High-voltage lateral transistor with a multi-layered extended drain structure
First Claim
1. A high-voltage transistor fabricated on a substrate comprising:
- a drain region of a first conductivity type;
a body region of a second conductivity type opposite to the first conductivity type;
a plurality of drift regions of the first conductivity type, each of the drift regions extending in a first direction from the drain region to the body region, adjacent ones of the drift regions being separated in a second direction substantially orthogonal to the first direction by a dielectric layer;
a field plate member disposed within the dielectric layer, the field plate member being insulated in the second direction from one of the plurality of drift regions by a portion of the dielectric layer, the portion of the dielectric layer having an insulation width that varies along the first direction, the insulation width being narrowest near the body region and widest near the drain region;
a source region of the first conductivity type, the source region being separated from the drift regions by the body region; and
an insulated gate member disposed adjacent to the body region.
1 Assignment
0 Petitions
Accused Products
Abstract
A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. The layered structure may be fabricated in a variety of orientations. A MOSFET structure may be incorporated into the device adjacent to the source region, or, alternatively, the MOSFET structure may be omitted to produce a high-voltage transistor structure having a stand-alone drift region. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
-
Citations
45 Claims
-
1. A high-voltage transistor fabricated on a substrate comprising:
-
a drain region of a first conductivity type;
a body region of a second conductivity type opposite to the first conductivity type;
a plurality of drift regions of the first conductivity type, each of the drift regions extending in a first direction from the drain region to the body region, adjacent ones of the drift regions being separated in a second direction substantially orthogonal to the first direction by a dielectric layer;
a field plate member disposed within the dielectric layer, the field plate member being insulated in the second direction from one of the plurality of drift regions by a portion of the dielectric layer, the portion of the dielectric layer having an insulation width that varies along the first direction, the insulation width being narrowest near the body region and widest near the drain region;
a source region of the first conductivity type, the source region being separated from the drift regions by the body region; and
an insulated gate member disposed adjacent to the body region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 26)
a drain electrode electrically connected to the drain region;
a source electrode electrically connected to the source region.
-
-
7. The high-voltage transistor according to claim 1 wherein the first conductivity type is n-type and the second conductivity type is p-type.
-
8. The high-voltage transistor according to claim 6 wherein the drain region extends in a vertical direction from the insulating layer to the drain electrode.
-
9. The high-voltage transistor according to claim 1 wherein the source region is disposed above the body region.
-
10. The high-voltage transistor according to claim 9 further comprising a gate electrode electrically connected to the insulated gate member.
-
11. The high-voltage transistor according to claim 1 wherein the source region is disposed in the body region.
-
12. The high-voltage transistor according to claim 1 wherein a channel region is defined in the body region adjacent the insulated gate member between the source region and at least one of the drift regions, the channel region extending substantially parallel to the top surface of the substrate.
-
13. The high-voltage transistor according to claim 1 wherein the field plate member comprises polysilicon.
-
14. The high-voltage transistor according to claim 1 wherein the drift regions are substantially uniformly doped.
-
15. The high-voltage transistor according to claim 1 wherein each of the drift regions has a substantially uniform width in the second direction.
-
16. The high-voltage transistor according to claim 1 wherein the field plate member is electrically coupled to the source region.
-
17. The high-voltage transistor according to claim 1 wherein the field plate member is electrically coupled to the insulated gate member.
-
18. The high-voltage transistor according to claim 1 wherein the field plate member has a width that varies in a complementary manner with the insulation width.
-
26. The high-voltage transistor according to claim 16 wherein the at least one field plate member comprises polysilicon.
-
19. A high-voltage transistor comprising:
-
a drain region of a first conductivity type;
at least one source region of the first conductivity type;
a plurality of drift regions of the first conductivity type arranged in parallel and extending in a first direction from the drain region to the at least one source region, adjacent ones of the drift regions being separated in a second direction substantially orthogonal to the first direction by a dielectric layer;
at least one field plate member disposed within the dielectric layer, the at least one field plate member being insulated in the second direction from one of the plurality of drift regions by a portion of the dielectric layer, the portion of the dielectric layer having an insulation width that varies along the first direction, the insulation width being narrowest near the source region and widest near the drain region. - View Dependent Claims (20, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32)
a drain electrode electrically connected to the drain region;
a source electrode electrically connected to the at least one source region.
-
-
25. The high-voltage transistor according to claim 19 wherein the first conductivity type is n-type and the second conductivity type is p-type.
-
27. The high-voltage transistor according to claim 19 wherein the at least one field plate member has a width in the second direction that varies in a complementary manner with respect to the insulation width.
-
28. The high-voltage transistor according to claim 19 wherein the drift regions are substantially uniformly doped.
-
29. The high-voltage transistor according to claim 19 wherein each of the drift regions has a substantially uniform width in the second direction.
-
30. The high-voltage transistor according to claim 19 wherein the drift regions comprise an epitaxial layer.
-
31. The high-voltage transistor according to claim 19 wherein the at least one field plate member is electrically coupled to the at least one source region.
-
32. The high-voltage transistor according to claim 19 further comprising an insulated gate member.
-
33. A high-voltage transistor fabricated on a substrate, comprising:
-
a drain region of a first conductivity type;
a source region of the first conductivity type;
a drift region of the first conductivity type extending from the drain region in a first direction substantially parallel to a bottom surface of the substrate;
a dielectric layer that adjoins the drift region, the dielectric layer having an insulation width in a second direction substantially orthogonal to the first direction;
a field plate member insulated in the second direction from the drift region by the dielectric layer; and
wherein the insulation width varies along the first direction, the insulation width being narrowest near the source region and widest near the drain region. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 45)
a source electrode electrically connected to the source region; and
a drain electrode electrically connected to the drain region.
-
-
36. The high-voltage transistor according to claim 33 wherein the drift region has a width in the second direction, the width of the drift region being substantially uniform along the first direction.
-
37. The high-voltage transistor according to claim 33 wherein the first conductivity type comprises n-type and the second conductivity type comprises p-type.
-
38. The high-voltage transistor according to claim 33 wherein the second direction is substantially parallel to a bottom surface of the substrate.
-
39. The high-voltage transistor according to claim 33 wherein the second direction is substantially orthogonal to a bottom surface of the substrate.
-
40. The high-voltage transistor according to claim 33 further comprising a body region of a second conductivity type opposite to the first conductivity type, the drift region extending from the drain region to the body region.
-
45. The high-voltage transistor according to claim 33 wherein the second direction that is substantially parallel to a bottom surface of the substrate.
-
41. A high-voltage transistor fabricated on a substrate, comprising:
-
a drain region of a first conductivity type;
a source region of the first conductivity type;
a drift region of the first conductivity type extending from the drain region in a first direction substantially orthogonal to a bottom surface of the substrate;
a dielectric layer that adjoins the drift region, the dielectric layer having an insulation width in a second direction substantially orthogonal to the first direction;
a field plate member insulated in the second direction from the drift region by the dielectric layer; and
wherein the insulation width varies along the first direction, the insulation width being narrowest near the source region and widest near the drain region. - View Dependent Claims (42, 43, 44)
a source electrode electrically connected to the source region; and
a drain electrode electrically connected to the drain region.
-
-
43. The high-voltage transistor according to claim 41 wherein the first conductivity type comprises n-type and the second conductivity type comprises p-type.
-
44. The high-voltage transistor according to claim 41 further comprising a body region of a second conductivity type opposite to the first conductivity type, the drift region extending from the drain region to the body region.
Specification