Patent ID: 6645817
Filing Date: 2003-11-11
Classification: H01L,Y10S

Abstract:
A method of manufacturing a semiconductor device comprising MOS-transistors of a first type having a gate oxide of a first thickness and MOS-transistors of a second type having a gate oxide of a second, greater thickness, in which method active regions and field oxide regions isolating said active regions from each other are formed in a silicon body, adjacently to a surface thereof, after which a layer of gate oxide of said first thickness is formed on said active regions, on which a layer of an electrode material is deposited, in which the gate electrodes for the MOS-transistors of said second type are formed, including removing the layer, of gate oxide of said first thickness around the MOS-transistor of the second type, after which the thickness of the gate oxide under said gate-electrodes is increased to the second, larger thickness by means of a thermal oxidation treatment, characterized in that the layer of electrode material on the active regions of the MOS-transistors of the first type is not disturbed during the formation of the gate electrodes for the MOS-transistors of the second type, and that the gate electrodes for the MOS-transistors of the first type are only formed therein after the oxidation treatment in which the thickness of the gate oxide of the MOS-transistors of the second type is increased to the second, greater thickness.