MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To manufacture a lateral MOSFET having an increased breakdown voltage between a drain and a source and a decreased on-resistance. SOLUTION: A P-type buried region 37 is formed in an extended drain region 33 by a high-energy boron ion implantation method using a thick film resist 35 formed by laminating relatively thin resist layers. When each resist layer is formed, the application of resist and a heating are repeated, whereby the thick film resist 35 having uniform thickness is produced. Heat treatment conditions for each resist layer is optimized to shape up the cross-sectional profile of the resist after transferring a pattern thereto.