Semiconductor substrate manufacturing equipment applicable to large diameter semiconductor substrates

Abstract

Provided is a semiconductor substrate manufacturing device which is capable of uniformly heating the surface of a semiconductor substrate that has a relatively large diameter or major axis.　The semiconductor substrate manufacturing device includes a container body for accommodating a semiconductor substrate and a heating furnace that has a heating chamber which accommodates the container body, and the heating furnace has a heating source in a direction intersecting the semiconductor substrate to be disposed inside the heating chamber.

Description

[Technical field]

[0001] The present invention relates to a semiconductor substrate manufacturing apparatus that is applicable to large-diameter semiconductor substrates. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a heating furnace used for heating a semiconductor substrate generally has a heater disposed on a side wall so as to surround the periphery of the semiconductor substrate.

[0003] For example, Patent Document 1 describes a SiC semiconductor wafer heat treatment apparatus that includes a plurality of heaters arranged to surround a SiC substrate and heater support parts that support each of the heaters, and each of the heaters can be removed together with the heater support part that corresponds to the heater. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-028446 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional semiconductor substrate manufacturing apparatuses are capable of uniformly heating the surface of a substrate when the diameter or major axis of the substrate is relatively small.

[0006] From the viewpoints of cost and manufacturing efficiency, it is required to heat-treat semiconductor substrates having a large diameter or major axis.

[0007] However, when the diameter or major axis of a semiconductor substrate is large, there is a problem that the center portion of the substrate cannot be heated sufficiently in the conventional apparatus, and the substrate cannot be heat-treated all at once.

[0008] An object of the present invention is to provide a semiconductor substrate manufacturing apparatus capable of uniformly heating the surface. [Means for solving the problem]

[0009] The present invention solves the above problems, a main container for accommodating a semiconductor substrate; a heating furnace having a heating chamber that accommodates the main container, The heating furnace is a semiconductor substrate manufacturing device having a heat source in a direction intersecting with a main surface of the semiconductor substrate to be placed in the heating chamber. In this way, by providing a heat source in a direction intersecting the main surface of the semiconductor substrate to be placed in the heating chamber, the entire main surface of the semiconductor substrate can be heated uniformly.

[0010] In a preferred embodiment of the present invention, the heat source has a uniform heating range for uniformly heating the main surface of the semiconductor substrate. With this configuration, the entire main surface of the semiconductor substrate can be heated more uniformly.

[0011] In a preferred embodiment of the present invention, the heat source has a heating portion that generates heat, The area of ​​the heating portion is equal to or greater than the area of ​​the semiconductor substrate. With this configuration, the entire main surface of the semiconductor substrate can be heated more uniformly.

[0012] In a preferred embodiment of the present invention, the heat source has a heating portion that generates heat, The heating portion is disposed substantially parallel to a main surface of the semiconductor substrate. By adopting such a configuration, the entire main surface of the semiconductor substrate can be heated more uniformly.

[0013] In a preferred embodiment of the present invention, the heat source is disposed at a position facing the main surface.

[0014] In a preferred embodiment of the present invention, the heating source includes a first heating source disposed at a position facing the main surface, A second heating source is provided at a position opposite to the first heating source, The main body container is provided at a position sandwiched between the first heating source and the second heating source. By adopting such a configuration, the main surface of the semiconductor substrate can be heated more uniformly.

[0015] In a preferred embodiment of the present invention, the first heating source is provided on the top surface side of the heating chamber, and the second heating source is provided on the bottom surface side of the heating chamber.

[0016] In a preferred embodiment of the present invention, the heating furnace is capable of heating the semiconductor substrate to be placed in the heating chamber so as to form a temperature gradient in a direction substantially perpendicular to the semiconductor substrate. This configuration allows for growth or etching of a semiconductor substrate using a temperature gradient as a driving force.

[0017] In a preferred embodiment of the present invention, the semiconductor substrate manufacturing apparatus is used for heating semiconductor substrates having a diameter or major axis of 6 inches or more. The semiconductor substrate manufacturing apparatus of the present invention is suitable for heating semiconductor substrates having a large diameter or major axis.

[0018] In a preferred embodiment of the present invention, at least a part of the main body container is a transmitter / receiver for transporting atoms to and from the semiconductor substrate. With this configuration, the growth or etching of the semiconductor substrate proceeds without the need to separately store a growth source material in the main body vessel.

[0019] In a preferred embodiment of the present invention, the main container is made of a material containing the atomic species that constitutes the semiconductor substrate. In a preferred embodiment of the present invention, the main container is made of a material containing all of the atomic species that constitute the semiconductor substrate.

[0020] In a preferred embodiment of the present invention, the apparatus further comprises a gas phase species vapor pressure space for accommodating the main container, in which a vapor pressure environment of gas phase species of atomic species constituting the semiconductor substrate is formed. With this configuration, heating can be performed while maintaining the environment inside the main container.

[0021] In a preferred embodiment of the present invention, the inside of the main container is evacuated via the gas phase species vapor pressure space. With this configuration, it is possible to prevent gaseous species including atomic species constituting the semiconductor substrate inside the main body container from being exhausted.

[0022] In a preferred embodiment of the present invention, the high-melting-point container has the gas phase species vapor pressure space and houses the main container.

[0023] In a preferred embodiment of the present invention, the high melting point vessel has therein a vapor supply source capable of supplying vapor pressure of a gas phase species including atomic species that constitute the semiconductor substrate.

[0024] With this configuration, it is possible to achieve a balance between the vapor pressure of the gas phase species inside the main container and the vapor pressure of the gas phase species outside the main container, thereby enabling the environment inside the main container to be maintained. Effect of the Invention

[0025] According to the disclosed technique, it is possible to uniformly heat the main surface of a semiconductor substrate having a large diameter or major axis. [Brief description of the drawings]

[0026] [Figure 1] 1 is a diagram showing a semiconductor substrate manufacturing apparatus according to a first embodiment. [Diagram 2] 1 is a diagram showing a semiconductor substrate manufacturing apparatus according to a first embodiment. [Diagram 3] 1 is a schematic diagram showing only a first heating source, and an area surrounding a main surface of a semiconductor substrate, a surface of a main body container, and a surface of a high-melting point container when the manufacturing apparatus according to Example 1 is viewed from above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a semiconductor substrate manufacturing apparatus (hereinafter, simply referred to as a manufacturing apparatus) according to an embodiment of the present invention will be described in detail with reference to the drawings. The technical scope of the present invention is not limited to the embodiment shown in the attached drawings, and can be appropriately modified within the scope of the claims.

[0028] FIG. 1 shows a manufacturing apparatus 100 according to the first embodiment. The manufacturing apparatus 100 includes a main container 20 that houses a semiconductor substrate 10, a high melting point container 30 that houses the main container 20, and a heating furnace .

[0029] The semiconductor substrate 10 has a main surface 11. In this specification, the main surface refers to the surface on which the semiconductor substrate is grown or etched. The main surface may be, for example, a surface having an off angle of 0.4 to 8° from the (0001) plane or the (000-1) plane.

[0030] Examples of the semiconductor substrate 10 include a semiconductor wafer sliced ​​into a disk shape from a semiconductor ingot produced by a sublimation method or the like, and a semiconductor substrate processed into a thin plate shape from a single crystal semiconductor. The semiconductor substrate is preferably a semiconductor substrate that can be grown by a vapor phase method, and a specific example of the semiconductor substrate is a SiC substrate.

[0031] The main container 20 is a fitting container that includes an upper container 22 and a lower container 23 that can fit together. A minute gap 24 is formed at the fitting portion between the upper container 22 and the lower container 23, and the main container 20 is configured to be able to be evacuated (vacuumed) through this gap 24 (see FIG. 2).

[0032] Main container 20 is made of a material containing the atomic species that constitutes the semiconductor substrate. For example, when semiconductor substrate 10 is a SiC substrate, the material of main container 20 can be, for example, a material containing polycrystalline SiC. In this specification, the term "atomic species constituting a semiconductor substrate" refers to atomic species that form the main skeleton constituting the semiconductor substrate, and does not include impurities such as dopants. Note that the "material containing atomic species constituting a semiconductor substrate" may contain impurities such as dopants.

