JP2006032411A - Inscribed conductivity region compound for silicon carbide semiconductor device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inscribed conductive region compound for a silicon carbide semiconductor device and a manufacturing method thereof wherein the reduction of effective areas of first and second conductive regions due to overlapping between them and the occurrence of asymmetry in electric characteristics of the compound are excluded. <P>SOLUTION: The inscribed conductive region compound for the silicon carbide semiconductor device comprises the first conductive region 2 formed on an SiC substrate 1, and second conductive regions 3a, 3b closely in contact with the first conductive region 2 and formed in a way of enclosing or clamping the first conductive region 2. The manufacturing method thereof is configured with the steps of forming a first mask for ion implantation on the SiC substrate 1, applying selective ion implantation to the SiC substrate 1 through openings of the first mask to form the first conductive region 2, forming a second mask for ion implantation in self-alignment to the first mask on the SiC substrate 1, and applying selective ion implantation to the SiC substrate 1 through openings of the second mask to form the second conductive regions 3a, 3b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inscribed conductive region composite of a silicon carbide semiconductor device and a method for manufacturing the same.

  Semiconductor silicon carbide (SiC) can form a pn junction, and has a wider forbidden band Eg than other semiconductor materials such as silicon (Si) and gallium arsenide (GaAs), and is 2.23 eV in 3C-SiC. A value of about 2.93 eV for 6H-SiC and about 3.26 eV for 4H-SiC has been reported. In addition, SiC is thermally, chemically and mechanically stable and has excellent radiation resistance, so it can be used not only for light-emitting elements and high-frequency devices, but also in harsh conditions such as high temperature, high power, and radiation irradiation. Application in various industrial fields is expected as a power semiconductor device (power device) exhibiting high reliability and stability.

  Similar to Si semiconductor devices, in SiC semiconductor devices, a composite composed of two or more conductive regions having different conductivity types, impurity species, impurity concentrations, and depths (abbreviated as a conductive region composite) is important. Is an element. One such conductive region composite is a conductive region composite in which the first conductive region is planarly surrounded or sandwiched by the second conductive region. Such a conduction region composite is referred to as “inscribed conduction region composite” or simply “conduction composite”. Note that “A is sandwiched between B” means that A is present between B. In this case, B may be a single connection or may be divided into a plurality of parts.

  As a typical example of such an inscribed conduction region composite, the structure of an n + source region and a p + base contact region of a vertical power MOSFET can be cited (the notation “+” attached to n and p is high). Meaning impurity concentration or high carrier concentration, and so on). Specific examples thereof are described in Non-Patent Document 1 below.

JP-A-10-308510 FIG. 1A of “Materials Science Forum, 433-436, 2003, pages 669-672”.

  In manufacturing the above inscribed conductive region composite, a first mask for ion implantation is formed on the surface of the semiconductor substrate, and selective ion implantation is performed on the substrate through the opening of the first mask. 1 (or second) conductive region is formed, a second mask for ion implantation is formed on the surface of the substrate, and selective ion implantation is performed on the substrate through the opening of the second mask to perform the second ( Alternatively, a first) conductive region is formed, and the impurity ion-implanted into the first conductive region and the impurity ion-implanted into the second conductive region are activated.

  In the prior art, independent photolithography processes are used in forming the first mask and the second mask. Therefore, when the first mask and the second mask are formed, errors occur in the alignment in the two photolithography processes due to mechanical and artificial factors. Therefore, the positions of the first conductive region and the second conductive region are different. The position is relatively shifted, and a common portion and a gap are formed between the first conduction region and the second conduction region. As a result, (1) the effective area of the first conduction region and the second conduction region is increased. (2) Asymmetry appears in the electrical properties of the composite and the intended electrical properties cannot be obtained. (3) To secure a desired effective area, the first conductive region and the second conductive region There is a problem that the design area must be designed to be larger by the error.

  The present invention has been made in view of the above problems in such a conventional inscribed conductive region composite and a method for manufacturing the same, and the problem to be solved by the present invention is the first conductive region and the second conductive region. An inscribed conductive region composite of a silicon carbide semiconductor device and a method of manufacturing the same are provided, which eliminates the reduction of the effective area of both regions due to the overlap with each other and the appearance of asymmetry in the electrical characteristics of the composite.

