Investigations on H+ and He+ implantation effects in n-InP using Raman scattering

The LEC grown (1 1 1) n-InP have been implanted with H+ and He+ for various doses ranging from 10(12) to 10(16) cm(-2). The Raman spectra of TO and LO modes in as-grown, H+ and He+ implanted n-InP an recorded and analyzed. FW HM of the LO Raman mode decreases while that of the TO mode remains the sam e for low doses up to 10(15) cm(-2) for H+ and 10(14) cm(-2) for He+. For h igher doses the FWHM of both the modes increase, the increase being larger for TO mode. LO-TO splitting decreases with the increase of dose, for all d oses. The ratio between the area under TO and LO modes decrease at low dose s but increase for higher doses. These results have been explained with car rier concentration reduction at low doses and lattice damage at high doses. Annealing effects on these Raman mode parameters have also been studied on the as-grown and implanted n-InP, where the thermal annealing anneals part ially the implantation induced lattice defects. (C) 1999 Elsevier Science B .V. All rights reserved.