Method of manufacturing a semiconductor power device
First Claim
1. A process for manufacturing a semiconductor power device, comprising the steps of:
- forming a semiconductor body of a first conductivity type and having a top surface;
forming, in said semiconductor body, a trench having side walls and a bottom;
coating said side walls and said bottom of said trench with a first dielectric material layer;
filling said trench with a second dielectric material layer and an auxiliary dielectric material layer;
etching said first, second, and auxiliary dielectric material layers via an etching process wherein, at the end of said etching step, said trench houses, at the bottom, portions of said first, second, and auxiliary dielectric material layers, said portions of the first and second dielectric material layers having a depth that is approximately equal and the auxiliary layer has a forked top profile;
forming a gate-oxide layer on said walls of said trench;
forming a gate region of conductive material within said trench and surrounded by said gate-oxide layer; and
forming, within said semiconductor body, a body region having a second conductivity type and a source region having said first conductivity type,said first, second, and auxiliary dielectric material layers comprising materials having similar responses to said etching process, and said etching step comprising simultaneously etching said first dielectric material layer, said second dielectric material layer, and said auxiliary dielectric material layer so as to remove a portion of each of said first, second, and auxiliary dielectric material layers in a partial, simultaneous and controlled way within said trench.
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Accused Products
Abstract
A trench is formed in a semiconductor body, the side walls and the bottom of the trench covered with a first dielectric material layer, the trench filled with a second dielectric material layer, the first and the second dielectric material layers are etched via a partial, simultaneous, and controlled etching such that the dielectric materials have similar etching rates, a gate-oxide layer having a thickness smaller than the first dielectric material layer deposited on the walls of the trench, a gate region of conductive material formed within the trench, and body regions and source regions formed within the semiconductor body at the sides of and insulated from the gate region. Thereby, the gate region extends only on top of the remaining portions of the first and second dielectric material layers.
11 Citations
19 Claims
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1. A process for manufacturing a semiconductor power device, comprising the steps of:
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forming a semiconductor body of a first conductivity type and having a top surface; forming, in said semiconductor body, a trench having side walls and a bottom; coating said side walls and said bottom of said trench with a first dielectric material layer; filling said trench with a second dielectric material layer and an auxiliary dielectric material layer; etching said first, second, and auxiliary dielectric material layers via an etching process wherein, at the end of said etching step, said trench houses, at the bottom, portions of said first, second, and auxiliary dielectric material layers, said portions of the first and second dielectric material layers having a depth that is approximately equal and the auxiliary layer has a forked top profile; forming a gate-oxide layer on said walls of said trench; forming a gate region of conductive material within said trench and surrounded by said gate-oxide layer; and forming, within said semiconductor body, a body region having a second conductivity type and a source region having said first conductivity type, said first, second, and auxiliary dielectric material layers comprising materials having similar responses to said etching process, and said etching step comprising simultaneously etching said first dielectric material layer, said second dielectric material layer, and said auxiliary dielectric material layer so as to remove a portion of each of said first, second, and auxiliary dielectric material layers in a partial, simultaneous and controlled way within said trench. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method, comprising:
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forming a trench in a semiconductor body; coating side walls and a bottom of the trench with a first dielectric material; forming an oxide layer on the first dielectric material layer; filling the trench with a second dielectric material; and removing a portion of the first dielectric material layer, the oxide, and the second dielectric material using an etching process that simultaneously and partially removes the first dielectric material layer, the oxide, and the second dielectric material and forms a forked top profile on the second dielectric material. - View Dependent Claims (16, 17, 18, 19)
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Specification