METHOD FOR FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE TO ELIMINATE NECESSITY OF CMP PROCESS AND PREVENT ACTIVE REGION FROM BEING DAMAGED BY PLANAR ETCH PROCESS

摘要

PURPOSE: A method for forming an isolation layer of a semiconductor device is provided to eliminate the necessity of a CMP(chemical mechanical polishing) process and prevent an active region from being damaged by a planar etch process by removing an isolating oxide layer remaining as a fence type after the planar etch process while performing a cleaning process using deionized water. CONSTITUTION: A semiconductor substrate(100) having a trench is prepared. An isolating oxide layer is deposited by using the depth of a trench as a deposition target to gap-fill the trench. After a planar mask is formed to open the isolating oxide layer deposited in an active region, a planar etch process using the planar mask is performed to pattern and eliminate the isolating oxide layer in the active region. By an ultrasonic cleaning process using deionized water, the isolating oxide layer remaining in the active region is removed to form an isolation layer.