LPCVD of silicon dioxide by pyrolysis of teos in a rapid thermal processor

Abstract

Low-pressure chemical vapor deposition of SiO 2 by pyrolysis of tetraethylorthosilicate (TEOS), in a lamp-heated, cold-wall rapid thermal processor has been investigated. Effects of rapid-thermal and furnace annealing on the chemical and electrical properties have been studied using standard etching and C- V techniques. Our results have shown that silicon dioxide can be deposited at rates as high as 1000 Å/min. Below 800°C, the deposition process is limited by the surface reactions and has an activation energy of 76 kcal/mol. Silicon dioxide films very close to thermal oxide in density can be obtained by following the deposition with a standard furnace or rapid thermal annealing cycle in a nitrogen ambient. The fixed interface charge density of the deposited films is higher than that of a dry oxide control sample processed under the same conditions. The charge densities range from 6.4 × 10 11 to 8.8 × 10 11 cm −2 for furnace annealed films and from 1.58 × 10 11 to 3.72 × 10 11 cm −2 for rapid thermally annealed films.