Method for embedding ruthenium and apparatus for embedding ruthenium

Abstract

The recesses formed on the substrate are created by repeatedly depositing and etching ruthenium films. When embedding ruthenium, reduce the differences in the embedding height of the ruthenium. [Solution] A method for embedding ruthenium in a substrate having a recess includes (a) a step of supplying a raw material gas containing a ruthenium compound into a processing container containing the substrate to form a ruthenium layer in the recess, and (b) a step of adding oxygen gas or ozone gas to the processing container, with an ozone concentration of 0 g / m³. 3 More than 150g / m 3 (c) A step of pre-treating the ruthenium layer by supplying a pre-treatment gas of less than 150 g / m³, and (c) a step of supplying ozone gas to the treatment container with an ozone concentration of 150 g / m³. 3 More than 400g / m 3 The process includes the step of supplying the following etching gas to etch a portion of the ruthenium layer, and the cycle in which steps (a) to (c) are performed in this order is repeated.

Description

[Technical Field]

[0001] This disclosure relates to a method for embedding ruthenium and an apparatus for embedding ruthenium. Regarding. [Background technology]

[0002] In the semiconductor device manufacturing process, there is a procedure to form a ruthenium film by creating recesses such as holes and trenches in the insulating film formed on the substrate for semiconductor device manufacturing, and then embedding ruthenium (Ru), which is a wiring material, into these recesses.

[0003] Patent Document 1 describes a process of forming a first ruthenium film in a recess formed in an insulating film on a substrate, stopping the process of forming the first ruthenium film, supplying ozone gas to the substrate, and etching the first ruthenium film until the side walls of the recess are exposed, while leaving the first ruthenium at the bottom of the recess, and then forming a second ruthenium film to fill the recess with ruthenium. This is disclosed to prevent the opening of the recess from closing and the formation of voids in the ruthenium embedded in the recess. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-117899 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] This disclosure provides a technique for reducing differences in the embedded height of ruthenium when embedding ruthenium in recesses formed on a substrate by repeatedly depositing and etching ruthenium films. [Means for solving the problem]

[0006] A method for embedding ruthenium in a substrate having a recess according to the present disclosure is as follows: (a) A step of supplying a source gas containing a ruthenium compound into a processing container housing the substrate to form a ruthenium layer in the recess; (b) A step of supplying a pretreatment gas containing oxygen gas or ozone gas and having an ozone concentration of 0 g / m 3 or more and less than 150 g / m 3 (standard at 0 °C and 101.3 kPa; hereinafter, the same applies to the ozone concentration) into the processing container to perform pretreatment on the ruthenium layer; (c) A step of supplying an etching gas containing ozone gas and having an ozone concentration of 150 g / m 3 or more and less than 400 g / m 3 into the processing container to etch a part of the ruthenium layer, and including: Repeating a cycle in which the steps (a), (b), and (c) are executed in this order.

Advantages of the Invention

[0007] According to the present disclosure, when embedding ruthenium in the recess formed in the substrate while repeating film formation and etching of ruthenium, the difference in the embedding height of ruthenium can be reduced.

Brief Description of the Drawings

[0008] [Figure 1] It is a plan view illustrating a substrate processing system according to an embodiment. [Figure 2] It is a longitudinal sectional side view showing a film formation processing module of the substrate processing system. [Figure 3A] It is a longitudinal sectional side view showing the surface layer of a substrate before processing. [Figure 3B] It is a first diagram showing the surface layer of a substrate related to an embedding process in a comparative form. [Figure 3C] It is a second diagram showing the surface layer of a substrate related to an embedding process in a comparative form. [Figure 3D] It is a third diagram showing the surface layer of a substrate related to an embedding process in a comparative form. [Figure 4]It is a graph showing the change in the etching amount with respect to the etching gas supply time. [Figure 5] It is a flowchart showing the ruthenium embedding process of the embodiment. [Figure 6A] It is a first diagram showing the surface layer of the substrate related to the embedding process of the embodiment. [Figure 6B] It is a second diagram showing the surface layer of the substrate related to the embedding process of the embodiment. [Figure 6C] It is a third diagram showing the surface layer of the substrate related to the embedding process of the embodiment. [Figure 6D] It is a fourth diagram showing the surface layer of the substrate related to the embedding process of the embodiment. [Figure 7] It is a graph showing the experimental results.

Mode for Carrying Out the Invention

[0009] (Embodiment) FIG. 1 is a schematic plan view illustrating a substrate processing system including a film forming apparatus according to an embodiment. The substrate processing system 1 is a multi-chamber system including a plurality of processing modules 101, 102, 103 including a processing module configured to embed ruthenium in a recess 13 (FIG. 3A) formed in a substrate W. Note that the structure of the surface layer of the substrate W to be processed will be described later with reference to FIG. 3A.

[0010] In the substrate processing system 1, two provided processing modules 101 perform cleaning processing, four provided processing modules 102 perform film forming processing for embedding ruthenium in the recess 13, and two provided processing modules 103 perform annealing processing, respectively. Hereinafter, the processing module 101 may be referred to as a cleaning processing module 1, the processing module 102 may be referred to as a film forming processing module (apparatus for embedding ruthenium) 102, and the processing module 103 may be referred to as an annealing processing module 103.

[0011] The cleaning module 101 performs a pre-cleaning treatment to remove the metal oxide film (Figure 3A) that constitutes the bottom wall of the recess 13 before the ruthenium embedding treatment. If the layer beneath the recess 13 in the substrate W is a tungsten layer, the cleaning module 101 removes the tungsten oxide film formed by the oxidation of tungsten. Also, for example, if the layer beneath the recess 13 in the substrate W is a ruthenium layer, the cleaning module 101 removes the ruthenium oxide film formed by the oxidation of ruthenium. The cleaning module 101 reduces and removes the metal oxide using hydrogen plasma, which is hydrogen gas that has been converted into a plasma.

[0012] The film deposition module 102 is configured to deposit a Ru film, for example, by thermal CVD. The film deposition module 102 uses a ruthenium compound, such as Ru3(CO3), as a ruthenium raw material. 12 Ruthenium is embedded in the recesses 13 of the substrate W using a source gas containing (hereinafter also referred to as DCR). The annealing apparatus 28 anneals the formed ruthenium layer 14. The annealing apparatus 28 is a device capable of heating the substrate W with a heating means such as a heater.

[0013] The number and arrangement of processing modules 101 to 103 are not limited to the example shown in Figure 1, and the number and arrangement of each device can be set to improve the overall throughput. For example, if the ruthenium embedding or annealing process takes a long time, the number of each processing module 101 to 103 can be changed or they can be placed in appropriate locations so that the ratio of cleaning processing module 101 and annealing processing module 103 is larger than the number of each processing module 101 to 103 shown above.

