METHOD FOR FORMING ISOLATION LAYER USING SELECTIVE EPITAXIAL GROWTH

摘要

PURPOSE: A method for forming an isolation layer is to prevent a thinning of a gate oxide layer and a residue of a gate electrode forming substance in patterning a gate, using SEG(selective epitaxial growth). CONSTITUTION: An oxide layer(21) is deposited on a silicon substrate(20) to form an insulating region. A photoresist pattern is formed on the oxide layer and then patterned. The photoresist pattern lies upon the isolation region. After selectively etching the oxide layer to expose the silicon substrate using the photoresist pattern as an etch mask, the photoresist pattern is removed. A nitride layer is deposited on the entire structure and then etched to form a nitride layer spacer(23a) on a sidewall of the oxide layer. The SEG silicon layer grows on the exposed silicon substrate to bury a hole defined by the oxide layer. By a profile of the nitride layer spacer, an over-growing of the SEG silicon layer is prevented.