Studies on optical, chemical, and electrical properties of rapid SiO2 atomic layer deposition using tris(tert-butoxy)silanol and trimethyl-aluminum

Abstract

Rapid SiO2 atomic layer deposition (ALD) was used to deposit amorphous, transparent, and conformal SiO2 films using tris(tert-butoxy)silanol (TBS) and trimethyl-aluminum (TMA) as silicon oxide source and catalytic agent, respectively. The growth rate of the SiO2 films drastically increased to a maximum value (2.3 nm/cycle) at 200 degrees C and slightly decreased to 1.6 nm/cycle at 275 degrees C. The SiO2 thin films have C-H species and hydrogen content (similar to 8 at%) at 150 degrees C because the cross-linking rates of SiO2 polymerization may reduce below 200 degrees C. There were no significant changes in the ratio of O/Si (similar to 2.1) according to the growth temperatures. On the other hand, the film density slightly increased from 2.0 to 2.2 although the growth rate slightly decreased after 200 degrees C. The breakdown strength of SiO2 also increases from 6.20 +/- 0.82 to 7.42 +/- 0.81 MV/cm. These values suggest that high cross-linking rate and film density may enhance the electrical property of rapid SiO2 ALD films at higher growth temperature. (C) 2012 Elsevier Ltd. All rights reserved.