ION-IMPLANTATION OF ISOELECTRONIC IMPURITIES INTO INP

Ion-implanted InP with several kinds of isoelectronic impurities (B+, N+, P+, As+, Sb+ and Bi+) was characterized by photoluminescence (PL) and Raman scattering spectroscopies. The ion concentration was varied between 1 x 10(15) and 1 x 10(20) cm-3. Remarkably broad emissions extending far above the band gap of InP were observed when B+ or N+ was singly implanted to a concentration of 1 x 10(20) cm-3. They appeared more intensively when InP was ion-implanted with B+ as well as with N+ to respective concentrations greater than 1 x 10(19) cm3. These features explicitly demonstrate that a new material was produced by introduction of the same amount of group III and V elements, suggesting that a mixed compound semiconductor between B, N, In and P, i.e., (BN)x(InP)1-x is fabricated. The formation of new materials was also shown by Raman scattering measurements. It is indicated that high dose ion implantation of isoelectronic elements of small mass is a promising method to produce mixed crystal semiconductors. For As+, Sb+ or Bi+ ion-implanted InP, a distinct PL emission was commonly observed below bound exciton emissions for concentrations around 1 x 10(16) cm-3 . These are, to our knowledge, the first-reported radiative recombination centers attributed to these isoelectronic impurities. Bi was found to form a sharp PL emission below bound exciton emissions, suggesting that implanted Bi becomes an efficient recombination center.