公开(公告)号：JPH08111453A

公开(公告)日：1996-04-30

申请号：JP24327195

申请日：1995-09-21

Applicant: CONS RIC MICROELETTRONICA

Inventor： SARUBATOORE YUUGO KANPISAANO ,  BIITO RAINEERI

IPC: H01L21/02 ,  H01L21/265 ,  H01L21/316 ,  H01L21/762 ,  H01L27/12

Abstract: PROBLEM TO BE SOLVED: To form a silicon oxide buried layer in a silicon wafer by a method, wherein a recess is formed in the silicon wafer, and light ions are injected at more shallow depth to form air bubbles, and the light ions are evaporated, and a cavity remains in a place of air bubbles for oxidizing the cavity via the recess. SOLUTION: If helium ions 3 are injected into the entire surface 2 of a silicon wafer 1, helium air bubbles 4 are formed at an average permeation depth of the ions 3. If the silicon wafer 1 is heated at a temperature of 700 deg.C or higher, helium diffuses to the surface 2 and a buried layer which is an empty cavity remains in a place of air bubbles 4. A recess or groove 5 is formed, so that its depth is deeper than the depth that the cavity 4 is installed and is divided into an upper portion 6a and a lower portion 6b. If the silicon wafer 1 is heated in a furnace at a dense oxygen concentration, the buried layer containing the cavity 4 is uniformly oxidized and a buried layer 7 of a silicon oxide can be formed in the silicon wafer 1.