JP2009245984A - Substrate processing apparatus and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the thickness of an oxide film from fluctuating by a large amount due to the concentration of hydrogen varying at substrate arrangement positions, when a plurality of substrates are subject to isotropic oxidization, and to manufacture a semiconductor device with high quality. <P>SOLUTION: The substrate processing apparatus is provided with: a reaction tube; a heating source for heating the reaction tube; a retainer for arranging and holding a plurality of substrates in the reaction tube; an oxygen-containing gas supply line to supply an oxygen-containing gas into the reaction tube from an upstream side than a substrate arrangement region; a hydrogen-containing gas supply line to supply a hydrogen-containing gas into the reaction tube from a plurality of points of a corresponding region to the substrate arrangement region; a discharge line to discharge a gas in the reaction tube; a vacuum pump to evacuate the reaction tube via a discharge line; and a pressure control section to control pressure in the reaction tube so that the pressure in the reaction tube may be lower an atmospheric pressure. The hydrogen-containing gas supply line includes a plurality of independent nozzles with different lengths, wherein each of the nozzles is provided with at least two or more gas-jetting holes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for processing a substrate and a method for manufacturing a semiconductor device including a step of processing a substrate using the substrate processing apparatus, and more particularly to an oxidation apparatus for oxidizing a surface of a substrate and the oxidation apparatus. The present invention relates to a method for manufacturing a semiconductor device including a step of oxidizing a substrate.

  In the process of directly oxidizing the surface of a Si substrate (wafer), which is exposed during the manufacturing process of a semiconductor device (device), where different Si crystal planes are exposed, the conventional oxidation technology depends on the crystal plane. As a result of the different oxidation rates, oxide films with different film thicknesses are formed on the substrate, and there is a problem that the characteristics vary depending on the location on the substrate.

The process of exposing different Si crystal planes on the substrate includes, for example, isolation between elements known as Shallow Trench Isolation (STI) and a process of forming a vertical MOS transistor in which the Si substrate is dug. By forming the groove by dry etching, different plane orientations are exposed on the side surface and the bottom surface of the groove. In the STI process, Si ₃ N ₄ is also exposed on the substrate surface in the oxidation process, and the oxidation rate on the Si ₃ N ₄ is made close to the oxidation rate on the Si substrate, so that the same oxide film thickness is obtained as much as possible. There is a process request to be made.

In a conventional oxidation method, the atmosphere in the reaction chamber is set to normal pressure or reduced pressure, oxygen alone or dry oxidation in which the substrate is oxidized in an atmosphere in which the oxygen partial pressure is adjusted with N ₂ , Ar, etc., and oxygen There is wet oxidation in which a substrate is oxidized using moisture formed by mixing hydrogen in the front stage of the reaction chamber. There are two methods for forming water by mixing hydrogen and oxygen: resistance heating and condensing lamp heating to raise the temperature of hydrogen and oxygen to a temperature higher than the ignition temperature and combustion; A reaction method has been widely used (see Patent Document 1).

In the conventional oxidation method, between the plane orientations of different Si substrates, for example, in the (100) plane and the (110) plane, the (110) plane having a higher Si atomic plane density depends on the Si atomic plane density on the Si substrate surface. The oxidation rate of is about twice that of the (100) plane in the thin film oxidation region. Further, Si ₃ N ₄ on at typically high oxidation resistance, Si ₃ N ₄ is sometimes used as a barrier layer against oxidation, it is hardly oxidized not proceed.

In contrast, in the method in which oxygen and hydrogen are introduced into the reaction chamber in a reduced pressure atmosphere from independent gas supply systems, the reaction with the substrate proceeds before moisture is formed, so the growth rate at the initial stage of oxidation is high. It is known that the difference in film thickness between the plane orientations of different Si substrates and the growth rate on Si ₃ N ₄ is reduced, so that the difference in film thickness can be remarkably reduced and isotropic oxidation is possible (patent) Reference 2).

  When isotropic oxidation is performed in a vertical semiconductor manufacturing apparatus that performs batch processing with multiple substrates arranged in multiple stages, the gas supply location is usually only upstream of the substrate being processed. Therefore, there is a problem that the oxide film thickness to be formed varies greatly as a result of the difference in hydrogen concentration in the reaction chamber depending on the substrate arrangement locations arranged in multiple stages in the vertical direction.

  It is known that isotropic oxidation in a vertical semiconductor manufacturing apparatus is such that oxygen and hydrogen react directly with the substrate, and the film formation rate is a hydrogen supply-determined reaction. In order to keep the film formation rate on the substrate constant, the hydrogen supply system to the reaction chamber is made up of two or more lines, and the hydrogen supplied from the upstream of the reaction chamber is also supplied from the upstream of the reaction chamber. It is known that the uniformity of the oxide film thickness on multiple substrates can be improved by eliminating the attenuation of the hydrogen concentration in the downstream direction of the gas flow inside the reaction chamber due to the reaction consumption of oxygen and the substrate. (See Patent Document 2).

