Semiconductor wafer manufacturing method and semiconductor wafer

Abstract

To provide a method for manufacturing a semiconductor wafer containing a carbon-containing silicon layer with no SiC precipitation on a wafer surface and other defects suppressed.SOLUTION: A method for manufacturing a semiconductor wafer comprises the steps of: (1) forming a silicon film doped with carbon on a silicon substrate at a first temperature; (2) forming a silicon film not doped with carbon on the silicon film doped with carbon at the first temperature to obtain a stacked wafer; and (3) annealing the stacked wafer at a second temperature higher than the first temperature or further forming a film on the stacked wafer at the second temperature to obtain a semiconductor wafer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a semiconductor wafer including a silicon layer containing carbon. [Background technology]

[0002] Carbon (C) doped silicon (Si) has been confirmed to have properties not seen in non-doped Si, such as metal gettering ability and oxygen collection effect. The above properties make it promising for application to various devices, but high-concentration C-doped Si has a problem in that SiC precipitates on the surface when heat treated. When applying it to devices, there are many situations where thermal stability is required, such as when a film is formed at high temperatures for annealing or lamination with a Si layer, so the thermal instability of C-doped Si has been an issue.

[0003] In the conventional deposition of a silicon layer containing carbon, a method for forming an epitaxial film stack has been proposed, which is characterized in that, when forming an epitaxial layer stack on a substrate, a layer containing carbon with a target carbon concentration of 200 ppm to 5% atoms is formed at 700°C or less, and then a cap layer not containing carbon is formed at 700°C or less, followed by etching with an etching gas (Patent Document 1). However, there has been no discussion of the increased cost due to the increased number of steps caused by the need for an additional etching step, and the impact on film quality, such as defects. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5090451 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a method for manufacturing a semiconductor wafer including a carbon-containing silicon layer in which there is no precipitation of SiC on the wafer surface and other defects are suppressed. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides A method for manufacturing a semiconductor wafer, comprising: (1) forming a carbon-doped silicon film on a silicon substrate at a first temperature; (2) forming a silicon film not doped with carbon on the carbon-doped silicon film at the first temperature to obtain a laminated wafer; and (3) annealing the laminated wafer at a second temperature higher than the first temperature, or performing further film formation on the laminated wafer at the second temperature, thereby obtaining a semiconductor wafer; The present invention provides a method for manufacturing a semiconductor wafer having the above structure.

[0007] In this manner, by forming a silicon film that is not doped with carbon at the first temperature, a semiconductor wafer including a silicon layer containing carbon can be manufactured in which there is no precipitation of SiC on the surface and other defects are suppressed.

[0008] The first temperature is preferably set to 400°C to 1000°C.

[0009] At this time, it is more preferable that the first temperature is set to 600°C to 800°C.

[0010] It is desirable to form carbon-doped and non-carbon-doped silicon films at such temperatures.

[0011] The silicon film not doped with carbon preferably has a thickness of 5 nm to 200 nm.

[0012] In this case, it is more preferable that the thickness of the silicon film not doped with carbon is set to 5 nm to 50 nm.

[0013] If the thickness of the silicon film not doped with carbon is set to such a value, the effect of the present invention can be more reliably exhibited.

[0014] The carbon atom concentration of the carbon-doped silicon film is set to 1.0E+17 atoms / cm 3 Above, 4.5E+22atoms / cm 3 It is preferable that:

[0015] At this time, the carbon atom concentration of the carbon-doped silicon film is set to 1.0E+18 atoms / cm 3 Above, 2.0E+22atoms / cm 3 It is more preferable to set it as follows:

[0016] At this time, the carbon atom concentration of the carbon-doped silicon film is set to 1.0E+19 atoms / cm 3 Above, 5.0E+21atoms / cm 3 It is even more preferable that:

[0017] It is preferable from a practical standpoint to set the carbon atom concentration of the carbon-doped silicon film to such a range.

[0018] In the present invention, A semiconductor wafer, The semiconductor wafer has at least a silicon substrate having an upper surface and a lower surface, a carbon-doped silicon film formed on the upper surface of the silicon substrate, and a non-carbon-doped silicon film formed on the carbon-doped silicon film, and The semiconductor wafer provided is one in which no SiC is precipitated on the surface opposite to the lower surface of the silicon substrate.

