The influence of diffusion temperature and ion dose on proximity getteringof platinum in silicon implanted with alpha particles at low doses

Platinum has been diffused into epitaxial n-type silicon at 600, 650, and 7 00 degrees C for 30 min following implantation with 3.3 MeV alpha particles . The doses employed were between 1 X 10(11) and 1 X 10(14) He+ cm(-2). The reafter the samples were characterized using deep level transient spectrosc opy (DLTS). The samples diffused at 700 degrees C show only the deep level at 0.23 eV below the conduction band that is attributed to substitutional p latinum. DLTS profiling reveals a decoration of the region of maximal damag e by the platinum for lower doses while for higher ones the platinum concen tration is observed to decrease or vanish in this region. In addition, othe r deep levels may appear (so-called K lines). As the implantation dose incr eases, so does the platinum concentration following diffusion at 700 degree s C at the shallow end of the DLTS working region. It is shown that, by con trolling the amount of implantation induced defects and the diffusion tempe rature, one can steer the amount of platinum that arrives in the region of maximal damage. (C) 1999 American Institute of Physics. [S0003-6951(99)0032 2-8].