Japanese Patent Laid-Open No. 11-204511 International Publication No. 2005/020309 Pamphlet

  By the way, depending on the difference in the materials constituting the semiconductor device exposed on the substrate surface of various processing substrates arranged in multiple stages in the reaction chamber in the vertical direction, and the surface area of the substrate surface, the oxidation reaction on the substrate surface As a result of the difference in the consumption of oxygen and hydrogen, there is a phenomenon in which a difference occurs in the oxide film thickness generated on the surface of the substrate due to hydrogen deficiency, which occurs as it goes downstream of the substrate disposed in the reaction tube.

  When isotropic oxidation is performed by arranging multiple substrates in the vertical direction with large consumption of oxygen and hydrogen due to the oxidation reaction on the substrate surface, two systems installed in the substrate region arranged in the vertical multiple stages in the reaction chamber By adjusting the flow rate of hydrogen supplied from the above hydrogen supply path, it is possible to reduce the difference in the oxide film thickness generated on the substrate surface due to hydrogen deficiency, which occurs as it goes downstream of the substrate disposed in the reaction tube. I can do it. However, the amount of hydrogen and oxygen consumed by the substrate surface reaction that occurs between the hydrogen supply points of the two or more installed hydrogen supply paths increases, and the film thickness between the hydrogen supply points in the midway supply increases. It cannot be corrected sufficiently.

  In addition, when isotropic oxidation is performed by arranging substrates with large oxygen and hydrogen consumption due to the oxidation reaction on the substrate surface in multiple vertical stages, it is necessary for the substrate surface reaction between the hydrogen supply points on the way. Due to the lack of hydrogen, the diffusion of the reaction gas toward the center of each substrate becomes dominant, and the oxide film thickness becomes thinner toward the center of the substrate.

  As shown in FIG. 11, independent hydrogen supply lines 91, 92, 93, 94 for supplying hydrogen from a plurality of locations in the middle corresponding to a region where a plurality of known substrates 1 exist, hydrogen supply nozzles 101, 102, By increasing the number of 103 and 104 as much as possible, the loss of hydrogen generated between each hydrogen supply point is compensated, the film thickness decreases in the gas supply downstream direction, and the oxide film goes toward the center of the substrate. It is considered that the problem of film thickness variation in the substrate surface where the thickness is reduced can be solved. However, there is a restriction on the installation space of the number of nozzles that can be installed inside the processing chamber 4, which occurs when substrates with large consumption of oxygen and hydrogen due to oxidation reaction on the substrate surface are arranged in multiple stages in the vertical direction. It was difficult to arrange a sufficient number of nozzles to correct the film thickness variation and the film thickness variation in the substrate surface.

  In addition, as a structure for correcting the film thickness variation between the substrates and the film thickness variation in the substrate surface in the isotropic oxidation in the vertical semiconductor manufacturing apparatus shown in FIG. 12, which is also known, the reaction consumption of oxygen and hydrogen is used. A perforated nozzle 13 having at least two or more holes 131 provided on a side surface to compensate for hydrogen deficiency generated downstream of the substrate arrangement region is known. However, since the hydrogen supply line 9 for supplying hydrogen to the substrate arrangement region is one system, the hydrogen flow rate supplied in the middle corresponding to the region where a plurality of substrates exist is provided in the porous nozzle 13. Since it is determined by the hole diameter of each hole 131, it is necessary to change the number of holes 131 provided in the porous nozzle 13 and the diameter of the hole 131 for each substrate having different reaction consumption amounts of oxygen and hydrogen. Versatility is reduced.

  The main object of the present invention is to perform isotropic oxidation in an apparatus in which a plurality of substrates are stacked and arranged, when a plurality of nozzles are used as hydrogen supply nozzles, Manufacture of a semiconductor device capable of manufacturing a high-quality semiconductor device while eliminating the above-mentioned problems that occur when using a multi-hole nozzle and suppressing a large variation in oxide film thickness due to different hydrogen concentrations depending on the substrate placement location It is an object of the present invention to provide a method and a substrate processing apparatus that can be suitably used for the method.

  According to one aspect of the present invention, a reaction tube that processes a plurality of substrates, a heating source that is provided around the reaction tube and heats the inside of the reaction tube, and the plurality of substrates are arranged in the reaction tube. A holding tool, an oxygen-containing gas supply line for supplying an oxygen-containing gas into the reaction tube from an upstream side of the region where the plurality of substrates are arranged, and a region where the plurality of substrates are arranged A hydrogen-containing gas supply line that supplies hydrogen-containing gas into the reaction tube from a plurality of locations in the corresponding region, an exhaust line that exhausts the reaction tube, and a vacuum pump that evacuates the reaction tube via the exhaust line; A pressure control unit that controls the pressure in the reaction tube to be lower than atmospheric pressure, and the hydrogen-containing gas supply line includes a plurality of independent nozzles having different lengths, Book Each nozzle, a substrate processing apparatus which has at least two gas injection holes is provided is provided.

