METHOD FOR FORMING FINE TRENCH, SEMICONDUCTOR TRANSISTOR AND ISOLATION METHOD

摘要

PURPOSE: A trench formation method is provided to improve an integration degree by forming fine trenches using a T-shaped gate and prevent damage or pollution by using a surface protection layer. CONSTITUTION: A trench formation method comprises the steps of forming a surface protection layer(24) for controlling height of gate on a semiconductor substrate(20) having a capping layer(22); forming a V-shaped groove(26) in the protection layer and the capping layer by RIE(reactive ion etching) or ICP(inductive coupled plasma) using sputtering effect; and forming a fine trench(27) having same width with the V-shaped groove(26) by using high etching selectivity of the capping layer(22) compared to the protection layer(24).