Orientation dependence and asymmetry of subthreshold characteristics in CMOSFETs

Orientation dependence and asymmetry of V_T (threshold voltage), g_m (transconductance), S (subthreshold slope), and I_off (off-state current at V_G =3D 0 V) in 0.18 ¿m n-MOSFETs were measured and analyzed. The test structure contains 8 different channel orientation angles of 0°/45°/90° and three kinds of process conditions. Although V_T, g_m and S scarcely show particular anisotropy except for the variation of MOSFET structure and/or impurity profile, the orientation dependence of GIDL characteristics is observed in the wafer with the higher extension dose.