[0019] According to the semiconductor wafer manufacturing method of the present invention, it is possible to manufacture a semiconductor wafer which includes a silicon layer containing carbon that is not deteriorated by heat and in which the surface silicon film is not doped with carbon and has good film quality.

[0020] The silicon film not doped with carbon preferably has a thickness of 5 nm to 200 nm.

[0021] In this case, it is more preferable that the silicon film not doped with carbon has a thickness of 5 nm to 50 nm.

[0022] If the silicon film not doped with carbon has such a thickness, the effect of the present invention can be more reliably exhibited.

[0023] The carbon atom concentration of the carbon-doped silicon film is 1.0E+17 atoms / cm 3 Above, 4.5E+22atoms / cm 3 It is preferable that:

[0024] At this time, the carbon atom concentration of the carbon-doped silicon film is 1.0E+18 atoms / cm 3 Above, 2.0E+22atoms / cm 3 It is more preferable that:

[0025] At this time, the carbon atom concentration of the carbon-doped silicon film is 1.0E+19 atoms / cm 3 Above, 5.0E+21atoms / cm 3 It is even more preferable that:

[0026] If the carbon atom concentration of the carbon-doped silicon film is within such a range, it is preferable from a practical standpoint. Effect of the Invention

[0027] According to the present invention, by forming a carbon-doped silicon film and then forming an undoped carbon silicon film on the carbon-doped silicon film at the same temperature, it is possible to prevent deterioration of the carbon-doped silicon film due to heat caused by a subsequent high-temperature heat treatment, and to manufacture a semiconductor wafer which includes a high-quality carbon-doped silicon layer and also has a good-quality undoped carbon silicon film on the surface. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a flow diagram showing an example of a first embodiment of a method for producing a semiconductor wafer according to the present invention. [Diagram 2] FIG. 2 is a flow diagram showing an example of a second embodiment of the method for producing a semiconductor wafer according to the present invention. [Diagram 3] 1 is a flowchart showing a process for forming a film on a semiconductor wafer in an example and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] As described above, there is a need to develop a method for producing a semiconductor wafer including a silicon layer containing carbon while preventing degradation due to heat.

[0030] As a result of intensive research into the above-mentioned problem, the inventors of the present invention have found that in an epitaxial wafer having a gettering effect, the carbon concentration is 1.0E+17 atoms / cm 3 More than 4.5E+22atoms / cm 3 The inventors have found that defects originating from the carbon-doped epitaxial layer on the epitaxial layer surface can be reduced by forming a silicon epitaxial layer doped as described below and an overlying non-carbon-doped silicon epitaxial layer, both at 700°C and a pressure of 1 to 80 Torr, and then forming a silicon epitaxial layer to serve as a device active layer at 1080°C, thereby completing the present invention.

[0031] That is, the present invention is a method for manufacturing a semiconductor wafer, comprising: (1) a step of forming a carbon-doped silicon film on a silicon substrate at a first temperature; (2) a step of forming a non-carbon-doped silicon film on the carbon-doped silicon film at the first temperature to obtain a laminated wafer; and (3) a step of annealing the laminated wafer at a second temperature higher than the first temperature, or performing further film formation on the laminated wafer at the second temperature to obtain a semiconductor wafer.

[0032] The present invention will be described in detail below, but the present invention is not limited thereto.

[0033] [Semiconductor wafer manufacturing method] The method for producing a semiconductor wafer of the present invention includes an embodiment (first embodiment) in which a carbon-doped silicon film and a non-carbon-doped silicon film thereon are formed on a silicon substrate at a first temperature in steps (1) and (2) to obtain a laminated wafer, and then a film is further formed on the laminated wafer at a second temperature higher than the first temperature in step (3), and an embodiment (second embodiment) in which steps (1) and (2) are performed in the same manner as in the first embodiment to obtain a laminated wafer, and then the laminated wafer is annealed at a second temperature higher than the first temperature in step (3). Each embodiment will be described in detail below with reference to the drawings.

[0034] [First aspect] Fig. 1 shows a flow diagram illustrating an example of a first embodiment of the method for producing a semiconductor wafer of the present invention. In the first embodiment, a semiconductor wafer is obtained by carrying out the following steps (1) to (3). The first embodiment will be described below with reference to Fig. 1.

