Experimental Study of $\langle \hbox{110}\rangle$ Uniaxial Stress Effects on p-Channel GaAs Quantum-Well FETs

The impact of
$\langle \hbox{110}\rangle$
uniaxial stress on 2-D hole gas (2DHG) transport and charge control in a GaAs quantum well (QW) is studied through wafer bending experiments. Ungated Hall bars and QW field-effect transistors (FETs) were characterized under various stress levels. Through Hall measurements, changes in hole mobility and concentration due to applied stress were separated. The piezoresistance coefficients of the 2DHG along the two
$\langle \hbox{110} \rangle$
directions in the GaAs QW have been determined for the first time. We found that the linear-regime current of the QW-FET changes due to a combination of piezoelectric effect and hole mobility changes. The value of these coefficients suggests that uniaxial strain engineering is a viable technique to improve p-channel GaAs QW-FET performance for future logic applications.