Quantum-size effects in sub 10-nm fin width InGaAs FinFETs

InGaAs FinFETs with sub-10 nm fin widths were fabricated for the first time using precision dry etching and digital etch. We find that the threshold voltage, V_t, becomes highly sensitive to the fin width, W_f, in the sub-10 nm W_f range. 2D Poisson-Schrodinger simulations suggest that this is due to quantization effects. We also show that in the quantum regime, a sidewall slope below 850 significantly reduce V_t variation at the same drawn dimensions.