Method of making high voltage metal oxide silicon field effect transistor

摘要

A manufacturing method of high voltage MOSFET includes a process forming the first and second conductive wells in a semiconductor substrate; process forming drift areas in the first and second conductive wells; process growing an isolation membrane on the substrate surface between the first and second conductive wells; process forming a gate insulation film; process forming a gate on the gate insulation film above the first and second conductive wells; process forming low concentration n-and p-type dopant areas in the drift areas of the parts adjacent to the gate; process forming buried diffusion areas in the first and second conductive wells; process forming source/drain having a body contact on a side on the buried diffusion areas in the first and second conductive wells; process forming an insulation film having a contact formed in such way that is exposed the surface of source/drain on the entire surface of the substrate including the gate and isolation membrane; process forming a metal film on the insulation film; and process forming source/drain electrodes and the metal field plates, by etching the metal film using a mask.