[0035] <Process (1)> Step (1), as shown in FIG. 1, is a step of forming a carbon-doped silicon film 2 on a silicon substrate 1 at a first temperature.

[0036] The silicon substrate 1 is not particularly limited, but is preferably a single crystal silicon substrate. The single crystal silicon substrate is also not particularly limited, and may be a CZ substrate or an FZ substrate. It may be non-doped or doped. If doped, it may be n-type or p-type. If it is n-type, it may be doped with, for example, P, Sb, or As. If it is p-type, it may be doped with, for example, B, Al, or Ga. There are also no particular limitations on the orientation, diameter, resistivity, etc. of the substrate.

[0037] On such a silicon substrate 1, a silicon film (silicon epitaxial layer) 2 doped with carbon is formed at a first temperature, for example, by CVD, preferably RP-CVD (reduced pressure CVD). The source gas used at this time is, for example, monomethylsilane or trimethylsilane as a carbon source, and dichlorosilane or monosilane as a silicon source. However, the source gas is not limited to this. The film formation temperature at this time is the "first temperature", and can be, for example, 400 to 1000°C, preferably 600 to 800°C, but is not limited thereto. The carbon atom concentration doped into the silicon layer can be adjusted by the flow rate of the source gas and the film formation temperature. In addition, the pressure during CVD can be 1 to 80 Torr (133 to 10640 Pa).

[0038] The carbon atom concentration of the carbon-doped silicon film 2 is preferably 1.0E+17 atoms / cm 3 More than 4.5E+22atoms / cm 3 More preferably, it is 1.0E+18 atoms / cm or less. 3 More than 2.0E+22atoms / cm 3 More preferably, it is 1.0E+19 atoms / cm or less. 3 More than 5.0E+21atoms / cm 3 The carbon atom concentration can be confirmed by SIMS (Secondary Ion Mass Spectroscopy).

[0039] The thickness of the carbon-doped silicon film 2 is not particularly limited, but may be, for example, 10 to 1000 nm, preferably 20 to 500 nm, and more preferably 30 to 200 nm.

[0040] <Process (2)> Step (2) is a step of obtaining a laminated wafer 10 by forming a non-carbon-doped silicon film 3 on a carbon-doped silicon film 2 at a first temperature, as shown in FIG. 1.

[0041] The silicon film (silicon epitaxial layer) 3 not doped with carbon can also be formed by, for example, CVD, preferably RP-CVD (reduced pressure CVD). The source gas used in this case is, for example, dichlorosilane or monosilane. However, the source gas is not limited to these. The pressure during CVD can be 1 to 80 Torr. However, the silicon film 3 not doped with carbon is formed at the same temperature (i.e., the first temperature) as the film formation temperature of the silicon film 2 doped with carbon described above.

[0042] The steps (1) and (2) may be performed in the same CVD apparatus or in different CVD apparatuses.

[0043] The silicon film not doped with carbon formed at the first temperature functions as a Si-Cap layer, and when further film formation is performed at a second temperature higher than the first temperature in step (3) described below, it is possible to suppress the diffusion of carbon from the carbon-doped silicon film 2 to upper layers due to the high temperature.

[0044] The thickness of the silicon film 3 not doped with carbon can be, for example, 5 nm to 200 nm, preferably 5 nm to 50 nm. With such a thickness, it is possible to more reliably suppress the diffusion of carbon from the carbon-doped silicon film 2 to the semiconductor wafer surface.

[0045] <Process (3)> Step (3) is a step of obtaining a semiconductor wafer 100 by further forming a film on the laminated wafer 10 at a second temperature higher than the first temperature, as shown in Fig. 1. Note that, although Fig. 1 shows an example in which a silicon film 4 serving as a device active layer is further formed on the laminated wafer 10, the layer further formed in this step is not limited thereto.

[0046] The silicon film (silicon epitaxial layer) 4 that becomes the device active layer can also be formed by, for example, CVD, preferably RP-CVD (reduced pressure CVD). The source gas used at this time is, for example, dichlorosilane or monosilane. However, the source gas is not limited to these. The pressure during CVD can be 1 to 80 Torr. However, the film formation in this process is performed at a second temperature higher than the first temperature.

