METHOD FOR MANUFACTURING A TRENCH ISOLATION

摘要

PURPOSE: A method for manufacturing a trench isolation is provided to make a projected range of source/drain impurity ions have a relatively small region on an interface between an active region and a non active region, by forming a trench isolation layer higher than a substrate, and by forming a spacer on a sidewall of the isolation layer. CONSTITUTION: A trench etch mask is formed by sequentially forming the first insulating layer and the second insulating layer on a substrate(210). A trench is formed on the substrate by using the trench etch mask. The trench is filled up with the third insulating layer. The second insulating layer is eliminated to form a trench isolation layer(218) higher than the substrate. A gate electrode layer(224) is formed in an active region(A) of the substrate. A low density source/drain(226) is formed by injecting low density impurity ions into the active region of the substrate. Spacers(228a,228b) are formed on sidewalls of the trench isolation layer and gate electrode layer. A high density source/drain is formed by injecting high density impurity ions into the active region of the substrate.