Patent ID: 6191447
Filing Date: 2001-02-20
Classification: H01L

Abstract:
A power semiconductor device, comprising:a semiconductor substrate having a drift region of first conductivity type therein;a first trench and a second trench in said semiconductor substrate, said first and second trenches defining a drift region mesa of first conductivity type therebewteen that has a uniform lateral doping concentration therein extending from a sidewall of the first trench to an opposing sidewall of the second trench;an electrically insulating region on a sidewall of said first trench, said electrically insulating region having a tapered sidewall that extends outwardly relative to a bottom of said first trench at an average slope in a range between about 500 .ANG./.mu.m and 1,500 .ANG./.mu.m relative to the sidewall of said first trench; andan electrode on the tapered sidewall of said electrically insulating region;wherein the drift region mesa has a uniform vertical doping concentration therein at a level greater than about 1.times.10.sup.17 /cm.sup.-3 ; andwherein a product of a width of the drift region mesa and the first conductivity type doping concentration in the drift region is in a range between about 5.times.10.sup.12 cm.sup.-2 and 7.5.times.10.sup.12 cm.sup.-2.