RESONANCE IONIZATION SPECTROSCOPY FOR QUANTITATIVE AND SENSITIVE SURFACE AND BULK MEASUREMENTS OF IMPURITIES IN II-VI MATERIALS

We have applied resonance ionization spectroscopy for the first time o n II-VI materials, Cd, Te, CdZnTe, and HgCdTe for the measurement of t race impurities. It is an analytical technique with extremely high sen sitivity, selectivity, dynamic range, and quantitation accuracy. The t echnique provides virtual freedom from matrix effects and minimizes is obaric and other mass interferences, known to be the shortcomings in s econdary ion mass spectroscopy and other mass spectroscopic measuremen ts. Quantitative analysis of Cu in bulk CdZnTe boules has shown Cu con centration in the range low 10(14) to low 10(15) cm(-3) with an averag e copper content in four different boules near 2 x 10(14) cm(-3). High Cu concentration (1-2 x 10(17) cm(-3)) measured in some HgCdTe epitax ial layers correlated with lower Hall mobility in the layer, and in on e case the intentionally In-doped, n-type HgCdTe layer turned p-type.