  According to another aspect of the present invention, the step of carrying a plurality of substrates into the reaction tube, the state in which the inside of the reaction tube is heated, and the pressure in the reaction tube is lower than the atmospheric pressure, A step of processing the plurality of substrates by supplying an oxygen-containing gas and a hydrogen-containing gas into a reaction tube, and a step of unloading the plurality of substrates after processing from the reaction tube, In the step of processing, the oxygen-containing gas is supplied into the reaction tube from an upstream side of the region where the plurality of substrates are arranged, and the hydrogen-containing gas is supplied to the region where the plurality of substrates are arranged. The hydrogen-containing gas that has passed through the plurality of nozzles is supplied to the reaction tube through a plurality of independent nozzles having different lengths from a plurality of locations in the corresponding region. Small set in The method of manufacturing a semiconductor device characterized by from Kutomo two or more gas jetting holes is supplied to the reaction tube is provided.

  According to the semiconductor device manufacturing method and the substrate processing apparatus of the present invention, when the isotropic oxidation is performed in an apparatus in which a plurality of substrates are stacked and arranged, a plurality of nozzles are used as hydrogen supply nozzles. In addition, while eliminating the above-mentioned problems that occur when using a single porous nozzle, the hydrogen concentration differs depending on the substrate placement location and the oxide film thickness is largely prevented from fluctuating. Can be manufactured.

  The inventors have provided hydrogen gas at least in two or more positions on at least one of the tip and side surfaces of a plurality of independent nozzles of different lengths installed in a plurality of independent hydrogen supply lines. By providing gas ejection holes to be introduced into the substrate, a substrate having a large consumption amount of oxygen and hydrogen due to an oxidation reaction on the substrate surface, which was a problem of the conventional structure, is arranged in multiple vertical stages. It has been found that the film thickness variation in the substrate and the film thickness variation in the substrate surface can be remarkably improved. Embodiments of the present invention will be described below with reference to the drawings.

  With reference to FIGS. 1-4, the batch type vertical semiconductor manufacturing apparatus (oxidation apparatus) as a substrate processing apparatus in a present Example is demonstrated. The reaction furnace 20 has a reaction tube 21, and a boat 2 as a substrate holder is inserted into a reaction chamber (processing chamber) 4 formed by the reaction tube 21. The boat 2 as a holder is configured to hold a plurality of semiconductor wafers (silicon wafers) 1 as substrates in a plurality of stages in a substantially horizontal state with a predetermined gap (substrate pitch interval). The lower part of the reaction tube 21 is opened to insert the boat 2, and this open part is sealed with a seal cap 22. The boat 2 is mounted on a boat receiver 28, and the boat receiver 28 is attached to a rotation mechanism 27 via a rotation shaft 26. A plurality of heat insulating plates 29 are mounted on the lower portion of the boat 2. A resistance heater 5 is disposed around the reaction tube 21 as a heating source.

The reaction tube 21 has an oxygen supply line 7 for supplying oxygen (O ₂ ) gas as an oxygen-containing gas, and hydrogen supply lines 91, 92, 93, 94 for supplying hydrogen (H ₂ ) gas as a hydrogen-containing gas. Is connected. The oxygen supply line 7 is configured to supply oxygen gas into the reaction tube 21 (processing chamber 4) from the upstream side of the region where the wafers 1 are arranged (wafer arrangement region). Reference numerals 92, 93, and 94 are configured to supply hydrogen gas into the reaction tube 21 from a plurality of locations in the region upstream of the region where the wafer 1 is arranged and the region corresponding to the region where the wafer 1 is arranged. . The oxygen supply line 7 is connected to the oxygen gas supply source 41, and the hydrogen supply lines 91, 92, 93, 94 are connected to the hydrogen gas supply source 42. An electromagnetic valve 6 and a mass flow controller 12 are installed in the oxygen supply line 7 and the hydrogen supply lines 91, 92, 93, 94, respectively.

A shower plate 44 is attached to the ceiling wall 31 of the reaction tube 21, and a buffer chamber 43 is formed by the ceiling wall 31 and the shower plate 44. The oxygen supply line 7 is connected to an oxygen supply pipe 72, and the oxygen supply pipe 72 extends outside the side wall 32 of the reaction tube 21 from the lower part of the reaction tube 21, and then the upper side of the ceiling wall 31 of the reaction tube 21. Is extended to communicate with the buffer chamber 43. In this embodiment, only O ₂ is introduced from the most upstream shower plate 44.

The hydrogen supply lines 91, 92, 93, and 94 are independent of each other and are connected to the hydrogen supply nozzles 101, 102, 103, and 104, respectively. The hydrogen supply nozzles 101, 102, 103, 104 are provided through the side wall 32 at the bottom of the reaction tube 21. The hydrogen supply nozzles 101, 102, 103 and 104 rise in the reaction tube 21 along the inner wall of the side wall 32 of the reaction tube 21, but have different lengths. As described above, the hydrogen supply nozzles 101, 102, 103, and 104 have different lengths with respect to the wafer arrangement direction, and H ₂ is supplied from the upstream side of the wafer arrangement area and from a plurality of locations in the wafer arrangement area. It is possible to adjust the hydrogen concentration in the reaction chamber 4 in the arrangement direction (vertical direction). The hydrogen supply nozzles 101, 102, 103, and 104 are provided along the inner wall closer to the inner wall of the side wall 32 of the reaction tube 21 than the wafer 1 (see FIGS. 2 and 3).