[0047] The second temperature is not particularly limited as long as it is higher than the first temperature, but can be, for example, 800°C or higher, and is preferably 1000 to 1200°C.

[0048] There is no particular limitation on the thickness of the silicon film 4 which is to be further formed in this step as a device active layer, and it may be set to an appropriate thickness depending on the application.

[0049] The step (3) may be carried out in the same CVD apparatus as the step (2), or in a different CVD apparatus.

[0050] In the present invention, the film formation at high temperature (second temperature) in step (3) is performed not directly on the carbon-doped silicon film 2, but on a silicon film (Si-Cap layer) 3 that is not doped with carbon and is formed thereon at a low temperature (first temperature). This makes it possible to suppress the diffusion of carbon from the carbon-doped silicon film 2 to upper layers. Therefore, the semiconductor wafer 100 manufactured by the present invention has no carbon diffused into the silicon film 4 that becomes the device active layer, i.e., no SiC precipitates on the surface of the epitaxial layer.

[0051] [Second aspect] Fig. 2 shows a flow diagram illustrating an example of the second embodiment of the method for producing a semiconductor wafer of the present invention. In the second embodiment of the method for producing a semiconductor wafer of the present invention, a semiconductor wafer is obtained by carrying out the following steps (1) to (3). The second embodiment will be described below with reference to Fig. 2.

[0052] <Process (1)> 2, step (1) is a step of forming a carbon-doped silicon film 2 on a silicon substrate 1 at a first temperature. Step (1) is as described in the first embodiment above.

[0053] <Process (2)> 2, step (2) is a step of forming a silicon film 3 not doped with carbon on a silicon film 2 doped with carbon at a first temperature to obtain a laminated wafer 10. Step (2) is also as described in the first embodiment above.

[0054] <Process (3)> Step (3), as shown in FIG. 2, is a step of obtaining a semiconductor wafer 100 by annealing the laminated wafer 10 at a second temperature higher than the first temperature.

[0055] The second temperature when annealing is performed is not particularly limited as long as it is higher than the first temperature, but can be, for example, 800°C or higher, and is preferably 1000 to 1200°C.

[0056] In the second embodiment, the annealing at high temperature (second temperature) in step (3) is performed after forming the silicon film (Si-Cap layer) 3 not doped with carbon at a low temperature (first temperature). Therefore, similar to the first embodiment, it is possible to suppress the diffusion of carbon from the carbon-doped silicon film 2 to the upper layer at high temperature. The semiconductor wafer 100 manufactured by the second embodiment of the present invention also has no SiC precipitation on the surface of the epitaxial layer.

[0057] [Semiconductor wafers] The present invention also provides a semiconductor wafer having at least a silicon substrate having an upper surface and a lower surface, a carbon-doped silicon film formed on the upper surface of the silicon substrate, and a non-carbon-doped silicon film formed on the carbon-doped silicon film, wherein SiC is not precipitated on the surface of the silicon substrate opposite the lower surface.

[0058] In the semiconductor wafer of the present invention, another epitaxial layer, for example a silicon film serving as a device active layer, may be formed on the silicon film that is not doped with carbon.

[0059] The semiconductor wafer of the present invention can be manufactured by the above-mentioned method for manufacturing the semiconductor wafer of the present invention. Therefore, the diffusion of carbon from the carbon-doped silicon film is suppressed by the non-carbon-doped silicon film formed thereon, so that SiC does not precipitate on the surface of the epitaxial layer.

[0060] Therefore, the semiconductor wafer of the present invention has the effects of improving metal gettering ability, oxygen collection effect, and RF characteristics, and the silicon film on the surface that is not doped with carbon is of high quality, so that the semiconductor wafer can be applied to various devices (RF devices and CIS). EXAMPLES

[0061] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited thereto. In the following examples and comparative examples, the defect evaluation on the semiconductor wafer surface was performed by measuring the number of LLS defects using SP3 manufactured by KLA-Tencor Corporation.

[0062] In the following Examples 1 to 8, steps (1) to (3) in the semiconductor wafer manufacturing method of the present invention were performed as shown in the flow of Figure 3. On the other hand, in the following Comparative Examples 1 to 7, as shown in the flow of Figure 3, only steps (1) and (3) in the semiconductor wafer manufacturing method of the present invention were performed, and step (2) was not performed.

