Nuclear Instruments and Methods 209/210 (1983) 737-742 737 North-Holland Publishing Company ION IMPLANTATION OF SILICON IN GALLIUM ARSENIDE: DAMAGE AND ANNEALING CHARACTERIZATIONS * D. PRIBAT, D. DIEUMEGARD and M. CROSET THOMSON-CSF, Laboratoire Central de Recherche, Domaine de Corbeville, B.P. 10, 91401 Orsay Cedex, France C. COHEN, R. NIPOTI and J. SIEJKA Groupe de Physique des" Solides de FENS, Tour 23, 2 Place Jussieu, 75251 Paris Cedex 05, France G.G. BENTINI, L. CORRERA and M. SERVIDORI Instituto LAMEL del C.N.R., 1 Via Castagnoli, 40126 Bologna, Italy The purpose of this work is twofold: (i) to study the damage induced by ion implantation, with special attention to low implanted doses: (ii) to study the efficiency of annealing techniques - particularly incoherent light annealing - in order to relate the electrical activity of implanted atoms to damage annealing. We have used three methods to study the damage induced by ion implantation: (1) RBS (or nuclear reactions) in random or in channeling geometry (2) RX double crystal diffractometry and (3) electrical measurements (free carrier profiling). Damage induced by silicon implantation at doses > 1014 at/cm 2 can be monitored by all three techniques. However, the sensitivity of RBS is poor and hence this technique is not useful for low implantation doses. As device technology requires dopant levels in the range of 5 x 1012 atoms/cm 2, we are particularly interested to the development of analytical techniques able to detect the damage at this implantation level. The sensitivity of such techniques was checked by studying homogeneously doped (5 X 1016 e /cm 3) and semi-insulating GaAs samples implanted with 3 × 1012 silicon atoms/cm 2 at 150 keV. The substrate temperature during implantation was 200°C. The damage produced in these samples and its subsequent annealing are evidenced by strong changes in X-ray double crystal diffraction spectra. This method hence appears as a good monitoring technique. Annealing of the implanted layers has been performed using incoherent light sources (xenon lamps) either in flash or continuous conditions. Reference samples have also been thermally annealed (850°C, 20 min in capless conditions). The results are compared, and the electrical carrier profiles obtained after continuous incoherent light irradiation indicate that the implanted silicon atoms are almost fully activated. The advantages and disadvantages of incoherent light irradiation are discussed (surface oxidation, surface damage) in comparison with standard thermal treatment. 1. Introduction During the last few years, a great deal of work has been carried out on the recovery of radiation damage and electrical activation mechanisms of ion implanted gallium arsenide crystals. The most conventional process for annealing ion implanted GaAs is a thermal treatment at temperatures up to and above 850°C under specific conditions in order to prevent arsenic loss from surface. Several techniques have been developed for surface stabilization during thermal annealing in order to create local As partial overpressure. Among these, there has been reported: (i) encapsu- lation of the implanted layers by dielectric films such as Si3N 4 [1], SiO 2 [2], AIN [3], (ii) use of * Work partially supported by CNRS (RCP n ° 157). controlled As vapor pressure [4,5] and (iii) use of an intimate contact between a silicon wafer and the implanted GaAs layer [6]. The most widely used encapsulant film has been Si3N4. Alternative annealing techniques have also been investigated. They make use of light or particle beams, such as coherent light (either CW or pulsed lasers [7,8]) and electron beams (continuous or pulsed [9,10]). The general features of these treat- ments are the crystalline recovery of the host GaAs material, along with the substitutional incorpora- tion of the implanted dopant impurities. It is generally admitted that the recrystallization regime involves either liquid or solid phase epi- taxial regrowth, depending on the irradiation con- ditions. In the case of short laser or e-beam irradi- ations (a few tenths of a nanosecond) the process involves surface melting and subsequent recrys- 0167-5087/83/0000-0000/$03.00 © 1983 North-Holland Vl. SEMICONDUCTORS