formed in an insulating layer formed on a semiconductor wafer (hereinafter, also referred to as a “wafer”) as a substrate, and a conductor as a wiring material is formed in the recess. At this time, a natural oxide film may be formed on a surface of a metal exposed in the recess due to contact with air. When the conductor is embedded without removing such a natural oxide film, wiring resistance may be increased.
Patent Document 1 discloses a technique for etching a substrate including a metal oxide layer, which may contain Si and one or more metals gases selected from the group consisting of alkali metals, alkaline earth metals, transition metals, lanthanides, actinides, and late transition metals, by exposing the substrate to a metal halide. In addition, Patent Document 2 discloses a technique for exposing an oxide layer containing one or more of hafnium, tungsten, molybdenum, and titanium to a fluorinating agent to form a fluoride layer, and then exposing the fluoride layer to a halide etchant to remove the fluoride layer.
However, in these patent documents, there is no description of a technique specifically effective in removing an oxide film of metal silicide.
According to one embodiment of the present disclosure, a method of processing a substrate includes: removing a silicon oxide portion contained in an oxide film on a surface of a metal silicide layer by supplying a hydrogen fluoride gas and an ammonia gas to the oxide film so as to react with the silicon oxide portion contained in the oxide film, wherein the metal silicide layer is provided by being stacked in a recess formed in an insulator layer which is stacked on a silicon-containing layer; and removing a metal oxide portion by supplying a metal halide gas to the oxide film so as to react with the metal oxide portion contained in the oxide film.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.
Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.
Hereinafter, an embodiment of an apparatus (hereinafter, referred to as a “substrate processing apparatus 1”) having a function of removing an oxide film (a MoSiOx layer 65a) on a surface of a MoSi layer 64, which is a metal silicide layer, and forming a Ru film 67, which is a conductor, will be described.
Before describing a configuration of the substrate processing apparatus 1, an example of a surface structure of a wafer W to be processed in the substrate processing apparatus 1 will be described. As illustrated in
When the wafer W having the above-described configuration is transferred in a semiconductor manufacturing factory toward the substrate processing apparatus 1, the MoSiOx layer 65a, which is an oxide film, is formed on the surface of the MoSi layer 64 due to contact with the air. Therefore, the substrate processing apparatus 1 of the present embodiment is configured to embed Ru after removing the MoSiOx layer 65a.
The first substrate transfer chamber 13 and the second substrate transfer chamber 14 are configured to have a square shape in a plan view, and are connected to each other via, for example, two delivery parts 17. Interiors of the first and second substrate transfer chambers 13 and 14 and the delivery parts 17 are kept in a vacuum pressure atmosphere. The first and second substrate transfer chambers 13 and 14 and the delivery parts 17 are configured to be equalized in pressure to each other. Further, first and second transfer mechanisms 131 and 141 are arranged inside the first and second substrate transfer chambers 13 and 14, respectively.
The delivery parts 17 delivers the wafer to and from the first transfer mechanism 131 provided in the first substrate transfer chamber 13 or to and from the second transfer mechanism 141 provided in the second substrate transfer chamber 14. The first substrate transfer chamber 13, the second substrate transfer chamber 14, and the delivery parts 17 correspond to the vacuum transfer chamber of the present embodiment. Further, the first transfer mechanism 131 and the second transfer mechanism 141 correspond to the substrate transfer mechanism of the present embodiment.
A direction where the first substrate transfer chamber 13 and the second substrate transfer chamber 14 are arranged will be referred to as a length direction, a place in which the first substrate transfer chamber 13 is positioned will be referred to as a front side and a place in which the second substrate transfer chamber 14 is positioned will be referred to as a rear side. In this case, the atmosphere transfer chamber 11 kept in the atmospheric pressure atmosphere is connected to the front side of the first substrate transfer chamber 13 via, for example, three load-lock chambers 12. Wafer transfer ports (not illustrated) and gate valves (not illustrated) for opening/closing the transfer ports are respectively provided between the first and second substrate transfer chambers 13 and 14 and the delivery parts 17, between the load-lock chambers 12 and the first substrate transfer chamber 13, and between the load-lock chambers 12 and the atmospheric transfer chamber 11.
