In-situ monitoring of chemical vapor deposition process by mass spectrometry

A method of chemical vapor deposition comprising the steps of:

• providing a semiconductor substrate in a chemical vapor reaction chamber;
• positioning a capillary tube proximate the semiconductor substrate for removal of a gas sample;
• providing measuring and monitoring means for measuring and monitoring one or more properties of one or more gaseous-by-products formed in the chemical vapor reaction chamber;
• providing a pump outside the chamber in communication with the capillary tube and measuring and monitoring means and positioned between the capillary tube and the measuring and monitoring means;
• introducing reactant materials into the chamber;
• effectuating a reaction between the reactant materials to produce a desired end product and at least one gaseous by-product;
• forming the desired end product on a surface of the substrate;
• removing with the pump a sample of the gases from the chamber including at least one gaseous by-product through the capillary tube and passing the pumped sample to the measuring and monitoring means;
• and
• measuring and monitoring one or more properties of one or more of the gaseous by-products during the reaction and controlling the deposition method based on the measured and monitored gaseous by-product properties.