Manufacturing method of semiconductor device
AssigneeSanyo Electric Co., Ltd.
InventorTakashi Ogura
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Abstract
A method of manufacturing a semiconductor device comprises the following steps: a step of depositing a silicon oxide film on the top surface of an epitaxial layer of the region where a high withstand voltage MOS transistor is formed; a step of subsequently depositing a silicon oxide film on the top surface of the epitaxial layer according to the thickness of a gate oxide film of a low withstand voltage MOS transistor; and a step of subsequently adjusting the thickness of the silicon oxide film on the top surface of the high withstand voltage MOS transistor by etching and forming a P-type diffusion layer by ion-implantation method. This method can manufacture elements having gate oxide films different in thickness at low cost.
Claims4
A method of manufacturing a semiconductor device wherein a semiconductor layer is prepared;
- and a first MOS transistor and a second MOS transistor having a gate oxide film thinner than that of the first MOS transistor are formed in a plurality of element formation regions partitioned by an isolation region formed in the semiconductor layer, comprising the steps of:
- selectively forming a first insulator film on a surface of the semiconductor layer of a formation region of the first MOS transistor and then forming a second insulator film on a surface of the semiconductor layer of a formation region of the first and second MOS transistors;
- forming a gate electrode in the formation region of the first MOS transistor and thinning the first and second insulator films on a top surface of a formation region of a drain region and a source region located adjacent to the gate electrode;
- and
- ion-implanting impurities from above the semiconductor layer so as to form the drain region and the source region in the semiconductor layer.
Dependencies are inferred from the claim text.