Method of manufacturing silicon carbide semiconductor device
First Claim
1. A method of manufacturing a silicon carbide semiconductor device that includes a semiconductor substrate and an electrode, the semiconductor substrate made of silicon carbide and having a first surface and a second surface opposing the first surface, the electrode formed on the second surface of the semiconductor substrate and being an ohmic electrode, the method comprising:
- preparing the semiconductor substrate and processing the second surface of the semiconductor substrate so that a surface roughness of the second surface is less than or equal to 10 nm and a value of (100%-reflectance-transmittance) at a wavelength of a laser light is greater than or equal to 80%;
forming a metal layer on the second surface of the semiconductor substrate after the processing the second surface; and
forming the electrode by irradiating the metal layer with the laser light.
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Accused Products
Abstract
In a method of manufacturing a silicon carbide semiconductor device, a semiconductor substrate made of silicon carbide and having first and second opposing surfaces is prepared. The second surface of the semiconductor substrate is processed so that a surface roughness of the second surface is less than or equal to 10 nm and a value of (100%-reflectance-transmittance) at a wavelength of a laser light is greater than or equal to 80%. A metal layer is formed on the second surface of the semiconductor substrate after the processing the second surface. The metal layer is irradiated with the laser light and thereby an ohmic electrode is formed on the second surface.
17 Citations
14 Claims
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1. A method of manufacturing a silicon carbide semiconductor device that includes a semiconductor substrate and an electrode, the semiconductor substrate made of silicon carbide and having a first surface and a second surface opposing the first surface, the electrode formed on the second surface of the semiconductor substrate and being an ohmic electrode, the method comprising:
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preparing the semiconductor substrate and processing the second surface of the semiconductor substrate so that a surface roughness of the second surface is less than or equal to 10 nm and a value of (100%-reflectance-transmittance) at a wavelength of a laser light is greater than or equal to 80%; forming a metal layer on the second surface of the semiconductor substrate after the processing the second surface; and forming the electrode by irradiating the metal layer with the laser light. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of manufacturing a silicon carbide semiconductor device that includes a semiconductor substrate and an electrode, the semiconductor substrate made of silicon carbide and having a first surface and a second surface opposing the first surface, the electrode formed on the second surface of the semiconductor substrate and being an ohmic electrode, the method comprising:
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preparing the semiconductor substrate and forming a metal layer on the second surface of the semiconductor substrate; processing a surface of the metal layer so that a value of (100%-reflectance-transmittance) at a wavelength of a laser light is greater than or equal to 80%; and forming the electrode by irradiating the metal layer with the laser light after the processing the surface of the metal layer. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification