Insulated-gate semiconductor device and method of manufacturing the same
AssigneeFuji Electric Co., Ltd.
InventorsTakamasa Ishikawa, Seiji Noguchi
Life of this patent
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Abstract
A method of manufacturing an insulated-gate semiconductor device, includes: digging a gate trench and a dummy trench; burying a dummy electrode in the dummy trench via a gate insulating film and burying a gate electrode in the gate trench via the gate insulating film; exposing an upper portion of the dummy electrode and selectively forming an insulating film for testing so as to cover the gate electrode; depositing a conductive film for testing on the dummy electrode and the insulating film for testing; and selectively testing an insulating property of the gate insulating film in the dummy trench by applying a voltage between the conductive film for testing and the charge transport, region.
Claims12
An insulated-gate semiconductor device, comprising:
- a charge transport region of a first conductivity-type;
- an injection control region of a second conductivity-type provided on the charge transport region;
- a main charge supply region of the first conductivity-type provided on the injection control region;
- a dummy electrode buried, via a gate insulating film, in a dummy trench penetrating the main charge supply region and the injection control region to reach the charge transport region;
- a gate electrode buried, via the gate insulating film, in a gate trench penetrating the main charge supply region and the injection control region to reach the charge transport region;
- a first interlayer insulating film provided on the gate electrode, having a stacked structure and including a first plurality of insulating films;
- a second interlayer insulating film provided on the dummy electrode, a number of insulating films included in the first interlayer insulating film being greater by at least one than a number of insulating films included in the second interlayer insulating film;
- and
- a main charge supply electrode deposited on the first interlayer insulating film and the second interlayer insulating film, the first interlayer insulating film and the second interlayer insulating film being provided under at least a portion of the main charge supply electrode.
A method of manufacturing an insulated-gate semiconductor device, comprising:
- forming an injection control region of a second conductivity-type on a charge transport region of a first conductivity-type;
- forming a main charge supply region of the first conductivity-type on the injection control region;
- digging a gate trench and a dummy trench so as to penetrate the main charge supply region and the injection control region;
- burying a dummy electrode in the dummy trench via a gate insulating film and burying a gate electrode in the gate trench via the gate insulating film;
- selectively forming an insulating film for testing so as to expose an upper portion of the dummy electrode and cover the gate electrode;
- depositing a conductive film for testing on the dummy electrode and the insulating film for testing;
- and
- selectively testing an insulating property of the gate insulating film in the dummy trench by applying a voltage between the conductive film for testing and the charge transport region.
Dependencies are inferred from the claim text.