Flash Cleaning Using CF4
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
CHF3 and C3F8 are gas mixtures frequently used in the reactive ion etching of various oxides during the course of the advanced semiconductor products. Unfortunately, for example, it has been recognized that these etching steps leave cluster or polymer "grass" at the bottom and on the wall of the etched holes, which prevents the subsequent formation of good electrical contact with the underlying silicon substrate. Same inconveniences have been noticed during the etching of polyimide layers when etched in an oxygen atmosphere. The present disclosure aims to remove such debris, by a flash cleaning of CF4 at the end of the etching steps. Ultra-clean surfaces of silicon have been obtained in this way.