SIMS characterization of HgCdTe and related II-VI compounds

The production of consistent high purity materials is critical for improvement in performance and sensitivity of II-VI photovoltaic and photoconductive devices. Information regarding the energy band structure and impurity or defect levels present in the material is essential to understand and enhance the performance of current detectors along with the development of future novel devices. Secondary ion mass spectrometry (SIMS) is capable of providing information of purity, junction depths, dopant distribution, and stoichiometry in the material. SIMS techniques can achieve high detection sensitivities in very small analytical volumes and for a wide range of elements (almost the entire periodic table). SIMS analysis also provides unique capabilities for localizing atomic distribution in two and three dimensions. Ion images can be obtained by registering the positions of mass selected ions formed in the sputtering process. The combination of excellent detection sensitivity, high mass resolution, depth profiling capability, and high resolution image acquisition on a wide spectrum of elements by a SIMS instrument is not matched by any other instrumentation technique.