METHOD FOR MANUFACTURING SHALLOW TRENCH ISOLATION LAYER

摘要

PURPOSE: A fabrication method of an STI(shallow trench isolation) is provided to restrain a dishing phenomenon and simplify manufacturing process by using double layer having different etching selectivity. CONSTITUTION: The method comprises the steps of forming a pad oxide pattern(12) and a nitride pattern(14) on a silicon substrate(10); forming a trench(T) by etching the exposed substrate using the oxide and the nitride patterns(12,14) as a first trench mask; sequentially forming an oxide layer(16) and a sacrificial oxide(18) made of organic ARC(anti-reflection coating) having high etching selectivity compared to the oxide layer(16); etching the sacrificial oxide(18) and the oxide layer(16) using a second trench mask pattern(19); removing the remained oxide layers(16, 18) on the nitride pattern(14) using CMP; and removing the pad oxide pattern(12) and the nitride pattern(14), thereby easily forming a shallow trench isolation layer(T').