Substrate processing apparatus, method of manufacturing semiconductor device, substrate processing method, and recording medium

Abstract

A substrate processing apparatus has: a first nozzle arranged corresponding to a first region in which a plurality of product substrates are arranged in a substrate arrangement region in which the plurality of substrates are arranged in a reaction tube, for supplying a hydrogen-containing gas into the reaction tube; a second nozzle arranged corresponding to the first region, for supplying an oxygen-containing gas into the reaction tube; a third nozzle arranged corresponding to a second region in which a dummy substrate or a heat insulator is arranged on a bottom opening side of the first region, for supplying a dilution gas into the reaction tube; and a control section configured to be able to control the supply of the hydrogen-containing gas from the first nozzle and the supply of the dilution gas from the third nozzle so that the hydrogen-containing gas concentration of the second region is lower than the hydrogen-containing gas concentration of the first region, the first nozzle being composed of a plurality of porous nozzles having injection holes corresponding to divided regions obtained by dividing regions including the first region but excluding the second region in an arrangement direction of the substrates.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus, a method for manufacturing a semiconductor device, a substrate processing method, and a recording medium. Background Technology

[0002] As a step in the manufacturing process of semiconductor devices (semiconductor equipment), there is a step in which an oxide film is formed on the surface of a substrate inside a reaction chamber. In this oxide film formation step, sometimes multiple substrates are loaded in the reaction chamber at intervals and processed simultaneously (see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-62528 Summary of the Invention

[0006] The different placement of multiple substrates within the reaction chamber can sometimes lead to variations in the thickness of the oxide film formed on the substrates (loading effect). To address this issue, it is necessary to maintain the uniformity of the oxidizing gas concentration within the reaction chamber. Therefore, adjusting the gas flow rate supplied to the reaction chamber has been considered, but further research is required to improve the uniformity of film thickness.

[0007] This disclosure was made in consideration of the above facts, and provides a technique that can improve the uniformity of oxide film thickness regardless of the substrate's placement.

[0008] According to one aspect of this disclosure, a substrate processing apparatus is provided, comprising: a reaction tube having a bottom opening for processing a plurality of substrates; a holding device for arranging the plurality of substrates within the reaction tube and holding them in a substrate arrangement region; a first nozzle disposed corresponding to a first region in the substrate arrangement region for arranging a plurality of product substrates, supplying hydrogen-containing gas into the reaction tube from a plurality of portions corresponding to the first region; a second nozzle disposed corresponding to the first region, supplying oxygen-containing gas into the reaction tube from a position corresponding to the first region; and a third nozzle disposed corresponding to a second region, supplying oxygen-containing gas into the reaction tube from a position corresponding to the second region. The device includes an internal supply of dilution gas, wherein the second region is located on the bottom opening side compared to the first region and is arranged for holding a dummy substrate or heat insulation body in the holding device; an exhaust port for venting gas from the reaction tube; and a control unit configured to control the supply of hydrogen-containing gas from the first nozzle and the supply of dilution gas from the third nozzle, such that the concentration of hydrogen-containing gas in the second region is lower than the concentration of hydrogen-containing gas in the first region. The first nozzle is composed of multiple porous nozzles, wherein the multiple porous nozzles have injection holes corresponding to the segmented regions formed by dividing the region including the first region but not the second region in the substrate arrangement direction.

[0009] Invention Effects

[0010] According to this disclosure, a technique can be provided that improves the uniformity of oxide film thickness regardless of the substrate's placement. Attached Figure Description

[0011] Figure 1 It is a three-dimensional perspective view showing the overall layout of the substrate processing apparatus.

[0012] Figure 2 This is a schematic cross-sectional view showing the structure of the heat treatment furnace in the substrate processing apparatus.

[0013] Figure 3 This is a schematic cross-sectional view showing the structure inside the reaction tube of the substrate processing apparatus.

[0014] Figure 4A This is a graph showing the distribution of atomic oxygen concentration in the reaction tube during the film-forming process of the first embodiment.

[0015] Figure 4B This is a graph showing the distribution of film thickness deviation in the reaction tube during the film formation process of the first embodiment.

[0016] Figure 5 This is a schematic cross-sectional view showing another structure inside the reaction tube of the substrate processing apparatus.

[0017] Figure 6 This is a schematic cross-sectional view showing the part of the reaction tube where the heat insulation component is installed.

[0018] Figure 7A This is a diagram showing the second embodiment, and also a diagram showing the atomic oxygen concentration distribution when a heat insulation member is arranged inside the reaction tube.

[0019] Figure 7A2 This is a diagram showing the second embodiment, and a graph showing the distribution of film thickness deviation when a heat insulation member is arranged inside the reaction tube.

[0020] Figure 7B This is a diagram showing the second embodiment, and also a diagram showing the atomic oxygen concentration distribution when no heat insulation component is provided in the reaction tube.

[0021] Figure 7B2 The diagram shows the second embodiment, and the graph shows the distribution of film thickness deviation when no heat insulation component is provided in the reaction tube.

[0022] Figure 8 This is a schematic cross-sectional view showing the structure inside the reaction tube in the third embodiment.

[0023] Figure 9 It is a graph showing the distribution of the arrangement of wafers, etc., and the film thickness deviation in the third embodiment.

[0024] Figure 10 This is a schematic cross-sectional view showing the structure inside the reaction tube in the third embodiment. Detailed Implementation

[0025] The inventors focused on the issue of varying film thicknesses arising from different arrangement positions of the dummy substrate or heat shield within the reaction tube, compared to other arrangement positions. Furthermore, since each product wafer has a larger film deposition area compared to the dummy substrate, the amount of atomic oxygen clusters consumed per unit time during film deposition differs between the areas arranged on the dummy substrate and the product wafer. Therefore, it was discovered that this difference results in different film thicknesses for product wafers arranged near the dummy substrate compared to those not arranged in this manner.

