Estimation of ultra-shallow plasma doping (PD) layer's optical absorption properties by spectroscopic ellipsometry (SE)

We evaluated the optical absorption properties of ultra-shallow (<10 nm) plasma doping (PD) layers by spectroscopic ellipsometry (SE). The optical absorption coefficients of PD layers are much larger than that of crystalline Si (c-Si) substrate by one figure at maximum in the wavelength range from 400 nm to 800 nm. We also found that higher DC bias during PD resulted in higher optical absorption coefficient for the same PD time of 60 seconds.