Annealing of ultrashallow p(+)/n junction by 248 nm excimer laser and rapid thermal processing with different preamorphization depths

Ultrashallow p(+)/n junctions formed by B+-ion implantation and annealed by spike rapid thermal annealing (RTA) or laser annealing were studied. The e ffect of the preamorphizing depth on the redistribution of boron atoms afte r annealing has also been investigated. Our results show that for ultrashal low junctions formed by ultra-low-energy ion implantation and spike RTA, th e depth of the preamorphizing implant has very little impact on the junctio n depth. By optimizing the laser fluence and preamorphization depth, a high ly activated, ultrashallow, and abrupt junction can be obtained using a 248 nm excimer laser. The secondary-ion-mass spectrometry results clearly indi cate that a step-like profile with a junction depth of 370 Angstrom (for a B+ implant at 1 keV) can be formed with a single-pulse laser irradiation at 0.5 J/cm(2). (C) 2000 American Institute of Physics. [S0003-6951(00)01322- X].