LOCOS ISOLATION METHOD OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an LOCOS isolation method of a semiconductor element wherein a stepped part formed between a field oxide film and an active region has a smooth gradient while preventing formation of bird's beak in an active region. SOLUTION: A first pad insulation film 120 and a first anti-oxidation film 130 are formed one by one on a semiconductor board 110. Pattern etching is performed for the first pad insulation film 120 and the first anti-oxidation film 130, and a first pad insulation film pattern 120a and an anti-oxidation film pattern 130a are formed to expose a specified region of the semiconductor board 110. A second pad insulation film 140 is formed in a surface of the exposed semiconductor board 110, and a second anti-oxidation film 150 is formed all over the semiconductor board 110. The second anti-oxidation film 150 is partially etched, a spacer 150a is formed in a side wall of the anti-oxidation film pattern 130a, a field oxide film 160 is formed by oxidizing the second pad insulation film 140 and the board 110 thereunder and LOCKS isolation is carried out by removing the first pad insulation pattern 120a, the anti- oxidation pattern 130a and the spacer 150a.