| 摘要 |
An isolating method of a semiconductor substrate is provided. In the method, a silicon oxide layer, a polycrystalline silicon or amorphous silicon layer, a silicon nitride layer, and a photosensitive film pattern are formed. A portion of a lower layer formed over the semiconductor substrate is patterned using the photosensitive film patterned. A polymer spacer is formed on sidewalls of the patterned lower layer and the photosensitive film pattern to form a trench in the semiconductor substrate. A step difference between the semiconductor substrate and the lower layer is formed by the polymer spacer. The sidewall and bottom of the trench and the polycrystalline silicon or amorphous silicon layer having a step difference are transformed into a thermal oxide layer by an oxidation process. Thus, leakage current of the semiconductor device can be effectively inhibited and an isolation region becomes larger due to a step difference. |