[0014] Returning to the explanation of Figure 1, in addition to processing modules 101 to 103, the substrate processing system 1 includes a loader module 61, a load lock module 62, first and second vacuum transport modules 63 and 64, and a connection module 65. The loader module 61, load lock module 62, first vacuum transport module 63, connection module 65, and second vacuum transport module 64 are arranged in a straight line in the front-to-back direction in this order in a plan view. In the following explanation of the substrate processing system 1, the side where the loader module 61 is located will be referred to as the front side, and the side where the second vacuum transport module 64 is located will be referred to as the rear side.

[0015] The loader module 61 comprises a housing that maintains atmospheric pressure internally, a substrate transport mechanism 61a provided within the housing for transporting substrates W, and load ports 68. In this example, there are four load ports 68, arranged side by side on the front side of the housing. A transport container C for storing substrates W, called a FOUP (Front Opening Unified Pod), is placed on each load port 68. The transport mechanism 61a is composed of, for example, a multi-jointed arm that can move left and right, and can transport substrates W between the transport container C on each load port 68 and each load lock module 62.

[0016] In this example, there are three load lock modules 62, arranged side by side when viewed from the front. Each load lock module 62 has a housing, which is connected to the loader module 61 and the first vacuum transport module 63 via gate valves (not shown) located on its front and rear sides. Each load lock module 62 can change the pressure inside its housing between atmospheric pressure and vacuum pressure when the gate valves on the front and rear sides of the housing are closed. A stage on which the substrate W is placed is provided inside the housing. The stage is provided with a plurality of substrate support pins that can protrude from its surface, and is configured to allow the substrate W to be transferred to the transport mechanism 61a and the vacuum transport mechanism 69 (described later), which access the load lock modules 62, respectively.

[0017] The first and second vacuum transport modules 63 and 64 are similarly configured and each comprises a housing 63a and 64a and a vacuum transport mechanism 69 provided inside the housings 63a and 64a. One end of an exhaust pipe is connected to the housings 63a and 64a, and the inside of the housings 63a and 64a is evacuated by a vacuum evacuation mechanism connected via the exhaust pipe, maintaining a vacuum atmosphere. The vacuum evacuation mechanism may, for example, use a turbomolecular pump to maintain the inside of the housings 63a and 64a at a desired high vacuum pressure, thereby suppressing oxidation of the surface portion of the Ru film.

[0018] In this example, two connection modules 65 are provided side by side. Each connection module 65 is equipped with a housing, which is connected to the housings 63a and 64a of the vacuum transport modules 63 and 64. The vacuum exhaust mechanism described above creates a vacuum atmosphere inside the housing of the connection module 65 at the same pressure as inside the housings 63a and 64a. Furthermore, each housing of the connection module 65 is provided with a stage similar in configuration to the stage of the load lock module 62 described above, and is configured to allow the placed substrate W to be transferred between the vacuum transport mechanisms 69 of the first and second vacuum transport modules 63 and 64.

[0019] On both the left and right sides of the housing 63a of the first vacuum transfer module 63, when viewed from the front, are a cleaning processing module 101 and a film deposition processing module 102, respectively, arranged in a front-to-back configuration. The processing modules 101 and 102 are connected to the housing 63a via a gate valve G1. The transfer of the substrate W between these processing modules 101 and 102 and the load lock module 62 is performed by a vacuum transfer mechanism 69, which is composed of, for example, a multi-joint arm that can move in all directions. The vacuum transfer mechanism 69 similarly handles the transfer of the substrate W between the processing modules 101 and 102, and between the connection module 65 and the load lock module 62.

[0020] On both the left and right sides of the housing 64a of the second vacuum transfer module 64, when viewed from the front, are the film deposition module 102 and the annealing module 103, which are arranged in a front-to-back configuration. The processing modules 102 and 103 are connected to the housing 64a via the gate valve G1. The transfer of substrates W between these processing modules 102 and 103 and the connection module 65 is performed, for example, by the vacuum transfer mechanism 69 of the second vacuum transfer module 64. The vacuum transfer mechanism 69 also performs the transfer of substrates W between the processing modules 102 and 103 in the same manner.

[0021] The substrate processing system 1 includes a control unit 200, which is a computer, and this control unit 200 contains a program. The program incorporates instructions (steps) for performing each of the processes described above in the substrate cleaning process, film deposition process, annealing process, and transport of the substrate W. This program is stored in a storage medium, such as a compact disc, hard disk, DVD, or non-volatile memory, and is read from the storage medium and installed in the control unit 200.

[0022] The control unit 200 outputs control signals to each part of the substrate processing system 1 according to the program, causing each part to operate. Specifically, it controls the operation of processing modules 101 to 103, opening and closing of gate valves G1, operation of transport mechanism 61a and vacuum transport mechanism 69, operation of exhaust mechanism, and switching of pressure within load lock module 62. Control of the operation of processing modules 101 to 103 includes, for example, temperature control of the substrate W by supplying power to heaters, etc., as described later, and control of the amount of each gas supplied to the processing container 2 in each processing module 101 to 103, as described later.

[0023] Here, we will explain the transport path of the substrate W in the substrate processing system 1. First, the substrate W is transported in the following order: transport container C → loader module 61 → load lock module 62 → first vacuum transport module 63 → cleaning processing module 101. Then, the substrate W that has undergone cleaning processing in the cleaning processing module 101 is transported in the following order: cleaning processing module 101 → first vacuum transport module 63 → film deposition processing module 102. When transporting to the film deposition processing module 102 on the second vacuum transport module 64 side, the substrate W is transported in the following order: first vacuum transport module 63 → connection module 65 → second vacuum transport module 64 → film deposition processing module 102.

[0024] Then, the substrate W that has undergone ruthenium embedding treatment in the film deposition module 102 is transported from the film deposition module 102 to the second vacuum transport module 64, and then to the annealing module 103. The substrate W that has undergone annealing treatment in the annealing module 103 is transported in the following order: annealing module 103 → second vacuum transport module 64 → connection module 65 → first vacuum transport module 63 → load lock module 62 → loader module 61, and returned to the transport container C.

[0025] The configurations of processing modules 101 to 103 will be explained using Figure 2, which shows a longitudinal cross-sectional side view of the film deposition processing module 102 as a representative example. The film deposition processing module 102 comprises a processing container 2 in which a substrate W is housed and a vacuum atmosphere is formed, and a mounting table 3 provided inside the processing container 2 for placing the substrate W. Furthermore, the film deposition processing module 102 is provided on the upper part of the processing container 2 so as to face the mounting table 3, and is equipped with a shower head 4 for supplying processing gas to the surface of the substrate W.

[0026] The mounting base 3 is formed in the shape of a flat disc, using a material such as aluminum nitride or quartz. A heater 31 is embedded inside the mounting base 3 to raise the substrate W to a preset temperature. The heater 31 is composed of, for example, a sheet-shaped resistance heating element and is installed so that its entire surface is covered by the mounting base 3. The heater 31 is powered by a power supply unit (not shown) to heat the substrate W placed on the mounting base 3 to a temperature within the range of 100°C to 250°C, which is the film deposition temperature for Ru, for example.

[0027] The mounting base 3 is preferably covered with a cover 32. The cover 32 is a removable cover member made of quartz and is positioned to cover the top and sides of the mounting base 3, preventing reaction products and by-products such as ruthenium from accumulating on the surface of the mounting base 3. A circular recess having a diameter slightly larger than the substrate W is formed in the central region of the top surface of the cover 32, forming the mounting surface of the mounting base 3. In this way, the mounting surface positions the substrate W on which it is placed. Furthermore, a through hole is provided on the top side of the cover 32 for housing the head of the lifting pin 35, which will be described later.

[0028] The mounting table 3 is supported, for example, at the center of its lower surface by a columnar support member 34, and the support member 34 is configured to be raised and lowered by a lifting mechanism 34a. By raising and lowering the support member 34, the mounting table 3 moves between a transfer position where the substrate W is transferred to and from an external wafer transport mechanism, and a processing position where the substrate W is processed.

[0029] As shown in Figure 2, the support member 34 penetrates the bottom of the processing container 2, more specifically the bottom of the lower container 22 which will be described later, and is connected to the lifting plate 23 which is raised and lowered by the lifting mechanism 34a described above. The lifting plate 23 and the lower container 22 are airtightly joined by a bellows 24.

[0030] The mounting base 3 supports the back surface of the substrate W and is equipped with, for example, three lifting pins 35 for placing the substrate W on the mounting surface of the mounting base 3 or raising it above the mounting surface. These lifting pins 35 penetrate the mounting base 3 vertically, with their lower ends protruding downward from the mounting base 3. A ring-shaped lifting member 36 is provided below each lifting pin 35. By lowering the mounting base 3 to the position where the substrate W can be received and then raising or lowering the lifting member 36, the substrate W supported by the lifting pins 35 can be placed on and raised relative to the mounting surface of the mounting base 3.

[0031] Next, the configuration of the processing container 2 will be described. The lower container 22 of the processing container 2 encloses a lower space and has an opening at the top, and an annular exhaust duct 21 is stacked on top of this opening to constitute the processing container 2. The lower container 22 is made of, for example, aluminum, and has a through hole at its bottom through which the support member 34 of the mounting base 3 passes, as described above. The lower container 22 also has a plurality of purge gas supply holes 22b around the through hole, and a purge gas supply mechanism 79 is connected to the purge gas supply holes 22b. Therefore, purge gas such as nitrogen gas supplied from the purge gas supply mechanism 79 can be supplied to the lower space of the lower container 22, which is below the mounting base 3 at the processing position. The side wall of the lower container 22 is provided with an inlet and outlet for loading and unloading the substrate W by the vacuum transport mechanism 69 described above, and the gate valve G1 described above is provided at this inlet and outlet.

[0032] The exhaust duct 21 is, for example, an annular body made of aluminum, and the inner circumferential wall of the exhaust duct 21 has a plurality of openings 21a that open toward the area above the mounting base 3. An exhaust pipe 29 is connected to the outer circumferential wall of the exhaust duct 21, and the processing container 2 is configured to be evacuated by a vacuum pump 29a, which corresponds to the exhaust section connected to the exhaust pipe 29. Upstream of the vacuum pump 29a in the exhaust pipe 29, an APC valve (not shown) is interposed as a pressure regulating valve.

[0033] Furthermore, the processing container 2 is provided with an inner ring 26, which is a surrounding member that surrounds the mounting base 3 at the processing position. The inner ring 26, together with the mounting base 3 at the position where it is positioned, is configured to divide the inside of the processing container 2 into an upper space, which is the processing space 40, and the lower space described above. The processing space 40 corresponds to the space "inside the processing container housing the substrate" in the claims. The inner ring 26 is an annular member made of, for example, aluminum, and is fitted between the inner surface of the side wall of the lower container 22 and the side surface of the cover 32. The outer circumference of the upper side of the inner ring 26 is widened to form a flange and is locked to the bottom wall of the exhaust duct 21 and positioned inside the processing container 2.

[0034] Next, the configuration of the shower head 4 will be described. The shower head 4 is disc-shaped, with the upper side being larger in diameter than the lower side, and the upper side is attached to the upper part of the inner circumference of the exhaust duct 21. An O-ring is provided between the shower head 4 and the exhaust duct 21 to seal the processing container 2. The shower head 4 is positioned in the processing container 2 so as to face the mounting base 3, and various processing gases can be supplied to the processing space 40 between the shower head 4 and the mounting base 3 to perform various processing on the substrate W. A gas diffusion space (not shown) is provided inside the shower head 4, and the lower part of the shower head 4 is a shower plate with multiple through holes formed therein. The shower head 4 can uniformly discharge the processing gases supplied to the gas diffusion space toward the surface of the substrate W placed on the mounting base 3. A discharge hole is formed in the upper center of the shower head 4 to which the gas supply mechanism 7, described later, is connected.

[0035] The gas supply mechanism 7 is configured to supply various processing gases to the processing vessel 2. Specifically, the gas supply mechanism 7 includes a raw material gas supply mechanism 71 for depositing ruthenium, an ozone gas supply mechanism 72 for supplying etching gas and a pretreatment gas described later, a reducing gas supply mechanism 73, and a gas supply pipe 74 branched to connect each of the supply mechanisms 71 to 73 to the discharge holes above the shower head 4. The raw material gas supply mechanism 71 includes a raw material gas supply source 71a of Ru (ruthenium), a flow meter 71b, and a valve V1, which are arranged in this order downstream in the branched gas supply pipe 74. The flow meter 71b detects the flow rate of the raw material gas supplied from the raw material gas supply source 71a, and the valve V1 cuts off the flow of the raw material gas. The raw material gas supply source 71a is configured to generate Ru3(CO) 12 (dodecacarbonyltriruthenium) gas, for example, using CO (carbon monoxide) gas as a carrier gas.

