Electrical characteristics of 0°/±45°/90°-orientation CMOSFET with source/drain fabricated by various ion-implantation methods

Abstract

Electrical characteristics of 0/spl deg///spl plusmn/45/spl deg//90/spl deg/-orientation 0.5-/spl mu/m CMOSFETs with source/drain regions fabricated by three ion-implantation methods are discussed. For asymmetrical one-sided 7/spl deg/-implantation method, large-device-orientation dependent fluctuation and asymmetry were observed in (saturation drain current I/sub D/ and maximum substrate current I/sub B/ of both n- and p-MOSFETs/threshold voltage V/sub T/ of p-MOSFETs) and (I/sub D/ of n-MOSFETs/I/sub B/ of both n- and p-MOSFETs), respectively. Almost comparable characteristics were obtained for n-MOSFETs fabricated by symmetrical 0/spl deg/-implantation and 7/spl deg//spl times/4-implantation methods. However, I/sub D/ difference in p-MOSFETs between 0/spl deg//90/spl deg/- and /spl plusmn/45/spl deg/-orientation devices, which may be affected by intraplanar anisotropy of hole drift velocity, was observed independently of the ion-implantation method.