For example, four load ports 101 are connected to the atmospheric transfer chamber 11, and a carrier C accommodating a plurality of wafers W is placed on each load port 101. The atmospheric transfer chamber 11 includes an atmospheric transfer mechanism 111 to transfer the wafers W between the carriers C connected to the atmospheric transfer chamber 11 and the load-lock chambers 12.
When viewed from the front side, one oxide removal (chemical oxide removal (COR)) module 151, one heat treatment (post heat treatment (PHT)) module 152 and two Ti film forming modules 153 are connected to two left and right walls of the first substrate transfer chamber 13. In addition, the first transfer mechanism 131 provided in the first substrate transfer chamber 13 is configured to transfer the wafers W among these four modules 151 to 153, the delivery parts 17, and the load-lock chambers 12. In
The COR process performed by the COR module 151 and the PHT process performed by the PHT module 152 are pre-cleaning processes that remove silicon oxide contained in the above-described MoSiOx layer 65a. Here, the MoSiOx layer 65a is configured as a composite oxide containing Si, Mo, and oxygen (O). In the present disclosure, an oxidized portion of Si (SiOx) contained in the composite oxide is referred to as a “silicon oxide portion”, and an oxidized portion of Mo (MoOx) contained in the composite oxide is also referred to as a “molybdenum oxide portion”. In the MoSiOx layer 65a, which is an oxide film of the metal silicide layer, the “molybdenum oxide portion” corresponds to the “metal oxide portion” of the metal silicide layer.
The COR module 151 is configured to perform an etching process (COR process) on the natural oxide film using a hydrogen fluoride (HF) gas and an ammonia (NH3) gas. In addition, the PHT module 152 is configured to perform the PHT process in which reaction products generated in the COR process are sublimated and removed by heating the wafer W. Configuration examples of the COR module 151 and PHT module 152 will be described later. The COR module 151 corresponds to a first processing module of the present embodiment.
Further, each of the Ti film forming module 153 is configured to form a Ti layer 66, which is a contact metal layer provided between the MoSi layer 64 and a Ru wire 67a. In addition, the Ti film forming modules 153 of the present embodiment also have a function of removing the MoSiOx layer 65a after the removal of the silicon oxide component by the COR process and the PHT process (hereinafter, the MoSiOx layer 65a is also referred to as “MoOx layer 65b” since SiOx has already been removed). The MoOx layer 65b corresponds to the metal oxide portion of the present embodiment. In addition, from the viewpoint of removing the MoOx layer 65b, the Ti film forming modules 153 correspond to a second processing module of the present embodiment.
A specific configuration example of the Ti film forming modules 153 will be described later with reference to
In addition, when viewed from the front side, a total of four Ru film forming modules 154 are connected two-by-two to two left and right walls of the second substrate transfer chamber 14. The second transfer mechanism 141 is configured to transfer the wafers W among these four Ru film forming modules 154 and the delivery parts 17. In
Each Ru film forming module 154 is configured to form the Ru film 67 with a raw material gas of Ru as a conductor by, for example, a chemical vapor deposition (CVD) method. The Ru film forming module 154 corresponds to a fourth processing module of the present embodiment.
Next, a specific configuration example of the Ti film forming module 153 will be described with reference to
A loading/unloading port 214 is formed in the side surface of the processing container 210 to load/unload the wafer W into/from the above-described first substrate transfer chamber 13. This loading/unloading port 214 is configured to be openable/closable by a gate valve 215 (GV1 in
In addition, a stage 22 configured to hold the wafer W substantially horizontally is provided inside the processing container 210. The stage 22 is supported by a support 221 extending from a bottom of the exhaust chamber 211. A heater 220 as a heating part may be embedded in the stage 22 to heat the wafer W to a set temperature. In the present example, a heating temperature of the wafer W is set within a range of 350 to 800 degrees C., for example, 450 degrees C.
