Higher device production rate while manufacturing the same high quality product, is a goal of the microelectronics industry. The principal investigators have developed a novel concept of programmed rate chemical vapor deposition (PRCVD), as a method to enhance device throughput and film properties in low pressure chemical vapor deposition (LPCVD) on patterned semiconductor wafers. In PRCVD, process conditions are varied with time to compensate for the increase in instantaneous feature aspect ratio as deposition proceeds. This should result in a larger average deposition rate than for constant rate chemical vapor deposition (CRCVD). The objective of this research is to experimentally validate the concept of PRCVD for four representative chemical vapor deposition chemistries of current industrial interest: (1) silicon dioxide deposition from tetraethylorthosilicate (TEOS), (2) silicon dioxide deposition from silane/oxygen mixtures, (3) aluminum deposition from triisobutylaluminum (TIBA) and (4) tungsten silicide deposition from tungsten hexafluoride/ dichlororosilane mixtures. These reaction systems exhibit markedly different deposition rate dependence on temperature and reactant partial pressures, and thus provide a comprehensive test of the PRCVD concept. Films will be deposited in a cold wall, single wafer microreactor over silicon based patterned substrates. Deposited films will be characterized to determine if PRVCD produces films which posses the same critical properties as CRCVD films. Successful completion of this research will provide a methodology for commercial implementation of PRCVD, which could increase device throughput and decrease production costs.
