METHOD FOR DEPOSITING INSULATION LAYER BY HIGH DENSITY PLASMA PROCESS TO PREVENT UPPER CORNER OF INTERCONNECTION FROM BEING CLIPPED IN INSULATION DEPOSITION

摘要

PURPOSE: A method for depositing an insulation layer by an HDP(high density plasma) process is provided to prevent an upper corner of an interconnection from being clipped in insulation deposition by an HDP process by decreasing the flowrate of O2 gas at an early state of depositing the insulation layer to improve an etch characteristic and by etching the insulation layer to form an excellent gap-fill structure and function as a barrier layer. CONSTITUTION: The first insulation layer is deposited on a semiconductor substrate(21) having interconnections(22) in a condition of a reduced composition ratio of O2 gas and SiH4 gas. The overhang portion formed at the upper corner of the interconnection in depositing the first insulation layer is etched. The second insulation layer(24) is deposited on the etched first insulation layer(23a). The third insulation layer(25) is deposited on the second insulation layer to carry out a gap-fill process.