Semiconductor device with Schottky contact
In an embodiment, a semiconductor device is provided. The semiconductor device may include a semiconductor body including a first doped region of a first conductivity type and a second doped region of a second conductivity type. The semiconductor device may include a metal structure, in the semiconductor body, overlying the second doped region. The metal structure may include a first sidewall adjacent a first portion of the first doped region, a second sidewall adjacent a second portion of the first doped region, and a third sidewall adjacent the second doped region. The semiconductor device may include a Schottky contact including a junction of the third sidewall of the metal structure with the second doped region.
1 . A semiconductor device, comprising:
a semiconductor body comprising:
a first doped region of a first conductivity type; and
a second doped region of a second conductivity type different than the first conductivity type; and
a metal structure, in the semiconductor body, overlying the second doped region of the second conductivity type, wherein:
the metal structure comprises:
a first sidewall adjacent a first portion of the first doped region of the first conductivity type;
a second sidewall adjacent a second portion of the first doped region of the first conductivity type; and
a third sidewall adjacent the second doped region of the second conductivity type; and
a Schottky contact comprises a junction of the third sidewall of the metal structure with the second doped region of the second conductivity type.
2 . The semiconductor device of claim 1 , wherein:
an ohmic contact comprises at least one of:
a junction of the first sidewall of the metal structure with the first portion of the first doped region; or
a junction of the second sidewall of the metal structure with the second portion of the first doped region.
3 . The semiconductor device of claim 1 , wherein:
a first side of the second doped region abuts a third portion of the first doped region underlying the first portion of the first doped region; and
a second side of the second doped region abuts a fourth portion of the first doped region underlying the second portion of the first doped region.
4 . The semiconductor device of claim 1 , wherein:
a first portion of the second doped region underlies the first portion of the first doped region;
a second portion of the second doped region underlies the second portion of the first doped region; and
a third portion of the second doped region, between the first portion of the second doped region and the second portion of the second doped region, underlies the metal structure.
5 . The semiconductor device of claim 1 , wherein:
a first concentration of first dopants of the second conductivity type in a first portion of the second doped region is greater than a second concentration of second dopants of the second conductivity type in a second portion of the second doped region; and
the first portion of the second doped region overlies the second portion of the second doped region.
6 . The semiconductor device of claim 1 , comprising:
a trench gate structure, in the semiconductor body, comprising a gate electrode and a gate dielectric layer separating the gate electrode from the semiconductor body; and
a source region, of the second conductivity type, between the trench gate structure and the metal structure.
7 . The semiconductor device of claim 6 , comprising:
a second trench gate structure, in the semiconductor body, comprising a second gate electrode and a second gate dielectric layer separating the second gate electrode from the semiconductor body, wherein the metal structure is between the trench gate structure and the second trench gate structure; and
a second source region, of the second conductivity type, between the second trench gate structure and the metal structure.
8 . The semiconductor device of claim 1 , wherein the first doped region comprises:
a shielding region; and
a body region over the shielding region.
9 . The semiconductor device of claim 1 , comprising:
a first portion comprising a first transistor;
a second portion comprising a second transistor; and
a third portion comprising a third transistor, wherein:
the second portion of the semiconductor device is between the first portion of the semiconductor device and the third portion of the semiconductor device;
the second doped region is in the first portion of the semiconductor device;
the third portion of the semiconductor device comprises:
a third doped region of the second conductivity type; and
a second metal structure;
a second Schottky contact comprises a junction of the second metal structure with the third doped region; and
a third portion of the first doped region separates the second doped region from the third doped region.
10 . The semiconductor device of claim 1 , comprising:
a superjunction region, of the first conductivity type, underlying the metal structure.
11 . The semiconductor device of claim 1 , wherein:
a vertical position of the metal structure matches:
a vertical position of the first portion of the first doped region; and
a vertical position of the second portion of the first doped region.
12 . The semiconductor device of claim 1 , wherein:
the metal structure comprises:
a filling structure; and
a metal contact layer separating the filling structure from the semiconductor body;
the first sidewall comprises a first portion of the metal contact layer;
the second sidewall comprises a second portion of the metal contact layer; and
the third sidewall comprises a third portion of the metal contact layer.
13 . The semiconductor device of claim 1 , wherein:
the metal structure comprises at least one of titanium, aluminum, titanium aluminide, or molybdenum nitride (MoN).
