Method for fabricating oxide layers with different thicknesses
AssigneeWinbond Electronics Corp.
InventorsShing-Sing Chiang, Kuo-Shi Teng, Hao-Chieh Yung, Yi-Shi Chen
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Abstract
A method for fabricating oxide layers with different thicknesses on a substrate is described. A field oxide layer is formed on the substrate to define a first active region and a second active region therebetween. A first oxide layer is formed over the first active region. A thin oxynitride layer is formed on the first oxide layer. The substrate is oxidized to form a second oxide layer over the second active region, wherein the second oxide layer has a thickness different from the thickness of the first oxide layer,
Claims6
A method for fabricating oxide layers of different thicknesses on a substrate, comprising:
- forming a field oxide layer on the substrate to define a first active region and a second active region therebetween;
- forming a first oxide layer over the first and the second active regions;
- implanting impurities into an upper portion of the first oxide layer, wherein the impurities depress the oxidation rate of the first oxide layer;
- removing the first oxide layer within the second active region;
- removing most of the upper portion of the remaining the first oxide layer within the first active region, thereby leaving a thin implanted oxide layer on a remaining portion of said first oxide layer;
- and
- oxidizing the substrate to form a second oxide layer over the second active region, wherein the second oxide layer has a thickness different from the thickness of the lower portion of the first oxide layer.
Dependencies are inferred from the claim text.