| 摘要 |
PROBLEM TO BE SOLVED: To improve a withstanding voltage of a vertical semiconductor device consisting of a group-III nitride semiconductor having pn junction.SOLUTION: First of all, dry etching of an element periphery is performed from a p-layer 12 surface to a depth reaching an n-layer 11 by using a Clgas to form an element isolation groove 15 (refer to Fig. 2(a)). An end part 19a of a pn junction interface 19 is exposed to a lateral face 15a of the element isolation groove 15. The n-layer 11 is exposed to the whole surface of a bottom face 15b of the element isolation groove 15 and to a part of the lateral face 15a. Next, dry etching of the lateral face 15a and the bottom face 15b of the element isolation groove 15 is performed by using CFgas to dope F to the lateral face 15a and the bottom face 15b of the element isolation groove 15. This F dope amount is set to a dope amount by which the vicinity of the surface of the n-layer 11 exposed to the lateral face 15a and the bottom face 15b of the element isolation groove 15 is made be p-type, and then, a p-type region 18 is formed (refer to Fig. 2(b)). |
