Evaluation of Strained Silicon by Electron Back Scattering Pattern Compared with Raman Measurement and Edge Force Model Calculation

Abstract

Global and local strained-Si samples, namely strained-Si on insulator (SSOI) wafer and a Si substrate with a patterned SiN film were each evaluated by electron backscattering pattern (EBSP). In the EBSP measurements for SSOI, biaxial tensile stresses (biaxial tensile strains and compressive strain perpendicular to the surface) were obtained, whose values were consistent with those obtained by UV-Raman spectroscopy. One-dimensional stress distributions in the Si substrate with the patterned SiN film were obtained by EBSP, UV-Raman spectroscopy with a deconvolution method, and edge force model calculation. The results were well consistent with each other. EBSP allows us to measure stress and strain in the patterned SiN sample with 150-nm wide space. Furthermore, anisotropic biaxial stress including shear stress was also obtained by EBSP.

Tensor Evaluation of Anisotropic Stress Relaxation in Mesa-Shaped SiGe Layer on Si Substrate by Electron Back-Scattering Pattern Measurement: Comparison between Raman Measurement and Finite Element Method Simulation

“…To precisely evaluate the edge stress relaxation by Raman spectroscopy, a resolution improvement technique, such as the super-resolution method, is necessary. 11,12) As a result, a consistent relationship between EBSP and Raman measurements, and FEM simulation was found in xx stress profiles. On the other hand, the results of EBSP measurement were not in agreement with those of FEM simulation and Raman measurement for the yy stress.…”

“…[6][7][8][9][10] We have reported that electron backscattering pattern (EBSP) measurement is useful for evaluating the stress tensor in Si nanostructures with high spatial resolution. [11][12][13][14][15][16] Raman spectroscopy is also useful for evaluating anisotropic biaxial stress with high stress sensitivity. 3,4,[11][12][13][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] In this study, we evaluated the anisotropic stress relaxation in mesa-shaped strained SiGe layers on Si substrates by EBSP measurement.…”

“…[11][12][13][14][15][16] Raman spectroscopy is also useful for evaluating anisotropic biaxial stress with high stress sensitivity. 3,4,[11][12][13][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] In this study, we evaluated the anisotropic stress relaxation in mesa-shaped strained SiGe layers on Si substrates by EBSP measurement. Moreover, we compared the results of EBSP measurement with those of Raman spectroscopy and finite element method (FEM) simulation.…”

Super-Resolution Raman Spectroscopy by Digital Image Processing

“…The superresolution method was applied to Raman spectroscopy (the so-called super-resolution Raman spectroscopy) to obtain extremely high spatial resolution. In super-resolution Raman spectroscopy, the bilateral total variation (BTV) deconvolution method was selected so that noise enhancement could be suppressed during the calculation [10][11][12][13][14]. In a previous study, it was reported that there was a good correlation between the stress calculated by the EFM and that measured by the Raman method with corrections for detection depth and beam spot size (in this case, the beam spot profile corresponded to the diffusion filter H) [15][16][17].…”

“…A detailed explanation of the BTV method is given in [11]. The EFM with corrections for detection depth and beam spot size [10,11] was employed to check the validation and to estimate the spatial resolution before and after super resolution. In this model, it is assumed that the stresses are concentrated to film edge and the edge forces are dependent on film thickness and stress [18,19].…”