Stresses in strained GeSi stripes: Calculation and determination from Raman measurements

Abstract

Three mechanisms by which edges induce stress relaxation in GeSi strained stripes are described and their relative importance is discussed. Relaxation of stresses in the middle of the layers with I/h( =half-width/thickness) varying from 3 to 100 is calculated including the efFect of the two mechanisms which are important in this range. The values calculated in this manner agree with our recent finite element calculations. Since the stresses in the stripes in the two orthogonal directions are not

Aperture based Raman spectroscopy on SiGe film structures with high spatial resolution

“…Assuming in a first approximation a biaxial stress state in the line center and using strain shift coefficients for SiGe films, 13 this peak shift corresponds to a stress relaxation of 15%. As pointed out in previous studies, 14,18 with decreasing linewidth the stress state in narrow lines should transform from a pure biaxial one into a more uniaxial-stress state. The stress component along the lines is approximately conserved, whereas essentially a relaxation of the stress component perpendicular to the lines occurs.…”

Stress Measurements in Si and SiGe by Liquid-Immersion Raman Spectroscopy

“…Among them, Raman spectroscopy has the advantages such as high sensitive to local strain, submicron spatial resolution, nondestructive measurements, fast measurements, and ease of use. Consequently, Raman spectroscopy has been frequently used by many researchers to measure the strain in Si [3,[7][8][9][17][18][19][20][21]. However, conventional Raman spectroscopy fails to measure the complicated stress states in Si.…”

Formation of compressively strained SiGe/Si(110) heterostructures and their characterization

“…Along with the formation of stress-induced crystalline defects during the growth, device fabrication processes also have significant influence on the lattice strain. For example, stress applied by surrounding materials [18][19][20][21][22][23] and change of strain as a result of micropatterning [24][25][26][27][28][29][30] affect the lattice strain and electronic properties. In this study, we investigated channel direction dependence of the strain in stripe-shaped SiGe-channel MOSFETs fabricated on Si(110) substrates.…”