Trench gated power device fabrication by doping side walls of partially filled trench
First Claim
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1. A method of fabricating a trench gated power device, the method comprising:
- (i) forming a trench in a semiconductor substrate using a mask to define the trench region;
(ii) either a) filling the trench with electrode material and removing part of the contents of the trench to leave a partially filled trench;
or b) partially filling the trench with electrode material;
(iii) doping the side walls of the partially filled trench with the mask still in place; and
(iv) filling the remainder of the trench after step (iii);
wherein the trench gated power device is one selected from the group consisting of a MOSFET, MESFET and IGBT.
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Abstract
A trench is formed in a semiconductor substrate using a mask. The trench is filled with electrode material, a part of which is removed; alternatively, the trench is partially filled with the electrode material. The side walls of the trench are doped with the mask still in place. After the side walls are doped, the remainder of the trench is filled. The result is a trench gated power device such as a MOSFET, MESFET or IGBT.
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Citations
10 Claims
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1. A method of fabricating a trench gated power device, the method comprising:
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(i) forming a trench in a semiconductor substrate using a mask to define the trench region;
(ii) either a) filling the trench with electrode material and removing part of the contents of the trench to leave a partially filled trench;
orb) partially filling the trench with electrode material;
(iii) doping the side walls of the partially filled trench with the mask still in place; and
(iv) filling the remainder of the trench after step (iii);
wherein the trench gated power device is one selected from the group consisting of a MOSFET, MESFET and IGBT. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
the semiconductor substrate comprises;
a doped lower layer selected from the group consisting of an n+++ doped lower layer and a p+++ doped lower layer;
an n−
drain drift region disposed on the doped lower layer; and
a p base region disposed on the n−
drain drift region; and
step (i) comprises forming the trench in the p base region.
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Specification