[0026] <First Embodiment>

[0027] Hereinafter, the first embodiment of the present disclosure will be described with reference to the accompanying drawings. Furthermore, the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not be consistent with reality. Additionally, the dimensional relationships and ratios of the elements may not be consistent between different drawings.

[0028] exist Figure 1 The diagram shows an overall view of the substrate processing apparatus S. The substrate processing apparatus S is configured to include: a wafer storage device 1 for mounting wafer cassettes; a boat 3; a wafer transfer unit (transfer machine) 2 for transferring wafers between the wafer cassette mounted on the wafer storage device 1 and the boat 3; a boat lifting unit (boat lifter) 4 for inserting and pulling the boat 3 into a heat treatment furnace 5; and a heat treatment furnace 5, which includes a heating unit (heater).

[0029] exist Figure 2 The diagram shows a schematic cross-sectional view of the structure of an exemplary heat treatment furnace 5. Figure 2 The "up" and "down" in this context refer to the vertical direction. In this embodiment, "up" and "down" refer to the vertical direction.

[0030] like Figure 2 As shown, the heat treatment furnace 5 has a resistance heater 9 as a heat source. The heater 9 is cylindrical and is vertically mounted by being supported on a heater base (not shown). Inside the heater 9, a reaction tube 10 is arranged concentrically with the heater 9. A processing chamber (reaction chamber) 4 for processing substrates is formed inside the reaction tube 10, configured to allow a boat 3, which serves as a substrate holding device, to be moved in. The boat 3 is configured to hold multiple wafers, such as silicon wafers, as multiple substrates in a generally horizontal state with gaps (substrate pitch) in multiple layers. In the following description, the uppermost wafer support position in the boat 3 is designated as #120, and the lowermost wafer support position is designated as #1. Furthermore, the wafer 6 held at the support position of the nth layer from the bottom of the boat 3 is designated as wafer #n. Furthermore, the wafer support positions mentioned here may include not only the positions for supporting wafer 6, but also the positions for supporting the dummy substrate and heat insulation plate described later. The spacing of the heat insulation plate support positions may be different from the spacing of the wafer support positions for supporting wafer 6.

[0031] A bottom opening 4A for inserting the boat dish 3 is formed below the reaction tube 10, and the bottom of the reaction tube 10 is open. The open portion of the reaction tube 10 (bottom opening 4A) is sealed by a sealing cap 13. A heat insulation cap 15 supporting the boat dish 3 from below is provided on the sealing cap 13. The heat insulation cap 15 is mounted on a rotation mechanism 14 by means of a rotation shaft (not shown) provided through the sealing cap 13. The rotation mechanism 14 is configured such that the wafer 6 supported on the boat dish 3 is rotated by rotating the heat insulation cap 12 and the boat dish 3 by means of the rotation shaft. If the heat insulation plate is arranged in a layer below the boat dish 3, the heat insulation cap 15 can be omitted.

[0032] A spray plate 12 is installed on the wall of the top 4B of the reaction tube 10, which is the closed end opposite to the bottom opening 4A. The top wall of the reaction tube 10 and the spray plate 12 form a buffer chamber 12a. An inactive gas supply nozzle 7 is connected to the upper part of the reaction tube 10, communicating with the buffer chamber 12a. This inactive gas supply nozzle 7 supplies inactive gas as a diluent gas to the wafer 6 from above in the reaction chamber 4. The gas injection port of the inactive gas supply nozzle 7 faces downwards, configured to spray inactive gas from above in the reaction chamber 4 downwards (along the wafer loading direction). The inactive gas supplied from the inactive gas supply nozzle 7 is conveyed into the buffer chamber 12a and supplied into the reaction chamber 4 via the spray plate 12. The spray plate 12 constitutes a gas supply port that supplies inactive gas in a spray pattern from one end of the wafer arrangement area where multiple wafers 6 are arranged to the other end. The spray plate 12 and the buffer chamber 12a constitute the top gas supply section.

[0033] As inert gases, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. More than one of these can be used as an inert gas. This also applies to other inert gases described later.

[0034] An inactive gas supply pipe 70, which serves as an inactive gas supply line, is connected to the inactive gas supply nozzle 7. On the inactive gas supply pipe 70, from the upstream side, an inactive gas supply source (not shown), an on / off valve 93, a mass flow controller (MFC) 92, which serves as a flow control unit (flow controller), and an on / off valve 91 are arranged in sequence.

[0035] A hydrogen-containing gas supply nozzle 8b is connected to the lower side of the reaction tube 10, penetrating the sidewall of the reaction tube 10, to supply hydrogen-containing gas from the side of the reaction chamber 4 to the wafer 6. The hydrogen-containing gas supply nozzle 8b is disposed in a region corresponding to the wafer arrangement region PW, which is the first region, that is, a cylindrical region in the reaction tube 10 that is opposite to and surrounds the wafer arrangement region PW. The hydrogen-containing gas supply nozzle 8b is composed of multiple (three in this embodiment) L-shaped nozzles of different lengths, which stand upright along the inner wall of the sidewall of the reaction tube 10.

[0036] Examples of hydrogen-containing gases include at least one of various hydrocarbon gases or mixtures thereof, such as hydrogen (H2), water vapor (H2O), ammonia (NH3), hydrazine (N2H4), diimine (N2H2), and N3H8.

[0037] In this embodiment, the wafer arrangement region PW is the area where the product wafer is mainly arranged, and as an example, it can be set as support positions #6 to #115. Furthermore, as an example, the upper dummy arrangement region SD-T on the top side, corresponding to the position where the side dummy substrate SD is supported by the holding member 3, can be set as support positions #116 to #120. Furthermore, as an example, the lower dummy arrangement region SD-U on the lower opening side, corresponding to the position where the side dummy substrate SD is supported by the holding member 3, can be set as support positions #1 to #5.

