Performance enhancement of gate-all-around InGaAs nanowire MOSFETs by raised source and drain structure

InGaAs gate-all-around (GAA) MOSFETs with implanted source and drain (S/D) structure have been demonstrated which offer large drive currents and excellent immunity to short channel effects down to deep sub-100 nm channel length [1-2]. In this work, we fabricate n⁺⁺ raised S/D InGaAs GAA MOSFETs with 10nm or 20nm thick nanowires and 200nm channel length. Maximum I_on over 1 mA/μm at V_gs-V_t=1V and V_ds=1V is obtained, which is attributed to small S/D series resistance (R_sd). The R_sd of small dimension devices is systematically studied. We find that R_sd is significantly reduced with the n⁺⁺ S/D structure compare to the implanted structure [1]. At the same time, we find that R_sd is inverse proportional to the perimeter of the nanowire on 20nm thick nanowire devices while R_sd is inverse proportional to the cross section area of the nanowire on 10nm thick nanowire devices. The significant difference confirms that the 10nm thick nanowire works in volume inversion mode while the 20nm nanowire or larger dimension still works in surface inversion mode.