Highly doped contact zone prodn. for weakly doped semiconductor zone - with min. number of process stages e.g. in MOSFET, bipolar transistor or IGBT mfr.

摘要

Prodn. of a highly doped contact zone (11) at the edge of a weakly doped zone (1) of the same conductivity type, so that both zones are on the same side of the semiconductor and over another zone (2), involves (a) producing an insulating layer (5) on the weakly doped zone (1); (b) proudcing a hole (8) in the insulating layer a window (7) in a photoresist layer (6), to expose an area of the weakly doped zone which is larger than the window but smaller than the area of the weakly doped zone; (c) implanting N in the weakly doped zone through the window; (d) producing an oxide mask on the unimplanted pt. of the weakly doped zone; (e) implanting dopant in the pt. of the surface not covered by the insulating layer to form the contact zone; and (f) etching the contact zone not covered by the ozide mask until pt. of the other zone (2) is exposed. USE/ADVANTAGE - The contact zone is produced with the fewest possible no. of stages with self-alignment. The process can be used in the prodn. e.g, of MOS-FETs, bipolar transistors or IGBTs.