The Vision 2000-A XD Residual Gas Analyzer (RGA) improves process productivity and product quality by providing real-time trace level monitoring of various gas species, including precursors, reaction byproducts, and contaminants during ALD and CVD processes. The Vision 2000-A XD system incorporates MKS’ patented V-lens™ technology, taking the proven performance of the Vision 2000-A XD system to a higher level of sensitivity and reliability, previously unachievable with conventional quadrupole mass spectrometry systems (QMS). The V-lens design provides increased sensitivity and reproducibility for the most challenging applications, such as tracking levels of various gas species or reaction byproducts during ALD and CVD deposition processes. With V-lens technology, process engineers can identify and prevent potentially costly issues faster and easier while maximizing yield.