METHOD FOR PRODUCING A SILICON CARBIDE SEMICONDUCTOR DEVICE

Abstract

A manufacturing method for a silicon carbide semiconductor device, the method comprising: - a step of forming a dielectric layer (55) over a portion of a silicon carbide layer (10); - a step of forming an ohmic electrode (70) adjacent to the dielectric layer (55) on the silicon carbide layer (10); - a step of removing an oxidized layer (75) on the ohmic electrode (70); - a step of forming a mask with its opening on the side opposite to the side on which the ohmic electrode (70) is adjacent to the dielectric layer (55) on the ohmic electrode (70) from which the oxidized layer (75) has been removed and on the dielectric layer (55); - a step of wet-etching a layer to be etched with hydrofluoric acid, whereby the mask is formed; and- a step in which the mask is removed after wet etching of the layer.

Claims

[1] A manufacturing method for a silicon carbide semiconductor device, the method comprising: - a step of forming a dielectric layer (55) over a portion of a silicon carbide layer (10); - a step of forming an ohmic electrode (70) adjacent to the dielectric layer (55) on the silicon carbide layer (10); - a step of removing an oxidized layer (75) on the ohmic electrode (70); - a step of forming a mask with its opening on the side opposite to the side on which the ohmic electrode (70) is adjacent to the dielectric layer (55) on the ohmic electrode (70) from which the oxidized layer (75) has been removed and on the dielectric layer (55); - a step of wet-etching a layer to be etched with hydrofluoric acid, wherein the mask is formed; and - a step in which the mask is removed after wet etching of the layer. [2] A manufacturing method for a silicon carbide semiconductor device according to claim 1, wherein the oxidized layer (75) is removed by weak etching with hydrofluoric acid. [3] A manufacturing method for a silicon carbide semiconductor device according to claim 1 or 2, wherein the ohmic electrode (70) is made of silicide. [4] A manufacturing method for a silicon carbide semiconductor device according to claim 3, wherein the silicide is nickel silicide. [5] A manufacturing method for a silicon carbide semiconductor device according to any one of claims 1 to 4, wherein the layer to be etched is made of silicon oxide. [6] A manufacturing method for a silicon carbide semiconductor device according to any one of claims 1 to 5, wherein the dielectric layer (55) is made of silicon oxide. [7] A manufacturing method for a silicon carbide semiconductor device according to any one of claims 1 to 6, wherein a Schottky interface at which the silicon carbide layer and the source electrode (80) are adjacent to each other is formed on the surface of the silicon carbide layer on which the layer has been removed by wet etching. [8] A manufacturing method for a silicon carbide semiconductor device according to claim 7, wherein the silicon carbide semiconductor device is a MOSFET having a built-in SBD, and the dielectric layer (55) is an intermetallic dielectric layer (55) formed adjacent to a gate electrode (60) of the MOSFET. [9] A manufacturing method for a silicon carbide semiconductor device according to claim 8, wherein the MOSFET having a built-in SBD with the ohmic electrode (70) and the Schottky barrier is arranged in a contact hole formed so as to penetrate the intermetallic dielectric layer (55). [10] A manufacturing method for a silicon carbide semiconductor device according to claim 9, wherein the Schottky barrier is formed to be surrounded by the ohmic electrode (70). [11] A manufacturing method for a silicon carbide semiconductor device according to any one of claims 8 to 10, wherein the MOSFET having a built-in SBD is arranged with a trench-type MOSFET and an SBD formed in a trench. [12] A manufacturing method for a silicon carbide semiconductor device according to claim 5, wherein the layer to be etched is the same layer as the dielectric layer. [13] A manufacturing method for a silicon carbide semiconductor device according to claim 5, wherein the layer to be etched is an oxidized sacrificial layer (51).

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