Our Vapor Sublimation Process Trap is widely used in silicon nitride LPCVD and Titanium nitride LPCVD processes where significant amount of NH4Cl byproducts have been observed in the foreline. An MKS trap, with its high capacity and high efficiency, reduces process downtime, increases process yield (because of its high flow conductance), and protects the vacuum pump. With the combination of an MKS heated line, heated valve, heated Baratron®, and trap, we can significantly improve the process yield and uptime for the silicon nitride LPCVD process.