Characterization of high oxygen: Tetraethylorthosilicate ratio plasma-enhanced chemical vapor deposited films

An investigation was conducted to characterize film properties of oxygen-rich tetraethylorthosilicate (TEOS) films deposited by single-wafer plasma-enhanced chemical vapor deposition. By increasing the oxygen:TEOS gas ratio from 1:1 to 4:1 and maintaining a reduced gas flow rate, undoped silicon glass (USG) and phosphorus-doped silicon glass (PSG) films exhibited a lower fixed charge, increased Si-O bonding sites, higher compressive film stresses, and higher refractive indexes. The USG and PSG deposition parameters were optimized to achieve a film nonuniformity of <2.7% (1 sigma) and deposition rates of 1500 and 3100 Angstrom/min, respectively.