Ion shower doping and plasma doping are attractive for low energy implant required for sub-quarter micron MOSFETs, owing to their high dose rate and large-area implantation capability. However, as ions are not mass-analyzed, various kinds of ion species are implanted, e.g. H-2(+), H-3(+) and BHx+ (x=0-3) when B2H6 is used as ion source gas. Thus, it may cause such problems as unintendedly doped hydrogen and boron energy contamination. In this work the technique is applied to the gate doping and the source/drain doping of 0.20 mu m PMOSFETs. Those PMOSFETs showed characteristics comparable to those implanted by the conventional implanter, in view of shea channel effects, leakage current and gate oxide reliability. (C) 1998 Elsevier Science S.A. All rights reserved. References: 8
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