Abstract: A first impurity region is formed by ion implantation through a first opening formed in a mask layer. By depositing a spacer layer on an etching stop layer on which the mask layer has been provided, a mask portion having the mask layer and the spacer layer is formed. By anisotropically etching the spacer layer, a second opening surrounded by a second sidewall is formed in the mask portion. A second impurity region is formed by ion implantation through the second opening. An angle of the second sidewall with respect to a surface is 90°±10° across a height as great as a second depth. Thus, accuracy in extension of an impurity region can be enhanced.

Abstract: A method for manufacturing a semiconductor device includes the steps of: preparing a substrate made of silicon carbide; forming, on one main surface of the substrate, a detection film having a light transmittance different from that of silicon carbide; confirming presence of the substrate by applying light to the detection film; and forming an active region in the substrate whose presence has been confirmed.

Abstract: A method for manufacturing a silicon carbide semiconductor device includes the following steps. A silicon carbide substrate is heated in an atmosphere containing oxygen, so as to form a gate insulating film on and in contact with the silicon carbide substrate. The silicon carbide substrate having the gate insulating film is heated at 1250° C. or more in an atmosphere containing nitrogen and nitrogen monoxide. A value obtained by dividing partial pressure of the nitrogen monoxide by a total of partial pressure of the nitrogen and the partial pressure of the nitrogen monoxide in the second heating step is more than 3% and less than 10%. Accordingly, there can be provided a method for manufacturing a silicon carbide semiconductor device having high mobility.

Abstract: A method of cleaning a SiC semiconductor includes the steps of forming an oxide film at the surface of a SiC semiconductor, and removing the oxide film. At the step of forming an oxide film, an oxide film is formed using ozone water having a concentration greater than or equal to 30 ppm. The forming step preferably includes the step of heating at least one of the surface of the SiC semiconductor and the ozone water. Thus, there can be obtained a method of cleaning a SiC semiconductor that can exhibit cleaning effect on the SiC semiconductor.

Abstract: A first impurity region is formed by ion implantation through a first opening formed in a mask layer. By depositing a spacer layer on an etching stop layer on which the mask layer has been provided, a mask portion having the mask layer and the spacer layer is formed. By anisotropically etching the spacer layer, a second opening surrounded by a second sidewall is formed in the mask portion. A second impurity region is formed by ion implantation through the second opening. An angle of the second sidewall with respect to a surface is 90°±10° across a height as great as a second depth. Thus, accuracy in extension of an impurity region can be enhanced.

Abstract: A first impurity region is formed by ion implantation through a first opening formed in a mask layer. By depositing a spacer layer on an etching stop layer on which the mask layer has been provided, a mask portion having the mask layer and the spacer layer is formed. By anisotropically etching the spacer layer, a second opening surrounded by a second sidewall is formed in the mask portion. A second impurity region is formed by ion implantation through the second opening. An angle of the second sidewall with respect to a surface is 90°±10° across a height as great as a second depth. Thus, accuracy in extension of an impurity region can be enhanced.

Abstract: A method for manufacturing a silicon carbide semiconductor device includes the following steps. A silicon carbide substrate is heated in an atmosphere containing oxygen, so as to form a gate insulating film on and in contact with the silicon carbide substrate. The silicon carbide substrate having the gate insulating film is heated at 1250° C. or more in an atmosphere containing nitrogen and nitrogen monoxide. A value obtained by dividing partial pressure of the nitrogen monoxide by a total of partial pressure of the nitrogen and the partial pressure of the nitrogen monoxide in the second heating step is more than 3% and less than 10%. Accordingly, there can be provided a method for manufacturing a silicon carbide semiconductor device having high mobility.

Abstract: A method for manufacturing a silicon carbide semiconductor device includes the step of forming a mask pattern of a silicon oxide film by removing a portion of the silicon oxide film by means of etching employing a gas containing oxygen gas and at least one fluorine compound gas selected from a group consisting of CF4, C2F6, C3F8, and SF6.

Abstract: There is provided a method for manufacturing a SiC semiconductor device achieving improved performance. The method for manufacturing the SiC semiconductor device includes the following steps. That is, a SiC semiconductor is prepared which has a first surface having at least a portion into which impurities are implanted. By cleaning the first surface of the SiC semiconductor, a second surface is formed. On the second surface, a Si-containing film is formed. By oxidizing the Si-containing film, an oxide film constituting the SiC semiconductor device is formed.

Abstract: A first impurity region is formed by ion implantation through a first opening formed in a mask layer. By depositing a spacer layer on an etching stop layer on which the mask layer has been provided, a mask portion having the mask layer and the spacer layer is formed. By anisotropically etching the spacer layer, a second opening surrounded by a second sidewall is formed in the mask portion. A second impurity region is formed by ion implantation through the second opening. An angle of the second sidewall with respect to a surface is 90°±10° across a height as great as a second depth. Thus, accuracy in extension of an impurity region can be enhanced.

Abstract: A silicon carbide substrate having a surface is prepared. An impurity region is formed by implanting ions from the surface into the silicon carbide substrate. Annealing for activating the impurity region is performed. The annealing includes the step of applying first laser light having a first wavelength to the surface of the silicon carbide substrate, and the step of applying second laser light having a second wavelength to the surface of the silicon carbide substrate. The silicon carbide substrate has first and second extinction coefficients at the first and second wavelengths, respectively. A ratio of the first extinction coefficient to the first wavelength is higher than 5×105/m. A ratio of the second extinction coefficient to the second wavelength is lower than 5×105/m. Consequently, damage to the surface of the silicon carbide substrate during laser annealing can be reduced.