14 . A semiconductor device, comprising:
a semiconductor body comprising:
a first doped region of a first conductivity type;
a second doped region of a second conductivity type different than the first conductivity type;
a third doped region of the first conductivity type; and
a source region of the second conductivity type;
a first metal contact layer overlying the semiconductor body and adjacent the source region of the second conductivity type; and
a metal structure in the semiconductor body, wherein:
the metal structure comprises at least three of:
a first sidewall adjacent a first portion of the first doped region of the first conductivity type and a first portion of the second doped region of the second conductivity type;
a second sidewall adjacent a second portion of the first doped region of the first conductivity type and a second portion of the second doped region of the second conductivity type;
a third sidewall adjacent the third doped region of the first conductivity type; or
a fourth sidewall adjacent the first metal contact layer; and
a Schottky contact comprises at least one of:
a junction of the first sidewall of the metal structure with the first portion of the second doped region of the second conductivity type; or
a junction of the second sidewall of the metal structure with the second portion of the second doped region of the second conductivity type.
15 . The semiconductor device of claim 14 , comprising:
a trench gate structure, in the semiconductor body, comprising a gate electrode and a gate dielectric layer separating the gate electrode from the semiconductor body, wherein the source region is between the trench gate structure and the metal structure;
a first superjunction region, of the first conductivity type, underlying the metal structure; and
a second superjunction region, of the second conductivity type, underlying the trench gate structure.
16 . The semiconductor device of claim 15 , comprising:
a first portion comprising a first transistor;
a second portion comprising a second transistor; and
a third portion comprising a third transistor, wherein:
the second portion of the semiconductor device is between the first portion of the semiconductor device and the third portion of the semiconductor device;
the second doped region is in the first portion of the semiconductor device;
the third portion of the semiconductor device comprises:
a fourth doped region of the second conductivity type; and
a second metal structure;
a second Schottky contact comprises a junction of the second metal structure with the fourth doped region; and
at least one of a third portion of the first doped region or a portion of the third doped region separates the second doped region from the fourth doped region.
17 . The semiconductor device of claim 14 , wherein:
a vertical position of a first portion of the metal structure matches:
a vertical position of the first portion of the first doped region; and
a vertical position of the second portion of the first doped region; and
a vertical position of a second portion of the metal structure matches:
a vertical position of the first portion of the second doped region; and
a vertical position of the second portion of the second doped region.
18 . The semiconductor device of claim 14 , wherein:
the metal structure comprises:
a filling structure; and
a second metal contact layer separating the filling structure from the semiconductor body; and
at least three of:
the first sidewall comprises a first portion of the second metal contact layer;
the second sidewall comprises a second portion of the second metal contact layer;
the third sidewall comprises a third portion of the second metal contact layer; and
the fourth sidewall comprises at least one of a fourth portion of the second metal contact layer or a portion of the filling structure.
19 . A semiconductor device, comprising:
a semiconductor body comprising:
a first doped region of a first conductivity type;
a second doped region of a second conductivity type different than the first conductivity type;
a third doped region of the first conductivity type; and
a source region of the second conductivity type;
a first metal contact layer overlying the semiconductor body and adjacent:
a first portion of the first doped region of the first conductivity type;
a second portion of the first doped region of the first conductivity type; and
a first portion of the second doped region of the second conductivity type; and
a second metal contact layer overlying the first metal contact layer and adjacent the source region of the second conductivity type, wherein:
the first portion of the second doped region of the second conductivity type separates the first portion of the first doped region of the first conductivity type from the second portion of the first doped region of the first conductivity type;
the second doped region of the second conductivity type overlies the third doped region of the first conductivity type; and
a Schottky contact comprises a junction of the first metal contact layer with the first portion of the second doped region of the second conductivity type.
20 . The semiconductor device of claim 19 , comprising:
a first trench gate structure, in the semiconductor body, comprising a first gate electrode and a first gate dielectric layer separating the first gate electrode from the semiconductor body; and
a second trench gate structure, in the semiconductor body, comprising a second gate electrode and a second gate dielectric layer separating the second gate electrode from the semiconductor body, wherein:
a second portion of the second doped region underlies the first portion of the first doped region and is adjacent the first trench gate structure; and
a third portion of the second doped region underlies the second portion of the first doped region and is adjacent the second trench gate structure.
21 . The semiconductor device of claim 19 , comprising:
a first portion comprising a first transistor;
a second portion comprising a second transistor; and
a third portion comprising a third transistor, wherein:
the second portion of the semiconductor device is between the first portion of the semiconductor device and the third portion of the semiconductor device;
the second doped region is in the first portion of the semiconductor device;
the third portion of the semiconductor device comprises a second Schottky contact comprising a junction of a fourth doped region of the second conductivity type with a third metal contact layer; and
at least one of a third portion of the first doped region or a portion of the third doped region separates the second doped region from the fourth doped region.
22 . The semiconductor device of claim 19 , comprising:
a trench gate structure; and
a superjunction region, of the second conductivity type, underlying the trench gate structure.