The front ends of the hydrogen supply nozzles 101, 102, 103, and 104 are opened, and the open portions serve as gas ejection ports 111, 112, 113, and 114 as first gas ejection holes, respectively. The gas outlet 111 of the longest nozzle 101 among the hydrogen supply nozzles 101, 102, 103, 104 is a position separated from the shower plate 44 and a position corresponding to the upper end of the wafer arrangement region (the most upstream wafer). Slightly upstream. That is, the gas outlet 111 supplies H ₂ from the upstream side of the wafer arrangement region, and the gas outlets 112, 113, and 114 are configured to supply H ₂ from a plurality of locations in the wafer arrangement region.

In addition, gas ejection ports 111a, 112a, 113a, and 114a as second gas ejection holes are provided on the side surfaces of the hydrogen supply nozzles 101, 102, 103, and 104, respectively. The gas jet port 111a is provided at an intermediate position between the gas jet port 111 and the gas jet port 112, and the gas jet port 112a is provided at an intermediate position between the gas jet port 112 and the gas jet port 113, and the gas jet port 113a. Is provided at an intermediate position between the gas outlet 113 and the gas outlet 114. The gas outlets 111, 111a, 112, 112a, 113, 113a, 114, 114a are provided, for example, at equal intervals. Thus, in addition to the conventionally provided gas outlets 111, 112, 113, 114 as the first gas outlets, the gas outlets 111a, 112a, 113a, 114a as the second gas outlets are provided. This makes it possible to supply H ₂ that is finely controlled in the wafer arrangement direction. Note that the gas outlet 114a of the shortest nozzle 104 among the hydrogen supply nozzles 101, 102, 103, and 104 may not be provided.

3 and 4, the tip of the hydrogen supply nozzle 101 is cut obliquely, and the gas outlet 111 is configured to face the inner wall 211 side in the vicinity of the inner wall 211 of the side wall 32 of the reaction tube 21. Yes. The gas outlet 111 a is also configured to face the inner wall 211 side in the vicinity of the inner wall 211 of the side wall 32 of the reaction tube 21. Accordingly, H ₂ supplied from the hydrogen supply nozzle 101 can be ejected toward the inner wall 211 of the side wall 32 of the reaction tube 21, and H ₂ and O are generated in the vicinity of the side wall 32 by the heat of the side wall 32 heated by the heater 5. ₂ can be reacted efficiently. When H ₂ and O ₂ are reacted in the vicinity of the side wall 32 by the heat of the side wall 32 of the reaction tube 21 in this way, reactive species are generated in the vicinity of the side wall 32, and the generated reactive species are in a stable state in the wafer 1. The film thickness uniformity can be improved.

As described above, in this embodiment, H ₂ and O ₂ are reacted in the vicinity of the side wall 32, which is different from the method in which H ₂ and O ₂ are reacted in the vicinity of the wafer by the heat of the wafer 1. If H ₂ and O ₂ are reacted in the vicinity of the wafer 1, it is considered that unstable reactive species generated at the initial stage of the reaction may affect the processing of the wafer 1 and affect the film thickness uniformity. . Although the hydrogen supply nozzle 101 has been described above, the same applies to the hydrogen supply nozzles 102, 103, and 104.

  An exhaust line 36 for exhausting the processing gas is connected to an exhaust pipe 36 provided at the lower part of the reaction tube 21, and a pressure control unit 37 and a vacuum exhaust pump 3 are connected to the exhaust line 23. During the wafer processing, the inside of the reaction tube 21 is set to a predetermined pressure (reduced pressure) lower than the atmospheric pressure by the vacuum pump 3, and this pressure control is performed by the pressure control unit 37 and the controller 24. The controller 24 is configured to control the operation of each unit constituting the oxidation apparatus at a desired timing.

  Next, a description will be given of a method of performing an oxidation process on a substrate as a process of manufacturing a semiconductor device using the above-described oxidation apparatus. In the following description, the operation of each part constituting the oxidizer is controlled by the controller 24.

When one batch of wafers 1 is transferred to the boat 2, the boat 2 loaded with a plurality of wafers 1 is loaded into the processing chamber 4 of the reaction furnace 20 maintained in a heated state by the heater 5. The reaction tube 21 is sealed with a seal cap 22. Next, the inside of the reaction tube 21 is evacuated by the vacuum pump 3 and controlled so that the furnace pressure becomes a predetermined processing pressure lower than the atmospheric pressure. The boat 2 is rotated at a predetermined rotation speed by the rotation mechanism 27. Further, the temperature in the furnace is raised and controlled so that the furnace temperature becomes a predetermined processing temperature. Thereafter, O ₂ is supplied into the processing chamber 4 from the oxygen supply line 7, and H ₂ is supplied into the processing chamber 4 from the hydrogen supply lines 91, 92, 93, 94. As a result, O ₂ and H ₂ react with each other in the atmosphere heated by the heater 5 to generate reactive species, and the wafer 1 is oxidized by the reactive species. The processing temperature is 500 to 1000 ° C., the processing pressure is 1 to 1000 Pa, the oxygen gas supply flow rate is 1 to 20 L / min, and the hydrogen gas supply flow rate (total flow rate) is 0.5 to 10 L / min. Is exemplified.

  When the oxidation treatment of the wafer 1 is completed, the residual gas in the furnace is removed by evacuation, purging with an inert gas, etc., the temperature in the furnace is lowered to a predetermined temperature, and then the boat 2 is carried out from the reaction furnace 20 ( The boat 2 is made to wait at a predetermined position until all the wafers 1 supported by the boat 2 are cooled. When the wafer 1 held in the waiting boat 2 is cooled to a predetermined temperature, the wafer 1 is recovered by a substrate transfer machine or the like.

  According to this embodiment, the difference in the growth rate of the oxide film on the silicon surface with different plane orientations on the wafer formed in the various semiconductor wafer process steps can be significantly reduced as compared with the conventional oxidation method. In addition, when processing a plurality of wafers in a vertical semiconductor manufacturing apparatus, the hydrogen concentration on each wafer, that is, variation in reaction species can be reduced. The accompanying variation in the oxide film thickness can be suppressed. This embodiment is particularly effective when the surface of the substrate to be oxidized is silicon having different crystal orientation planes, or a silicon-containing material such as polycrystalline silicon by CVD or silicon nitride. It becomes. In addition, according to this example, when the substrates with large consumption of oxygen and hydrogen due to the oxidation reaction on the substrate surface are arranged in multiple stages in the vertical direction, the film thickness variation between the substrates and the film thickness variation within the substrate surface are reduced. It can be remarkably improved.

In the above-described embodiment, the case where oxygen gas is used as the oxygen-containing gas has been described. However, as the oxygen-containing gas, oxygen (O ₂ ) gas and nitrous oxide (N _At least one gas selected from the group consisting of ₂ O) gas can be used, and the hydrogen-containing gas includes a group consisting of hydrogen (H ₂ ) gas, ammonia (NH ₃ ) gas, and methane (CH ₄ ) gas. At least one gas selected from can be used.

Next, with reference to FIG. 5, the oxidation apparatus as the substrate processing apparatus in the second embodiment will be described in detail.
In the above embodiment, only the O ₂ are supplied into the reaction chamber 4 from the most upstream of the shower plate 44, in this embodiment, the buffer chamber 43, a mixture of H ₂ and O _2, H ₂ and O The mixed gas ₂ was introduced into the reaction chamber 4 from the uppermost shower plate 44. Thus, even when O ₂ and H ₂ are premixed and then introduced into the reaction chamber 4, reactive species that are more reactive than O ₂ and H ₂ O are generated.

Referring to FIG. 5, in the oxidizer according to the present embodiment, a hydrogen supply line 8 independent from the hydrogen supply lines 91, 92, 93, 94 is further provided, and this hydrogen supply line 8 is connected to the hydrogen supply pipe 82. The hydrogen supply pipe 82 extends from the lower part of the reaction tube 21 to the outside of the side wall 32, and then extends to the upper side of the ceiling wall 31 of the reaction tube 21 to communicate with the buffer chamber 43. The _second embodiment is different from the first embodiment in that a mixed gas of H ₂ and O ₂ is supplied into the reaction chamber 4 after mixing H ₂ and O ₂ in the buffer chamber 43.

Further, in the oxidation apparatus according to the present embodiment, the gas outlet 111 of the longest nozzle 101 among the hydrogen supply nozzles 101, 102, 103, and 104 is located away from the shower plate 44 and at the upper end of the wafer arrangement region. The first embodiment is different from the first embodiment in that it is located below the position corresponding to (the most upstream wafer), and H ₂ is flown not from one end side of the wafer arrangement area but from the middle of the area corresponding to the wafer arrangement area. Is different. Further, in the oxidation apparatus in the present embodiment, the upper surfaces of the tips of the hydrogen supply nozzles 101, 102, 103, and 104 are closed, and the gas ejection ports 111, 112 as the first gas ejection holes are formed on the side surfaces of the nozzle tips. 113 and 114 are different from the first embodiment in that the gas outlets 111, 112, 113, and 114 are configured to face the inner wall 211 near the inner wall 211 of the side wall 32 of the reaction tube 21. . Other points are the same as those of the first embodiment. In FIG. 5, elements that are substantially the same as those described in FIGS. 1 to 4 are given the same reference numerals, and descriptions thereof are omitted.

  Also in the oxidation apparatus according to the present embodiment, the same operational effects as those of the oxidation apparatus according to the first embodiment can be obtained.

Next, with reference to FIG. 6, the oxidation apparatus as a substrate processing apparatus in Example 3 will be described in detail.
In the above embodiment, the gas outlets 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a provided in the hydrogen supply nozzles 101, 102, 103, 104 are located near the inner wall 211 of the side wall 32 of the reaction tube 21. In the present embodiment, the gas outlets 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a are the inner walls of the side wall 32 of the reaction tube 21. In the vicinity of 211, it is configured to face in a different direction from the inner wall 211 side.

  Referring to FIG. 6, in the oxidation apparatus according to the present embodiment, the gas injection ports 111, 112, 113, 114 as the first gas injection holes provided in the hydrogen supply nozzles 101, 102, 103, 104 are provided on the wafer. The gas outlets 111a, 112a, 113a, 114a serving as the second gas ejection holes are open in a direction parallel to the arrangement direction, that is, upward, and are perpendicular to the wafer arrangement direction and toward the wafer 1 side. The second embodiment is different from the second embodiment. The other points are the same as in the second embodiment. In FIG. 6, elements that are substantially the same as those described in FIGS. 1 to 5 are given the same reference numerals, and descriptions thereof are omitted.

