Manufacturing method of semiconductor device

摘要

A semiconductor device includes a first-conductivity-type semiconductor layer including an active region in which a transistor having impurity regions is formed and a marginal region surrounding the active region, a second-conductivity-type channel layer formed between the active region and the marginal region and forming a front surface of the semiconductor layer, at least one gate trench formed in the active region to extend from the front surface of the semiconductor layer through the channel layer, a gate insulation film formed on an inner surface of the gate trench, a gate electrode formed inside the gate insulation film in the gate trench, and at least one isolation trench arranged between the active region and the marginal region to surround the active region and extending from the front surface of the semiconductor layer through the channel layer, the isolation trench having a depth equal to that of the gate trench.

主权项

1. A manufacturing method of a semiconductor device, comprising:
forming a hard mask on a first-conductivity-type semiconductor layer having an active region and a marginal region surrounding an outer periphery of the active region; simultaneously forming at least one gate trench in the active region and at least one isolation trench surrounding the outer periphery of the active region between the active region and the marginal region, by selectively etching the semiconductor layer from a front surface thereof using the hard mask; forming a channel layer extending between the active region and the marginal region and divided by the at least one isolation trench between the active region and the marginal region, by implanting a second-conductivity-type impurity into a surface layer portion of the semiconductor layer while keeping an entire area of the front surface of the semiconductor layer exposed; forming a gate insulation film on an inner surface of the at least one gate trench; forming a gate electrode by filling an electrode material into the at least one gate trench inside the gate insulation film; and forming a plurality of impurity regions in the active region by selectively implanting impurities into the surface layer portion of the semiconductor layer, the impurity regions forming a transistor in cooperation with the gate electrode.