Semiconductor device and method for manufacturing the same

Abstract

Disclosed is a semiconductor device (100) comprising a semiconductor substrate (10) of a first conductivity type which is composed of silicon carbide, a silicon carbide epitaxial layer (20) of the first conductivity type formed on a major surface (10a) of the semiconductor substrate (10), a well region (22) of a second conductivity type formed in a part of the silicon carbide epitaxial layer (20),and a source region (24) of the first conductivity type formed in a part of the well region (22). A channel epitaxial layer (30) composed of silicon carbide is formed on the silicon carbide epitaxiallayer (20), the well region (22) and the source region (24), and a part of the channel epitaxial layer (30) located on the well region (22) functions as a channel region (40). A dopant of the first conductivity type is implanted into portions (33, 35) of the channel epitaxial layer (30), namely portions other than the channel region (40).

Description

Semiconductor device and manufacturing method thereof technical field The present invention relates to a semiconductor device and a manufacturing method thereof. In particular, the invention relates to a power semiconductor device made of silicon carbide for high withstand voltage and high current. Background technique A power semiconductor device is a semiconductor element used for passing a large current at a high withstand voltage, and preferably has low loss. Existing power semiconductor devices mainly use silicon (Si) substrates, but power semiconductor devices using silicon carbide (SiC) substrates have attracted attention in recent years and have been continuously developed (for example, refer to Patent Documents 1 to 6 Wait). Because silicon carbide (SiC) has a one-digit higher insulation breakdown voltage than silicon (Si), it has the advantage that even if the depletion layer in the pn junction and Schottky junction is thinner, it can Maintain reverse withsta...

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Problems solved by technology

However, the inventors of the present application found that the current may be concentrated in a part of the channel epitaxial layer 105, and the reduction of the on-resistance will be hindered due to the current concentration.

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