Lattice sites of ion-implanted li in indium-antimonide
Hofsass, H Wahl, Ulrich Restle, M Ronning, C Recknagel, E Jahn, Sg
Elsevier science bv
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms vol:85 issue:1-4 pages:468-473
We have studied the interaction of Li and implantation defects using the emission channeling technique after implantation of 60 keV Li-8 ions into n- and p-InSb. Emission channeling patterns of alpha-particles emitted in the nuclear decay of Li-8(t1/2 = 838 ms) were measured for temperatures between 50 and 600 K. A quantitative determination of Li site fractions was achieved by comparing the experimentally observed channeling and blocking patterns to calculated emission channeling effects from Monte Carlo simulations. Below 130 K about 60% of the Li atoms occupy tetrahedral interstitial sites. Between 130 and 200 K a site change to substitutional sites is observed for p-InSb as well as n-InSb, resulting in substitutional fractions of Li of about 60-70%. Substitutional Li is stable up to about 425 K in p-InSb and 475 K in n-InSb. From these temperatures we have estimated dissociation energies of 1.1 and 1.2 eV, respectively. For higher temperatures out-diffusion of Li to the surface is observed. The behavior of Li in InSb was found to be similar to the other III-V semiconductors GaAs, GaP and InP. Whether diffusion of Li or the mobilization of vacancy defects is the dominant process responsible for the observed lattice site changes is discussed.