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AssigneeKoninklijke Philips Electronics N.V.
InventorsKlaas Gerbrand Druijf, Hendrik Hubertus Van Der Meer
Estimating the term…
Method of manufacturing a semiconductor device comprising MOS-transistors of a first type (A) having a gate oxide (3) of a first thickness and MOS-transistors of a second type (B) having a gate oxide (10) of a second, greater thickness. In this method, active regions (4) and field oxide regions (5) are formed in a silicon body (1). Then a layer of gate oxide (6) of said first thickness is formed on the active regions, on which a layer (7,8) of an electrode material is deposited. In the layer of electrode material, the gate electrodes (9) for the transistors of the second type are formed. Then an oxidation treatment is carried out, in which the thickness of the gate oxide under said gate-electrodes increases to the desired second thickness (10). During these processes, the electrode layer on the active regions of the MOS-transistors of the first type is not disturbed. The gate electrodes for the transistors of the first type are formed after the oxidation treatment. Thus a semiconductor device comprising MOS-transistors having gate oxides of different thicknesses can be manufactured in a simple manner.
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.
Dependencies are inferred from the claim text.