Power semiconductor device having an electrode with an embedded material
A semiconductor device is described. The semiconductor device includes: a semiconductor substrate; a trench formed in a first main surface of the semiconductor substrate; a field plate electrode in the trench and reaching a same level as the first main surface of the semiconductor substrate; an insulating material that separates the field plate electrode from the semiconductor substrate; and a material embedded in the field plate electrode. The field plate electrode is made of a different material than the material embedded in the field plate electrode. The trench adjoins a region of the semiconductor substrate through which current flows in a first direction during operation of the semiconductor device. Additional device embodiments and methods of producing the semiconductor device are also described.
1 . A semiconductor device, comprising:
a semiconductor substrate;
a trench formed in a first main surface of the semiconductor substrate;
a field plate electrode in the trench and reaching a same level as the first main surface of the semiconductor substrate;
an insulating material that separates the field plate electrode from the semiconductor substrate; and
a material embedded in the field plate electrode,
wherein the field plate electrode comprises a different material than the material embedded in the field plate electrode,
wherein the trench adjoins a region of the semiconductor substrate through which current flows in a first direction during operation of the semiconductor device,
wherein the field plate electrode has a void,
wherein the material embedded in the field plate electrode lines sidewalls and a bottom of the void,
wherein an inner region of the void spaced inward from the sidewalls and the bottom of the void is unfilled.
2 . The semiconductor device of claim 1 , further comprising:
an additional trench formed in the first main surface of the semiconductor substrate and laterally spaced apart from the trench with the field plate electrode; and
a gate electrode disposed in the additional trench.
3 . The semiconductor device of claim 1 , wherein the material embedded in the field plate electrode comprises silicon oxide.
4 . The semiconductor device of claim 1 , wherein the semiconductor device is an n-channel device, and wherein the material embedded in the field plate electrode comprises a material selected from the group consisting of silicon oxide, silicon nitride, a piezoelectric material, and graphenic carbon.
5 . The semiconductor device of claim 1 , wherein the semiconductor device is a p-channel device, and wherein the material embedded in the field plate electrode comprises a material selected from the group consisting of silicon nitride, titanium nitride, tungsten, and a silicide.
6 . The semiconductor device of claim 1 , wherein the material embedded in the field plate electrode comprises a piezoelectric material, and wherein an additional electrode is embedded in the piezoelectric material.
7 . A semiconductor device, comprising:
a semiconductor substrate;
a first trench and a second trench formed in a first main surface of the semiconductor substrate and laterally spaced apart from one another;
a field plate electrode in the first trench and reaching a same level as the first main surface of the semiconductor substrate;
a field dielectric insulating material that separates the field plate electrode from the semiconductor substrate;
a gate electrode in the second trench;
a gate dielectric insulating material that separates the gate electrode from the semiconductor substrate; and
a material embedded in the field plate electrode,
wherein the field plate electrode comprises a different material than the material embedded in the field plate electrode,
wherein the field plate electrode has a void,
wherein the material embedded in the field plate electrode lines sidewalls and a bottom of the void, and
wherein an inner region of the void spaced inward from the sidewalls and the bottom of the void is unfilled.
8 . The semiconductor device of claim 7 , wherein the first trench is needle-shaped and the second trench is stripe-shaped.
9 . The semiconductor device of claim 7 , wherein the first trench is needle-shaped or stripe-shaped and the second trench is shaped as a grid that laterally surrounds the first trench.
10 . The semiconductor device of claim 7 , wherein the material embedded in the field plate electrode comprises silicon oxide.
11 . The semiconductor device of claim 7 , wherein the semiconductor device is an n-channel device, and wherein the material embedded in the field plate electrode comprises a material selected from the group consisting of silicon oxide, silicon nitride, a piezoelectric material, and graphenic carbon.
12 . The semiconductor device of claim 7 , wherein the semiconductor device is a p-channel device, and wherein the material embedded in the field plate electrode comprises a material selected from the group consisting of silicon nitride, titanium nitride, tungsten, and a silicide.
13 . The semiconductor device of claim 7 , wherein the material embedded in the field plate electrode comprises a piezoelectric material, and wherein an additional electrode is embedded in the piezoelectric material.