Title :
High dose p+ buried layers for reduced diode leakage
Author :
Rubin, L.M. ; Lee, K.H. ; Oh, J.G. ; Lee, J.Y. ; Lee, S.K.
Author_Institution :
Eaton Corp., Beverly, MA, USA
Abstract :
We report on the effectiveness of moderate to high dose (1×1014 cm-2-1×1015 cm-2) blanket boron implants (1.8 MeV) at reducing diode leakage and gettering surface oxygen. Diode leakage correlates strongly with the near surface defect density resulting from the buried layer implant. This leakage decreases by orders of magnitude as the buried layer dose increases from 3×1014 cm-2 to 1×1015 cm-2. The reduction depends on the post-buried layer implant annealing conditions at moderate doses. For a 3×1014 cm-2 dose, a two-step annealing process (RTA followed by furnace annealing) produced lower leakage than either furnace or RTA annealing alone. TEM micrographs indicate that the best leakage is obtained for minimum widths of the damage band at the projected range of the buried layer implant. High dose buried layers also getter oxygen effectively. Oxygen levels from the surface down to 2 μm are reduced below 2×1017 cm-3 by buried layer implants using a dose of 3×1014 cm-2 and a 1000°C furnace anneal, increasing the buried layer dose above this level has little effect on oxygen SIMS profiles, but GOI performance continues to improve
Keywords :
annealing; boron; buried layers; doping profiles; elemental semiconductors; energy loss of particles; getters; ion implantation; leakage currents; oxygen; rapid thermal annealing; secondary ion mass spectra; semiconductor diodes; semiconductor doping; silicon; transmission electron microscopy; 1.8 MeV; 1000 C; GOI performance; RTA; Si:B,O; TEM micrographs; blanket boron implants; buried layer dose; buried layer implant; furnace annealing; gettering surface oxygen; high dose buried layers; high dose p+ buried layers; near surface defect density; oxygen SIMS profile; post-buried layer implant annealing conditions; projected range; reduced diode leakage; two-step annealing process; Annealing; Boron; Degradation; Diodes; Furnaces; Gettering; Implants; Optical microscopy; Silicon; Transmission electron microscopy;
Conference_Titel :
Ion Implantation Technology Proceedings, 1998 International Conference on
Conference_Location :
Kyoto
Print_ISBN :
0-7803-4538-X
DOI :
10.1109/IIT.1999.812062