A simple way to analyze infrared reflectivity spectra of p-type Hg_0.78Cd_0.22Te implanted in various conditions

摘要

Different ion-implanted p-type Hg_0.78Cd_0.22Te samples were analyzed by infrared reflectivity in the 2-20 #mu#m wavelength range. We show how to derive some characteristic values of the free carriers induced by ion implantation from simple models of the implanted samples. For low energy implantations (Al (320 keV)) an excess of electrons with concentration n~+ approx approx 5X10~17 cm~-3 for doses 10~12 and 10~14 ions cm~-2 is observed between the surface between the surface and the projected range R_p of the ions, in agreement with the well-known change of type of the free carriers induced by the ion implantation in this kind of samples. High energy #alpha# particle (0.8 and 2 MeV, 10~14 ions com~-2) implantations lead to a pronounced inhomogeneous concentration of free electrons with n~+ approx approx 9.2X10~16 cm~-3 between the surface and R_p where a negligible amount of defects due to the nuclear energy loss is formed, and n~+ approx approx 1.6X10~17 cm~-3 between R_p and R_p+#DELTA#R_p, #DELTA#R_p being the longitudinal straggling, where the defect production rate through the nuclear energy loss mechanism is maximum. direct c 1999 Elsevier Science B.V. All rights reserved.