Semiconductor device and method for forming the same

Abstract

A method for forming a semiconductor device includes: forming a first drift layer on a first side of a substrate; forming a second drift layer above the first drift layer, wherein the second drift layer is a silicon layer; forming a source electrode above the second drift layer; forming a gate structure above the second drift layer and adjacent to the source electrode; performing a polishing process on a second side of the substrate relative to the first side; and forming a drain electrode on the second side of the substrate.

Claims

1. A method of forming a semiconductor device, comprising: forming a first drift layer on a first side of a substrate; forming a second drift layer above the first drift layer, wherein the second drift layer is a silicon layer, and the substrate and the first drift layer are silicon carbide layers, and wherein the substrate, the first drift layer and the second drift layer are doped with an n-type dopant; forming a source electrode above the second drift layer; forming a gate structure above the second drift layer and adjacent to the source electrode; performing a polishing process on a second side of the substrate relative to the first side; and forming a drain electrode on the second side of the substrate.

2. The method as described in claim 1, wherein the first drift layer is exposed after the polishing process is performed.

3. The method as described in claim 2, wherein the drain electrode contacts the first drift layer.

4. The method of claim 1, wherein the n-type doping concentration of the substrate is greater than the n-type doping concentration of the first drift layer and the second drift layer.

5. A semiconductor device comprising: a first drift layer, the first drift layer being a silicon carbide layer; a second drift layer located above the first drift layer, wherein the second drift layer is a silicon layer; a source electrode located above the second drift layer; a gate structure located above the second drift layer and adjacent to the source electrode; a drain electrode located below the first drift layer; and a substrate located between the first drift layer and the drain electrode, wherein the substrate, the first drift layer, and the second drift layer are doped with an n-type dopant.

6. The semiconductor device as claimed in claim 5, wherein the gate structure extends into the second drift layer.

7. The semiconductor device of claim 5, wherein the doping concentration of the substrate is greater than the doping concentration of the first drift layer and the second drift layer.

8. A semiconductor device comprising: a first drift layer, the first drift layer being a silicon carbide layer; a second drift layer located above the first drift layer, wherein the second drift layer is a silicon layer; a source electrode located above the second drift layer; a gate structure located above the second drift layer and adjacent to the source electrode; and a drain electrode located below the first drift layer, wherein the drain electrode contacts the first drift layer.

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