PROCESS FOR MAKING SILICON CARBIDE SEMICONDUCTOR DEVICE

摘要

The present invention provides a process for producing a semiconductor device having a breakdown voltage heightened by improving the step coverage properties of the interlayer dielectric for covering polysilicon electrodes. The process includes a step in which a gate insulating film is formed on a silicon carbide substrate, a step in which a polysilicon film is formed on the gate insulating film, a step in which one or more dopants of N, P, As, Sb, B, Al, and Ar are ion implanted into the polysilicon film, and a step in which a mask is selectively formed on the polysilicon film. The exposed portions of the polysilicon film are removed by isotropic dry etching. Thus, polysilicon electrodes can be formed so that in each polysilicon electrode, the hem part sandwiched between the bottom surface and the lateral surface of the polysilicon electrode has an inclination angle of 60° or less.

主权项

1. A method of manufacturing a silicon carbide semiconductor device, comprising:
forming a gate insulating film on a silicon carbide substrate; forming a polysilicon film on the gate insulating film; ion implanting one or more dopants of N, P, As, Sb, B, Al, and Ar into the polysilicon film; selectively forming a mask on the polysilicon film; forming a polysilicon electrode by removing an exposed portion of the polysilicon film via isotropic dry etching; removing the mask; and forming an interlayer insulating film on the polysilicon electrode, wherein, in the step of ion implanting the dopant into the polysilicon film, an ion implantation angle of the dopant is 60° or lower.