公开(公告)号：JPH1187310A

公开(公告)日：1999-03-30

申请号：JP20675098

申请日：1998-07-22

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： KIN SOKI ,  KIN SHODAI ,  KU JIN-KUN ,  NAM KI-SU ,  RI DAIU ,  RO TAIBUN

IPC: H01L21/302 ,  H01L21/3065

Abstract: PROBLEM TO BE SOLVED: To enable formation of an oxide film pattern the lateral side of which has a gentle degree of inclination, by selectively etching a multilayered oxide layer, and thus forming an oxide film pattern with an inclined sidewall. SOLUTION: After a first oxide film 302a is evaporated on a semiconductor substrate 301, heat treatment is carried out at a temperature of 200-1400 deg.C, and a second oxide film 302b is evaporated on the first oxide film 302a. In this case, the evaporation temperature of the second oxide film 302b is lower than the evaporation temperature of the first oxide film 302a. The lateral inclination of first and second oxide film patterns to be formed after etching is very moderate. This form is made because the second oxide film 302b is etched faster than the first oxide film 302a. That is, the first oxide film 302a and the second oxide film 302b of heterojunction are different in structure and physical characteristics. When these oxide films are etched by using the same etchant, the sidewalls of these oxide films have a very gentle inclination because the etching ratios differ from each other.