Semiconductor device having integrated diode

Claim 1

A semiconductor device comprising: a body of semiconductor material having first and second major opposing surfaces; a first region within said body having one type conductivity, said first region being adjacent said second surface; a second region within said body adjacent said first surface having a second type conductivity and forming a first PN junction with said first region at the interface therebetween, said first PN junction having a positionally dependent breakdown voltage associated therewith and having a point of lowest value of breakdown voltage therealong; said second region comprising a relatively thicker portion and a relatively thinner portion, said relatively thicker portion substantially completely peripherally surrounding said relatively thinner portion; said second region having a surface impurity concentration on the order of about 10 17 carriers/cm 3 , said relatively thicker portion extends to a depth of about 60 micrometers from said first surface; and said relatively thinner portion extending to a depth of about 30 micrometers from said first surface; a third region having said one type conductivity adjacent said first surface and extending into said second region, said third region forming a second PN junction with said second region at the interface therewith; said third region extending into said relatively thicker portion of said second region and substantially completely peripherally surrounding said relatively thinner portion; and a first electrode overlying and electrically contacting said third region and the portion of said second region overlying said point of lowest value.