[0033] In the present invention, the main container is preferably made of a material containing all of the atomic species that constitute the semiconductor substrate, and more preferably made of a material consisting only of the atomic species that constitute the semiconductor substrate.

[0034] By heating main body container 20 made of such a material, it is possible to form an atmosphere containing the atomic species that make up semiconductor substrate 10. In this case, a part of main body container 20 becomes sender / receiver 21 that transports atoms to and from semiconductor substrate 10. Note that the sender / receiver is a general term for a material that contains the atomic species that make up the semiconductor substrate and that, when heated, sends atoms to or receives atoms from the semiconductor substrate. In the first embodiment, the transmitter / receiver 21 is a part of the main container 20 located at a position opposite to the main surface 11 .

[0035] The high-melting-point container 30 is configured to include a high-melting-point material, such as C, which is a general-purpose heat-resistant member, W, Re, Os, Ta, and Mo, which are high-melting-point metals, Ta9C8, HfC, TaC, NbC, ZrC, Ta2C, TiC, WC, and MoC, which are carbides, HfN, TaN, BN, Ta2N, ZrN, and TiN, and HfB2, TaB2, ZrB2, NB2, TiB2, and polycrystalline SiC, which are borides.

[0036] The atmosphere containing atomic species constituting the semiconductor material in the heating chamber 41 according to this embodiment has a vapor supply source 34 capable of supplying vapor pressure of gaseous species containing atomic species constituting the semiconductor substrate 10 into the high-melting point container 30 (see FIG. 2). The vapor supply source 34 may be configured to generate the vapor pressure of the above-mentioned gaseous species in the high-melting point container 30 during the heat treatment (vapor-phase species vapor pressure space). For example, when the semiconductor substrate 10 is a SiC substrate, examples of the vapor supply source include solid Si (single crystal Si pieces, Si pellets such as Si powder, etc.) and Si compounds.

[0037] Like the main container 20, the high melting point container 30 is a fitting container having an upper container 31 and a lower container 32 that can fit together, and is configured to be able to accommodate the main container 20. A minute gap 33 is formed at the fitting portion between the upper container 31 and the lower container 32, and the high melting point container 30 is configured to be able to be evacuated (vacuumed) through this gap 33.

[0038] In this embodiment, main body container 20 is placed in a high melting point container 30 having a gaseous species vapor pressure space in which a vapor pressure environment of gaseous species including atomic species that constitute the semiconductor substrate is formed. Main container 20 is exhausted through the gaseous species vapor pressure space, thereby making it possible to suppress exhaust of gaseous species including atomic species constituting a semiconductor substrate from within main container 20. Furthermore, by heating semiconductor substrate 10 within main container 20, which has a space that is exhausted through the gaseous species vapor pressure space, a balance is achieved between the vapor pressure of the gaseous species within main container 20 and the vapor pressure of the gaseous species outside main container 20 (inside high-melting point container 30), making it possible to maintain the environment within main container 20.

[0039] The heating furnace 40 includes a main heating chamber 41 capable of heating the workpiece (such as the semiconductor substrate 10) to a temperature of 800° C. or more and 2500° C. or less, and a preheating chamber 42 capable of preheating the workpiece to a temperature of 500° C. or more. The heating furnace 40 also includes a moving means 43 (moving stage) capable of moving the workpiece from the preheating chamber 42 to the main heating chamber 41.

[0040] The preheating chamber 42 is connected to the main heating chamber 41, and is configured to be able to move the high-melting point container 30 by a moving means 43. The preheating chamber 42 in this embodiment is configured to be able to be heated by the residual heat of the heat source 44 of the main heating chamber 41. For example, when the main heating chamber 41 is heated to 2000°C, the preheating chamber 42 is heated to about 1000°C, and degassing of the workpiece (semiconductor substrate 10, main container 20, high-melting point container 30, etc.) can be performed.

