ELECTRICALLY ACTIVE DEFECTS DUE TO END-OF-ION-RANGE DAMAGE IN SILICONIRRADIATED WITH MEV AR+ IONS

Damage induced by MeV Ar+ ion implantation and end of range defects in Si have been studied by capacitance-voltage, thermally stimulated cap acitance, deep level transient spectroscopy (DLTS) and time analyzed t ransient spectroscopy (TATS). Unlike earlier studies, which focus on d efects induced during post-implantation annealing steps, we study as i mplanted p-type silicon samples. We report the occurrence of mid-gap a cceptor levels using DLTS and TATS in a region well beyond the ion ran ge. The presence of temperature dependent series resistance due to dam aged region distorts DLTS lineshapes, even leading to sign reversal of DLTS peaks in some cases. A new and better method of correcting serie s resistance effects in capacitance transients has been employed. It i s based on detecting the point of inversion of isothermal transients w hich are nonmonotonic due to the presence of series resistance. The ca pture process is found to be thermally activated with a high barrier e nergy. Possible origin of capture barrier and broadening in activation energy are discussed. Our results indicate that these deep levels are associated with point defects with local disorder in the neighbourhoo d.