  A first conduction region is formed by selective ion implantation into a semiconductor silicon carbide substrate, and a second conduction region is formed by selective ion implantation into the substrate so as to be in close contact with and surround or sandwich the region. An inscribed conductive region composite of a silicon carbide semiconductor device, wherein the inscribed conductive region complex of the silicon carbide semiconductor device has no common part and no gap between the first conductive region and the second conductive region. A conductive region composite is constructed.

  Implementation of the present invention eliminates the reduction in effective area of both regions due to the overlap between the first conduction region and the second conduction region and the appearance of asymmetry in the electrical characteristics of the composite. It becomes possible to provide a region complex and a method for producing the same.

  Next, an embodiment of the present invention will be described with reference to the drawings. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Accordingly, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  FIGS. 1 (1) to 1 (4) are ideal planar structures of the inscribed conductive region composites desired in various SiC semiconductor devices according to the present invention. In the figure, 1 is a SiC substrate of a desired conductivity type, which is a semiconductor silicon carbide substrate, 2 is a first conduction region formed by selective ion implantation in a minute region of the surface of the SiC substrate 1, and 3a and 3b are the first conductivity regions. This is a second conduction region which is provided by selective ion implantation so as to surround (see FIGS. 1 (1) to (3)) or sandwich (FIG. 1 (4)) and to be close to one conduction region. Here, the second conductive regions 3a and 3b are formed simultaneously.

  The first conductive region 2 and the second conductive regions 3a and 3b are different in at least one of conductivity type (p-type and n-type distinction), ion-implanted impurity species, impurity concentration, and impurity implantation depth. Furthermore, the first conduction region does not suffer from ion implantation when forming the second conduction region, and similarly, the second conduction region also does not receive ion implantation when forming the first conduction region. It shall be formed.

FIG. 2 schematically shows an ideal cross-sectional structure when the SiC semiconductor device shown in FIG. 1 is cut along a line AA. In the figure, _{L 2} is the first conductive region 2 of the _width, the _{L 3a} and _{L 3b} is the width of the second conductive region 3a, 3b left piece and the right piece. L _3a and L _3b are often required to have the same size, but this is not always the case.

  In the prior art, since the first conductive region 2 and the second conductive regions 3a and 3b are formed based on the independent positioning, the first conductive region 2 and the second conductive regions 3a and 3b are formed. The mutual positional relationship is not ideal as shown in FIGS. 1 and 2, and an overlap and a gap are generated between the two regions, and the problems (1) to (3) described above are generated.

  On the other hand, in the present invention, an inscribed conductive region composite having an ideal relative positional relationship as shown in FIGS. 1 and 2 is manufactured by a method for manufacturing the inscribed conductive region composite described below. And can be provided.

(First embodiment)
A first embodiment of the present invention will be described with reference to process cross-sectional views shown in FIGS.

  Here, the SiC substrate 1 is a 4H-SiC substrate, the first conductive region 2 is a high impurity concentration p + region, and the second conductive regions 3a and 3b are high impurity concentration n + regions. I will decide.

(1A) First, a SiO ₂ film having a thickness of about 1.5 μm is deposited on the entire surface of the 4H—SiC substrate 1 by chemical vapor deposition (CVD) to form a p + region (first conductive region 2). The SiO ₂ film deposited on the region is selectively removed by a well-known photolithography method and reactive ion etching technique (RIE), and an opening is formed in the region, as shown in FIG. A first ion implantation mask 20 which is a first mask for ion implantation is formed.

(1B) Subsequently, a first ion implantation through film made of a thin SiO ₂ film by CVD again on the entire surface of the SiC substrate 1 in the first ion implantation mask 20 and its opening (not shown because it is very thin) To deposit. Under the Al ⁺ (aluminum ion) implantation conditions described later, the thickness of the first ion implantation through film is 15 to 25 nm.

After the first ion-implanted through film is deposited, p-type impurity ions Al ⁺ are ion-implanted on the entire surface of the SiC substrate 1 so as not to impair the crystallinity of SiC, and as shown in FIG. An Al ion implantation layer (first ion implantation layer 21) is formed in the opening of the mask 20. This ion implantation is preferably performed in multiple stages while changing the acceleration energy and the dose amount to the heated SiC substrate 1. For example, an example of conditions for performing multi-stage ion implantation of Al ⁺ into the SiC substrate 1 is as follows:
◎ p + region (= first conduction region) ion implantation condition ion species Al ⁺
Injection temperature 750 ° C
Acceleration conditions 30 keV 1.0 × 10 ¹⁵ / cm ²
50 keV 1.0 × 10 ¹⁵ / cm ²
70 keV 2.0 × 10 ¹⁵ / cm ²
100 keV 3.0 × 10 ¹⁵ / cm ²
It becomes.

