Far-infrared transmittance of boron-implanted germanium at liquid-helium temperatures

The transmission of far-infrared radiation of 100-μm wavelength through Ge wafers ion implanted with B was measured at a temperature of approximately 4 K. Transmittance ranged from approximately 0.5 to 0.08 for doses from 3×${10}^{12}$ to 3×${10}^{15}$ ${\mathrm{cm}}^{\mathrm{-}2}$. The resistivity at temperatures between 4 and 1 K, and the impurity profiles of the implanted layers were also measured and correlated with the infrared transmittance.