[0041] The moving means 43 is configured to be capable of placing the high melting point container 30 thereon and moving it between the main heating chamber 41 and the preheating chamber 42. The transfer between the main heating chamber 41 and the preheating chamber 42 by this moving means 43 can be completed in as little as one minute, making it possible to realize a temperature increase / decrease rate of 1 to 1000° C. / min. Since the temperature can be increased and decreased rapidly in this manner, it is possible to observe the surface shape that does not have a history of low-temperature growth during the temperature increase and decrease, which was difficult to do with conventional devices. In addition, in FIG. 1, the preheating chamber 42 is disposed to the left of the main heating chamber 41, but this is not limiting and the chamber may be disposed in any direction.

[0042] Connected to the main heating chamber 41 are a vacuum forming valve 45 for evacuating the inside of the main heating chamber 41, an inert gas injection valve 46 for introducing an inert gas into the main heating chamber 41, and a vacuum gauge 47 for measuring the degree of vacuum inside the main heating chamber.

[0043] The vacuum forming valve 45 is connected to a vacuum pump (not shown) that evacuates the inside of the main heating chamber 41 to create a vacuum. By using the vacuum forming valve 45 and the vacuum pump, the degree of vacuum in the main heating chamber 41 can be set to, for example, 10 Pa or less, more preferably 1 Pa or less, and even more preferably 10 -3 The pressure can be adjusted to be equal to or less than Pa. The vacuum pump can be, for example, a turbo molecular pump.

[0044] The inert gas injection valve 46 is connected to an inert gas supply source (not shown). The inert gas is injected into the heating chamber 41 by the inert gas injection valve 46 and the inert gas supply source. -5 It can be introduced at a pressure in the range of up to 10,000 Pa. As the inert gas, Ar, He, N2, etc. can be selected. Moreover, the inert gas injection valve 46 is a dopant gas supplying means capable of supplying a dopant gas into the main body container 20. That is, by selecting a dopant gas (e.g., N2, etc.) as the inert gas, the growth layer 12 can be doped with the dopant to increase the doping concentration.

[0045] The heating furnace 40 is equipped with a heat source 44 for heating the inside of the main heating chamber 41 . As the heat source 44, a first heat source 44a is provided on a top surface 40a inside the main heating chamber 41, and a second heat source 44b is provided on a bottom surface 40b inside the main heating chamber. In other words, a first heating source 44a is provided at a position facing the main surface 11, and a second heating source 44b is provided at a position facing the first heating source 44a and sandwiching the high-melting point container 30 that houses the main container 20.

[0046] It should be noted that the terms "first heating source" and "second heating source" are merely used for convenience in order to clearly distinguish between the heating sources.

[0047] The first heating source 44a and the second heating source 44b each have a heating portion p that generates heat.

[0048] 3 is a schematic diagram showing only the first heating source 44a, the main surface of the semiconductor substrate 10, the surface of the main body container 20 facing the first heating source 44a, and the surface of the high-melting-point container 30 facing the first heating source 44a when the manufacturing apparatus 100 is viewed from above. The area R of the heated portion p of the first heating source 44a is equal to or greater than the area of ​​the main surface 11, the area of ​​the surface of the main body container 20, and the area of ​​the high-melting-point container 30. Although not shown, the area R of the heated portion p of the second heating source 44b is substantially the same as the area R of the heated portion p of the first heating source 44a.

[0049] Such a first heating source 44a has a uniform heating range for uniformly heating the main surface 11 of the semiconductor substrate 10, the surface of the main body container 20 facing the first heating source 44a, and the surface of the high-melting point container 30 facing the first heating source 44a. In this specification, the term "uniform heating range" refers to a range in which any region can be heated almost uniformly, and as long as the state of any region after heat treatment is uniform, some temperature difference at each point within the region is acceptable. The allowable temperature difference is, for example, -10 to +10°C, preferably -8 to +8°C, more preferably -6 to +6°C, even more preferably -4 to +4°C, particularly preferably -2 to +2°C, and most preferably -1 to +1°C.

