Multidimensional depth profile analysis of oxide layers by plasma profiling techniques: GD-OES and PP-TOFMS

摘要

Plasma Profiling Techniques provide direct measurement of the chemical composition of materials as a function of depth, with nanometre resolution and the capability to measure both thin and thick layers. These techniques rely on the fast sputtering of a representative area of the material of interest by a high density (1014/cm3) and low energy plasma. The unique characteristics of this plasma allow very fast erosion (2 - 10 nm/s) with minimum surface damage (as the incident particles have an average energy of about 50 eV) which has been shown to be advantageous for SEM sample preparation. When coupled to a high resolution optical system, the resulting technique is called RF GD-OES and is well established, when coupled to TOFMS detection, it is named Plasma Profiling Time of Flight Mass Spectrometry, a newly commercialized variation of the same technique. Both instruments feature an advanced pulsed RF source allowing the measurements of conductive and non conductive layers. Various applications will be presented ranging from thin film analysis for composition, contamination detection, surface area measurements and doping level to characterization of diffusion mechanisms. Aspects of analytical performance with regards to sensitivity, quantification, repeatability and sample throughput will be discussed.