In addition, a radio-frequency power source 223 configured to supply radio-frequency power for ion attraction is connected to the stage 22 via a matcher 222. Further, the stage 22 is provided with lifting pins (not illustrated) configured to raise/lower the wafer W while holding the wafer W on the stage 22. The wafer W may be transferred between the stage 22 and the first transfer mechanism 131 in the first substrate transfer chamber 13 by raising/lowering the lift pins.
In addition, a flat disk-shaped shower head 23 configured to supply a substrate processing gas toward the wafer W is provided on a ceiling surface of the processing container 210. The shower head 23 is attached to the processing container 210 via an insulating member 217.
A diffusion chamber 231 configured to diffuse a gas is formed inside the shower head 23. In addition, a large number of ejection holes 232 through which a gas is discharged toward the wafer W are provided in a distributed manner on a bottom surface of the shower head 23. Further, a heater 235 is embedded in an upper surface of the shower head 23.
A radio-frequency power source 234 configured to supply radio-frequency power for plasma formation is connected to the above-mentioned shower head 23 via a matcher box 233. That is, the substrate processing apparatus 1 of the present embodiment constitutes a parallel plate-type plasma processing apparatus by the shower head 23 serving as an upper electrode and the stage 22 serving as a lower electrode. By placing the wafer W in a space between the shower head 23 and the stage 22, supplying the film forming gas, and applying the radio-frequency power, the gas is ionized to form plasma. The radio-frequency power source 234 may be configured to supply the radio-frequency power of a frequency of 450 KHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, 100 MHz, or 2.45 GHz. For example, the radio-frequency power source 234 supplies the radio-frequency power which is greater than 0 W and equal to or lower than 2,000 W.
In addition, a downstream end of the gas supply path 40 is connected to the diffusion chamber 231 of the shower head 23. A TiCl4 gas supply pipe 41, which is a flow path for supplying a TiCl4 gas constituting the film forming gas for the Ti layer 66, an Ar gas supply pipe 42, which is a flow path for supplying an Ar gas added for plasma generation, and a H2 gas supply pipe 43, which is a flow path for supplying a H2 gas as a reaction gas, are joined at an upstream side of the gas supply path 40.
A TiCl4 gas source 410 is connected to an upstream end of the TiCl4 gas supply pipe 41. A flow rate regulator M41 and a valve V41 are interposed in this order from an upstream side of the TiCl4 gas supply pipe 41. In addition, an Ar gas source 420 is connected to an upstream end of the Ar gas supply pipe 42. A flow rate regulator M42 and a valve V42 are interposed in this order from an upstream side of the Ar gas supply pipe 42. Further, a H2 gas source 430 is connected to an upstream end of the H2 gas supply pipe 43. A flow rate regulator M43 and a valve V43 are interposed in this order from an upstream side of the H2 gas supply pipe 43.
A mixed gas (film forming gas) of the TiCl4 gas, the H2 gas, and the Ar gas flows into the diffusion chamber 231 of the shower head 23 via the gas supply path 40, and is supplied into the processing container 210 via the ejection holes 232.
In addition, a WCl5 gas supply pipe 51 is joined at the upstream side of the gas supply path 40. The WCl5 gas corresponds to a metal halide gas for removing the MoOx layer 65b. A WCl5 gas source 510 is connected to an upstream end of the WCl5 gas supply pipe 51. A flow rate regulator M51 and a valve V51 are interposed in this order from an upstream side of the WCl5 gas supply pipe 51. The WCl5 gas source 510 configured to supply the WCl5 gas, the flow rate regulator M51, and the like constitute a metal halide gas supplier of the present embodiment. The WCl5 gas also flows into the diffusion chamber 231 of the shower head 23 via the gas supply path 40 and is supplied into the processing container 210 via the ejection holes 232.