[0036] The ozone gas supply mechanism 72 includes an O2 (oxygen) gas supply source 72a, a flow rate adjustment unit 72b, two valves V2a, V2b, and an ozonizer 72d. The O2 gas supply source 72a, valve V2a, flow rate adjustment unit 72b, ozonizer 72d, and valve V2b are arranged in this order downstream in the branched gas supply pipe 74.

[0037] The oxygen gas supplied from the O2 gas supply source 72a is controlled in flow rate by the flow rate adjustment unit 72b and supplied to the ozonizer 72d. The ozonizer 72d is configured as, for example, a silent discharge type discharge tube, and discharges by the electrical energy applied from an external power source not shown, and can supply ozone (O3) gas by activating at least a part of the supplied oxygen gas. And the ozonizer 72d can adjust the ozone gas concentration to, for example, 0 g / m 3 to 400 g / m 3 (based on 0 °C, 101.3 kPa. The same applies to the ozone concentration hereinafter) by adjusting the applied voltage from the external power source. For this reason, the ozonizer 72d can supply oxygen gas (ozone concentration 0 g / m 3 ) or ozone-containing oxygen gas (ozone gas concentration 0 g / m 3Higher at 400g / m 3 The following will be supplied and distributed.

[0038] In this disclosure, the ozonizer 72d has an ozone concentration of 0 g / m³. 3 More than 150g / m 3 For example, an ozone concentration of 0 g / m³ within the range of less than 0 g / m³. 3 Oxygen gas is supplied as a pretreatment gas. In addition, the Ozonizer 72d has an ozone concentration of 150 g / m³. 3 More than 400g / m 3 Within the following range, for example, an ozone concentration of 150 g / m³ 3 The ozone-containing oxygen gas is supplied as the etching gas. The flow rate of the oxygen gas supplied from the O2 gas supply source 72a to the ozonizer 72d is, for example, 400 sccm to 2000 sccm for both the pretreatment gas and etching gas supply. Therefore, the common ozonizer constituting the ozone gas supply mechanism 72 corresponds to both the pretreatment gas supply mechanism and the etching gas supply mechanism.

[0039] The reducing gas supply mechanism 73, like the raw material gas supply mechanism 71, is equipped with a CO gas supply source 73a, a flow rate adjustment unit 73b, and a valve V3. The gas supply mechanism 7, like the supply mechanisms 71 to 73 for each processing gas, preferably includes an inert gas supply mechanism connected to the discharge port at the top of the shower head 4. In this case, the supplied inert gas purges each processing gas and suppresses the reaction between the processing gases and the deposition of products. In addition to the reducing gas supply process described later, the reducing gas supply mechanism 73 also supplies CO gas together with the Ru raw material gas in the ruthenium film deposition process. The CO gas supplied together with the raw material gas suppresses the decomposition of the Ru raw material gas in the gas supply pipe 74, inside the shower head 4, and in the processing space 40, and plays a role in suppressing the deposition of ruthenium on surfaces other than the substrate W.

[0040] In the film deposition module 102 of this disclosure, it is preferable to provide a clamp ring 5 for suppressing the leakage of Ru raw material gas to the lower surface of the substrate W placed on the mounting table 3. The clamp ring 5 comprises a main body 51 made of an annular plate material, and is placed in the processing container 2 with the lower surface of the main body 51 resting on the inner ring 26. The inner edge of the main body 51 extends further inward than the inner circumference of the inner ring 26, and its inner end is located above the peripheral edge of the substrate W placed on the mounting table 3. When the inner end of the main body 51 is resting on the inner ring 26, it extends downward from the upper surface of the inner ring 26, and the lower surface of the inner end is a flat contact surface.

[0041] The clamping ring 5 is displaced upward as its contact surface contacts almost the entire circumference of the peripheral edge of the substrate W on the mounting table 3, which is moving to the processing position, and it is lifted away from the inner ring 26. When the mounting table 3 is lowered to the transport position, the clamping ring 5 is supported by the inner ring 26 and moves away from the peripheral edge of the substrate W on the mounting table 3. The clamping ring 5 has a weight sufficient to suppress the leakage of reaction gas by pressing its contact surface against the substrate W on the mounting table 3, for example, several hundred grams to several kilograms.

[0042] The lower surface of the main body 51 is provided with a cylindrical wall portion 54 formed in a cylindrical shape along the circumferential direction of the clamp ring 5. The cylindrical wall portion 54 is positioned between the mounting base 3, which is located at the processing position, and the inner ring 26. The lower surface of the main body 51 is provided with a plurality of protrusions 53 for positioning. The clamp ring 5 is placed at the mounting position on the inner ring 26 by positioning the protrusions 53 in recesses provided on the upper surface of the inner ring 26. The clamp ring 5 is made of a metal such as aluminum or a ceramic such as alumina.

[0043] In the film deposition module 102, the mounting stage is heated to, for example, 155°C or 180°C, and the temperature inside the processing space 40 is set to, for example, 2.21 Pa (16.6 mTorr).

[0044] The following briefly describes the structures of the cleaning module 101 and the annealing module 103, focusing on the differences from the film deposition module 102. As shown in Figure 2, the gas supply mechanism of the cleaning module 101 includes an H2 gas supply mechanism and a purge gas supply mechanism. The H2 gas supply mechanism, like the reduction gas supply mechanism 73, consists of an H2 gas supply source, a flow rate adjustment unit, and a valve, and the purge gas supply mechanism is configured similarly. The processing container and mounting base of the cleaning module 101, which supplies H2 gas plasma, are both grounded. The shower head is attached to the processing container via a ring-shaped insulating member and connected to a high-frequency power supply via a matching unit to function as an upper electrode. The matching unit matches the internal impedance of the high-frequency power supply with the load impedance, and the high-frequency power supply applies power to the shower head at a preset frequency to plasmaize the H2 gas supplied by the gas supply mechanism described above. The mounting base 3 is provided at the bottom of the processing container via an insulating member and functions as a lower electrode.

[0045] The cleaning processing module 101 described above converts the H2 gas supplied between the showerhead and the mounting base into plasma and supplies it to the substrate W. Processing modules 101 and 103 do not necessarily require an inner ring, exhaust duct, or purge gas supply hole to partition the space below the mounting base from the processing space. In this case, processing modules 101 and 103 are configured to have an exhaust hole at the bottom of the processing container to which an exhaust mechanism is connected, and to exhaust the entire area inside the processing container.

[0046] The annealing module 103 includes an inert gas supply mechanism that supplies an inert gas, such as N2 gas.

[0047] In the substrate processing system 1 of this disclosure, which has the configuration described above, cleaning of the metal oxide film formed on the surface of the substrate W, ruthenium embedding, and annealing are performed. These series of processes will be explained with reference to Figures 1 and 2. In advance, the first and second vacuum transport modules 63 and 64 are set to a vacuum atmosphere with a predetermined pressure, and the processing modules 101 to 103 each adjust the pressure inside the processing container 2 to a predetermined vacuum atmosphere using an exhaust mechanism. Then, in each processing module 101 to 103, the mounting stage 3 is preheated to, for example, 200°C.

[0048] Figure 3A is a longitudinal cross-sectional side view illustrating the central and peripheral sides of the surface layer of the substrate W before a series of processing, and shows the central recess 13 and the peripheral recess 13 as excerpts. As shown in the figure, the surface layer of the substrate W before a series of processing consists of a metal layer 11, which is a tungsten layer, and an insulating layer 12, which is, for example, a Si oxide film, provided on the metal layer 11. Multiple recesses 13 are formed in the insulating layer 12 by etching. The recesses 13 are provided to embed the ruthenium layer 14, which is a wiring layer, and open to the surface of the substrate W. The recesses 13 are elongated vertically, and their width narrows towards the bottom, with the bottom being made of the metal layer 11. Specifically, the bottom surface of the recesses 13 exposes a tungsten oxide film (not shown) that has been oxidized by an atmospheric environment, etc.

[0049] Therefore, first, the oxide film on the metal layer 11 that constitutes the bottom surface of the recess 13 is removed in the cleaning processing module 101 using plasma-generated H2 gas. Next, the substrate W from which the oxide film on the metal layer 11 has been removed is transported toward the film deposition processing module 102. Then, the gate valve G1 of the film deposition processing module 102 shown in Figure 2 is opened, and the substrate W is transported from the entrance to the processing container 2 by the vacuum transport mechanism 69 and transferred to the mounting table 3 at the transport position. After that, the vacuum transport mechanism 69 is withdrawn from the processing container 2 and the gate valve G1 is closed. Then, when the mounting table 3 is moved to the processing position, the clamp ring 5 is positioned so that its contact surface is in contact with the entire peripheral edge of the substrate W. The clamp ring 5 prevents the Ru film from being deposited on the peripheral edge or back surface of the substrate W when thermal CVD is performed later. After the clamp ring 5 is positioned in this way, the substrate W is heated by the mounting table 3 to the aforementioned film deposition temperature, and the processing gases are supplied to the processing space 40 to carry out film deposition and other processes.

[0050] Before describing the details of the ruthenium embedding method of this disclosure, a comparative ruthenium embedding method will be described. Figures 3B to 3D are longitudinal cross-sectional side views showing the surface layer changes of the substrate W on which the comparative ruthenium embedding method is performed. Figures 3A and 3B show the surface layer changes of the substrate W that are common to the comparative method described using Figures 3B to 3D and the ruthenium embedding method of this disclosure described using Figures 6A to 6D.

[0051] Once the substrate W reaches a predetermined heating temperature, the gas supply mechanism 7 supplies Ru raw material gas, CO gas, and inert gas into the processing space 40 while adjusting the pressure inside the processing container 2. Purge gas is continuously supplied to the lower space of the processing container 2 from the purge gas supply mechanism 79.

[0052] As a result, the Ru source gas decomposes on the heated surface of the substrate W, and a ruthenium film is deposited on the substrate W surface by thermal CVD. During this process, ruthenium is deposited at the bottom and sides of the recess 13 (Figure 3B). Specifically, at the bottom of the recess 13, a ruthenium layer 14a is formed by deposition from the bottom surface upwards (bottom-up). Additionally, lateral ruthenium 14b is deposited in an island-like manner from the side of the recess 13. Note that in Figure 3B, the Ru film deposited on surface areas of the substrate W other than the recess 13 is not shown.

[0053] Next, to prevent the opening of the recess 13 from closing and void formation from occurring due to the increase in thickness caused by further deposition of ruthenium 14b on the sides, etching gas is supplied (Figure 3C). In the ruthenium embedding according to the comparative form, as previously described, an ozone gas, for example, with an ozone concentration of 150 g / m³, is used, generated by the ozonizer 72d. 3 Only ozone-containing oxygen gas is supplied. As a result, the surface portion of the bottom ruthenium layer 14a and the side ruthenium 14b react with the ozone gas to form volatile RuO4 (ruthenium tetroxide), which is then exhausted and removed by the vacuum pump 29a. In Figure 3C, the surface of the bottom ruthenium layer 14a before etching gas supply is shown by a dashed line.

[0054] After the etching gas is supplied, the surface portion of the remaining bottom ruthenium layer 14a is converted to ruthenium oxide (RuO2: ruthenium dioxide) 14c through a reaction with ozone gas and oxygen gas. Note that the O2 gas contained in the etching gas does not have an etching effect on ruthenium, but it oxidizes ruthenium to RuO2.

[0055] The ruthenium embedding process is completed by performing the above film deposition and etching cycles sequentially a predetermined number of times (Figure 3D). Regarding the ruthenium embedding method described above in the comparative form, the inventors noticed that the embedding height of the ruthenium layer 14 embedded in the recess 13 could be uneven. That is, the ruthenium layer 14 in the recess 13 was higher as it moved from the center to the periphery of the substrate W, and was not uniform across the surface of the substrate W. After investigating the cause of this uneven embedding state, the inventors focused on the difference in the etching rate of ruthenium due to ozone gas.

[0056] The first factor that could cause a difference in etching rate is the influence of temperature differences within the plane of the substrate W. Generally, in metal etching with etching gas, the etching rate tends to be higher under high temperature conditions and lower under low temperature conditions. In the film deposition module 102 with the configuration shown in Figure 2, the cover 32 and clamp ring 5 are attached to the periphery of the mounting table 3 in which the heater 31 is embedded. As a result, the heat capacity of the periphery of the mounting table 3 is higher than that of the center. Therefore, the heat supplied from the heater 31 is also transferred to these components 32 and 5, and the temperature of the mounting table 3 tends to be lower on the periphery side than on the center side. As a result, the temperature of the substrate W also tends to be lower on the periphery side than on the center side. Due to the influence of this temperature distribution of the substrate W, it is presumed that in the comparative configuration, the etching rate of the bottom ruthenium layer 14a surface decreased as the substrate W moved from the center side to the periphery side (Figure 3C).

