Clean Method for Contamination Monitoring During the Production of Tungsten Silicide
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Thinned regions of a silicon wafer with a deposited tungsten silicide layer are decomposed in a decomposition apparatus where volatile silicon fluoride and tungsten fluoride are formed and removed and contaminants are retained and subsequently determined by atomic absorption spectroscopy. The chemicals used and the process for producing the silicide are characterized with regard to purity as a function of the amount of contaminants determined. A silicon wafer with an about 2 mm thick boron-doped surface layer is selectively thinned from the opposite surface with a pyrocatechol solution. Thinning stops at the boron-doped surface layer. A tungsten silicide layer of predetermined thickness is deposited on top of the boron-doped surface layer. Fig.