Published online by Cambridge University Press: 25 February 2011
Borophosphosilicate glass (BPSG) films used in integrated circuit processing are grown from combinations of toxic and pyrophoric silane, diborane, and phosphine at atmospheric and reduced pressures. A safe, alternative chemical system has been developed with liquid source replacements for each dangerous gas. 2,4,6,8 tetramethylcyclotetrasiloxane (TMCTS) and oxygen are used as the silicon oxide sources, and trimethylphosphite (TMP) and trimethylborate (TMB) are the phosphorous and boron sources, respectively. Films grown in a hot wall LPCVD reactor with standard diffusion boats have thickness uniformities of ± 2 % and doping uniformities < ± 5 %.