Method for mfg. improed structure high-voltage elements

The present invention provides a making method for improved high-voltage element structure, it can be smoothly integrated into the deep submicrometer process using shallow channel isolated structure. Said invention is characterized by that between drain and semiconductor base multiple deeper and lighter doped regions are formed, which include N-type drift region and N-type doped well region, and the adulterant concentration between drain region and semiconductor base is successively decreased. Said invention utilizes the decreased doped concentration of that the concentration of drain is greater than that of N-type doped well region and the concentration of N-type doped well region is greater than that of drift region to reduce electric field intensity of their combined face, and raise breakdown voltage, at the same time can improve drive current of high-voltage transistor.