High-voltage lateral transistor with a multi-layered extended drain structure

• US 20030047788A1
• Filed: 09/07/2001
• Published: 03/13/2003
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: Power Integrations Incorporated
• Original Assignee: Power Integrations Incorporated
• Inventors: Disney, Donald Ray, Darwish, Mohamed
• Granted Patent: US 6,555,873 B2
• Time in Patent Office: Days
• US Class Current: 257/367
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• CPC Class Codes: H01L 29/0886 Shape
• CPC Class Codes: H01L 29/402 Field plates
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/41741 for vertical or pseudo-vertical devices
• CPC Class Codes: H01L 29/4232 with insulated gate
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/4238 characterised by the surface lay-out
• CPC Class Codes: H01L 29/7802 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/7824 with a substrate comprising an insulating layer, e.g. SOI-LDMOS transistors
• CPC Class Codes: H01L 29/7825 with trench gate electrode trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/86 controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
• CPC Class Codes: H01L 29/861 Diodes
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

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. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. 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.

Claims

1. A lateral high-voltage transistor fabricated on a substrate comprising:

an insulating layer that covers a top surface of the substrate;

a drain region of a first conductivity type disposed above the insulating layer;

a body region of a second conductivity type opposite to the first conductivity type disposed above the insulating layer;

a plurality of parallel-arranged drift regions of the first conductivity type disposed above the insulating layer, 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 orthogonal to the first direction by a dielectric layer;

a field plate member disposed within each dielectric layer, the field plate member being fully insulated from the drift regions;

a source region of the first conductivity type that adjoins the body region and is spaced-apart from the drift regions; and

an insulated gate member disposed adjacent to the body region, with a channel region being defined in the body region adjacent the insulated gate member between the source region and at least one of the drift regions.

2. The lateral high-voltage transistor according to claim 1 wherein the second direction is oriented perpendicular to a bottom surface of the substrate.

3. The lateral high-voltage transistor according to claim 1 wherein the second direction is oriented parallel to a bottom surface of the substrate.

4. The lateral high-voltage transistor according to claim 3 wherein each of the drift regions also extends in a vertical direction to the insulating layer.

5. The lateral high-voltage transistor according to claim 2 wherein the substrate comprises a bottom field plate member.

6. The lateral high-voltage transistor according to claim 1 further comprising:

a drain electrode electrically connected to the drain region;

a source electrode electrically connected to the source region.

7. The lateral 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 lateral 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 lateral high-voltage transistor according to claim 1 wherein the source region is disposed above the body region.

10. The lateral high-voltage transistor according to claim 9 further comprising a gate electrode electrically connected to the insulated gate member.

11. The lateral high-voltage transistor according to claim 1 wherein the source region is disposed in the body region.

12. The lateral high-voltage transistor according to claim 11 wherein the channel region extends parallel to the top surface of the substrate.

13. A lateral 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 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 fully insulated from the drift regions.

14. The lateral high-voltage transistor according to claim 13 further comprising:

source electrode electrically connected to the at least one source region; and

a drain electrode electrically connected to the drain region.

15. The lateral high-voltage transistor according to claim 13 wherein the lateral high-voltage transistor is fabricated on a semiconductor substrate having a planar bottom surface, the first direction being oriented parallel to the planar bottom surface and the second direction being oriented perpendicular to the planar bottom surface.

16. The lateral high-voltage transistor according to claim 13 wherein the high-voltage transistor is fabricated on a semiconductor substrate having a planar bottom surface, the first and second directions being oriented parallel to the planar bottom surface.

17. The lateral high-voltage transistor according to claim 13 wherein the first conductivity type comprises n-type and the second conductivity type comprises p-type.