Method for manufacturing a silicon carbide DIMOSFET

摘要

According to one embodiment, a semiconductor device includes a first, a second, a third, a fourth, and a fifth semiconductor region, an insulating film, a control electrode, and a first and a second electrode. The first, the second, the third, the fourth and the fifth semiconductor region include silicon carbide. The first semiconductor region has a first impurity concentration, and has a first portion. The second semiconductor region is provided on the first semiconductor region. The third semiconductor region is provided on the second semiconductor region. The fourth semiconductor region is provided between the first portion and the second semiconductor region. The fourth semiconductor region is provided between the first portion and the third semiconductor region. The fifth semiconductor region includes a first region provided between the first portion and the second semiconductor region, and has a second impurity concentration higher than the first impurity concentration.

主权项

1. A method for manufacturing a semiconductor device, comprising:
forming a first film on a main surface of a first semiconductor region, the first film including silicon carbide of a first conductivity type, the first film having a first impurity concentration, and forming a first mask pattern on the first film; forming a second film on the first film and the first mask pattern, forming a second mask pattern using the second film remaining on a side surface of the first mask pattern through etching of the second film; forming a second semiconductor region by implanting ions to the first semiconductor region through the second mask pattern, the second semiconductor region including silicon carbide of a second conductivity type; forming a third semiconductor region, on the second semiconductor region, by implanting ions to the second semiconductor region through the second mask pattern, the third semiconductor region including silicon carbide of the first conductivity type; removing the second mask pattern; forming a fourth semiconductor region in a region of the first semiconductor region outside of the second semiconductor region between the second semiconductor region and the third semiconductor region and the first mask pattern as viewed in a direction orthogonal to the main surface, by implanting ions to the first semiconductor region through the first mask pattern, the fourth semiconductor region including silicon carbide of the second conductivity type; and forming a fifth semiconductor region in a first region adjacent to the second semiconductor region on the lower side of the fourth semiconductor region, by implanting ions to the first semiconductor region through first mask pattern, the fifth semiconductor region including silicon carbide of the first conductivity type, the fifth semiconductor region having a second impurity concentration higher than the first impurity concentration.