[0038] like Figure 3 As also shown, the multiple nozzles constituting the hydrogen-containing gas supply nozzle 8b have at least one injection hole at different positions along the wafer alignment direction. Hydrogen-containing gas is supplied to the reaction tube 10 from multiple segmented regions corresponding to the wafer alignment region PW and the upper dummy alignment region SD-T in the wafer alignment direction, thereby adjusting the hydrogen concentration in the reaction chamber 4 in the wafer alignment direction (vertical direction). With three segments and each nozzle having one injection hole, the gas is supplied to the reaction tube 10 from three locations. Furthermore, the hydrogen-containing gas supply nozzle 8b is positioned along the inner wall of the reaction tube 10 on the side closer to the sidewall than to the wafer 6. The hydrogen-containing gas supply nozzle 8b constitutes the first nozzle.

[0039] The upper surfaces of the tips of the multiple nozzles constituting the hydrogen-containing gas supply nozzle 8b are respectively sealed, and at least one gas injection hole is provided on the side of the tip of each nozzle, more preferably multiple gas injection holes. Figure 3In the diagram, arrows extending from the hydrogen gas supply nozzle 8b toward the wafer 6 indicate the injection direction of the hydrogen gas from each gas injection hole, and the root of each arrow represents the gas injection hole. That is, the gas injection holes face the wafer 6, configured to inject hydrogen gas from the side of the reaction chamber 4 in a horizontal direction (along the direction along the main surface of the wafer) toward the wafer 6. A nozzle having multiple gas injection holes along the substrate arrangement direction is a type of multi-hole nozzle. Furthermore, in this embodiment, the longest nozzle (hereinafter referred to as "hydrogen gas supply nozzle 8b-1") has 5 gas injection holes, the second longest nozzle (hereinafter referred to as "hydrogen gas supply nozzle 8b-2") has 5 gas injection holes, and the third longest nozzle (hereinafter referred to as "hydrogen gas supply nozzle 8b-3") has 7 gas injection holes. These multiple (17 in this embodiment) gas injection holes are arranged at equal intervals in each nozzle.

[0040] The injection holes formed by the hydrogen gas supply nozzles 8b-1, 8b-2, and 8b-3 are sequentially designated as injection holes H4 to H20, starting from the bottom opening 4A side. In this embodiment, as an example, such as... Figure 3 As shown, the injection holes H16 to H20 of the hydrogen gas supply nozzle 8b-1 are formed corresponding to the highest segmented region, the injection holes H11 to H15 of the hydrogen gas supply nozzle 8b-2 are formed corresponding to the second highest segmented region, and the injection holes H4 to H10 of the hydrogen gas supply nozzle 8b-3 are formed corresponding to the third highest segmented region. In this way, the hydrogen gas supply nozzles 8b-1, 8b-2, and 8b-3 share the gas supply to the segmented regions. Furthermore, product wafers can be arranged at constant intervals in the segmented regions. Moreover, it is also possible to arrange all injection holes H4 to H20 at equal intervals, and set the number of product wafers allocated to each injection hole to a constant number greater than 1. The height of the segmented regions (length in the wafer arrangement direction) is arbitrary and can be different for each region, or the heights of the segmented regions (i.e., the highest and second highest segmented regions) can be equal, except for the lowest segmented region. For example, the same number of substrates as the number of substrates housed in one wafer cassette (25 sheets) can be arranged in these segmented regions.

[0041] A hydrogen gas supply pipe 80b, serving as a hydrogen gas supply line, is connected to the hydrogen gas supply nozzle 8b. The hydrogen gas supply pipe 80b consists of multiple (three in this embodiment) pipes, each connected to one of the multiple nozzles constituting the hydrogen gas supply nozzle 8b. On the hydrogen gas supply pipe 80b, from the upstream side, are sequentially arranged a hydrogen gas supply source (not shown), an on / off valve 96b, a mass flow controller (MFC) 95b serving as a flow control unit (flow controller), and an on / off valve 94b. Furthermore, the on / off valve 96b, the mass flow controller 95b, and the on / off valve 94b are respectively installed on the multiple pipes constituting the hydrogen gas supply pipe 80b, enabling independent control of the hydrogen gas flow rate for each of the multiple nozzles constituting the hydrogen gas supply nozzle 8b.

[0042] Furthermore, to balance the hydrogen-containing gas ejection from the injection holes H4 to H20, it is preferable to set the ejection flow rate of each of the injection holes H4 and H5 to be relatively high, approximately 1.3 to 2.1 times that of the injection holes H6 to H10. As an example, it is possible to supply 168 sccm from H4 and H5 respectively, and 100 sccm from H6 to H20 respectively.

[0043] In this embodiment, the ejection flow rate of equally spaced injection holes is controlled, but it is also possible to control the flow rate per unit length by monotonically increasing such openings (injection holes) or by varying the intervals.

[0044] A non-reactive gas supply nozzle 8c, shorter than the hydrogen-containing gas supply nozzle 8b-3, is connected to the lower side of the reaction tube 10, penetrating the sidewall of the reaction tube 10. The non-reactive gas supply nozzle 8c is disposed in a cylindrical region located on the bottom opening 4A side relative to the wafer alignment region PW, opposite to and surrounding the region where the dummy substrate or heat insulation body held to the boat 3 is arranged (hereinafter referred to as the "lower dummy alignment region SD-U"). The non-reactive gas supply nozzle 8c forms the third nozzle.

[0045] The upper surface of the tip of the inactive gas supply nozzle 8c is closed, and at least one gas injection hole (two in this embodiment) is provided on the side of the nozzle tip. Figure 3 In the diagram, arrows extending downwards from the inactive gas supply nozzle 8c towards the dummy arrangement region SD-U indicate the injection direction of the inactive gas from each gas injection hole, with the root of each arrow representing the respective gas injection hole. That is, the gas injection holes face downwards towards the dummy arrangement region SD-U, configured to inject inactive gas as a dilution gas from the side of the reaction chamber 4 in a horizontal direction (along the main surface of the wafer) towards the dummy wafer or heat shield.

[0046] The two injection holes formed by the inactive gas supply nozzle 8c are designated as injection holes H1 and H2, starting from the lower opening 4A side. Let the largest interval between adjacent injection holes H4 to H20 be defined as interval D. M Let the interval between the injection holes H1 and H2 be set as interval D. 1-2 The interval D between injection holes H2 and H4 is... 2-4 Comparison interval D M and interval D 1-2 Either one is large. As an example, the interval D... 2-4 It is interval D M Twice that. In other words, it can be considered that there is a non-jet part H3 without holes at a position M away from the jet holes H2 and H4.

[0047] An inactive gas supply pipe 80c, which serves as an inactive gas supply line, is connected to an inactive gas supply nozzle 8c. On the inactive gas supply pipe 80c, from the upstream side, an inactive gas supply source (not shown), an on / off valve 96c, a mass flow controller (MFC) 95c, which serves as a flow control unit (flow controller), and an on / off valve 94c are arranged in sequence.

[0048] At the lower side of the reaction tube 10, an oxygen-containing gas supply nozzle 8a is connected through the side wall of the reaction tube 10, supplying oxygen-containing gas (oxidizing gas) from the side of the reaction chamber 4 to the wafer 6. The oxygen-containing gas supply nozzle 8a is positioned in a region corresponding to the wafer alignment region PW, that is, a cylindrical region within the reaction tube 10 that is opposite to and surrounds the wafer alignment region PW. The oxygen-containing gas supply nozzle 8a is an L-shaped nozzle, standing upright along the inner wall of the side wall of the reaction tube 10. The oxygen-containing gas supply nozzle 8a is positioned along the inner wall on the side closer to the side wall of the reaction tube 10 than to the wafer 6. The oxygen-containing gas supply nozzle 8a constitutes the second nozzle.

[0049] As an oxygen-containing gas, it is possible to use at least one of oxygen (O2), ozone (O3), hydrogen peroxide (H2O2), nitric oxide (NO), or a mixture thereof.

[0050] The upper surface of the tip of the oxygen-containing gas supply nozzle 8a is sealed, and a gas injection hole is provided on the side of the tip of the nozzle. Figure 3In the diagram, arrows extending from the oxygen-containing gas supply nozzle 8a toward the wafer 6 indicate the injection direction of the oxygen-containing gas from each gas injection hole, and the root of each arrow represents the respective gas injection hole. That is, the gas injection holes face the wafer side, configured to inject oxygen-containing gas from the side of the reaction chamber 4 toward the wafer 6 in a horizontal direction (along the direction along the main surface of the wafer). Furthermore, in this embodiment, corresponding injection holes are provided that correspond one-to-one with the wafer 6, that is, corresponding injection holes are provided at the same spacing as the support spacing of the wafer formed in the boat 3. The injection holes of the oxygen-containing gas supply nozzle 8a, the hydrogen-containing gas supply nozzles 8b-1, 8b-2, 8b-3, and the inactive gas supply nozzle 8c can be arranged to open horizontally toward the center of the wafer 6, that is, the central axis of the reaction tube 10.

[0051] An oxygen-containing gas supply pipe 80a, which serves as an oxygen-containing gas supply pipeline, is connected to an oxygen-containing gas supply nozzle 8a. On the oxygen-containing gas supply pipe 80a, from the upstream side, an oxygen-containing gas supply source (not shown), an on / off valve 96a, a mass flow controller (MFC) 95a, which serves as a flow control unit (flow controller), and an on / off valve 94a are arranged in sequence.

[0052] A gas exhaust port 11 for venting the processing chamber is provided on the lower side of the reaction tube 10 (located below the lower dummy arrangement area SD-U). A gas exhaust pipe 50, serving as a gas exhaust line, is connected to the gas exhaust port 11. On the gas exhaust pipe 50, starting from the upstream side, an APC (Automatic Pressure Controller) 51, serving as a pressure adjustment unit (pressure controller), and a vacuum pump 52, serving as an exhaust unit (exhaust device), are sequentially arranged. The exhaust system mainly consists of the gas exhaust port 11, the gas exhaust pipe 50, the APC 51, and the vacuum pump 52.

[0053] The various components of the substrate processing apparatus, including the resistance heater 9, mass flow controllers 92, 95a, 95b, 95c, on / off valves 91, 93, 94a, 94b, 96a, 96b, APC 51, vacuum pump 52, and rotating mechanism 14, are connected to a controller 100, which serves as a control unit (control unit). The controller 100 is configured to control the environment and operation of each component of the substrate processing apparatus, including the flow rates of hydrogen gas supplied from the hydrogen gas supply nozzle 8b, oxygen gas supplied from the oxygen gas supply nozzle 8a, inactive gas supplied from the spray plate 12, inactive gas supplied from the inactive gas supply nozzle 8c, and the temperature and pressure within the reaction tube 10. The controller 100 is configured as a computer equipped with a CPU, memory, HDD, and other storage devices, an FPD, and input devices such as a keyboard and mouse.

[0054] Next, a method for performing oxidation treatment on a wafer 6, which serves as a substrate, using the heat treatment furnace 5 of the substrate processing apparatus S described above as a process in the manufacture of a semiconductor device will be described. Furthermore, in the following description, the operation of each component constituting the substrate processing apparatus S is controlled by the controller 100.

[0055] First, a batch (e.g., 100 wafers) of wafers 6 are transferred to the wafer arrangement region PW of the boat 3 using a substrate transfer machine (wafer loading). Additionally, side dummy substrates SD are placed in the upper dummy arrangement region SD-T and the lower dummy arrangement region SD-U of the boat 3. Each side dummy substrate SD has a smaller film deposition area compared to the wafers 6. The boat 3, containing the wafers 6 and the side dummy substrates SD, is then moved into the reaction chamber 4 of the heat treatment furnace 5, which is maintained under heat by the heater 9 (boat loading). The reaction tube 10 is then sealed with a sealing cap 13. Next, a vacuum pump 52 is used to evacuate the reaction tube 10, and the vacuum is controlled by an APC 51 to ensure that the pressure inside the reaction tube 10 (furnace pressure) is a predetermined processing pressure lower than atmospheric pressure. The boat 3 is rotated at a predetermined speed using a rotating mechanism 14. Furthermore, the temperature inside the reaction chamber 4 (furnace temperature) is controlled to rise and reach a predetermined processing temperature.

