| 摘要 |
The field oxide film is prepared by (A) forming a pad oxide film(22) of 200-300Ang. thickness on a semiconductor substrate(21), then depositing a nitride film(23) of 1,000-2,000Ang. thickness, (B) remaining the nitride film(23) of 300-700Ang. thickness by etching the definite part of the nitride film(23) not to expose the pad oxide film(22), (C) depositing a polysilicon film(28) of 300-1,000Ang. thickness on the over all the surface of the film then spacer-etching the polysilicon film(28), the nitride film(23), the pad oxide film(22) without mask, and (D) forming a pad oxide film(26) after removing the remained polysilicon film(28). This method is useful for controlling the length and thickness of the L-type spacer easily, then decreasing the difficulties of process, and the stress and defect of the semiconductor substrate. So it makes the necessary separating process of semiconductor easy.
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