(1C) When the Al ion implantation is completed, the SiC substrate 1 is sufficiently washed and dried. Thereafter, a second ion implantation mask material 22, for example, polycrystalline silicon, which is a mask material for a second mask for ion implantation, having sufficient resistance in re-etching (RIE) of the first ion implantation mask 20 described later. When a thick film is formed in conformal mapping on the entire surface of the substrate, the opening of the first ion implantation mask 20 is completely embedded with the first ion implantation mask material 22 as shown in FIG. As another material suitable for such a purpose, a Si ₃ N ₄ film formed by a low pressure CVD method or a plasma CVD method can be given.

(1D) Subsequently, the first ion implantation mask material 22 deposited on the surface of the substrate 1 is etched back by the plasma etching apparatus, and the etching is terminated when the first ion implantation mask (SiO ₂ ) 20 is exposed. . As the etchant gas when the second ion implantation mask material 22 is polycrystalline silicon, a CF ₄ + O ₂ (4%) mixed gas can be used. As shown in FIG. 3D, the opening of the first ion implantation mask 20 is filled with the second ion implantation mask material 22, which precisely forms the first ion implantation mask 20 and the first ion implantation layer 21. A self-aligned second ion implantation mask 23 which is a constituent element of the second mask for ion implantation is formed.

  In the above, plasma etching is used to etch back the second ion implantation mask material (polycrystalline silicon) 22, but in addition to this, etching back is performed using chemical mechanical polishing (CMP). A structure similar to (d) may be formed. In this polycrystalline silicon CMP, good results can be obtained by using a slurry in which 1% or less of alumina particles are suspended as abrasive grains in an organic amine solution to which a small amount of KOH is added.

  (1E) When the second ion implantation mask 23 is formed, a photoresist mask 24 as shown in FIG. 4E is formed by photolithography. The photoresist mask 24 is defined so as to expose all of the regions where the n + regions (that is, the second conductive regions 3a and 3b) are to be formed and all or most of the regions of the second ion implantation mask 23.

(1F) Next, using the photoresist mask 24 as a mask, re-RIE of the first ion implantation mask (SiO ₂ ) 20 on the surface of the substrate 1 is performed. At this time, it is important to use an etchant gas that does not etch the second ion implantation mask (polycrystalline silicon) 23. If the second ion implantation mask 23 is polycrystalline silicon, a CF ₄ + H ₂ mixed gas etchant gas may be used. When the etching is completed, the photoresist mask 24 is ashed. The substrate 1 has the structure shown in FIG. Here, reference numeral 25 denotes a third ion implantation mask which is formed by using SiO ₂ which is a mask material of the first ion implantation mask 20 as a constituent element of the second mask for ion implantation.

(1G) Next, after depositing a second ion-implanted through film (not shown) made of SiO ₂ having a thickness of 20 to 30 nm on the entire surface of the substrate by the CVD method, an n-type impurity P ( When phosphorus is selectively ion-implanted, a second ion-implanted region layer 26 is formed (FIG. 4G). As is apparent from FIGS. 4F and 4G, the second mask for ion implantation used at this time is a second ion implantation mask (polycrystalline silicon) 23 and a third ion implantation mask (SiO ₂ ). 25.

This P ⁺ ion implantation is preferably performed in multiple stages while changing the acceleration energy and the dose amount to the heated SiC substrate 1. The following is an example of injection conditions. ◎ n + region (= second conduction region) ion implantation condition ion species P ⁺ (phosphorus)
Injection temperature 500 ° C
Acceleration conditions 40 keV 5.0 × 10 ¹⁴ / cm ²
70 keV 6.0 × 10 ¹⁴ / cm ²
100 keV 1.0 × 10 ¹⁵ / cm ²
160 keV 2.0 × 10 ¹⁵ / cm ² .

  (1H) When the second ion implantation is completed, the substrate 1 is immersed in a mixed solution of hydrofluoric acid and nitric acid to completely remove the ion implantation mask (23 and 25) and the second ion implantation through film from the substrate surface. . Then, after drying, if the substrate 1 is subjected to a rapid heat treatment at 1700 ° C. for 1 minute in an atmospheric pressure Ar atmosphere, Al and P, which are ion-implanted impurities, are activated, and an Al ion-implanted layer (first layer) The 1 ion implantation layer 22) becomes a p + region (first conduction region 2), and the P ion implantation layer (second ion implantation layer 26) becomes an n + region (second conduction regions 3a and 3b). The pn region structure is completed.