Although not illustrated, the COR module 151, the PHT module 152, and the Ru film forming module 154 are similar to the above-described Ti film forming module 153 in that the modules includes the processing container 210 and the stage 22. In addition, in the COR module 151, a mixed gas of an HF gas and a NH3 gas used for the COR process is supplied to the processing container 210 via the gas supply path 40. Gas sources which supply the HF gas and the NH3 gas, a flow rate regulator, and the like constitute a mixed-gas supplier of the present embodiment.
In addition, in the PHT module 152, a N2 gas, which forms an inert gas atmosphere where the PHT process is performed, is supplied to the processing container 210 via the gas supply path 40. In the PHT module 152, the wafer W is heated to, for example, 200 degrees C. in the range of 60 to 250 degrees C. by the heater 220 of the stage 22.
In addition, the COR module 151 or the PHT module 152 of the present embodiment is not provided with the radio-frequency power source 234 for plasma formation or the like.
Further, in the Ru film forming module 154, a Ru3 (CO)12 gas, which is a raw material gas for the Ru film 67, and a CO gas, which is a carrier gas, are supplied to the processing container 210 via the gas supply path 40. Gas sources which supply the Ru3 (CO)12 gas and the CO gas, a flow rate regulator, and the like correspond to a raw material gas supplier of the present embodiment. In addition, the Ru film forming module 154 of the present embodiment is configured to form the Ru film 67 by, for example, a thermal CVD method. Therefore, unlike the Ti film forming module 153 described with reference to
The substrate processing apparatus 1 having the above-described configuration includes a controller 100 as illustrated in
Details of the substrate processing to be performed by the substrate processing apparatus 1 configured as above will be described with reference to
In the substrate processing apparatus 1, first, the atmospheric transfer mechanism 111 takes out the wafer W accommodated in the carrier C and transfers the same to the load-lock chamber 12 kept in the atmospheric pressure atmosphere, and the interior of the load-lock chamber 12 is regulated to be in a vacuum pressure atmosphere. Subsequently, the first transfer mechanism 131 transfers the wafer W in the load-lock chamber 12 to the COR module 151 and places the same on the stage 22 in the processing container 210.
In the COR module 151, the temperature of the wafer W placed on the stage 22 is regulated to 60 degrees C. or less, for example, 27 degrees C. Then, the mixed gas of the HF gas and the NH3 gas is supplied from the aforementioned mixed-gas supplier to the wafer W in the processing container 210 (
The reaction products produced in the COR process include ammonium fluorosilicate ((NH4)2SiF6) and water (H2O). The reaction products are attached to the bottom and sidewall surfaces of the recess 60, the upper surface of the SiO layer 62, and the like. In addition, in this COR process, ammonium fluoride (NH4F) is also produced by the reaction between the hydrogen fluoride gas and the ammonia gas. The molecules of this ammonium fluoride also act as an etchant and react with the silicon oxide portion to form reaction products. Further, in the COR process, ammonium fluoride itself may be deposited on the surface of the wafer W as a solid component.
The wafer W from which the silicon oxide has been removed by the COR process is transferred from the COR module 151 to the PHT module 152 and placed on the stage 22 in the processing container 210. In the PHT module 152, the wafer W is heated to sublimate and remove the reaction products and solid ammonium fluoride generated in the COR process. Specifically, the N2 gas is supplied into the processing container 210, and the temperature of the wafer W placed on the stage 22 is regulated to 200 degrees C. As a result, the reaction products and solid ammonium fluoride attached to the heated wafer W sublimate, and the N2 gas is discharged to the outside of the processing container 210 together (Operation P11 in
Subsequently, the first transfer mechanism 131 transfers the wafer W to the Ti film forming module 153. As described above, the Ti film forming module 153 executes two operations of removing the MoOx layer 65b (the metal oxide portion) remaining after the removal of the silicon oxide portion from the MoSiOx layer 65a, and forming the Ti layer 66.
