Patent ID: 6600178
Filing Date: 2003-07-29
Classification: G02B,H01L,H03F

Abstract:
A semiconductor device comprising: a first semiconductor region having a first conductivity type, a second semiconductor region and a third semiconductor region each forming a junction with the first semiconductor region and each having a second conductivity type opposite to the first conductivity type, wherein a band gap for the first semiconductor region is smaller than the band gap for the second and the third semiconductor regions, wherein the band gap of the first semiconductor region has a substantially constant region near the junction between the first semiconductor region and the second semiconductor region, and wherein said band gap of the first semiconductor region decreases from the substantially constant region to the junction between the first semiconductor region and the third semiconductor region, wherein the second semiconductor region has a fourth semiconductor region of said second conductivity type with a band gap larger than that for the second semiconductor region connected with the second semiconductor region on the opposite side of the junction between the first semiconductor region and the second semiconductor region.