[0057] A second possible factor is the difference in the concentration of ozone gas in the etching gas supplied uniformly across the surface. In thermal CVD, ruthenium (Ru) is deposited on the clamp ring 5, which is positioned to cover the periphery of the substrate W. Therefore, when etching gas is supplied, the Ru film deposited on the clamp ring 5 also consumes ozone gas in the etching gas. For this reason, it is presumed that the ozone gas concentration of the etching gas supplied across the surface of the substrate W decreases on the periphery side of the substrate W adjacent to the clamp ring 5. From the above, it is thought that the etching rate on the surface of the bottom ruthenium layer 14a decreases on the periphery side of the substrate W (Figure 3C).

[0058] A third possible factor is the difference in etching rates between the unoxidized bottom ruthenium layer 14a and ruthenium oxide 14c. Figure 4 is a graph showing the change in the amount of ruthenium etched with respect to etching gas supply time. Figure 4 shows the results for a bare wafer with a uniform Ru film on its surface, at an ozone concentration of 300 g / m². 3 150g / m 3 The etching amount was measured at each point in time by supplying different etching gases. As shown in Figure 4, at all ozone concentrations, the etching rate was relatively high immediately after the start of etching gas supply, and as time passed from the start of supply, the etching amount approached a constant level and the etching rate decreased. Also, the higher the ozone concentration, the greater the etching amount during the period when the etching rate was high. As a result, a significant difference in etching amount was observed between the center and the periphery of the substrate W during the period of high etching rate immediately after the start of etching gas supply. The third factor is considered to be that the large difference in etching amount between the center and the periphery immediately after the start of etching gas supply is due to the influence of temperature differences and differences in etching gas concentration, which were considered as the first and second factors.

[0059] The etching rate immediately after the start of etching, which was explained as the third factor here, is thought to be greatly influenced by the surface state of Ru. Specifically, the surface of the Ru film before the start of etching is generally unoxidized ruthenium. For this reason, the etching rate of unoxidized ruthenium is relatively high. On the other hand, ruthenium oxide 14c (Figure 3C) is formed on the surface of the Ru film by the etching gas after some time has passed since the start of etching. This ruthenium oxide 14c is removed by ozone gas in the etching gas to become RuO4, but its etching rate is lower compared to unoxidized ruthenium. Therefore, in the ruthenium embedding method of this disclosure, as indicated by the arrows in Figure 4, before supplying the etching gas, a pretreatment is performed to convert the surface of the bottom ruthenium layer 14a into ruthenium oxide 14c over the entire surface of the substrate W using a low concentration of ozone gas, which has a low etching rate immediately after the start of gas supply.

[0060] The ruthenium embedding process of this disclosure involves repeating a cycle in the order of film deposition process (step (a)), pretreatment process (step (b)), and etching process (step (c)) multiple times in the film deposition process module 102. This will be explained using Figure 5, which shows a flowchart of the ruthenium embedding process of this disclosure. In the ruthenium embedding process of this disclosure, first the substrate W is placed on the mounting stage 3 (step S1), and after the mounting stage 3 is positioned in the processing location, the first film deposition cycle is performed. Specifically, as in the comparative form, as shown in Figure 3B, various gases are supplied based on the film deposition recipe to form a ruthenium layer 14a in the recess 13 (step S2, process of forming the ruthenium layer). Next, it is preferable to purge the inside of the processing container 2 with a purge gas supply mechanism (not shown) provided in the gas supply mechanism 7 (step S3) and to make the inside of the processing space 40, for example, 133.3 Pa (1 Torr) in order to perform pretreatment.

[0061] Next, as shown in Figure 6A, the ozone gas supply mechanism 72 supplies pretreatment gas to pretreat the bottom ruthenium layer 14a (Step S4, step of pretreating the ruthenium layer). As discussed using Figure 4, the ozone concentration is 0 g / m³. 3More than 150g / m 3 Pretreatment gases within the range of less than 150 g / m³ have an ozone concentration of 150 g / m³. 3 More than 400g / m 3 Compared to etching gases within the following ranges, the etching rate immediately after gas supply starts is relatively small (ozone concentration of 0 g / m³). 3 (The pretreatment gas does not have the ability to etch ruthenium.) On the other hand, ozone-containing oxygen gas in these concentration ranges has the ability to oxidize ruthenium. Therefore, a pretreatment is performed using the pretreatment gas to oxidize the surface side of the bottom ruthenium layer 14a and the side ruthenium 14b to ruthenium oxide 14c. Then, as shown in Figure 6B, etching gas is supplied by the ozone gas supply mechanism 72 to remove the side ruthenium 14b and the surface side of the bottom ruthenium layer 14a (step S5, process of etching a part of the ruthenium layer). Since the side ruthenium 14b and the surface side of the bottom ruthenium layer 14a are already ruthenium oxide 14c before the etching gas is supplied, the etching rate is low from the start of etching gas supply. For this reason, the difference in etching rate due to the first to third factors described above can be suppressed in the bottom ruthenium layer 14a located on the central and peripheral sides of the substrate W, and the amount of etching can be made uniform within the plane of the substrate W.

[0062] Furthermore, even if all the areas corresponding to ruthenium oxide 14c formed before etching are removed, the etching gas removes the exposed bottom-side ruthenium layer 14a by sequentially oxidizing it. At this stage, the heating state of the substrate W reaches a steady state, the temperature difference within the plane becomes smaller, and the amount of Ru deposited on the surface of the clamp ring 5 also decreases. Therefore, in this etching process, the difference in etching rate between the central and peripheral parts of the substrate W, as described above, is reduced. In this pretreatment, it is sufficient to cover the surface side of all the bottom-side ruthenium layer 14a with ruthenium oxide 14c, for example, by about 500-600 seconds.

[0063] After the etching gas supply is completed, the processing container 2 is purged by a purge gas supply mechanism (not shown) provided in the gas supply mechanism 7 (step S6), and reducing gas is supplied by the reducing gas supply mechanism 73 (step S7, Figure 6C. Step (d))). As a result, the ruthenium oxide 14c on the surface side of the bottom ruthenium layer 14a is reduced to an unoxidized bottom ruthenium layer 14a. Since ruthenium oxide 14c is a factor that increases the electrical resistance, it is preferable to perform the reduction treatment from the viewpoint of improving the electrical characteristics of the ruthenium layer 14 after the completion of the embedding process. After the supply of the reducing gas, the processing container 2 is purged (step S8), and the first cycle of the ruthenium embedding process is completed. Next, the control unit 200 determines whether the number of cycles has reached the target number set in the film deposition recipe (step S9), and repeats the cycle until it is determined that the target number has been reached, and the embedding of the ruthenium layer 14 in the recess 13 is completed (Figure 6D). Each embedded ruthenium layer 14 is connected to the metal layer 11.