First, when the wafer W is placed on the stage 22 of the Ti film forming module 153, the vacuum exhauster 213 evacuates the interior of the processing container 210 to a preset pressure. In addition, the wafer W is heated to 450 degrees C. by the heater 220 as described above. Thereafter, the WCl5 gas is supplied from the metal halide gas supplier into the processing container 210 (
As illustrated in
2MoO3(s)+2WCl5(g)→WO2Cl2(g)+2MoO2Cl2(g)+WCl2(s) (1)
Solid WCl2 remains on the surface of the wafer W. When residue of chlorine is undesirable, the H2 gas is supplied from the H2 gas source 430 in addition to the supply of the WCl5 gas so that the reaction represented in Equation (2) below proceeds.
WCl2(s)+H2(g)→W(s)+2HCl(g) (2)
By reacting the WCl5 gas with the H2 gas, chlorine is removed as the HCl gas, leaving only metallic tungsten (W) on the surface of the wafer W.
By proceeding with the above-mentioned Equation (1), the MoOx layer 65b remaining in the recess 60 after the COR process may be removed (Operation P12 in
After completing the operation of removing the MoOx layer 65b, the Ti layer 66, which is a metal layer for contact, is formed. Specifically, the supply of the WCl5 gas to the processing container 210 of the Ti film forming module 153 is stopped. Then, the TiCl4 gas, the H2 gas, and the Ar gas are supplied from respective gas sources 410, 420, and 430 at preset flow rates, respectively, while continuously heating the wafer W and regulating the internal pressure of the processing container 210. As a result, the film forming gas, which is a mixture of these gases, is introduced into the processing container 210. Further, by applying the radio-frequency power from the radio-frequency power source 234 to turn the film forming gas into plasma, the formation of a Ti film on the wafer W proceeds (Operation P13 in
After the formation of the Ti film is performed for a preset period of time, the supply of the film forming gas and the application of the radio-frequency power are stopped. As a result, the Ti layer 66 is formed on the bottom surface of the recess 60, as illustrated in
Subsequently, the wafer W is transferred to the Ru film forming module 154 by the first transfer mechanism 131, the delivery part 17, and the second transfer mechanism 141. The inert gas is supplied to the first substrate transfer chamber 13, the delivery part 17, and the second substrate transfer chamber 14 to prevent the gas from diffusing from the film forming module. The pressure is controlled to, for example, 100 Pa in the range of 20 to 200 Pa. In addition, in order to prevent oxidation of the surface during the transfer, an ultimate degree of vacuum of a vacuum exhaust mechanism (not illustrated), which to evacuate these spaces (the first substrate transfer chamber 13, the delivery part 17, and second substrate transfer chamber 14) is set to 1.33×10−5 Pa or lower. In the Ru film forming module 154, the Ru film 67 is formed such that Ru is embedded in the upper surface of the Ti layer 66 formed in the recess 60 (Operation P14 in
Specifically, the wafer W is loaded into the processing container 210 of the Ru film forming module 154 and placed on the stage 22. The wafer W is heated to, for example, 150 degrees C. in the range of 130 to 200 degrees C. by the heater 220. In addition, the internal pressure of the processing container 210 is regulated, and the Ru3 (CO)12 gas (containing the CO gas as a carrier gas) is supplied into the processing container 210.
As a result, thermal CVD in which the Ru3 (CO)12 supplied into the processing container 210 is thermally decomposed on the wafer W proceeds. Then, by performing the thermal CVD for a preset period of time, the Ru film 67 may be embedded in the recess 60 from which the MoSiOx layer 65a has been removed, as illustrated in
After the formation of the Ru film 67 is completed, the wafer W is transferred to the load-lock chamber 12 by the second transfer mechanism 141, the delivery part 17, and the first transfer mechanism 131. Subsequently, after the internal atmosphere of the load-lock chamber 12 is switched to the atmospheric pressure atmosphere, the atmospheric transfer mechanism 111 returns the processed wafer W to the carrier C. The unloaded wafer W is polished by an external chemical mechanical polishing (CMP) device. Through this process, it is possible to obtain the wafer W in which the upper surface is removed and the Ru wire 67a is embedded in the recess 60, as illustrated in
According to the above-described embodiment, the oxide film (MoSiOx layer 65a) on the surface of the metal silicide layer (MoSi layer 64) formed in the recess 60 of the substrate may be removed. As a result, an increase in wire resistance after the embedding of the Ru film 67 (the Ru wire 67a) in the recess 60 may be suppressed. In particular, in the substrate processing apparatus 1 in which the wafers W are transferred among the processing modules 151 to 154 via the first and second substrate transfer chambers 13 and 14, the substrate processing is performed while avoiding exposure to the air, which makes it possible to suppress the formation of an unnecessary natural oxide film.
