Indium Diffusion Behavior and Implantation-Induced Damage in Indium Implanted Silicon-on-Insulator

Ion implantation induced damage and the diffusion behavior of indium implanted into silicon-on-insulater (SOI) substrates at different energies and doses and annealing at different temperatures were studied. Using Rutherford backscattering spectroscopy (RBS) in the channeling mode and secondary ion mass spectrometry (SIMS), the redistribution of indium in both the top silicon and buried SiO2 layer of SOI after annealing was investigated. At a relatively high implantation energy and dose (200 kV, 1e14cm-2), the diffusion behavior of indium in SOI is different from that in bulk silicon. Indium segregates to the buried Si/SiO2 interface and the effects of end of range indium damage are quite prominent. Our results indicate that in-diffusion (TED) is less pronounced in SOI than in bulk Si, thereby making it easier to get a steep retrograde channel profile (SRCP) in SOI that is beneficial to subsequent device fabrication. Hence, the use of indium as an n-channel dopant in SOI is a distinct possibility.