[0063] Example 1 Using RP-CVD on a silicon substrate, a C-doped Si layer (carbon atom concentration: 1.0E+20 atoms / cm) was grown in a mixed gas atmosphere containing SiH4 and SiH(CH3)3 under conditions of 700°C and 5 Torr. 3 ) was grown to 100 nm. Then, a C-non-doped Si layer (Si-cap layer) was grown to 30 nm at the same temperature of 700°C. The temperature was then raised to 1080°C, and a Si layer was grown to produce a semiconductor wafer. At this time, the LLS was 32 nm up and there were 16 pieces.

[0064] Example 2 The semiconductor wafer to be evaluated was manufactured under the same conditions as in Example 1, except that the thickness of the C-non-doped Si layer (Si-cap layer) was 100 nm. The number of LLS was 25 at 32 nmup.

[0065] Example 3 The semiconductor wafer to be evaluated has a carbon atom concentration of 3.0E+21atoms / cm 3 When semiconductor wafers were manufactured under the same conditions as in Example 1 except for the above, the number of LLS was 15 at 32 nmup.

[0066] Example 4 The semiconductor wafer to be evaluated has a carbon atom concentration of 8.0E+21atoms / cm 3 When a semiconductor wafer was manufactured under the same conditions as in Example 1 except for the above, the number of LLS was 165 at 32 nmup.

[0067] Example 5 The semiconductor wafer to be evaluated has a carbon atom concentration of 2.5E+22atoms / cm 3When a semiconductor wafer was manufactured under the same conditions as in Example 1 except for the above, the number of LLS was 861 at 32 nmup.

[0068] Example 6 Using RP-CVD on a silicon substrate, a C-doped Si layer (carbon atom concentration: 2.0E+19 atoms / cm) was grown in a mixed gas atmosphere containing SiH4 and SiH3(CH3) at 850°C and 5 Torr. 3 ) was grown to 100 nm. Then, a C-non-doped Si layer (Si-cap layer) was grown to 30 nm at the same temperature of 850°C. The temperature was then raised to 1080°C, and a Si layer was grown to produce a semiconductor wafer. At this time, the LLS was 32 nm up and there were six pieces.

[0069] Example 7 The semiconductor wafer to be evaluated has a carbon atom concentration of 2.0E+18atoms / cm 3 A semiconductor wafer was manufactured under the same conditions as in Example 6 except for the above, and the number of LLS was 26 at 32 nmup.

[0070] Example 8 The semiconductor wafer to be evaluated has a carbon atom concentration of 4.0E+17atoms / cm 3 A semiconductor wafer was manufactured under the same conditions as in Example 6 except for the above, and the number of LLS was 12 at 32 nmup.

[0071] Comparative Example 1 Using RP-CVD on a silicon substrate, a C-doped Si layer (carbon atom concentration: 1.0E+20 atoms / cm) was grown in a mixed gas atmosphere containing SiH4 and SiH(CH3)3 under conditions of 700°C and 5 Torr. 3 ) was grown to 100 nm. After that, the temperature was raised to 1080°C and a Si layer was grown to produce a semiconductor wafer. At this time, the LLS was overloaded at 32 nmup. Note that overload roughly means that there are more than 30,000 LLS per wafer.

[0072] Comparative Example 2 The semiconductor wafer to be evaluated has a carbon atom concentration of 3.0E+21atoms / cm 3 When a semiconductor wafer was manufactured under the same conditions as in Comparative Example 1 except for the above, the LLS was overloaded at 32 nmup.

[0073] Comparative Example 3 The semiconductor wafer to be evaluated has a carbon atom concentration of 8.0E+21atoms / cm 3 When a semiconductor wafer was manufactured under the same conditions as in Comparative Example 1 except for the above, the LLS was overloaded at 32 nmup.

[0074] Comparative Example 4 The semiconductor wafer to be evaluated has a carbon atom concentration of 2.5E+22atoms / cm 3 When a semiconductor wafer was manufactured under the same conditions as in Comparative Example 1 except for the above, the LLS was overloaded at 32 nmup.

