Patent ID: 6228770
Filing Date: 2001-05-08
Classification: H01L

Abstract:
A method to form air gaps between metal interconnects in the manufacture of an integrated circuit device comprising:providing metal interconnects overlying a semiconductor substrate;depositing a silicon nitride liner layer overlying said metal interconnects and said semiconductor substrate;depositing a gap filling oxide layer overlying said silicon nitride liner layer to fill gaps between adjacent said metal interconnects;polishing down said gap filling oxide layer stopping when the top surface of said silicon nitride liner layer is exposed;depositing a silicon nitride thin layer overlying said silicon nitride liner layer and said gap filling oxide layer;patterning said silicon nitride thin layer to create openings to thereby expose parts of said gap filling oxide layer;etching away said gap filling oxide layer; anddepositing a self-sealing oxide layer overlying said silicon nitride liner layer and said silicon nitride thin layer to thereby form permanent air gaps between adjacent said metal interconnects to complete said integrated circuit device.