U.S. Philips Corporation

Hermanus Josephus Wilting

Eduard Ferdinand Stikvoort

Leonard J Esser

Frits Landheer

By the use of high-resistivity polycrystalline silicon (poly) in MIS elements, a depletion layer can be formed in the poly material which brings about an electric decoupling between the poly (gate) and the underlying semiconductor body. This effect can be utilized advantageously in various circuit elements, such as in CCD's, in order to obtain a favorable potential distribution in the substrate; in MOS transistors in order to reduce the parasitic capacities; and in high-voltage devices in order to increase the breakdown voltage at the edge of the field plate (resurf).

DMOS with high-resistivity gate electrode

An undoped polycrystalline silicon layer 6 is provided on an electrically insulating layer 2 at the surface 8 of a semiconductor body 1 and a metal layer 4, for example of molybdenum, is provided on layer 6. After heating to convert part of layer 3 into a metal silicide layer 5 a dopant, for example phosphorus, is introduced into the polycrystalline layer 4 through layer 5. This method can be used to make an insulated gate field effect device where the gate comprises a double layer structure of metal silicide on polycrystalline silicon.

Method of manufacturing a semiconductor device

A method of manufacturing a metal silicide pattern with respect to which two electrode zones are to be provided in a self-registering manner. According to the invention the pattern is provided in the form of a layer of polycrystalline silicon and, by selective oxidation and masking, only the upper surface of the pattern is exposed to the silicide formation so that passivation problems and short circuit are avoided. The use of silicides which cannot withstand high temperatures is also possible.

Method of manufacturing a semiconductor device and device manufactured

A semiconductor device having a Schottky junction formed by providing a semiconductor body at least two metal layers one on top of the other which can each form a Schottky barrier with the semiconductor, in which, according to the invention, the formed Schottky diode has a higher barrier than each of the metals individually relative to the semiconductor, by heating the assembly above 400.degree.C. Preferably nickel or cobalt is first provided and thereon aluminum, and heating is carried out at 500.degree.C.

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Eindhoven, Netherlands

Hermanus Josephus Wilting