GD-OES depth profiling and calibration of B doped dielectric layers

摘要

Doped Si-based glasses such as boron silicate glass have a variety of applications in photovoltaics. A well suited, fast method for analysing the elemental composition of these layers is glow discharge optical emission spectroscopy. In addition to qualitative depth profiling, quantitative analysis is of special interest. This requires a calibration in the relevant concentration range, which cannot be achieved by certified commercial standards and therefore requires laboratory standards. In context of calibration, the influence of the substrate surface on the depth profile is investigated. It is found that calibration is not unambiguously possible with a rough surface. Optical effects can be identified and a layer system consisting of a SiN_x:H interface layer is used, which was optimized by simulating reflection on interfaces using the transfer matrix method so that calibration is possible using such laboratory standards.