Characteristics of a buried-channel graded drain with punchthrough stopper (BGP) MOS device

MOS device structures having a graded-drain (G), a buried-channel (B), and a punchthrough stopper (P) are realized by a triimplantation technique without additional masking. Combined effects of B, G, and P are experimentally investigated. Significant improvements in source-to-drain (S-D) breakdown voltage and the short-channel effect are observed in a BGP device. The BGP device structure will be durable for 5-V operation in the coming VLSI era.