Ge p-channel MOSFETS with La₂O₃ and A1 ₂O₃ Gate dielectrics

We report on p-MOSFETs based on La2O3, A1 2O3 and a mixture of both as high-k dielectric deposited by molecular beam epitaxy (MBE). Mobilities of about 140 cm2/Vs were achieved, which are 1.3 to 1.5 times larger than the universal hole mobility of Si/SiO2 This demonstrates the potential advantage of La 2O2-based Ge p-MOSFETs over Si devices. The negative threshold voltages KT, which range between -0.2 and -1 V, make these gate stacks particularly attractive, given the fact that in several cases Ge p-MOSFETs exhibit an unwanted positive VT shift. © 2008 IEEE.