TRENCH TYPE DMOS TRANSISTOR MANUFACTURED BY RELATIVELY SMALL NUMBER OF MASKING PROCESSES AND HAVING THICK OXIDE LAYER IN DISTAL REGION, AND ITS MANUFACTURING METHOD

摘要

PPROBLEM TO BE SOLVED: To provide a DMOS transistor which is manufactured in the relatively small number of masking processes and improves a process controllability and a stability of a breakdown voltage, and its manufacturing method. PSOLUTION: The trench type DMOS transistor is manufactured by using seven masking processes, and one of the processes defines a p+ type deep main body region and forms an active region of the transistor in which its mask is formed in a LOCOS process. Another masking process defines an insulating oxide layer of a distal region thicker than the active region of the transistor, whereby a contamination of a substrate in a production process is reduced and the process controllability can be improved. Further, a field effect distribution is improved by the thick field oxide layer in the distal region, and an electron avalanche yield voltage can be stably expected. PCOPYRIGHT: (C)2008,JPO&INPIT