  As is clear from the detailed description of the structure and the manufacturing method described above, in the inscribed conduction region composite according to the present invention, ion implantation into the first conduction region 2 and ion implantation into the second conduction regions 3a and 3b. And the first conductive region 2 and the second conductive regions 3a and 3b have no common part and no gap as a result. . In addition, when the first conductive region 2 and the second conductive regions 3a and 3b are different in impurity species, the first conductive region 2 does not include the ion-implanted impurities of the second conductive regions 3a and 3b. The two conduction regions 3a and 3b do not contain the ion implantation impurity of the first conduction region 2.

  In the pn region structure which is the inscribed conduction region composite body of the silicon carbide semiconductor device according to the present invention manufactured in the present embodiment, the above-described problems of the conventional technology are solved. That is, since the first conduction region 2 and the second conduction regions 3a and 3b do not have a common part, the first conduction region and the second conduction region overlap each other, so that each area operates normally (effective The problem that the area is reduced, that is, the problem (1) of the above-described prior art is solved. For the same reason, in order to secure a desired effective area, there is a problem in the prior art that the design areas of the first conduction region and the second conduction region must be designed to be larger by the error. 3) is also solved. Further, since the two regions are formed as designed, the problem (2) of the prior art that the asymmetry appears in the electrical characteristics due to the asymmetry of the structure and the intended electrical characteristics cannot be obtained is solved.

(Second Embodiment)
The second embodiment of the present invention is a very useful technique that can solve all the problems (1) to (3) of the conventional inscribed conductive region composite as in the first embodiment.

Hereinafter, the manufacturing method of the pn region structure which is the inscribed conductive region composite according to the present invention will be described with reference to the process cross-sectional views shown in FIGS. Here, the SiC substrate is a 4H-SiC substrate, the first conductive region 2 is a high impurity concentration p + region, and the second conductive region is a high impurity concentration n + region.

(2A) First, a SiO ₂ film having a thickness of about 1.5 μm is deposited on the entire surface of the 4H—SiC substrate 1 by a chemical vapor deposition (CVD) method, and an n + region (second conductive regions 3a, 3b). The SiO ₂ film on the region to be formed is selectively removed by a well-known photolithography method and reactive ion etching technique (RIE), and an opening is formed in that region as shown in FIG. Then, a first ion implantation mask 30 which is a first mask for ion implantation is formed.

(2B) Subsequently, after depositing an ion-implanted through film made of a thin SiO ₂ film on the surface of the substrate 1 again by the CVD method, n-type impurity P (phosphorus) ions are not impaired on the entire surface of the substrate 1 without damaging the crystallinity of SiC. The first ion implantation layer 31 is formed in the opening of the first ion implantation mask 30 as shown in FIG. Under the conditions of P ⁺ (phosphorus ion) implantation described later, the thickness of this ion implanted through film is 20 to 30 nm. Since this ion-implanted through film is very thin, it is not shown in the figure below.

The ion implantation is preferably performed in multiple stages on the heated substrate 1 while changing the acceleration energy and the dose amount. The following is an example of injection conditions.
◎ n + region (= second conduction region) ion implantation condition ion species P ⁺ (phosphorus)
Injection temperature 500 ° C
Acceleration conditions 40 keV 5.0 × 10 ¹⁴ / cm ²
70 keV 6.0 × 10 ¹⁴ / cm ²
100 keV 1.0 × 10 ¹⁵ / cm ²
160 keV 2.0 × 10 ¹⁵ / cm ² .

(2C) When the P ion implantation is completed, the substrate 1 is sufficiently washed and dried. Thereafter, a second ion implantation mask material 32, which is a mask material for the mask for ion implantation, is formed on the surface of the substrate 1 to be thick in conformal mapping as shown in FIG. As the second ion implantation mask material 32, a material having sufficient resistance to an etchant gas is selected when re-etching (RIE) of the first ion implantation mask 30 described later. For example, polycrystalline silicon deposited by low pressure CVD or plasma CVD, Si ₃ N _{4, and the} like are applicable, but the present invention is not limited to this. When the film formation is completed, the opening of the first ion implantation mask 30 is completely embedded with the second ion implantation mask material 32 as shown in FIG.

