Experimental investigation on direction dependence of Si (100) and Si (110) hole mobility in ultra-thin body pFETs

The direction dependence of hole mobility in (100) and (110) UTB pFETs has been investigated experimentally using special test device structures exclusive for the direction dependence measurements. It is found that there is no direction dependence under quantum confinement in (100) UTB pFETs with SOI thickness of 5nm. On the other hand, in (110) UTB pFETs, it is shown that hole mobility superiority in <;110>; to <;100>; decreases at low temperature and in high inversion carrier density.