Chemical vapor deposition of SiO 2 films by TEOS/O 2 supermagnetron plasma

Abstract

A TEOS/O 2 supermagnetron double electrode plasma system was used to deposit SiO 2 films. Deposition rates were measured as a function of rf power and substrate stage temperature. With an increase of rf power on both electrodes from 40 to 80W, the deposition rate increased; however, with a further increase of rf power from 80 to 120W, the deposition rate ceased to increase or decreased only a small amount. The presence of O–H bonds from bonded water in the film was evaluated using buffered HF (BHF) etching solution. With an increase of rf power from 40 to 120W, the BHF etch rate decreased; i.e., the number of O–H bonds were reduced. A minimum BHF etch rate was observed at a rf phase difference of 180° between the two rf power sources. A SiO 2 film was deposited on a trench-patterned quartz substrate. A flat surface SiO 2 layer with air gaps (voids) was formed on the high-aspect ratio (depth/width=1.5–2) trench area.