(2D) Subsequently, the second ion implantation mask material 32 deposited on the surface of the substrate 1 is etched back by the plasma etching apparatus, and the first ion implantation mask (SiO ₂ ) 30 as shown in FIG. Etching is terminated when is exposed. As the etchant gas when the second ion implantation mask material 32 is polycrystalline silicon, a mixed gas of CF ₄ + O ₂ (4%) can be used. As shown in FIG. 5D, the opening of the first ion implantation mask 30 is filled with the second ion implantation mask material 32, and this is precisely applied to the first ion implantation mask 30 and the first ion implantation layer 31. The second ion implantation mask 33 is a self-aligned second ion implantation mask which is a component of the second mask for ion implantation.

  In the above, plasma etching is used to etch back the second ion implantation mask material 32, but in addition to this, etching back is performed using a chemical mechanical polishing method (CMP), as in FIG. 5D. The structure may be formed. For CMP when the second ion implantation mask material 32 is polycrystalline silicon, it is preferable to use a slurry in which 1% or less of alumina particles are suspended as abrasive grains in an organic amine-based solution to which a small amount of KOH is added. Results are obtained.

  (2E) When the second ion implantation mask 33 is formed, a photoresist mask 34 having a shape as shown in FIG. 6E is formed on the surface of the substrate 1 by photolithography. As can be seen from the figure, the photoresist mask 34 is defined so as to expose all of the region to be the p + region (that is, the first conductive region 2) and approximately half of the region of the second ion implantation mask 33. In this photolithography, the end of the opening of the photoresist mask 34 may be located anywhere on the upper surface of the second ion implantation mask 33, and this is necessary for the positional accuracy of the first conductive region, as will be described later. Since it does not affect, no precise alignment is required.

(2F) Next, RIE is performed to selectively remove a portion of the first ion implantation mask (SiO ₂ ) 30 on the surface of the substrate 1 sandwiched between the second ion implantation masks 33, and a third ion implantation mask. (SiO ₂ ) 35 is formed. At this time, it is important to use an etchant gas that does not etch the second ion implantation mask (polycrystalline silicon) 33 whose surface is exposed. If the second ion implantation mask 33 is polycrystalline silicon, a CF ₄ + H ₂ mixed gas type etchant gas may be used. When the etching is completed and the photoresist mask 34 is removed by ashing, the substrate 1 has the structure shown in FIG.

(2G) Next, an ion-implanted through film made of SiO ₂ having a thickness of 15 to 25 nm is deposited on the entire surface of the substrate by CVD, and then p-type impurity Al (aluminum) is ion-implanted toward the surface of the substrate 1 Then, as shown in FIG. 6G, the second ion implantation layer 36 is accurately formed at a desired position. The second mask for ion implantation used at this time has a second ion implantation mask (polycrystalline silicon) 33 and a third ion implantation mask (SiO ₂ ) 35 as components.

The ion implantation of Al ⁺ is preferably performed in multiple stages while changing the acceleration energy and the dose amount to the heated SiC substrate 1. An example of injection conditions is:
◎ p + region (= first conduction region) ion implantation condition ion species Al ⁺
Injection temperature 750 ° C
Acceleration conditions 30 keV 1.0 × 10 ¹⁵ / cm ²
50 keV 1.0 × 10 ¹⁵ / cm ²
70 keV 2.0 × 10 ¹⁵ / cm ²
100 keV 3.0 × 10 ¹⁵ / cm ²
It becomes.

  (2H) When the second ion implantation is completed, the substrate 1 is immersed in a mixed solution of hydrofluoric acid and nitric acid to completely remove the ion implantation masks 33 and 35 and the second ion implantation through film from the substrate surface. When the substrate 1 is subjected to a rapid heat treatment at 1700 ° C. for 1 minute in an atmospheric pressure Ar atmosphere after being washed with water and dried, the ion-implanted impurities Al and P are activated, and the second ion-implanted layer 36 becomes In the p + region (first conduction region 2), the first ion implantation layer 31 becomes an n + region (second conduction regions 3a, 3b), and the desired pn region structure shown in FIG. 2 is completed.

