| 摘要 |
A method for forming an isolation layer in a semiconductor device, to avoid the occurrence of an angular formation phenomenon at the edge portions of the upper and lower portions of the trench during formation of a shallow trench isolation layer (STI), so that malfunction of the device and the deterioration of its performance due to a parasitic transistor and leakage current, can be prevented. Advantageously, silicon nitride films are formed at the side wall of the pad oxide film and the surface of trench silicon through a nitrogen (N+) plasma nitrification process, after a trench etching process, for formation of STI, so that the generation of a moat is inhibited and deterioration of the device is prevented. The isolation layer in a semiconductor device is formed by forming a pad oxide film in a wet oxidation process on a silicon substrate, forming a pad nitride film in a low pressure chemical vapor deposition process on the pad oxide film, forming a shallow trench by etching the pad nitride film, the pad oxide film and the silicon substrate to a predetermined depth, forming a silicon nitride film in a nitrogen plasma nitrification process on the inner wall of the trench, filling the trench where the silicon nitride film is formed with an oxide film, and planarizing the pad nitride film and the pad oxide film in a chemical mechanical polishing process so that the silicon substrate can be exposed.
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