[0064] As described above, according to the ruthenium embedding method of this disclosure, a pretreatment gas is supplied after the formation of the bottom ruthenium layer 14a and before the supply of etching gas to uniformly convert the surface side of the bottom ruthenium layer 14a into ruthenium oxide 14c. This reduces the etching rate immediately after the supply of etching gas and stabilizes the etching rate. Therefore, the difference in the amount of etching, which was significant across the central and peripheral sides of the bottom ruthenium layer 14a in the comparative embodiment, can be reduced, and the difference in the embedding height of the ruthenium layer 14 embedded in the recess 13 can be suppressed.

[0065] (modified version) The surface shape of the substrate is not limited to those shown in this disclosure. For example, the metal layer 11 connected to the ruthenium layer 14 is not limited to a tungsten layer, but may be a metal-containing layer containing other metals. The metal-containing layer may be a layer containing, for example, Si (silicon) or Ge (germanium). The insulating layer 12 may be an insulating layer other than silicon oxide, for example, a silicon nitride (Si3N4) layer.

[0066] The pretreatment gas in this disclosure has an ozone gas concentration of 0 g / m³. 3 While oxygen gas was used as an example, the explanation is not limited to this, and includes, for example, oxygen gas or ozone gas, with an ozone gas concentration of 0 g / m³. 3 More than 150g / m 3 It may be less than 0 g / m³. And as previously mentioned, the pretreatment gas should have an ozone gas concentration of 0 g / m³. 3 However, it is sufficient if it contains oxygen gas, and the ozone concentration is 0 g / m³. 3 If the concentration is higher, it does not need to contain oxygen, and may contain other gases, such as inert gases.

[0067] The etching gas in this disclosure has an ozone gas concentration of 150 g / m³. 3 While ozone-containing oxygen gas is given as an example, it is not limited to this. The etching gas contains ozone gas, and the ozone gas concentration is, for example, 150 g / m³. 3 More than 400g / m 3 The following is also acceptable. Therefore, the etching gas does not have to be ozone-containing oxygen gas, that is, it does not have to contain oxygen gas, as long as the ozone gas concentration is within the specified range. Such an etching gas that does not contain oxygen gas may contain other gases, such as an inert gas. If the inert gas is, for example, N2, then NO2 (nitrogen dioxide) gas, which is formed by the reaction of ozone gas, may be supplied as the etching gas.

[0068] The ozone gas supply mechanism 72 in the film deposition module 102 includes, but is not limited to, a silent discharge type ozone generator 72d that generates plasma as described above. For example, if it is possible to supply pretreatment gases and etching gases of various ozone concentrations as described above, an ozone generator using a chemical method, electric field method, ultraviolet method, etc., may be used instead of the ozone generator 72d. In addition, while it is preferable that the film deposition module 102 is provided with one ozone generator 72d as described herein, it may also be provided with two or more. If two ozone generators 72d are provided, one ozone generator 72d may supply the pretreatment gas and the other ozone generator 72d may supply the etching gas.

[0069] Furthermore, while it is preferable, from the viewpoint of simplifying the equipment and improving processing efficiency, to supply the pretreatment gas together with the etching gas through the ozone gas supply mechanism 72, this is not a mandatory requirement. For example, the pretreatment gas may be other gases that have sufficient oxidizing power to sufficiently oxidize the surface side of the bottom ruthenium layer 14a, such as an H2O (moisture)-containing gas, in addition to ozone gas or oxygen gas supplied by the ozonizer 72d. The reducing gas supply source 73a of the reducing gas supply mechanism 73 is not limited to CO gas, but may be other reducing gases such as H2 (hydrogen) gas, as long as it can sufficiently reduce the ruthenium oxide 14c on the surface of the bottom ruthenium layer 14a. CO gas and H2 gas may be supplied simultaneously or alternately.

[0070] In the example described above, we explained the case where the steps "film deposition process (a) → pretreatment process (b) → etching process (c) → reduction process (d)" are performed in this order in each cycle (hereinafter also referred to as the "first cycle example"). However, a cycle in which each step is performed in the order "reduction process (d) → film deposition process (a) → pretreatment process (b) → etching process (c)" (similarly referred to as the "second cycle example") is also conceivable. However, the second cycle example is substantially the same as the first cycle example, except for the first and last cycles. In contrast to these, for example, in each cycle, the reduction process (d) may be performed first before the pretreatment process (b), such as "film deposition process (a) → reduction process (d) → pretreatment process (b) → etching process (c)". In this case, by reducing the surface of the ruthenium layer 14 after the film deposition process (a) with a reducing gas and then oxidizing it with a pretreatment gas, the surface can be oxidized more uniformly, which is effective in reducing differences in the amount of etching. Furthermore, if there are no particular problems with the electrical properties of the ruthenium layer 14, it is not necessary to supply reducing gas during that cycle.

[0071] Furthermore, a sheathed heater may be attached to the inner ring 26 or the clamp ring 5 for preheating the clamp ring 5. In this case, the aforementioned low temperature reduction on the peripheral side of the substrate W can be suppressed, and the difference in the amount of etching on the bottom side ruthenium layer 14a surface between the central side and the peripheral side can be further reduced. Alternatively, the clamp ring 5 may not be provided, and an electrostatic chuck may be provided on the upper surface of the mounting table 3. This allows the back surface of the substrate W to be brought into close contact with the mounting table 3 by electrostatic attraction force, preventing gas from seeping in.

[0072] The mounting stage 3 of the film deposition module 102 was set to 155°C or 180°C, which provides good ruthenium embedding. However, it is not limited to these temperatures; for each cycle including ruthenium deposition, pretreatment, and etching, the temperature can be set within the range of 100°C to 250°C, and may be varied as appropriate within this range. In addition, the pressure in the processing space 40 during each cycle is set to 0.13 to 2666 Pa (1.0 × 10⁻⁶). -3The pressure should be within the range of ~20 Torr. In detail, the example given shows that the pressure in the processing space 40 of the film deposition module 102 was set to 133.3 Pa (1 Torr) during the pretreatment process, but it may be appropriately varied within the range of, for example, 6.7 to 400 Pa (0.05 to 3 Torr) throughout the pretreatment and etching processes.