Even if the gas outlets 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a are not configured to face the inner wall 211 side of the side wall 32 of the reaction tube 21 as in this embodiment, the gas outlet Since 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a are provided in the vicinity of the inner wall 211 of the side wall 32 of the reaction tube 21, H ₂ and O are generated in the vicinity of the side wall 32 by the heat of the side wall 32 heated by the heater 5. ₂ can be reacted efficiently. That is, also in the oxidation apparatus in the present embodiment, the same operational effects as those in the oxidation apparatuses in the first and second embodiments can be obtained.

Next, with reference to FIG. 7, the oxidation apparatus as a substrate processing apparatus in Example 3 will be described in detail.
In the above embodiment, the gas jet ports 111a, 112a, 113a, 114a as the second gas jet holes provided in the hydrogen supply nozzles 101, 102, 103, 104 are opened toward the wafer 1 side. As described above, in this embodiment, the gas outlets 111a, 112a, 113a, 114a are in a different direction from the wafer 1 side and in a different direction from the inner wall 211 side of the side wall 32 of the reaction tube 21. It is configured.

  Referring to FIG. 7, in the oxidation apparatus according to the present embodiment, the gas injection ports 111a, 112a, 113a, and 114a as the second gas injection holes provided in the hydrogen supply nozzles 101, 102, 103, and 104 are the wafers. Example 3 is that it is open in a direction perpendicular to the arrangement direction and perpendicular to a straight line connecting the centers of the hydrogen supply nozzles 101, 102, 103, and 104 and the center of the wafer 1. Different. Moreover, the point from which each two gas jet nozzles 111a, 112a, 113a, and 114a are provided differs from Example 3. FIG. The other points are the same as in the third embodiment. In FIG. 7, elements that are substantially the same as those described in FIGS. 1 to 6 are given the same reference numerals, and descriptions thereof are omitted.

Even if the gas outlets 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a are not configured to face the inner wall 211 side of the side wall 32 of the reaction tube 21 as in this embodiment, the gas outlet Since 111, 111 a, 112, 112 a, 113, 113 a, 114, 114 a are provided in the vicinity of the inner wall 211 of the side wall 32 of the reaction tube 21, H ₂ and O are generated in the vicinity of the side wall 32 by the heat of the side wall 32 heated by the heater 5. ₂ can be reacted efficiently. That is, also in the oxidation apparatus in the present embodiment, the same effects as the oxidation apparatuses in the first to third embodiments can be obtained.

  With reference to FIGS. 8 to 10, experimental results, considerations, and the like according to the present invention will be described.

  With reference to FIG. 8, a mechanism for suppressing variations in oxide film thickness when hydrogen gas is supplied from the middle of the wafer arrangement region by a combination of the multi-stage supply and the multi-hole nozzle according to the present invention will be described. The horizontal axis in FIG. 8 indicates the wafer position, and the vertical axis indicates the film thickness of the oxide film formed on the wafer disposed at each position. In the figure, the film thickness data group indicated by a triangle (Δ) is obtained by using a multistage supply of hydrogen gas, which is a conventional technique. The symbol represented by Nzl ▽ indicates the position of the nozzle tip (gas ejection hole). The hydrogen gas supplied halfway from each nozzle reacts with the oxygen gas supplied from the upstream and generates new reactive species, resulting in a reactive species deficiency that is consumed in the upstream wafer of the wafer array and generated downstream. Compensates for film thickness reduction. The wafer surface to be oxidized is different in the amount of reactive species that contribute to the oxidation process in each wafer due to differences in the exposure and shape of various materials in the semiconductor manufacturing process. Is oxidized, the oxide film thickness formed on the wafer installed between the nozzle tip (gas ejection hole) and the nozzle tip (gas ejection hole) adjacent to it (between adjacent nozzle tips) is hydrogen gas. Compared to a wafer arranged near the tip of the nozzle that supplies the toner, it is significantly lowered and it is difficult to correct.

  On the other hand, the film thickness data group indicated by squares (□) in the figure is based on the combination of the multi-stage supply and the multi-stage supply according to Example 3 of the present invention, and hydrogen gas is supplied from the middle of the wafer arrangement region. This is obtained by increasing the supply paths. The symbol represented by NzlΔ indicates the position of the first gas ejection hole at the nozzle tip, and the symbol represented by HoleΔ indicates the position of the second gas ejection hole on the side surface of the nozzle. By installing a horizontal hole (second gas ejection hole) in the middle of the distance between adjacent nozzle tip opening holes (first gas ejection holes), hydrogen can be added to the area between the nozzle tips that could not be corrected by the prior art. It becomes possible to supply gas, and by newly generating reactive species, it is possible to suppress a decrease in film thickness in this region. According to the present invention, the variation of the oxide film thickness in the batch can be suppressed to about 1/3 compared with the conventional method.

