TERMINATION STRUCTURE FOR POWER DEVICES

• US 20120267708A1
• Filed: 09/16/2011
• Published: 10/25/2012
• Est. Priority Date: 04/21/2011
• Status: Abandoned Application

• Current Assignee: Anpec Electronics Corporation
• Original Assignee: Anpec Electronics Corporation
• Inventors: Lin, Yung-Fa, Hsu, Shou-Yi, Wu, Meng-Wei, Chen, Main-Gwo, Shih, Yi-Chun, Chan, Jing-Qing
• Application Number:
  US13/234,150
• Publication Number:
  US 20120267708A1
• Time in Patent Office: Days
• US Class Current: 257/330
• CPC Class Codes: H01L 21/2256 through the applied layer
• CPC Class Codes: H01L 29/0619 with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction
• 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 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/423 not carrying the current to be rectified, amplified or switched
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402

Abstract

A termination structure for a power MOSFET device includes a substrate, an epitaxial layer on the substrate, a trench in the epitaxial layer, a first insulating layer within the trench, a first conductive layer atop the first insulating layer, and a column doping region in the epitaxial layer and in direct contact with the first conductive layer. The first conductive layer is in direct contact with the first insulating layer and is substantially level with a top surface of the epitaxial layer. The first conductive layer comprises polysilicon, titanium, titanium nitride or aluminum.

Claims

1. A termination structure for power devices, comprising:

a substrate of a first conductivity type;

an epitaxial layer of the first conductivity type on the substrate;

a trench in the epitaxial layer of the first conductivity type;

a first insulating layer within the trench;

a first conductive layer atop the first insulating layer within the trench; and

a column doping region of a second conductivity type disposed in the epitaxial layer of the first conductivity type adjacent to the trench, the column doping region being in direct contact with the first conductive layer.

2. The termination structure for power devices according to claim 1 wherein the first conductive layer comprises polysilicon, titanium, titanium nitride or aluminum.

3. The termination structure for power devices according to claim 1 wherein the first conductive layer is in directly contact with the first insulating layer and is substantially level with a top surface of the epitaxial layer of the first conductivity type.

4. The termination structure for power devices according to claim 1 further comprising:

a field oxide layer covering the first conductive layer and the column doping region of a second conductivity type.

5. The termination structure for power devices according to claim 4 further comprising:

a second conductive layer on the field oxide layer.

6. The termination structure for power devices according to claim 5 further comprising:

a second insulating layer covering the field oxide layer and the second conductive layer.

7. The termination structure for power devices according to claim 6 further comprising:

a gate line on the second insulating layer and a first contact plug in the second insulating layer for connecting the second conductive layer to the gate line.

8. The termination structure for power devices according to claim 1 wherein the first insulating layer is in direct contact with the substrate of the first conductivity type.

9. The termination structure for power devices according to claim 8 wherein the column doping region of a second conductivity type is connected to the substrate of the first conductivity type.

10. The termination structure for power devices according to claim 1 wherein the first conductivity type is N type and the second conductivity type is P type.

11. The termination structure for power devices according to claim 7 further comprising:

an ion well of the second conductivity type disposed in the epitaxial layer of the first conductivity type.