Note 1 to entry: Surface micromachining is a processing technique that applies for example chemical vapour deposition (CVD) to form various thin films on the substrate and uses a mask to perform selective removal of the substrate surface to produce movable parts and other structures. The dissolved layer that was deposited initially is called the sacrificial layer. A typical sacrificial layer material is phosphosilicate glass (PSG). This technology is applied to the fabrication of micro-beams, bearings, and links, etc.