FIG. 9 shows experimental values comparing differences in oxide film thickness due to differences in consumption of reactive species that occur when the material on the wafer surface is different. The horizontal axis in FIG. 9 indicates the wafer position, and the vertical axis indicates the thickness of the oxide film formed on the wafer disposed at each position. The film thickness data group indicated by the rhombus (◇) and the straight line indicates the film thickness of the oxide film formed on the SiO ₂ wafer, and the film thickness data group indicated by the rhombus (◇) (no straight line) The film thickness of the oxide film formed on the silicon wafer is shown. Under the same oxidation conditions, since the consumption amount due to the oxidation process of the reactive species on the silicon is larger than that on the silicon oxide film (SiO ₂ ), the reactive species is lost downstream of the wafer arrangement on the right side in the figure. It can be confirmed that the film thickness is reduced.

  FIG. 10 is a comparison of film formation experimental values in which oxidation treatment was performed by the multistage supply method of hydrogen gas according to the present invention and the prior art. In FIG. 10A, the horizontal axis indicates the wafer position, and the vertical axis indicates the film thickness value (Å) of the oxide film formed on the wafer disposed at each position. The horizontal axis in FIG. 10B indicates the wafer position, and the vertical axis indicates the in-plane film thickness uniformity (±%) of the oxide film formed on the wafer arranged at each position. As the present invention, oxidation treatment was performed using the oxidation apparatus according to Example 3. From FIG. 10, according to the present invention, hydrogen gas is also supplied to the middle of the multi-stage nozzle, and the reaction species concentration is made uniform in the batch, so that not only the oxide film thickness variation in the batch but also the in-plane in each processing wafer. It was confirmed that the film thickness variation can be remarkably improved.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

  According to one aspect of the present invention, a reaction tube that processes a plurality of substrates, a heating source that is provided around the reaction tube and heats the inside of the reaction tube, and the plurality of substrates are arranged in the reaction tube. A holding tool, an oxygen-containing gas supply line for supplying an oxygen-containing gas into the reaction tube from an upstream side of the region where the plurality of substrates are arranged, and a region where the plurality of substrates are arranged A hydrogen-containing gas supply line that supplies hydrogen-containing gas into the reaction tube from a plurality of locations in the corresponding region, an exhaust line that exhausts the reaction tube, and a vacuum pump that evacuates the reaction tube via the exhaust line; A pressure control unit that controls the pressure in the reaction tube to be lower than atmospheric pressure, and the hydrogen-containing gas supply line includes a plurality of independent nozzles having different lengths, Book Each nozzle, a substrate processing apparatus which has at least two gas injection holes is provided is provided.

  Preferably, one of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection hole opened at the nozzle tip is Opening is performed in a direction parallel to the direction in which the plurality of substrates are arranged.

  Preferably, the tip of each of the plurality of nozzles is closed, and the at least two or more gas ejection holes provided in each of the plurality of nozzles are provided in the nozzle side surface, and the nozzle side surface The gas ejection holes provided in the direction are perpendicular to the direction in which the plurality of substrates are arranged and open toward the substrate.

  Preferably, the tip of each of the plurality of nozzles is closed, and the at least two or more gas ejection holes provided in each of the plurality of nozzles are provided in the nozzle side surface, and the nozzle side surface The gas ejection holes provided in the direction are perpendicular to the direction in which the plurality of substrates are arranged and open toward the inner surface of the reaction tube.

  Preferably, one of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection hole opened at the nozzle tip is An opening is made in a direction parallel to the direction in which the plurality of substrates are arranged, and the remaining of the at least two gas ejection holes is provided on the nozzle side surface, and is provided on the nozzle side surface. The gas ejection hole is in a direction perpendicular to the direction in which the plurality of substrates are arranged, and opens toward the substrate.

  Preferably, one of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection hole opened at the nozzle tip is An opening is made in a direction parallel to the direction in which the plurality of substrates are arranged, and the remaining of the at least two gas ejection holes is provided on the nozzle side surface, and is provided on the nozzle side surface. The gas ejection holes are in a direction orthogonal to the direction in which the plurality of substrates are arranged and open toward the inner surface of the reaction tube.

  Preferably, the hydrogen-containing gas supply line is configured to supply a hydrogen-containing gas into the reaction tube from an upstream side of a region where the plurality of substrates are arranged.

  According to another aspect of the present invention, the step of carrying a plurality of substrates into the reaction tube, the state in which the inside of the reaction tube is heated, and the pressure in the reaction tube is lower than the atmospheric pressure, A step of processing the plurality of substrates by supplying an oxygen-containing gas and a hydrogen-containing gas into a reaction tube, and a step of unloading the plurality of substrates after processing from the reaction tube, In the step of processing, the oxygen-containing gas is supplied into the reaction tube from an upstream side of the region where the plurality of substrates are arranged, and the hydrogen-containing gas is supplied to the region where the plurality of substrates are arranged. The hydrogen-containing gas that has passed through the plurality of nozzles is supplied to each of the plurality of nozzles through a plurality of independent nozzles having different lengths from a plurality of locations in the corresponding region. Small set in The method of manufacturing a semiconductor device in which the fed into the reaction tube from Kutomo two or more gas ejection holes are provided.