  As is clear from the detailed description of the structure and the manufacturing method described above, in the inscribed conduction region composite according to the present invention, ion implantation into the first conduction region 2 and ion implantation into the second conduction regions 3a and 3b. And the first conductive region 2 and the second conductive regions 3a and 3b have no common part and no gap as a result. . Therefore, the problem that the area (effective area) in which each of the two regions operates normally decreases due to the overlap of the two regions, that is, the above-described problem (1) of the conventional technology is solved. For the same reason, in order to secure a desired effective area, there is a problem in the prior art that the design areas of the first conduction region and the second conduction region must be designed to be larger by the error. 3) is also solved. Further, since the two regions are formed as designed, the problem (2) of the prior art that the asymmetry appears in the electrical characteristics due to the asymmetry of the structure and the intended electrical characteristics cannot be obtained is solved. In particular, in the present embodiment, the opening end of the photoresist mask 34 may be located anywhere on the upper surface of the second ion implantation mask 33, and the position does not affect the ion implantation range. There is also a feature that precise alignment is not particularly required for forming the mask 34.

It is a figure which shows the planar structure of the inscribed conduction | electrical_connection area composite body of the SiC semiconductor device which concerns on this invention. It is a figure which shows typically the cross-section of the inscribed conduction | electrical_connection area composite body of the SiC semiconductor device which concerns on this invention. It is a figure explaining the manufacturing method of the 1st Embodiment of this invention. It is a figure explaining the manufacturing method of the 1st Embodiment of this invention. It is a figure explaining the manufacturing method of the 2nd Embodiment of this invention. It is a figure explaining the manufacturing method of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... SiC substrate, 2 ... 1st conduction region, 3a, 3b ... 2nd conduction region, 20 ... 1st ion implantation mask, 21 ... 1st ion implantation layer, 22 ... 2nd ion implantation mask material, 23 ... 2nd Ion implantation mask, 24 ... Photoresist mask, 25 ... Third ion implantation mask, 26 ... Second ion implantation layer, 30 ... First ion implantation mask, 31 ... First ion implantation layer, 32 ... Second ion implantation mask material 33 ... Second ion implantation mask, 34 ... Photoresist mask, 35 ... Third ion implantation mask, 36 ... Second ion implantation layer.

Claims (5)

  A first conductive region formed by selective ion implantation into a limited portion of the surface of the semiconductor silicon carbide substrate; and a surface of the substrate so as to be in close contact with the first conductive region and to surround or sandwich the region. The second conductive region formed by selective ion implantation into a limited portion is characterized in that there is no common portion and no gap between the first conductive region and the second conductive region. Inscribed conductive region composite of silicon carbide semiconductor device.   2. The silicon carbide semiconductor according to claim 1, wherein the first conductive region and the second conductive region differ in at least one of conductivity type, impurity species, impurity concentration, and impurity implantation depth. Inscribed conduction region composite of the device.   The first conduction region and the second conduction region are different in impurity species, the first conduction region does not include ion-implanted impurities of the second conduction region, and the second conduction region is the first conduction region. 2. The inscribed conductive region composite body of a silicon carbide semiconductor device according to claim 1, which does not contain an ion implantation impurity. A first conductive region formed by selective ion implantation into a limited portion of the surface of the semiconductor silicon carbide substrate; and a surface of the substrate so as to be in close contact with the first conductive region and to surround or sandwich the region. Manufacturing method of inscribed conductive region composite of silicon carbide semiconductor device, manufacturing inscribed conductive region composite of silicon carbide semiconductor device, comprising second conductive region formed by selective ion implantation to limited portion Because
Forming at least a first mask for ion implantation on a surface of the substrate; performing selective ion implantation on the substrate through an opening of the first mask to form the first conductive region; and Forming a second mask for ion implantation in self-alignment with the first mask on the surface of the substrate; and performing selective ion implantation into the substrate through the opening of the second mask to form the second conductive region. And a step of activating the impurity ion-implanted into the first conductive region and the impurity ion-implanted into the second conductive region. A method for producing a composite. A first conductive region formed by selective ion implantation into a limited portion of the surface of the semiconductor silicon carbide substrate and a surface of the substrate so as to be in close contact with the first conductive region and surround or sandwich the region; Manufacturing method of inscribed conductive region composite of silicon carbide semiconductor device, manufacturing inscribed conductive region composite of silicon carbide semiconductor device, comprising second conductive region formed by selective ion implantation into limited portion Because
At least a step of forming a first mask for ion implantation on the surface of the substrate; a step of performing selective ion implantation into the substrate through an opening of the first mask to form the second conductive region; Forming a second mask for ion implantation in self-alignment with the first mask on the surface of the substrate; and performing selective ion implantation into the substrate through an opening of the second mask to form the first conductive region. And a step of activating the impurity ion-implanted into the first conductive region and the impurity ion-implanted into the second conductive region. A method for producing a composite.

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