Semiconductor device and method for manufacturing same

摘要

[Problem] To provide an SiC semiconductor device, with which stabilization of high-temperature operation can be achieved by decreasing mobile ions in a gate insulating film, and a method for manufacturing the SiC semiconductor device.;[Solution Means] A semiconductor device 1 has an MIS structure including an SiC epitaxial layer 3, a gate insulating film 9 and a gate electrode 10 formed on the gate insulating film 9. A gate insulating film 9 includes a silicon oxide film in contact with the SiC epitaxial layer 3. In the MIS structure, an area density QM of positive mobile ions in the gate insulating film 9 is made no more than 1×1012 cm−2.

主权项

1. A method for manufacturing a semiconductor device comprising:
forming a gate insulating film, which includes a silicon oxide film formed by thermal oxidation of a semiconductor layer made of SiC and with which the area density QM of positive mobile ions in its interior is no more than 1×1012 cm−2; and forming an MIS structure by forming a gate electrode on the gate insulating film, wherein the forming the gate insulating film comprises forming a temporary electrode on a front surface of the silicon oxide film, applying a negative bias to the temporary electrode to attract the positive mobile ions in the silicon oxide film toward a front surface portion of the silicon oxide film, removing the temporary electrode after attracting the positive mobile ions, and etching the front surface portion of the silicon oxide film after removing the temporary electrode.