[0075] Comparative Example 5 Using RP-CVD on a silicon substrate, a C-doped Si layer (carbon atom concentration: 2.0E+19 atoms / cm) was grown in a mixed gas atmosphere containing SiH4 and SiH3(CH3) at 850°C and 5 Torr. 3 ) was grown to 100 nm. The temperature was then raised to 1080°C, and a Si layer was grown to produce a semiconductor wafer. At this time, the LLS was overloaded at 32 nmup.

[0076] Comparative Example 6 The semiconductor wafer to be evaluated has a carbon atom concentration of 2.0E+18atoms / cm 3 When a semiconductor wafer was manufactured under the same conditions as in Comparative Example 5 except for the above, the LLS was overloaded at 32 nmup.

[0077] Comparative Example 7 The semiconductor wafer to be evaluated has a carbon atom concentration of 4.0E+17atoms / cm 3When a semiconductor wafer was manufactured under the same conditions as in Comparative Example 5 except for the above, the LLS was overloaded at 32 nmup.

[0078] The results of Examples 1 to 8 and Comparative Examples 1 to 7 are summarized in Table 1.

[0079] [Table 1]

[0080] As is clear from Table 1, the semiconductor wafers manufactured by the semiconductor wafer manufacturing method of the present invention such as Examples 1 to 8 have no SiC precipitation on the surface of the epitaxial layer, have very little LLS, and the carbon diffusion is suppressed by the Si-Cap layer. In particular, the carbon concentration of the C-doped Si layer is 3.0E21 atoms / cm 3 The results were particularly excellent in the following cases: On the other hand, in Comparative Examples 1 to 7, the step (2) of the present invention was not performed, and the device active layer was formed directly on the C-doped Si layer at a high temperature, which resulted in carbon diffusing from the C-doped Si layer and SiC precipitating on the surface of the device active layer, resulting in a very large LLS (Overload).

[0081] This specification includes the following inventions.

[0082] [1]: A method for manufacturing a semiconductor wafer, comprising: (1) a step of forming a carbon-doped silicon film on a silicon substrate at a first temperature; (2) a step of forming a non-carbon-doped silicon film on the carbon-doped silicon film at the first temperature to obtain a laminated wafer; and (3) a step of annealing the laminated wafer at a second temperature higher than the first temperature, or performing further film formation on the laminated wafer at the second temperature to obtain a semiconductor wafer.

[0083] [2]: The method for producing a semiconductor wafer according to the above [1], wherein the first temperature is set to 400°C to 1000°C.

[0084] [3]: The method for producing a semiconductor wafer according to the above [1] or [2], wherein the first temperature is set to 600°C to 800°C.

[0085] [4]: The method for producing a semiconductor wafer according to [1], [2], or [3] above, wherein the silicon film not doped with carbon has a thickness of 5 nm to 200 nm.

[0086] [5]: The method for producing a semiconductor wafer according to [1], [2], [3], or [4], characterized in that the thickness of the silicon film not doped with carbon is 5 nm to 50 nm.

[0087] [6]: The carbon atom concentration of the carbon-doped silicon film is 1.0E+17 atoms / cm 3 Above, 4.5E+22atoms / cm 3 A method for producing a semiconductor wafer according to the above [1], [2], [3], [4], or [5], characterized in that:

[0088] [7]: The carbon atom concentration of the carbon-doped silicon film is 1.0E+18 atoms / cm 3 Above, 2.0E+22atoms / cm 3 A method for producing a semiconductor wafer according to [1], [2], [3], [4], [5], or [6], characterized in that:

[0089] [8]: The carbon atom concentration of the carbon-doped silicon film is 1.0E+19 atoms / cm 3 Above, 5.0E+21atoms / cm 3 A method for producing a semiconductor wafer according to the above [1], [2], [3], [4], [5], [6], or [7], characterized in that:

[0090] [9]: A semiconductor wafer comprising at least a silicon substrate having an upper surface and a lower surface, a carbon-doped silicon film formed on the upper surface of the silicon substrate, and a non-carbon-doped silicon film formed on the carbon-doped silicon film, wherein the semiconductor wafer does not have SiC precipitated on the surface of the silicon substrate opposite the lower surface.

[0091]

[10] : The semiconductor wafer according to the above [9], wherein the silicon film not doped with carbon has a thickness of 5 nm to 200 nm.