[0056] Furthermore, inactive gas is supplied into the reaction chamber 4 from inactive gas supply nozzles 7 and 8c. That is, the on / off valves 91 and 93 are opened, thereby supplying inactive gas, whose flow rate is controlled by the mass flow controller 92, into the reaction chamber 4 via the inactive gas supply pipe 70 from the inactive gas supply nozzle 7. The inactive gas supplied from the inactive gas supply nozzle 7 is supplied into the reaction chamber 4 in a spray pattern through the buffer chamber 12a and by means of the spray plate 12.

[0057] In addition, oxygen-containing gas, hydrogen-containing gas, and inert gas are supplied to the reaction chamber 4 from oxygen-containing gas supply nozzle 8a, hydrogen-containing gas supply nozzle 8b, and inert gas supply nozzle 8c, respectively. Specifically, valves 94a and 96a are opened, allowing oxygen-containing gas (flow rate controlled by mass flow controller 95a) to be supplied to the reaction chamber 4 via oxygen-containing gas supply pipe 80a from oxygen-containing gas supply nozzle 8a. Similarly, valves 94b and 96b are opened, allowing hydrogen-containing gas (flow rate controlled by mass flow controller 95b) to be supplied to the reaction chamber 4 via hydrogen-containing gas supply pipe 80b from hydrogen-containing gas supply nozzle 8b. Finally, valves 94c and 96c are opened, allowing inert gas (flow rate controlled by mass flow controller 95c) to be supplied to the reaction chamber 4 via inert gas supply pipe 80c from inert gas supply nozzle 8c. Oxygen gas supplied from oxygen gas supply nozzle 8a and hydrogen gas supplied from hydrogen gas supply nozzle 8b are supplied into reaction chamber 4 from multiple locations (multiple injection holes) in the region corresponding to the wafer arrangement region.

[0058] Thus, oxygen-containing gas and hydrogen-containing gas are supplied from injection holes (ejection holes) corresponding to the wafer arrangement regions within the reaction chamber 4, and mix within the reaction chamber. Additionally, inactive gas is supplied from one end side (top side) corresponding to the wafer arrangement regions within the reaction chamber 4, and also from multiple injection holes corresponding to the lower dummy arrangement region SD-U within the reaction chamber 4, which is located below the wafer arrangement region PW. The oxygen-containing gas and hydrogen-containing gas supplied to the reaction chamber 4 flow down within the reaction chamber 4 together with the inactive gas and are exhausted from the gas exhaust port 11 located on the bottom opening 4A side of the wafer arrangement region PW. The mixing of oxygen-containing gas and hydrogen-containing gas injected towards the center of the wafer from the oxygen-containing gas supply nozzle 8a and the hydrogen-containing gas supply nozzle 8b, and the generation of oxide seeds, can occur in any of the annular spaces between the arranged wafers and between the outer periphery of the wafer and the reaction tube 10. At this point, regarding the proportion of gas molecules moving from the edge of the wafer towards the center, the proportion of diffusion and convection is greater for oxygen-containing gases than for hydrogen-containing gases. In other words, hydrogen-containing gases diffuse more easily, and even with injection holes spaced at intervals different from the wafer spacing, it is difficult to generate a concentration gradient near the center of the wafer.

[0059] At this point, oxygen-containing gas and hydrogen-containing gas mix and react in the depressurized reaction chamber 4, which has been heated by heater 5, to generate H2O. However, intermediate products such as H, O, and OH, which are intermediate products of the combustion reaction, also remain at a specified equilibrium concentration, among which the concentration of atomic oxygen O is relatively high. As described in the specification filed by the applicant under Japanese Patent Application No. 2008-133772, the intermediate product that directly contributes to the formation of the oxide film is atomic oxygen O. Other intermediate products, H2O, and the raw material gas itself are not dominant in the surface reactions related to oxide film growth. That is, atomic oxygen O in the intermediate products generated by the reaction of oxygen-containing gas and hydrogen-containing gas acts as a reaction seed (oxidation seed), thereby performing oxidation treatment on wafer 6 and forming a silicon oxide film (SiO2 film) as an oxide film on the surface of wafer 6. Furthermore, the concentration of atomic oxygen O is a convex function of the supply ratio of oxygen-containing gas to hydrogen-containing gas. The concentration of atomic oxygen O decreases regardless of whether the ratio is lower or higher than the maximum point. The technique in this example, which adjusts the supply amount from each injection hole of the hydrogen-containing gas supply nozzle 8b, can be appropriately applied in a hydrogen-deficient state relative to the maximum point. In a hydrogen-deficient state, the oxygen-containing gas itself can also act as a diluent gas.

[0060] Examples of the processing conditions (oxidation treatment conditions) at this time are as follows:

[0061] Processing temperature (indoor processing temperature): 500~1000℃

[0062] Processing pressure (processing room pressure): 1~500Pa

[0063] The oxygen-containing gas supply flow rate from oxygen-containing gas supply nozzle 8a is 3.0–6.0 slm, and the hydrogen-containing gas supply flow rate from hydrogen-containing gas supply nozzle 8b (total flow rate) is 1500–3000 sccm.

[0064] The inactive gas supply flow rate from the inactive gas supply nozzle 8c is 1.0–1.5 slm.

[0065] The flow rate of the inactive gas supplied from spray plate 12 is 400–1000 sccm.

[0066] The various processing conditions are kept constant at values ​​within their respective ranges to perform oxidation on wafer 6.

