“…Raman spectroscopy, based on measuring changes in phonon frequency that are dependent on stress or strain, has been widely used to measure the stress distribution of single-crystal silicon (SCS). [12][13][14][15][16][17][18] In general, a small laser wavelength for Raman spectroscopy is chosen, because it gives a small penetration depth in silicon. For instance, wavelengths of 488 and 632 nm are approximately correspond to penetration depths of 500 and 2,600 nm, respectively.…”