Abstract: A residual gas analyzer can be used as a deposition rate monitor. A deposition rate monitor is based on the detection of growth precursors and reaction byproducts of the thin film growth in deposition equipment such as chemical vapor deposition (CVD) systems. The growth precursors and byproducts are identified and quantified by using a residual gas analyzer (RGA). The ion current from gas species associated with the growth rate is then empirically correlated with the thickness of the film. The specific chemical species detected by the RGA is unique to the material that is deposited and to the technique in which the material is deposited.