Disclosed is the use of metal silicide (e.g. Pt-Si) contacts in boron lightly doped P.sup.- type silicon between two contiguous but not adjacent N.sup.+ type regions instead of employing the usual P.sup.+ implanted or diffused channel stoppers. The invention finds a particularly interesting application in polyimide filled deep trench isolated integrated circuits.
The trench sidewalls are coated with an insulating material which is removed from the trench bottom at the all contact etch step. The Pt-Si is formed at the bottom of the trenches at the same time that the device contacts are made.