Nondestructive Characterization Of The Surface Aging Of HgI2 Crystal

Autor: Ralph B. James, Huade Yao, M. Natarajan, J. C. Erickson
Rok vydání: 1996
Předmět:
Zdroj: MRS Proceedings. 442
ISSN: 1946-4274
0272-9172
Popis: Variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) measurements have been employed to characterize the surface aging of HgI2 crystals. A surface model including top surface roughness and subsurface defects was established and studied by VASE analysis, as a function of real time, after the 10% KI chemical etching. In this model, the surface defects associated with the surface aging were modeled by the Bruggeman effective-medium approximation (EMA) as a HgI2/voids mixed layer. The relative 2-dimensional (2D) surface-defectdensities were monitored as the surface aging proceeds. The VASE measurements indicated that high surface aging rates were related to high initial effective 2D surface-defect densities. The AFM profile revealed increasing physical surface roughness as surface aging took place. The cleaved HgI2 crystal surface presented a smooth surface and the lowest surface aging rate, while the as-grown HgI2 surface also presented a very low surface aging. The HgI2 surfaces baked at elevated temperatures presented accelerated surface aging phenomena after a 30 min. baking.
Databáze: OpenAIRE
Externí odkaz: