Semiconductor device and method of manufacturing the same

• US 20070158726A1
• Filed: 12/28/2006
• Published: 07/12/2007
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: DSS Technology Management, Inc. (Document Security Systems, Inc.)
• Original Assignee: Dongbu Electronics Ltd. (DB HiTek Co., Ltd.)
• Inventors: Kim, Jong, Sim, Gyu
• Granted Patent: US 7,723,190 B2
• Time in Patent Office: Days
• US Class Current: 257/301
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 29/0634 Multiple reduced surface field (multi-RESURF) structures, e.g. double RESURF, charge compensation, cool, superjunction (SJ), 3D-RESURF, composite buffer (CB) structures
• 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 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/66666 Vertical transistors H01L29/66712, H01L29/66742 take precedence
• CPC Class Codes: H01L 29/7828 without inversion channel, e.g. vertical ACCUFETs, normally-on vertical MISFETs

Abstract

Disclosed are a semiconductor device having a vertical trench gate structure to improve the integration degree and a method of manufacturing the same. The semiconductor device includes an epitaxial layer having a second conductive type on a first conductive type substrate having an active region and an isolation region, a trench in the isolation region, a first conductive type first region in the epitaxial layer at opposite side portions of the trench, an isolation layer at a predetermined depth in the trench, a gate insulation layer along upper side portions of the trench, a gate electrode in an upper portion of the trench, a body region in the active region, a source electrode on the body region, a source region in an upper portion of the body region at opposite side portions of the gate electrode, and a drain electrode at a rear surface of the substrate.

Claims

1. A semiconductor device comprising:

a first conductive type substrate;

a second conductive type epitaxial layer on the first conductive substrate and having a trench therein;

a P-N junction aligned vertically along an inner wall of the trench;

an insulation layer covering an inner portion and an outer wall of the trench;

a gate electrode on the insulation layer;

a body region at sides of the gate electrode;

a source electrode on an upper portion of the body region; and

a drain electrode on a bottom surface of the first conductive type substrate.

2. The semiconductor device as claimed in claim 1, wherein the P-N junction is defined by the epitaxial layer and a second conductive type layer at an inner wall of the trench in the epitaxial layer.

3. The semiconductor device as claimed in claim 1, wherein the insulation layer includes an isolation layer and a gate insulation layer in the trench having a predetermined height.

4. The semiconductor device as claimed in claim 1, wherein the first conductive type is a P-type and the second conductive type is an N-type.

5. The semiconductor device as claimed in claim 1, wherein the trench has a depth reaching the first conductive type substrate.

6. The semiconductor device as claimed in claim 1, wherein the trench has a depth of at least a thickness of the epitaxial layer.

7. A method of forming a semiconductor device, the method comprising the steps of:

forming an epitaxial layer having a second conductivity type on a first conductive type substrate;

forming a trench in the epitaxial layer;

forming a P-N junction along an inner wall of the trench;

forming an insulation layer in the trench;

forming a gate electrode on the insulation layer;

forming a source region at opposite sides of the gate electrode; and

forming source and drain electrodes.

8. The method as claimed in claim 7, wherein the step of forming the P-N junction includes forming a first conductive type layer on an inner wall of the trench.

9. The method as claimed in claim 7, wherein the step of forming the insulation layer in the trench includes the sub-steps of:

forming an isolation layer filling the trench to a predetermined height; and

forming a gate insulation layer on the isolation layer.

10. The method as claimed in claim 7, wherein the step of forming the first conductive type layer on the inner wall of the trench includes a step of implanting first conductive type ions.

11. The method as claimed in claim 7, wherein the first conductive type is a P-type and the second conductive type is an N-type.

12. The method as claimed in claim 7, wherein the trench has a depth reaching the first conductive type substrate.

13. The method as claimed in claim 7, wherein the step of forming the trench in the epitaxial layer includes a step of forming a pad insulation layer on the epitaxial layer to protect a surface of the epitaxial layer.

14. The method as claimed in claim 7, wherein the step of forming the insulation layer in the trench includes the sub-steps of:

depositing the insulation layer such that trench is filled with the insulation layer; and

etching the insulation layer such that an upper side section of the trench is exposed.

15. The method as claimed in claim 7, wherein the step of forming the insulation layer in the trench includes forming an isolation layer having a predetermined height in the trench.

16. The method as claimed in claim 15, wherein the step of forming the insulation layer in the trench further includes forming a gate insulation layer on the isolation layer.

17. The method as claimed in claim 7, wherein the trench has a depth of at least a thickness of the epitaxial layer.