[0067] Once the oxidation process of wafer 6 is complete, the supply of oxygen-containing gas and hydrogen-containing gas to the reaction chamber 4 is stopped, and the reaction tube 10 is evacuated and purged with inactive gases to remove residual gases. Then, the furnace pressure is restored to atmospheric pressure, and the furnace temperature is lowered to the specified temperature. Next, the boat 3 supporting the processed wafer 6 is removed from the reaction chamber 4 (boat unloading), and the boat 3 is left in a designated position until all the processed wafers 6 supported on it have cooled down. If the processed wafers 6 held on the boat 3 cool to the specified temperature, they are retrieved using a substrate transfer machine (wafer discharge). This completes the series of processes for oxidizing wafer 6.

[0068] The purpose of this disclosure will be explained below.

[0069] In this embodiment, side dummy substrates SD are mounted on the upper dummy arrangement region SD-T and the lower dummy arrangement region SD-U of the boat 3. Therefore, during the oxide film formation process, the consumption of atomic oxygen groups in these regions is low. Thus, by controlling the flow rates of the hydrogen-containing gas supplied from the hydrogen-containing gas supply nozzle 8b and the inactive gas supplied from the inactive gas supply nozzle 8c, the hydrogen-containing gas concentration in the lower dummy arrangement region SD-U is lower than the hydrogen-containing gas concentration in the wafer arrangement region PW.

[0070] exist Figure 4A The diagram shows the flow rate of the gas supplied from each nozzle to the reaction tube 10 and the concentration distribution of atomic oxygen. Figure 4B The graph shows the film thickness (vertical axis) at support position #N (horizontal axis). These graphs were obtained through simulation of the reaction tube 10 under conditions of a processing pressure of 55 Pa and a temperature of 850 °C. At this time, inactive gas is injected at 1.2 slm from injection holes H1 and H2, hydrogen-containing gas is injected at 200 sccm from injection hole H4, hydrogen-containing gas is injected at 135 sccm from injection hole H5, hydrogen-containing gas is injected at 100 sccm from injection holes H6 to H10 respectively, hydrogen-containing gas is injected at a total of 570 sccm from injection holes H11 to H15, hydrogen-containing gas is injected at a total of 400 sccm from injection holes H16 to H20, and inactive gas is injected at 600 sccm from spray plate 12. Additionally, oxygen-containing gas is injected at a total of 5.0 slm from oxygen-containing gas supply nozzle 8a.

[0071] The atomic oxygen concentration in the reaction tube is substantially uniform in the wafer arrangement region PW, and the difference at the boundary portion between the wafer arrangement regions PW is also small. In the lower dummy arrangement region SD-U where the consumption of atomic oxygen is small, the concentration becomes higher, but the inert gas ejected by the inert gas supply nozzle 8c suppresses the diffusion of the atomic oxygen component from the lower dummy arrangement region SD-U to the wafer arrangement region PW. In addition, the film thickness of the formed oxide film is also within ±0.6% in the entire support position.

[0072] Thus, it is possible to reduce the loading effect in which the film thickness of the oxide film formed on the wafer 6 varies depending on the support position.

[0073] In addition, in the present embodiment, the side dummy substrate SD is loaded in the upper dummy arrangement region SD-T, but as Figure 5 shown, it may also be a structure in which the wafers 6 are aligned upward (Japanese: upper packing) and the side dummy substrate SD is not arranged. In this case, there is no upper dummy arrangement region SD-T, and the end portion on the top 4B side becomes the wafer arrangement region PW.

[0074] <Second Embodiment>

[0075] Next, the second embodiment will be described. In this embodiment, it is different from the first embodiment in that the heat insulating member DP is used, and the other configurations are the same as those in the first embodiment.

[0076] As Figure 6 shown, the side dummy substrate SD disposed in the lower dummy arrangement region SD-U is covered with the heat insulating member DP. As the heat insulating member, a quartz plate can be used. The heat insulating member DP has a disk-shaped portion DP1 that covers the plate surface of the side dummy substrate SD and a cylindrical portion P2 that is connected to the disk-shaped portion DP1 on the lower side of the disk-shaped portion DP1.

[0077] In FIG. 7, the distribution of the atomic oxygen concentration near the lower dummy arrangement region SD-U during the oxide film formation process is shown in shades. The darker the gray scale, the higher the atomic oxygen concentration. Figure 7A is the case where the heat insulating member DP is arranged, Figure 7B is the case where the heat insulating member DP is not arranged. In addition, Figure 7A2 represents the deviation of the film thickness in the case where the heat insulating member DP is arranged, Figure 7B2 represents the deviation of the film thickness in the case where the heat insulating member DP is not arranged. In the case where the heat insulating member DP is arranged, the diffusion of the atomic oxygen component from the lower dummy arrangement region SD-U to the wafer arrangement region PW is suppressed. And the deviation of the film thickness of the oxide film formed on the wafer 6 is ±0.4% in the case where the heat insulating member DP is arranged, and is suppressed compared with ±0.9% in the case where the heat insulating member DP is not arranged.

[0078] Therefore, it can reduce the loading effect of different film thicknesses depending on the support position of wafer 6, and further improve the uniformity of film thickness.

[0079] Furthermore, in this embodiment, an example of covering the dummy substrate SD with the heat insulation member DP has been described, but the heat insulation member DP can also be used to cover the heat insulation board instead of the dummy substrate SD. That is, the heat insulation board can also be arranged in the lower dummy arrangement area SD-U, and the heat insulation board can be covered by the heat insulation member DP.

[0080] <Third Implementation>

[0081] Next, the third embodiment will be described. In this embodiment, the case where there are relatively few product wafers 6 placed on the boat 3 and a filler substrate FD is used will be described. The configuration of the substrate processing apparatus S, the heat treatment furnace 5, the reaction tube 10, and various gas supply nozzles is the same as in the first embodiment.

[0082] This embodiment is based on the case of processing a relatively small batch of any number of product wafers 6, such as processing 25, 50, or 75 wafers 6.

