High mobility p-channel GaN heterostructures grown by MOCVD through impurity engineering

The p-GaN/AlGaN/GaN heterostructures with integrated n-channel and p-channel have been extensively applied in p-channel field effect transistor (p-FET) devices and complementary (CMOS) logic circuits. However, the hole mobility of the p-channel is still low, especially in the heterostructures grown by metalorganic chemical vapor deposition (MOCVD). In this work, an impurity engineering was designed by introducing Ga vacancies in the p-channel, so that the diffused Mg impurity could substitute the Ga site and form Mg-Ga(-1) rather than Mg-inter(+2). The charged impurity scattering was hence suppressed due to the reduction of the impurity charge. As a result, the GaN heterostructure with a hole mobility of 21.8 cm(2)/V<middle dot>s with a sheet hole density of 1.02 x 10(13)/cm(2) was realized at room temperature by MOCVD. This work paves a way for improving the transport properties of GaN heterostructures and lays a foundation of high performance GaN-based p-FET devices and CMOS logic circuits on Si substrates.