[0050] Moreover, the heating furnace 40 is capable of heating so as to form a temperature gradient in a direction approximately perpendicular to the main surface 11 . By forming a temperature gradient in a direction approximately perpendicular to the main surface 11, the semiconductor substrate 10 and the sender / receiver 21 transport atoms with the temperature gradient as a driving force, causing growth or etching of the semiconductor substrate 10.

[0051] Examples of means for forming a temperature gradient include a means for creating a difference in the amount of heat generated by the first heating source 44a and the second heating source 44b, and a means for arranging a heat reflecting member such as a multilayer heat reflecting metal plate in the heating furnace 40 so as to form a temperature gradient in the above-mentioned direction. In this embodiment, a small amount of heat is released from the contact portion between the moving means 43 (moving stage) and the high melting point container 30. That is, even when the same intensity of current is applied to the first heating source 44a and the second heating source 44b, a temperature gradient is formed in which the temperature decreases from the top to the bottom of the high melting point container 30.

[0052] Heat source 44 preferably has a diameter or major axis of 6 inches or more, and more preferably 8 inches or more. Moreover, the heat source 44 preferably has an area larger than the area of ​​the main surface of a semiconductor substrate having a diameter of 6 inches or more, and more preferably has an area larger than the area of ​​the main surface having a diameter of 8 inches or more.

[0053] The manufacturing apparatus 100 of the first embodiment thus configured can uniformly heat the entire main surface 11. Therefore, the manufacturing apparatus of the present invention is preferably used for heating semiconductor substrates having a diameter or major axis of 6 inches or more, and more preferably used for heating semiconductor substrates having a diameter or major axis of 8 inches or more.

[0054] Although the manufacturing apparatus 100 according to the first embodiment has been described above, the manufacturing apparatus of the present invention is not limited to this.

[0055] The heat source may be provided in a direction intersecting with the main surface of the semiconductor substrate to be placed in the heating chamber, and is preferably provided in a direction approximately perpendicular to the main surface. It is also preferable that the heating portion of the heat source is approximately parallel to the main surface of the semiconductor substrate. Furthermore, as a heating source, it is more preferable that a first heating source is provided at a position facing the main surface of the semiconductor substrate, and it is even more preferable that a second heating source is provided at a position facing the first heating source and sandwiching the main container. The heating source preferably includes a first heating source on the top surface side and a second heating source on the bottom surface side.

[0056] The area of ​​the heating portion of the heat source is preferably greater than or equal to the area of ​​the main surface of the semiconductor substrate, more preferably greater than or equal to the area of ​​the surface of the main container facing the heat source, and even more preferably greater than or equal to the area of ​​the surface of the high-melting point container facing the heat source. In a configuration including a first heating source and a second heating source, it is preferable that the areas of the heated portions of the first heating source and the second heating source are substantially the same.

[0057] The first heating source may be a first heating source group including a plurality of independent heating sources, each of which is disposed substantially parallel to the main surface of the semiconductor substrate and positioned on the same plane opposite the main surface. The area of ​​the above-mentioned heated portion in the first heat source group is the total area obtained by adding up the areas of the heated portions of the first heat sources constituting the first heat source group. The second heating source may be similarly grouped into a second heating source group.

[0058] In addition, it is preferable that the heating source has a uniform heating range that uniformly heats the main surface of the semiconductor substrate, it is more preferable that the heating source has a uniform heating range that uniformly heats the surface of the main container facing the heating source, and it is even more preferable that the heating source has a uniform heating range that uniformly heats the surface of the high-melting point container facing the heating source.

[0059] Whether or not the heat source has the above-mentioned uniform heating range can be estimated, for example, by observing the amount of etching or the amount of growth in the surface direction of a semiconductor substrate that has been heat-treated in a manufacturing apparatus.