[0083] exist Figure 8 The diagram shows the arrangement of the side dummy substrate SD, wafer 6 (product wafer), and filling dummy substrate FD within the reaction tube 10.

[0084] Wafer 6 is arranged in the wafer arrangement area PW with top-side alignment. A large-area dummy LAD is disposed on the bottom opening 4A side of wafer 6. The large-area dummy LAD is a dummy substrate with a surface area approximately 1.5 times (1.2 to 1.8 times) that of the product wafer 6. Approximately 10 large-area dummy LADs are arranged in the boat 3.

[0085] A filling dummy substrate FD is arranged between the large-area dummy LAD group and the side dummy substrate SD arranged in the lower dummy arrangement region SD-U. The filling dummy substrate FD is used to fill the space of the unsupported wafer 6 in the buried vessel 3.

[0086] As in this embodiment, by filling a large area of ​​dummy LAD between the product wafer group 6 and the dummy substrate FD group, the influence of residual atomic oxygen components in the area of ​​the dummy substrate FD side can be suppressed.

[0087] exist Figure 9 The configurations for processing 25 (A), 50 (B), and 75 (C) wafers are shown respectively. Figure 8The left side is the top 4B side of reaction tube 10, and the right side is the bottom opening 4A side. Figure 9 The graph shows the film thickness (vertical axis) at support position #N (horizontal axis) when film deposition was performed with this arrangement. Regardless of the product wafer count of 6 sheets, the film thickness distribution was suppressed within ±1.0%.

[0088] <Fourth Implementation>

[0089] Next, the fourth embodiment will be described. In this embodiment, as... Figure 10 As shown, there is no structure for supplying inactive gas on the top 4B side of the reaction tube 10. Furthermore, the injection hole of the oxygen-containing gas supply nozzle 8a is not located in the portion corresponding to the dummy arrangement area SD-T.

[0090] In the above structure, hydrogen-containing gas is supplied to the upper dummy arrangement region SD-T, while oxygen-containing gas is not supplied. As a result, the oxygen-containing gas concentration in the upper dummy arrangement region SD-T decreases, becoming a hydrogen-rich state relative to the aforementioned maximum point, effectively reducing the atomic oxygen concentration. Furthermore, when, for example, H2 gas is used as the hydrogen-containing gas, the easily diffusing nature of H2 gas also affects the film-forming rate under hydrogen-deficient conditions where the supply amount of hydrogen-containing gas dominates. Even if hydrogen-containing gas is not supplied locally to the upper dummy arrangement region SD-T, or even if the supply amount of oxygen-containing gas is doubled, the atomic oxygen concentration can hardly be reduced.

[0091] In the upper dummy arrangement region SD-T, the concentration of atomic oxygen is relatively reduced, thereby decreasing the impact of the remaining atomic oxygen components on wafer 6. This reduces the film thickness distribution and improves the loading effect. This method can be appropriately utilized even when the number of wafers processed changes while the height of the upper dummy arrangement region SD-T remains constant.

[0092] The above-described forms and variations can be appropriately combined and used. The processing steps and conditions can be set to be the same as those in the above-described forms and variations. In addition to being appropriately applied to the oxidation of silicon-based substrates such as Si, SiC, and SiGe, the technology disclosed herein can also be widely applied to the deposition of films requiring oxidizing materials, such as metal oxide films.

[0093] Explanation of reference numerals in the attached figures

[0094] 3: Boat-shaped dish (keeping vessel)

[0095] 6: Wafer (substrate)

[0096] 4A: Bottom opening

[0097] 4B: Top

[0098] 10: Reaction tube

[0099] 8a: Oxygen-containing gas supply nozzle (No. 2)

[0100] 8b: Hydrogen gas supply nozzle (No. 1)

[0101] 8c: Inactive gas supply nozzle (3rd nozzle)

[0102] PW: Wafer alignment region (Region 1)

[0103] SD-U: Lower virtual arrangement area (region 2)

[0104] SD-T: Virtual arrangement region (region 3)

[0105] SD: Side-mounted dummy substrate (dummy substrate)

[0106] 11: Gas exhaust port (exhaust port)

[0107] 100: Controller (Control Unit)

[0108] 8b-1, 8b-2, 8b-3b: Hydrogen-containing gas supply nozzles (multi-hole nozzles).

Claims

1. A substrate processing apparatus comprising: A reaction tube having a bottom opening for the entry and exit of multiple substrates for processing the multiple substrates; A holding device that holds the plurality of substrates in a substrate arrangement region within the reaction tube; The first nozzle is configured corresponding to the first region in the substrate arrangement region for arranging multiple product substrates, and supplies hydrogen-containing gas into the reaction tube from multiple locations corresponding to the first region. A second nozzle, configured corresponding to the first region, supplies oxygen-containing gas into the reaction tube from a position corresponding to the first region; A third nozzle, configured corresponding to the second region, supplies dilution gas into the reaction tube from a position corresponding to the second region, wherein... The second region is located on the bottom opening side compared to the first region, and is arranged for the dummy substrate or heat insulation body to be held in the holding device; An exhaust port is used to vent air from the reaction tube; and The control unit is configured to control the supply of hydrogen-containing gas from the first nozzle and the supply of dilution gas from the third nozzle, such that the concentration of hydrogen-containing gas in the second region is lower than the concentration of hydrogen-containing gas in the first region. The first nozzle is composed of multiple multi-hole nozzles, wherein the multiple multi-hole nozzles have spray holes corresponding to the segmented regions formed by dividing the region including the first region but not the second region in the arrangement direction of the substrate.

2. The substrate processing apparatus according to claim 1, wherein, The vertical distance between the upper spray hole of the third nozzle and the lower spray hole of the first nozzle is greater than the distance between any of the adjacent spray holes of the first nozzle.

