High-voltage multiple-resistivity drift-region LDMOS

A new multiple-resistivity drift-region structure which leads to an improvement of the on-resistance of high voltage LDMOS devices is proposed. The distinctive feature of the novel structure is the low sensitivity of the breakdown voltage to process variations. The important parameters of the structure such as on-resistance, threshold voltage and punchthrough voltage in the challen are discussed, and related to breakdown voltage. Experimental structures are fabricated and characterized to illustrate the advantages of the structure.