[0073] In the substrate processing system 1 of this disclosure, pre-treatment and etching are performed in the film deposition module 102, but they may be performed in other processing modules. Furthermore, a processing module for pre-treatment and a processing module for etching may be provided separately. In addition to the processes described above, the substrate processing system 1 may be configured to perform a degassing treatment, for example, to release gaseous components contained in the substrate W (e.g., H2O in the air adsorbed on the surface of the substrate W that has been brought in) before the cleaning treatment. In this case, a degassing treatment module configured to heat the substrate W under a vacuum atmosphere may be newly provided, or the degassing treatment may be performed in the annealing treatment module 103 or the load lock module 62. Also, in the substrate processing system 1, it is not a mandatory requirement that the first and second vacuum transport modules 63, 64 and the connection module 65 be provided. For example, the second vacuum transport module 63 and the connection module 65 may not be provided, and the processing modules 101 to 103 may be arranged around the first vacuum transport module 63. [Examples]

[0074] (experiment) To confirm the in-plane etching uniformity in the ruthenium embedding method of this disclosure, the etching amount was confirmed by performing etching in a comparative example as shown in the comparative form described above, and in an example as shown in the embodiment, which underwent pretreatment and etching.

[0075] A. Experimental conditions Two flat bare wafers were prepared, each having a ruthenium layer on its surface that was not patterned and had a uniform thickness. The surface of the bare wafer to be treated in the example was subjected to four cycles of the pretreatment, etching gas supply for 60 seconds, and reduction gas supply in that order. The surface of the bare wafer to be treated in the comparative example was not pretreated, and etching gas supply and reduction gas supply were performed three times under the same conditions as in the example. For each bare wafer that underwent the above treatment, the amount of ruthenium etched at the same radial position was measured.

[0076] B. Experimental Results Figure 7 is a graph showing the experimental results, specifically the measurement results of the etching amount at each position on the same radius of each substrate used in the comparative example and the example experiments. In this figure, a center-to-center distance of 0 nm indicates the center of the substrate surface, and a center-to-center distance of 150 nm indicates the peripheral edge of the substrate surface.

[0077] As shown in Figure 7, in the comparative example substrate, the amount of etching was greatest at the center and decreased towards the periphery. From this data, the NU (within wafer non-uniformity), which indicates the in-plane processing uniformity of etching in the comparative example, was calculated as the standard deviation / mean value of the etching amount at each pre-set measurement point in the plane, and was 3.7%.

[0078] In the substrate of the example, the etching amount at each radial position was close to the etching amount at the center position and did not decrease as it moved from the center towards the periphery. The NU of etching in the example was calculated to be 1.4%, similar to the comparative example, indicating more uniform in-plane etching than the comparative example. Based on these experimental results, it was concluded that the ruthenium embedding method of this disclosure, when pretreated, can make the etching amount by subsequent etching uniform in-plane and the embedding height of ruthenium uniform.

[0079] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The above embodiments may be omitted, substituted, modified, and combined in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0080] W board 13 recess 14a Bottom ruthenium layer 2 Processing container

Claims

1. A method for embedding ruthenium in a substrate having a recess, (a) A step of supplying a raw material gas containing a ruthenium compound into a processing container containing the substrate to form a ruthenium layer in the recess, (b) The processing container contains oxygen gas or ozone gas, and the ozone concentration is 0 g / m³. ３ Above, 150g / m ３ A step of supplying a pretreatment gas of less than (based on 0°C and 101.3 kPa; the same applies to ozone concentration hereafter) to pretreatment the ruthenium layer, (c) The processing container contains ozone gas and has an ozone concentration of 150 g / m³. ３ Above, 400g / m ３ The process includes supplying the following etching gas to etch a portion of the ruthenium layer, A method comprising repeating a cycle in which the steps (a), (b), and (c) described above are performed in this order.

2. The method according to claim 1, comprising the step of supplying a reducing gas to reduce the ruthenium layer oxidized by supplying the pretreatment gas or the etching gas into the processing container, wherein step (d) is performed before step (b) or after step (c) in the cycle.

3. The method according to claim 2, wherein the reducing gas includes at least one of hydrogen gas or carbon monoxide gas.

4. The method according to claim 1, wherein in the cycle, the substrate is heated to a temperature in the range of 100 to 250°C.

5. The method according to claim 1, wherein in the cycle, the pressure inside the processing container is adjusted to a range of 0.13 to 2666 Pa.

6. An apparatus for embedding ruthenium in a substrate having a recess, A processing container for housing the aforementioned substrate, A raw material gas supply mechanism that supplies a raw material gas containing a ruthenium compound into the processing container, The aforementioned processing container contains oxygen gas or ozone gas, and the ozone concentration is 0 g / m³. ３ Above, 150g / m ３ A pretreatment gas supply mechanism that supplies pretreatment gas of less than 50%, The aforementioned processing container contains ozone gas and has an ozone concentration of 150 g / m³. ３ Above, 400g / m ３ An etching gas supply mechanism that supplies the following etching gases, It comprises a control unit and, The control unit, An apparatus configured to output a control signal for repeatedly executing a cycle in which the following steps are performed in this order: (a) supplying the raw material gas into the processing container containing the substrate to form a ruthenium layer in the recess; (b) supplying the pre-treatment gas into the processing container to perform pre-treatment on the ruthenium layer; and (c) supplying the etching gas into the processing container to etch a portion of the ruthenium layer.

7. The processing container is equipped with a reducing gas supply mechanism for supplying reducing gas, The apparatus according to claim 6, wherein the cycle includes, before step (b) or after step (c), step (d) supplying the reducing gas into the processing vessel to reduce the ruthenium layer oxidized by supplying the pretreatment gas or the etching gas.

8. The apparatus according to claim 7, wherein the reducing gas includes at least one of hydrogen gas or carbon monoxide gas.

9. The mounting platform is configured to be able to move up and down between a processing position and a transfer position located below the processing position where the substrate is transferred to and from the outside. A surrounding member is provided to enclose the mounting platform at the processing position, and divides the inside of the processing container into an upper processing space and a lower space. An exhaust unit for vacuuming the processing space, A clamping ring is placed on the enclosure member when the mounting table is in the transfer position, and lifts up from the enclosure member when the mounting table is in the processing position, with its inner edge contacting the entire circumference of the peripheral edge of the substrate on the mounting table to prevent reaction gas from seeping into the back side of the substrate. The apparatus according to claim 6, comprising:

10. The aforementioned pretreatment gas supply mechanism and the aforementioned etching gas supply mechanism are configured by a common ozone gas supply mechanism. The apparatus according to claim 6, wherein the ozone gas supply mechanism includes an ozonizer configured to supply the pretreatment gas and the etching gas separately by adjusting the ozone concentration.

Images