公开(公告)号：JPH05160251A

公开(公告)日：1993-06-25

申请号：JP14874592

申请日：1992-05-15

Applicant: IBM

Inventor： KURAUSU DEIITORIKU BEIYAA ,  RUISU RUUCHIEN SHIYU ,  SUBODO KESHIYAFU KURUKAANI

IPC: H01L21/76 ,  H01L21/764

Abstract: PURPOSE: To improve a method of forming an isolation trench which is filled with air in a semiconductor substrate. CONSTITUTION: An isometrical CVD silicon dioxide 38 is deposited on an inactivated surface 19 of a semiconductor substrate. Then, a crossed trench is formed, and the crossed trench is partially filled up with a water-soluble glass and a polymer material such as polyimide, which can be continuously removed from under the isometrical CVD silicon dioxide 38. The isometric CVD silicon dioxide 38 is etched back up to the inactivated surface 19 of the semiconductor substrate, and an opening is provided to the isometric CVD silicon dioxide 38 at a trench intersection, so as to reach a trench-filled material. The filling material is removed through the opening. An anisometric CVD silicon dioxide 48 is deposited to fill up the opening, and the silicon dioxide cap 38 is left to bridge the trench filled with air.