Abstract: Provided is a III nitride semiconductor electronic device having a structure capable of reducing leakage current. A laminate 11 includes a substrate 13 and a III nitride semiconductor epitaxial film 15. The substrate 13 is made of a III nitride semiconductor having a carrier concentration of more than 1×1018 cm?3. The epitaxial structure 15 includes a III nitride semiconductor epitaxial film 17. A first face 13a of the substrate 13 is inclined at an angle ? of more than 5 degrees with respect to an axis Cx extending in a direction of the c-axis. A normal vector VN and a c-axis vector VC make the angle ?. The III nitride semiconductor epitaxial film 17 includes first, second and third regions 17a, 17b and 17c arranged in order in a direction of a normal to the first face 13a. A dislocation density of the third region 17c is smaller than that of the first region 17a. A dislocation density of the second region 17b is smaller than that of the substrate 13.

Abstract: A method for manufacturing a SiC semiconductor device includes: a step of forming an oxide film on a surface of a SiC substrate; and a step of removing the oxide film. In the step of forming the oxide film, ozone gas is used. In the step of removing the oxide film, it is preferable to use halogen plasma or hydrogen plasma. In this way, problems associated with a chemical solution can be reduced while obtaining a method and device for manufacturing a SiC semiconductor device, by each of which a cleaning effect can be improved.

Abstract: A silicon carbide substrate having a surface is prepared. An impurity region is formed by implanting ions from the surface into the silicon carbide substrate. Annealing for activating the impurity region is performed. The annealing includes the step of applying first laser light having a first wavelength to the surface of the silicon carbide substrate, and the step of applying second laser light having a second wavelength to the surface of the silicon carbide substrate. The silicon carbide substrate has first and second extinction coefficients at the first and second wavelengths, respectively. A ratio of the first extinction coefficient to the first wavelength is higher than 5×105/m. A ratio of the second extinction coefficient to the second wavelength is lower than 5×105/m. Consequently, damage to the surface of the silicon carbide substrate during laser annealing can be reduced.

Abstract: The present method of forming a nitride semiconductor epitaxial layer includes the steps of growing at least one layer of nitride semiconductor epitaxial layer on a nitride semiconductor substrate having a dislocation density lower than or equal to 1×107 cm?2 with a chemical decomposition layer interposed therebetween, the chemical decomposition layer being chemically decomposed at least with either a gas or an electrolytic solution, and decomposing the chemical decomposition layer at least with either the gas or the electrolytic solution at least either during or after the step of growing the nitride semiconductor epitaxial layer, thereby separating the nitride semiconductor epitaxial layer from the nitride semiconductor substrate. A high-quality nitride semiconductor epitaxial layer suffering less damage when separated from the nitride semiconductor substrate is thereby formed.

Abstract: Substrates are mounted on a plurality of susceptors respectively. The plurality of susceptors on which respective substrates are mounted are placed on a rotational mechanism so that the susceptors are vertically spaced at a predetermined interval. The rotational mechanism on which the plurality of susceptors are placed is rotated. The plurality of susceptors on which the substrates are mounted respectively are heated. Semiconductor thin-films are deposited by supplying a source gas to each of the susceptors that are heated while being rotated, the source gas having been heated while passing through gas flow paths of respective path lengths substantially equal to each other.

Abstract: There are provided a semiconductor device of low cost and high quality, a combined substrate used for manufacturing the semiconductor device, and methods for manufacturing them. The method for manufacturing the semiconductor device includes the steps of: preparing a single-crystal semiconductor member; preparing a supporting base; connecting the supporting base and the single-crystal semiconductor member to each other through a connecting layer containing carbon; forming an epitaxial layer on a surface of the single-crystal semiconductor member; forming a semiconductor element using the epitaxial layer; separating the single-crystal semiconductor member from the supporting base by oxidizing and accordingly decomposing the connecting layer after the step of forming the semiconductor element; and dividing the single-crystal semiconductor member separated from the supporting base.

Abstract: A method of fabricating a SiC semiconductor device includes the steps of preparing a silicon carbide semiconductor including a first surface having impurities implanted at least partially, forming a second surface by dry etching the first surface of the silicon carbide semiconductor using gas including hydrogen gas, and forming an oxide film constituting the silicon carbide semiconductor device on the second surface.

Abstract: There is provided a method for manufacturing a SiC semiconductor device achieving improved performance. The method for manufacturing the SiC semiconductor device includes the following steps. That is, a SiC semiconductor is prepared which has a first surface having at least a portion into which impurities are implanted. By cleaning the first surface of the SiC semiconductor, a second surface is formed. On the second surface, a Si-containing film is formed. By oxidizing the Si-containing film, an oxide film constituting the SiC semiconductor device is formed.

Abstract: A method for manufacturing a silicon carbide semiconductor device includes the step of forming a mask pattern of a silicon oxide film by removing a portion of the silicon oxide film by means of etching employing a gas containing oxygen gas and at least one fluorine compound gas selected from a group consisting of CF4, C2F6, C3F8, and SF6.