[0060] In Example 1, an example was given of a form in which the main container 20 is made of a material containing the atomic species that make up the semiconductor substrate 10, but the present invention is not limited to this, and it is sufficient that a sender / receiver that transports atoms between the semiconductor substrate and the main container is present within the main container. For example, the main container may be provided with a holding section for holding a material that serves as a sender / recipient for transporting atoms between the semiconductor substrate and the main container.

[0061] The manufacturing apparatus of the present invention is preferably configured so that the semiconductor substrate is disposed in a semi-closed space. In this specification, the term "semi-closed space" refers to a space in which it is possible to evacuate the inside of the container, but in which it is possible to confine at least a portion of the above-mentioned gas generated within the container. By creating a semi-closed space, unintended reactions between the semiconductor substrate and the main container can be suppressed. [Explanation of symbols]

[0062] 10. Semiconductor Substrate 11 Main surface 20 Main container 21 Transmitter and receiver 22 Upper container 23 Lower container 24 Gap 30 High melting point container 31 Upper container 32 Lower container 33 Gap 34 Steam supply source 40 Furnace 40a Top 40b Bottom 40c Side wall 41 main heating chamber 42 Pre-heating chamber 43 Transportation 44a 1st heating source 44b Second heating source 45 Vacuum forming valve 46 Inert gas injection valve 47 Vacuum gauge 100 Semiconductor substrate manufacturing equipment p heating part R Area of ​​heated part

Claims

1. a main body container made of SiC that contains a SiC semiconductor substrate sliced ​​from an ingot; a high melting point container that accommodates the main container; a heating furnace having a heating chamber that accommodates the main container and the high melting point container, the main body container is a fitting container having an upper container and a lower container that can be fitted to each other, and at least a part of the fitting container is a transmitter / receiver that transports atoms between the SiC semiconductor substrate and the main body container; The high-melting-point container is a fitting container having an upper container and a lower container that can be fitted to each other, the heating furnace has a heat source in a direction intersecting a main surface of the SiC semiconductor substrate to be placed in the heating chamber, the heating source has a first heating source disposed at a position opposite to the high melting point container and a second heating source disposed at a position opposite to the first heating source, and is capable of heating the SiC semiconductor substrate to be disposed in the heating chamber so as to grow or etch the SiC semiconductor substrate by forming a temperature gradient in a substantially vertical direction of the SiC semiconductor substrate to be disposed in the heating chamber and driving atomic transport between the SiC semiconductor substrate and the sender / receiver; The area of ​​the heating portion of the first heating source and the second heating source is equal to or larger than the area of ​​one surface of the high melting point container facing each other, and the area of ​​the heating portion of the first heating source and the second heating source is substantially the same; Manufacturing equipment for SiC semiconductor substrates.

2. 2. The SiC semiconductor substrate manufacturing apparatus according to claim 1, wherein the heat source has a uniform heating range for uniformly heating the main surface of the SiC semiconductor substrate.

3. The heat source has a heating portion that generates heat, 3. The SiC semiconductor substrate manufacturing apparatus according to claim 1, wherein the heating portion is disposed substantially parallel to a main surface of the SiC semiconductor substrate.

4. The SiC semiconductor substrate manufacturing apparatus according to any one of claims 1 to 3, wherein the first heating source is provided on a top surface side of the heating chamber, and the second heating source is provided on a bottom surface side of the heating chamber.

5. The SiC semiconductor substrate manufacturing apparatus according to any one of claims 1 to 4, which is used for heating a SiC semiconductor substrate having a diameter or major axis of 6 inches or more.

6. The SiC semiconductor substrate manufacturing apparatus according to any one of claims 1 to 5, further comprising a gas phase species vapor pressure space for accommodating the main body container and forming a vapor pressure environment of gas phase species of atomic species constituting the SiC semiconductor substrate.

7. The SiC semiconductor substrate manufacturing apparatus according to claim 6 , wherein the inside of the main body container is evacuated through the gas phase species vapor pressure space.

8. The SiC semiconductor substrate manufacturing apparatus according to any one of claims 1 to 7, wherein the high melting point container has a vapor supply source capable of supplying vapor pressure of a gas phase species including an atomic species constituting the SiC semiconductor substrate therein.

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