Process for Making Silicon Dioxide Films With Improved Thickness Uniformity Control
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
By depositing a film of pure Si by low pressure chemical vapor deposition (LPCVD) and then completely oxidizing it, the previous problems of highly varying thickness and etch rate characteristics (and consequent pattern dimensional control problems) of SiO2 films deposited by LPCVD are eliminated. It has been found that the conventional LPCVD process for depositing SiO2 is lacking in thickness and etch uniformity control for the new, one-micron geometries required to make VLSI (very large-scale integrated) circuits - especially on larger wafers. Experimentally, it has been determined that the process of LPCVD of pure Si (often used for the deposition of polycrystalline, pure Si) produces far superior thickness uniformity of deposited films.