Revealing the high room and low temperature mobilities of 2D holes in a strained Ge quantum well heterostructures grown on a standard Si(001) substrate

Abstract

We report an extremely high 2DHG mobility of 4500 cm2V-1s-1 and 777000 cm2V-1s-1 at 293 and 0.333 K, respectively, in a compressively strained Ge QW grown by industrial type RP-CVD on a standard Si(001) substrate. The obtained 2DHG mobility is substantially higher than those reported so far and in structures grown by research type epitaxial growth techniques, i.e. SS-MBE and LEPE-CVD. Also, the room and low temperature hole mobilities obtained are the highest not only among the group-IV Si and Ge based semiconductors, but also among p-type III-V and II-VI ones. These results demonstrate the very high quality of the strained Ge QW epilayers grown by RP-CVD and the huge potential for further applications of such materials in modern and future CMOS, p-MOSFET and p-MODFET electronic devices. The 2DHG mobility is already sufficiently high to fabricate sub-100 nm electronic devices and demonstrate ballistic transport therein at or around room temperature.