Micro-Raman spectroscopic analysis of single crystal silicon microstructures for surface stress mapping

Abstract

In this paper, an experimental analysis using a micro-Raman spectroscope for surface stress distribution in single crystal silicon (SCS) microstructures is described. Specially developed tensile test equipment applies a uniaxial tensile stress on SCS specimens with a 270 nm-high, 4 µm 2 convex structures in the gauge section. Raman spectra around the convex region are measured using an ultraviolet laser with an excitation line of 363.8 nm. The shape of the Raman spectrum on the flat surface is symmetrical, whereas that around the edge of the convex is asymmetrical due to the multi-stress condition. Two-curve fitting is adopted for the asymmetric spectrum obtained at the edge, and the stress distribution estimated by the two peak positions is much closer to finite element analysis (FEA) results than that obtained by the one peak position. In partial least squares (PLS) analysis that is performed at the edge of the convex section only, explanatory variables are Raman spectral parameters, such as peak position, peak intensity, and full width at half maximum, and the response variable is the FEA stress distribution. The plane stress distributions derived from PLS analyses on each component are in good agreement with that from FEA. The combination of micro-Raman spectroscopy and tensile testing enables us to directly determine the stress components as well as stress magnitudes on SCS microstructures.

Origin of additional broad peaks in Raman spectra from thin germanium-rich silicon–germanium films

“…[1][2][3][4][5][6][7][8][9][10] For each device, several parameters in the thin SiGe film should be optimized, e.g., strain, crystal quality, impurity, temperature, and composition, for which Raman spectroscopy can be a powerful tool as many researchers have demonstrated it. [11][12][13][14][15][16][17][18][19][20][21][22][23] Actually, SiGe exhibits interesting features in the Raman analysis. The crystal structure of SiGe is that of a diamond and can hold the whole Ge or Si concentration range in the matrix.…”

Temperature-dependent stress in diamond-coated AlGaN/GaN heterostructures

“…The ω 0 and k values are listed in Table 1. It is worth to mention that k values slightly differ for different crystallographic orientations and have different values for singlet and doublet phonons (as for Si [33,34] as diamond [22,32,35]). However, in many spectra the splitting of the characteristic Raman line is not detectable.…”

Mechanical Property Measurement of Micro/Nanoscale Materials for MEMS: A Review

“…Raman spectroscopy [43][44][45] and Cathodoluminescence spectroscopy [46] are powerful tools to measure a surface stress in Si and SiO x , respectively, and work well for nondestructive stress analysis for Si devices. The combination of Raman spectroscope and biaxial tensile tester enabled to understand not only stress magnitude but also its component around a microscale structural pattern on Si MEMS [32,44,45].…”