Next, a configuration and operation of the substrate processing apparatus 1a according to the second embodiment will be described with reference to
The substrate processing apparatus 1a according to the second embodiment has a configuration that copes with a matter causing a reaction different from that of Equation (1) above when the MoOx layer 65b, which is a metal oxide portion, is removed with the WCl5 gas, which is a metal halide. As will be described later, in such a reaction, an oxide of tungsten (W) (hereinafter, also referred to as “first metal” in the second embodiment) contained in the WCl5 gas is formed in place of the MoOx layer 65b. When the oxide of W remains in the recess 60, since the oxide of W causes an increase in wire resistance after Ru is embedded, it may be necessary to remove the oxide of W in some cases.
Therefore, in order to remove the oxide of W, the substrate processing apparatus 1a of the present embodiment forms a film of a metal that is more easily oxidized than W, such as titanium (Ti) (hereinafter, referred to as a “second metal” in the second embodiment). As a result, the substrate processing apparatus 1a has the configuration in which the oxide of W is reduced by Ti, and the oxide of Ti formed in place of the MoOx layer 65b is removed by the etching gas.
From the above point of view, the substrate processing apparatus 1a includes: a pre-cleaning module 156 configured to perform only the removal of the MoOx layer 65b with the WCl5 gas; a reduction Ti film forming module 155 configured to form a Ti film for reducing the oxide of W and remove the oxide of W; and a Ti film forming module 153a configured to form only the Ti layer 66 for contact.
Although individual illustrations are omitted, each of the pre-cleaning module 156, the reduction Ti film forming module 155, and the Ti film forming module 153a is similar in configuration to the Ti film forming module 153 described above with reference to
The pre-cleaning module 156 includes only the metal halide gas supplier (the WCl5 gas supply pipe 51, the WCl5 gas source 510, the flow rate regulator M51, and the valve V51) illustrated in
The reduction Ti film forming module 155 is substantially similar in configuration to the Ti film forming module 153 illustrated in
The Ti film forming module 153a is substantially similar in configuration to the Ti film forming module 153 illustrated in
The substrate processing apparatus 1a shown in
The processing of the wafer W using the substrate processing apparatus 1a will be described with reference to
The COR process and the PHT process are performed on the wafer W to be processed by the COR module 151 and the PHT module 152 (Operation P11 in
At this time, as illustrated in
MoO3(s)+WCl5(g)→WO3(s)+2MoCl5(g) (3)
Here, the Gibbs free energy when the MoOx layer 65b and the WCl5 gas react in the reaction of Equation (1) is −241 KJ/mol at an absolute temperature of 673K. On the other hand, the Gibbs free energy in the reaction of Equation (3) is −126 KJ/mol under the same temperature condition. Therefore, the Gibbs free energy in both Equations (1) and (3) is negative, and the reaction proceeds in both cases.
By the reaction of Equation (3), while the MoOx layer 65b is removed, the oxide of W (WO3), which is the first metal, is formed on the surface of the wafer W. Therefore, in the substrate processing apparatus 1a of the second embodiment, the wafer W is loaded into the reduction Ti film forming module 155, and the film forming gas is supplied to form the film of Ti for reduction which is the second metal (Operation P12B in
WO3(s)+3Ti(s)→W+3TiO (4)
Thereafter, the supply of the film forming gas is stopped, and the gas supplied into the processing container 210 is switched to the Cl2 gas. As a result, the reaction represented in Equation (5) below proceeds, and TiO is removed (Operation P12C in
TiO(s)+Cl2(g)→TiOCl2(g) (5)
Through the above-mentioned processes, metallic tungsten (W) remains on the surface of the wafer W. In addition, Ti that did not come into contact with WO3 also remains on the surface of the wafer W without being etched. Ti formed in the recess 60 is integrated with Ti formed by the Ti film forming module 153a provided in the subsequent stage, to form the Ti layer 66. Further, Ti formed on the surface of the SiO layer 62 is removed by being polished by the CMP process after the Ru film 67 is formed.
As described above, the reaction of Equation (1) proceeds in parallel with the reaction of Equation (3) in which the oxide of W (WO3) is formed. As a result, when it is undesirable for solid WCl2 to remain on the surface of the wafer W, for example, the H2 gas may be supplied before forming the Ti film for reduction so that the reaction of Equation (2) proceeds to remove chlorine, which is the same as in the substrate processing apparatus 1 according to the first embodiment.
At a timing at which the removal of TiO is completed, the wafer W is loaded into the Ti film forming module 153a, and the film forming gas is supplied to form the Ti layer 66, which is a metal layer for contact (Operation P13A in
Here, the second metal is not limited to titanium (Ti). For example, a film of Mo or Ta may be formed as the second metal that is more easily oxidized than tungsten (W), and then the oxide of Mo or Ta may be etched with the chlorine gas.
Next, a configuration and operation of the substrate processing apparatus 1b according to a third embodiment will be described with reference to
The substrate processing apparatus 1b according to the third embodiment is not provided with the PHT module 152 for the PHT process that removes reaction products generated in the COR process. Therefore, the substrate processing apparatus 1b is configured such that the removal of reaction products is performed in parallel with the heating operation of the wafer W when removing the MoOx layer 65b by the pre-cleaning module 156.
In the substrate processing apparatus 1b illustrated in
In addition, the substrate processing apparatus 1b in
The processing of the wafer W using the substrate processing apparatus 1b will be described with reference to
First, the COR process is performed on the wafer W to be processed using the COR module 151 (Operation P11A in
Here,
In particular, the substrate processing apparatus 1b according to the third embodiment illustrated in
In addition, in the example of the substrate processing apparatus 1b illustrated in
However, even when the COR process and the process using WCl5 gas are repeated multiple times, the execution of the PHT process using the PHT module 152 is not excluded. The processes using the COR module 151, the PHT module 152, and the Ti film forming module 153 may be repeated.
When both the COR process and the PHT process are repeated a predetermined number of times and the MoSiOx layer 65a is removed, the Ti layer 66 for contact is formed by the Ti film forming module 153a, and the Ru film 67 is formed by the Ru film forming module 154. The subsequent operation of unloading the wafer W is the same as that in the case of using the above-described substrate processing apparatus 1, and therefore, a redundant description thereof is omitted.
In each of the embodiments described above, the metal halide gas used to remove the metal oxide component (the MoOx layer 65b) on the surface of the MoSi layer 64 is not limited to the WCl5 gas exemplified herein. For example, the MoOX layer 65b may be removed with a WCl6 gas or a MoCl5 gas.
In addition, the configuration of the silicon-containing layer is not limited to the SiGe layer 61 exemplified with reference to
Further, in the removal of the silicon oxide portion by the COR process (the HF gas and the NH3 gas) and the removal of the metal oxide portion by the metal halide gas, the COR process does not necessarily have to be executed preferentially. The COR process may be performed after the execution of the processes using the metal halide gas.
According to the present disclosure, it is possible to remove an oxide film on a surface of a metal silicide layer formed in a recess of a substrate.
It should be noted that the embodiments disclosed in the present disclosure are merely exemplary in all respects and are not to be construed in a limited way. The above-described embodiments may be omitted, replaced and changed in various forms without departing from the appended claims and the gist thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-069426 | Apr 2023 | JP | national |