[0092]

[11] : The semiconductor wafer according to the above [9] or

[10] , wherein the silicon film not doped with carbon has a thickness of 5 nm to 50 nm.

[0093]

[12] : The carbon atom concentration of the carbon-doped silicon film is 1.0E+17 atoms / cm 3 Above, 4.5E+22atoms / cm 3 The semiconductor wafer according to the above [9],

[10] , or

[11] , characterized in that:

[0094]

[13] : The carbon atom concentration of the carbon-doped silicon film is 1.0E+18 atoms / cm 3 Above, 2.0E+22atoms / cm 3 The semiconductor wafer according to [9],

[10] ,

[11] , or

[12] above, characterized in that:

[0095]

[14] : The carbon atom concentration of the carbon-doped silicon film is 1.0E+19 atoms / cm 3 Above, 5.0E+21atoms / cm 3The semiconductor wafer according to [9],

[10] ,

[11] ,

[12] , or

[13] above, characterized in that:

[0096] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0097] 1...silicon substrate; 2...carbon-doped silicon film; 3...Si film not doped with carbon; 4...silicon film serving as a device active layer; 10...laminated wafer; 100...semiconductor wafers.

Claims

1. A method for manufacturing a semiconductor wafer, comprising: (1) forming a carbon-doped single crystal silicon film on a single crystal silicon substrate at a first temperature; (2) forming a single crystal silicon film not doped with carbon on the carbon-doped single crystal silicon film at the first temperature to obtain a laminated wafer; and (3) forming a single crystal silicon film not doped with carbon on the stacked wafers at a second temperature higher than the first temperature to obtain a semiconductor wafer; having The thickness of the single crystal silicon film not doped with carbon is 5 nm to 200 nm (excluding 10 nm or less), A method for producing a semiconductor wafer, characterized in that the carbon doped single crystal silicon film has a carbon atom concentration of 1.0E+17 atoms / cm 3 or more and 4.5E+22 atoms / cm 3 or less.

2. 2. The method for producing a semiconductor wafer according to claim 1, wherein the first temperature is set to 400° C. to 1000° C.

3. 3. The method for producing a semiconductor wafer according to claim 2, wherein the first temperature is set to 600° C. to 800° C.

4. 2. The method for producing a semiconductor wafer according to claim 1, wherein the thickness of the single crystal silicon film not doped with carbon is set to 5 nm to 50 nm (excluding thicknesses of 10 nm or less).

5. The carbon atom concentration of the carbon-doped single crystal silicon film is set to 1.0E+18 atoms / cm ３ Above, 2.0E+22atoms / cm ３ 2. The method for producing a semiconductor wafer according to claim 1, wherein the following steps are performed:

6. The carbon atom concentration of the carbon-doped single crystal silicon film is set to 1.0E+19 atoms / cm ３ Above, 5.0E+21atoms / cm ３ 6. The method for producing a semiconductor wafer according to claim 5, wherein the following is performed:

7. A semiconductor wafer, The semiconductor wafer has at least a single crystal silicon substrate having an upper surface and a lower surface, a carbon-doped single crystal silicon film formed on the upper surface of the single crystal silicon substrate, and a carbon-undoped single crystal silicon film formed on the carbon-doped single crystal silicon film, the carbon-undoped single crystal silicon film having a thickness of 5 nm to 200 nm (excluding thicknesses of 10 nm or less); the carbon atom concentration of the carbon-doped single crystal silicon film is 1.0E+17 atoms / cm 3 or more and 4.5E+22 atoms / cm 3 or less; and, The semiconductor wafer is characterized in that no SiC is precipitated on the surface opposite to the lower surface of the single crystal silicon substrate.

8. 8. The semiconductor wafer according to claim 7, wherein the thickness of the single crystal silicon film not doped with carbon is 5 nm to 50 nm (excluding a thickness of 10 nm or less).

9. The carbon atom concentration of the carbon-doped single crystal silicon film is 1.0E+18 atoms / cm ３ Above, 2.0E+22atoms / cm ３ 8. The semiconductor wafer according to claim 7, wherein:

10. The carbon atom concentration of the carbon-doped single crystal silicon film is 1.0E+19 atoms / cm ３ Above, 5.0E+21atoms / cm ３ 10. The semiconductor wafer according to claim 9, wherein:

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