In situ HDP-CVD process diagnostics based on quadrupole mass spectrometry

The technique of quadrupole mass spectrometry is assessed for in situ process monitoring of an HDP-CVD process. A direct, sensitive correlation was obtained between the QMS signal intensity of critical gas phase reactants and by-products, and the physical and chemical properties of the deposited oxide layers themselves, i.e. oxide thickness and chemical content in the layers. The technique was successfully used to investigate a process first wafer effect, resulting in a solution of this manufacturing issue. It was also shown that F-containing species reside in the chamber during deposition, but have almost no influence on the properties of the oxide layer