Proposal of new interconnection technique for very high-voltage IC's

A new, cost-effective, high-voltage interconnection technique for very high-voltage IC's, called the “self-shielding technique”, is proposed. To avoid reduction of the breakdown voltage of high-voltage devices due to the electric potential of overlying interconnections, only the self-PN-junction structures of the high-voltage devices themselves are utilized in the self-shielding technique. No additional shielding structure is required, even to realize a very high-voltage IC above 1000 V. The design concept and device structures are presented with the experimental results on the electrical characterictics of self-shielded interconnections and on the operations of self-shielded 1200-V level shifters. Comparison between self-shielded and conventional high-voltage IC's (HVIC's) and the process and the devices of self-shielded HVIC technology are also described.