SILICON-OXIDE DEPOSITION IN AN ELECTRON-CYCLOTRON-RESONANCE PLASMA WITH MICROWAVE SPECTROSCOPIC MONITORING OF SIO

A 2.45 GHz electron cyclotron resonance reactor was used to deposit si licon oxide films using both tetraethoxysilane (TEOS)/O-2 and silane/O -2. The reactor is equipped with an in situ microwave spectrometer in the frequency range 75-110 GHz,that is used to monitor the gas phase c hemical species in this environment. The J = 1 --> 2 rotational transi tion of the vibrational ground state of silicon monoxide (SiO) was det ected and monitored in plasmas of both gas mixtures. The integrated in tensity of the microwave transition was used to obtain absolute densit ies of SiO integrated along the path length for both of these plasma c hemistries. Silicon oxide films were deposited at pressures of a few m Torr and at low wafer temperature. The properties of the deposited fil ms were characterized using infrared absorption and wet etch rate. The refractive indices of the films were measured by using multicolor ell ipsometry. Deposition rates were determined as a function of oxygen/TE OS or oxygen/silane flow ratio. An inverse correlation was found for b oth sources between SiO abundance and deposition rate. An inverse corr elation between SiO abundance and film quality was observed for the si lane source. (C) 1995 American Vacuum Society.