Analysis of boron- and phosphorus-doped diamond layers by glow discharge optical emission spectroscopy in argon and neon

Boron- and phosphorus-doped diamond layers were analysed by glow discharge optical emission spectroscopy. A methodology for quantitative depth profiling of layers was developed, based on multi-matrix calibration with a calibration model assuming matrix-independent emission yields. Factors affecting accuracy and sensitivity of analysis are discussed. Analysis of boron with the B I line at 208.959 nm yielded a satisfactory performance. Analysis of phosphorus with the P I line at 178.284 nm in an argon glow discharge is affected by an argon-related interference, which can be avoided by using a neon discharge. The use of which leads to an eightfold improvement in the phosphorus detection limit. A light interference effect affecting the analysis in transparent layers is described, indicating that layers are transparent far into the ultraviolet region.