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US 6,720,616 B2Granted
Trench MOS transistor
AssigneeInfineon Technologies AG
InventorsFranz Hirler, Manfred Kotek, Joost Larik, Frank Pfirsch
Life of this patent
Estimating the term…
Abstract
A trench MOS-transistor includes a body region strengthened by an implantation area that faces the drain region to increase the avalanche resistance.
Claims9
A trench MOS transistor, comprising:
- a semiconductor body with a first conductivity type forming at least one drain zone and formed of a semiconductor substrate and an epitaxial layer on said substrate, said epitaxial layer and said substrate having a junction therebetween;
- said semiconductor body having:
- a trench ending in a vicinity of said junction and having:
- a gate electrode;
- a trench side area contacting a side face of said trench;
- a trench upper end;
- and
- a trench lower end extending into said semiconductor body;
- at least one source zone with said first conductivity type, said source zone:
- disposed in said trench side area at said trench upper end;
- and
- having a source lower end;
- a first region with a second conductivity type disposed in said trench side area between said trench and an adjacent trench, said first region having a dopant gradient;
- and
- a second region with said second conductivity type, said second region:
- buried in said first region in said trench side area;
- having a higher doping and a steeper dopant gradient than said first region;
- disposed between said source zone and said drain zone;
- shaped in a strip;
- and
- having a charge carrier concentration of between 1017 to 1019 charge carriers/cm3;
- an insulating layer electrically isolating said gate electrode from said source zone, said first region, and said drain zone;
- and
- said insulating layer having a step forming:
- a first layer portion having a given thickness at said trench lower end;
- and
- a second layer portion having a thickness smaller than said given thickness at said trench upper end.
24 more elements
A trench MOS transistor configuration, comprising:
- a semiconductor body with a first conductivity type forming at least one drain zone and formed of a semiconductor substrate and an epitaxial layer on said substrate, said epitaxial layer and said substrate having a junction therebetween;
- said semiconductor body having:
- trenches ending in a vicinity of said junction and each having:
- a gate electrode;
- a trench side area contacting a side face of said trench;
- a trench upper end;
- and
- a trench lower end extending into said body;
- at least one source zone with said first conductivity type, said source zone:
- disposed in said trench side area at said trench upper end;
- and
- having a source lower end;
- a first region with a second conductivity type disposed in said trench side area between said trench and an adjacent trench, said first region having a dopant gradient;
- and
- a second region with said second conductivity type, said second region:
- buried in said first region in said trench side area;
- having a higher doping and a steeper dopant gradient than said first region;
- disposed between said source zone and said drain zone;
- shaped in a strip;
- and
- having a charge carrier concentration of between 1017 to 1019 charge carriers/cm3;
- at least one insulating layer electrically isolating said gate electrode from said source zone, said first region, and said drain zone;
- and
- said insulating layer having a step forming:
- a first layer portion having a given thickness at said trench lower end;
- and
- a second layer portion having a thickness smaller than said given thickness at said trench upper end.
24 more elements
Dependencies are inferred from the claim text.