METHOD OF FABRICATING TRENCH ISOLATION

摘要

PURPOSE: The method can remove a dent generated around the edge of a trench isolation(120), and can prevent a gate bridge. CONSTITUTION: A trench(106) is formed by etching a semiconductor substrate(100) using a nitride mask. A SiN liner(110) is formed on the nitride mask including an oxide after the oxide is formed on the bottom and on both side walls of the trench. A trench isolation film(112) is formed on the SiN liner until the trench is filled completely. The trench isolation film and the SiN liner is planarized by etching until the upper surface of the nitride mask is revealed. After the nitride mask is striped, a sacrificial oxide is formed on the front surface of the semiconductor substrate. After the sacrificial oxide is striped, the SiN liner remained around the dent is etched. The dent around the edge of the trench isolation is removed by making the upper surface of an active equal to the depth of the dent by applying the sacrificial oxide formation process after the nitride mask strip process, and the gate bridge generated because a poly remains behind around the dent during a gate poly formation.