Micro-Raman depth analysis of residual stress in machined germanium
1991; Elsevier BV; Volume: 13; Issue: 3 Linguagem: Inglês
10.1016/0141-6359(91)90097-3
ISSN1873-2372
AutoresR G Sparks, W S Enloe, M. A. Paesler,
Tópico(s)Integrated Circuits and Semiconductor Failure Analysis
ResumoRaman spectroscopy has proved to be a useful nondestructive technique for measuring residual stresses in semicondutors. The Raman microprobe is used to investigate the effects of machine parameters on residual stresses in single point diamond turned germanium (Ge). A profiling technique that provides a method of obtaining the residual stress information as a function of depth with depth resolutions of 10.0 nm is discussed. This method is used to analyze the asymmetrically broadened and shifted spectral features in the machined samples. Residual stresses are sampled across ductile feed cuts in (100) Ge wafers, which were single point diamond turned using various feed rates (12.5, 25 nm/rev), rake angles (0°, −10°, −30°), and clearance angles (6°, 16°). In general a region of plastically deformed material that shows slight compressive stresses exist near the surface of the diamond turned sample. The compressive surface stress increases to a maximum at a depth of ≈ 50 nm beneath the surface at which point the stress rapidly changes sign. The rapid sign change is indicative of the transition from plastic to elastic deformation. Deeper probe regions exhibit increasing tensile stresses, which reach a maximum and then relax to zero at greater depths in the sample. A related study of the stress field occurring around Vicker's hardness indents provides a link between theoretical and experimental stress profiles and demonstrates the accuracy of the micro-Raman profiling technique.
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