It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus which concerns on Example 1 of this invention. It is an AA line schematic cross-sectional view of FIG. FIG. 2 is a partially enlarged schematic longitudinal sectional view of a portion B in FIG. 1. FIG. 4 is a schematic cross-sectional view taken along line CC of FIG. 3. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus which concerns on Example 2 of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus concerning Example 3 of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus concerning Example 4 of this invention. It is a figure for demonstrating the mechanism which suppresses the variation in an oxide film thickness at the time of supplying hydrogen gas from the middle of a wafer arrangement | positioning area | region by the combination of the porous nozzle which concerns on this invention, and multistage supply. It is a figure showing the experimental value which compared the difference in the oxide film thickness resulting from the difference in the consumption of the reactive species which generate | occur | produces when the material of a wafer surface differs. It is the comparison of the film-forming experimental value which implemented the oxidation process by this invention and the multistage supply method of the hydrogen gas which is a prior art. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus (multistage supply) which concerns on a prior art. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus (porous nozzle) which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2 Boat 3 Vacuum pump 4 Processing chamber 5 Heater 7 Oxygen supply line 8 Hydrogen supply line 21 Reaction tube 23 Exhaust line 37 Pressure control part 91 Hydrogen supply line 92 Hydrogen supply line 93 Hydrogen supply line 94 Hydrogen supply line 101 Hydrogen supply nozzle DESCRIPTION OF SYMBOLS 102 Hydrogen supply nozzle 103 Hydrogen supply nozzle 104 Hydrogen supply nozzle 111 Gas ejection port 112 Gas ejection port 113 Gas ejection port 114 Gas ejection port 111a Gas ejection port 112a Gas ejection port 113a Gas ejection port 114a Gas ejection port

Claims (8)

A reaction tube for processing a plurality of substrates;
A heating source provided around the reaction tube for heating the inside of the reaction tube;
A holder for arranging and holding the plurality of substrates in the reaction tube;
An oxygen-containing gas supply line for supplying an oxygen-containing gas into the reaction tube from the upstream side of the region where the plurality of substrates are arranged;
A hydrogen-containing gas supply line for supplying a hydrogen-containing gas into the reaction tube from a plurality of locations corresponding to a region where the plurality of substrates are arranged;
An exhaust line for exhausting the reaction tube;
A vacuum pump for evacuating the reaction tube through the exhaust line;
A pressure control unit for controlling the pressure in the reaction tube to be lower than atmospheric pressure,
The substrate processing apparatus, wherein the hydrogen-containing gas supply line includes a plurality of independent nozzles having different lengths, and each of the plurality of nozzles is provided with at least two gas ejection holes.   One of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection holes opened at the nozzle tip are formed by the plurality of nozzles. 2. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is opened in a direction parallel to a direction in which the substrates are arranged.   The tip of each of the plurality of nozzles is closed, and the at least two gas ejection holes provided in each of the plurality of nozzles are provided in the nozzle side surface, and are provided in the nozzle side surface. The substrate processing apparatus according to claim 1, wherein the gas ejection holes are open in a direction perpendicular to a direction in which the plurality of substrates are arranged.   The tip of each of the plurality of nozzles is closed, and the at least two gas ejection holes provided in each of the plurality of nozzles are provided in the nozzle side surface, and are provided in the nozzle side surface. The substrate processing apparatus according to claim 1, wherein the gas ejection holes are open in a direction orthogonal to a direction in which the plurality of substrates are arranged and toward the inner surface of the reaction tube.   One of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection holes opened at the nozzle tip are formed by the plurality of nozzles. Opening in a direction parallel to the direction in which the substrates are arranged, and the remaining of the at least two gas ejection holes is provided on the nozzle side surface, and the gas ejection holes provided on the nozzle side surface The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is open in a direction orthogonal to a direction in which the plurality of substrates are arranged.   One of the at least two gas ejection holes provided in each of the plurality of nozzles is opened at the nozzle tip, and the gas ejection holes opened at the nozzle tip are formed by the plurality of nozzles. Opening in a direction parallel to the direction in which the substrates are arranged, and the remaining of the at least two gas ejection holes is provided on the nozzle side surface, and the gas ejection holes provided on the nozzle side surface 2. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is open in a direction perpendicular to a direction in which the plurality of substrates are arranged and toward an inner surface of the reaction tube.   The hydrogen-containing gas supply line is also configured to supply a hydrogen-containing gas into the reaction tube from an upstream side of a region where the plurality of substrates are arranged. Substrate processing equipment. Carrying a plurality of substrates into the reaction tube;
The plurality of substrates are processed by supplying an oxygen-containing gas and a hydrogen-containing gas into the reaction tube while the reaction tube is heated and the pressure in the reaction tube is lower than atmospheric pressure. Process,
And unloading the plurality of substrates after processing from the reaction tube,
In the step of processing the substrate, the oxygen-containing gas is supplied into the reaction tube from an upstream side of a region where the plurality of substrates are arranged, and the hydrogen-containing gas is arranged in the plurality of substrates. The hydrogen-containing gas that has passed through the plurality of nozzles is supplied to the reaction tube through a plurality of independent nozzles having different lengths from a plurality of regions corresponding to the region. A method of manufacturing a semiconductor device, comprising: supplying the reaction tube through at least two or more gas ejection holes provided in each of the first and second gas ejection holes.

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