Semiconductor device with two layers of opposite conductivity - has one layer with zone of reduced thickness peripherally surrounding semiconductor device (NL 23.12.77)

摘要

A junction is produced between the two semiconductor layers. Two ideal, single-dimensional depletion thickness region in the two layers. In order to increase the device breakdown voltage, it has a relatively thin zone (28) in the first semi-conductor layer (24) which surrounds the device. A zone of a relatively constant thickness (Y), smaller than the thickness of the single-dimensional depletion region in the first semiconductor layer (24). This relatively thin zone (28) has a width at least equal to half the coupling distance of the pn-junction. Preferably the semi-conductor layers have different impurity concentrations. The pre-junction may be flat or planar.