Global Patent Index - EP 1761953 A4

EP 1761953 A4 2009-02-25 - TRENCH MOSFET WITH RECESSED CLAMPING DIODE

Title (en)

TRENCH MOSFET WITH RECESSED CLAMPING DIODE

Title (de)

GRABEN-MOSFET MIT AUSGESPARTER KLEMMDIODE

Title (fr)

TRANSISTOR MOS A TRANCHES COMPRENANT UNE DIODE DE BLOCAGE

Publication

EP 1761953 A4 (EN)

Application

EP 04756535 A

Priority

US 2004021211 W

Abstract (en)

[origin: WO2006011882A1] In a trench-gated MOSFET (840) including an epitaxial layer (842) over a substrate (841) of like conductivity and trenches containing thick bottom oxide (846), sidewall gate oxide (850), and conductive gates (844), body regions (843) of the complementary conductivity are shallower than the gates (844), and clamp regions (853) are deeper and more heavily doped than the body regions but shallower than the trenches. Zener junctions clamp a drain-source voltage lower than the FPI breakdown of body junctions near the trenches, but the zener junctions, being shallower than the trenches, avoid undue degradation of the maximum drain-source voltage. The epitaxial layer (842) may have a dopant concentration that increases step-wise or continuously with depth. Chained implants of the body (843) and clamp regions (853) permit accurate control of dopant concentrations and of junction depth. Alternative fabrication processes permit implantation of the body (843) and clamp regions (853) before gate bus (852) formation or through the gate bus (852) after gate bus formation.

IPC 8 full level (invention and additional information)

H01L 27/108 (2006.01); H01L 29/06 (2006.01); H01L 29/76 (2006.01); H01L 29/94 (2006.01); H01L 31/119 (2006.01)

CPC (invention and additional information)

H01L 29/7813 (2013.01); H01L 29/0878 (2013.01); H01L 29/66734 (2013.01); H01L 29/7808 (2013.01); H01L 29/0696 (2013.01); H01L 29/42368 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

EPO simple patent family

WO 2006011882 A1 20060202; CN 100517719 C 20090722; CN 101002323 A 20070718; EP 1761953 A1 20070314; EP 1761953 A4 20090225; JP 2008505480 A 20080221

INPADOC legal status


2016-02-10 [18R] REFUSED

- Effective date: 20151003

2015-10-03 [REG DE R003] REFUSAL DECISION NOW FINAL

2009-06-24 [17Q] FIRST EXAMINATION REPORT

- Effective date: 20090525

2009-02-25 [A4] DESPATCH OF SUPPLEMENTARY SEARCH REPORT

- Effective date: 20090126

2009-02-25 [RIC1] CLASSIFICATION (CORRECTION)

- IPC: H01L 27/108 20060101AFI20060223BHEP

2009-02-25 [RIC1] CLASSIFICATION (CORRECTION)

- IPC: H01L 29/76 20060101ALI20090121BHEP

2009-02-25 [RIC1] CLASSIFICATION (CORRECTION)

- IPC: H01L 29/94 20060101ALI20090121BHEP

2009-02-25 [RIC1] CLASSIFICATION (CORRECTION)

- IPC: H01L 31/119 20060101ALI20090121BHEP

2009-02-25 [RIC1] CLASSIFICATION (CORRECTION)

- IPC: H01L 29/06 20060101ALI20090121BHEP

2007-10-03 [DAX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT (TO ANY COUNTRY) (DELETED)

2007-06-20 [RIN1] INVENTOR CHANGED BEFORE GRANT

- Inventor name: WILLIAMS, RICHARD

2007-06-20 [RIN1] INVENTOR CHANGED BEFORE GRANT

- Inventor name: CORNELL, MICHAEL

2007-06-20 [RIN1] INVENTOR CHANGED BEFORE GRANT

- Inventor name: CHAN, WAI TIEN 2/F, HOUSE 80B, JC CASTLE

2007-03-14 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20061110

2007-03-14 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR