METHOD FOR PRODUCING LOW-RESISTANCE OHMIC CONTACTS BETWEEN SUBSTRATES AND WELLS IN CMOS INTEGRATED CIRCUITS

摘要

A method of fabricating a semiconductor connective region of a first conductivity type through a semiconductor layer of a second conductivity type which at least partly separates a bulk portion of semiconductor body (substrate) of the first conductivity type from a semiconductor well of the first conductivity type includes a step of implanting ions into a portion of the layer to convert the conductivity of the implanted portion to the first conductivity type. This electrically connects the well to the bulk portion of the body. Any biasing potential applied to the bulk portion of the body is thus applied to the well. This eliminates any need to form a contact in the well for biasing the well and thus allows the well to be reduced in size.