3. The substrate processing apparatus according to claim 1, wherein, The reaction tube has a top gas supply section, which is located at the top of the closed end opposite to the bottom opening, and supplies inactive gas into the reaction tube.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The nozzle of the plurality of porous nozzles, having the nozzle closest to the bottom opening, has a nozzle or spacing that monotonically increases in ejection amount per unit length from the top side of the reaction tube toward the bottom opening.

5. The substrate processing apparatus according to any one of claims 1 to 3, wherein, It also includes a gas supply port for supplying dilution gas into the reaction tube from the top side. The exhaust port is located below the first region.

6. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The segmented area is divided by arranging 25 or multiples of 25 substrates in the segmented area.

7. The substrate processing apparatus according to any one of claims 1 to 3, wherein, It also has a cover that covers multiple dummy substrates or heat insulation bodies in the second region.

8. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The diluting gas is an inactive gas or an oxygen-containing gas.

9. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The injection holes of the first nozzle and the second nozzle are configured such that, for the proportion of gas molecules moving from the edge of the substrate toward the center, the proportion of diffusion and the proportion of convection, the proportion of convection of oxygen-containing gas is greater than the proportion of convection of hydrogen-containing gas.

10. The substrate processing apparatus according to any one of claims 1 to 3, wherein, At least one of the injection holes of the first nozzle and the second nozzle is open in a direction parallel to the substrate.

11. The substrate processing apparatus according to any one of claims 1 to 3, wherein, At least one of the injection holes of the first nozzle and the second nozzle opens toward the center of the substrate.

12. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The number of injection holes in the first nozzle is less than the number of injection holes in the second nozzle.

13. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The injection holes of the second nozzle are respectively provided corresponding to the plurality of product substrates disposed in the first region.

14. The substrate processing apparatus according to claim 3, wherein, The second nozzle has spray holes that correspond one-to-one with the product substrate arranged in the first region. The injection hole is not configured to correspond to the third region in the substrate arrangement region that is closest to the top side of the reaction tube and is used for the arrangement of multiple dummy substrates. The injection holes of the first nozzle are configured corresponding to the third region.

15. The substrate processing apparatus according to claim 9, wherein, The second nozzle has spray holes that correspond one-to-one with the product substrate arranged in the first region. The injection hole is not configured to correspond to the third region in the substrate arrangement region that is closest to the top side of the reaction tube and is used for the arrangement of multiple dummy substrates. The injection holes of the first nozzle are configured corresponding to the third region.

16. A method for manufacturing a semiconductor device, comprising the following steps: The process of moving multiple substrates from the bottom opening into the reaction tube and holding them in the substrate arrangement area; and The process involves supplying hydrogen-containing gas into the reaction tube from a first nozzle, which is configured at least corresponding to a first region in the substrate arrangement region for arranging multiple product substrates, and from multiple locations corresponding to the first region; supplying oxygen-containing gas into the reaction tube from a second nozzle, which is configured corresponding to the first region, and from a location corresponding to the first region; and supplying dilution gas into the reaction tube from a third nozzle, which is configured corresponding to a second region located closer to the bottom opening side than the first region and for arranging dummy substrates or heat insulation elements, and from a location corresponding to the second region, and processing the substrate. In the process of processing the substrate, the supply of hydrogen-containing gas from the first nozzle and the supply of dilution gas from the third nozzle are controlled such that the concentration of hydrogen-containing gas in the second region is lower than the concentration of hydrogen-containing gas in the first region. The hydrogen-containing gas is supplied from the first nozzle, which consists of multiple porous nozzles, wherein, The multi-hole nozzle has injection holes corresponding to the segmented regions formed by dividing the region including the first region but not the second region.

17. A substrate processing method comprising the following steps: The process of moving multiple substrates from the bottom opening into the reaction tube and holding them in the substrate arrangement area; and The process involves supplying hydrogen-containing gas into the reaction tube from a first nozzle, which is configured at least corresponding to a first region in the substrate arrangement region for arranging multiple product substrates, and from multiple locations corresponding to the first region; supplying oxygen-containing gas into the reaction tube from a second nozzle, which is configured corresponding to the first region, and from a location corresponding to the first region; and supplying dilution gas into the reaction tube from a third nozzle, which is configured corresponding to a second region located closer to the bottom opening side than the first region and for arranging dummy substrates or heat insulation elements, and from a location corresponding to the second region, and processing the substrate. In the process of processing the substrate, the supply of hydrogen-containing gas from the first nozzle and the supply of dilution gas from the third nozzle are controlled such that the concentration of hydrogen-containing gas in the second region is lower than the concentration of hydrogen-containing gas in the first region. The hydrogen-containing gas is supplied from the first nozzle, which consists of multiple porous nozzles, wherein, The multi-hole nozzle has injection holes corresponding to the segmented regions formed by dividing the region including the first region but not the second region.

18. A recording medium, which is a computer-readable recording medium, recording a program that enables a substrate processing apparatus to perform a process using a computer, the process comprising the following steps: The steps of moving multiple substrates into the reaction tube from the bottom opening and holding them in the substrate arrangement area; and The steps include: supplying hydrogen-containing gas into the reaction tube from a first nozzle, which is configured at least corresponding to a first region in the substrate arrangement region for arranging multiple product substrates, and from multiple locations corresponding to the first region; supplying oxygen-containing gas into the reaction tube from a second nozzle, which is configured corresponding to the first region, and from a location corresponding to the first region; and supplying dilution gas into the reaction tube from a third nozzle, which is configured corresponding to a second region located closer to the bottom opening side than the first region and for arranging dummy substrates or heat insulation bodies, and from a location corresponding to the second region; and processing the substrate. In the step of processing the substrate, the supply of hydrogen-containing gas from the first nozzle and the supply of dilution gas from the third nozzle are controlled such that the concentration of hydrogen-containing gas in the second region is lower than the concentration of hydrogen-containing gas in the first region. The hydrogen-containing gas is supplied from the first nozzle, which consists of multiple porous nozzles, wherein, The multi-hole nozzle has injection holes corresponding to the segmented regions formed by dividing the region including the first region but not the second region.

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