High voltage semiconductor device with non-linear resistively graded edge termination

摘要

A high voltage semiconductor device (1) with an improved edge termination arrangement is proposed. The high voltage semiconductor device (1) comprises a semiconductor substrate (2) with at least two differently doped regions (3, 4) and at least one junction (5) at which the two differently doped regions (3, 4) adjoin and an edge termination (9) at which the junction (5) reaches a surface of the semiconductor substrate (2). The edge termination (9) is covered by a grading layer (8) comprising a material having highly non-linear electrical resistivity characteristics due to an incorporation of microvaristors having an internal boundary structure. Electrical characteristics of the grading layer (8) comprising the microvaristors may be adapted to the specific requirements of the semiconductor device, particularly to its rated maximum voltage and to the length of the grading layer. Due to the highly non-linear electrical resistivity characteristics of the grading layer (8), critical local enhancements of an electric field adjacent to the edge termination may be prevented while at the same time keeping any leakage currents and frequency dependencies small.