The effect of surface roughness scattering on hole mobility in double gate silicon-on-insulator devices

The effect of surface roughness of the Si/SiO2 interfaces on hole mobility in double gate silicon-on-insulator p-channel devices is studied. Wave functions and dispersion relationships of the hole subbands were computed self-consistently with the potential profile, employing a 6 x 6 k . p model. The roughness of both silicon-oxide interfaces was thoroughly taken into account as a scattering mechanism by extending a model previously developed for n-channel double gate devices and adapting it to the requirements of the k . p calculation. Hole mobility was computed using the Kubo-Greenwood formula and the impact of surface roughness was discussed. Volume inversion (mobility increase with regard to conventional bulk channel mobility in a range of silicon layer thicknesses) was observed to have a significant effect, as in n-channel devices. (C) 2009 American Institute of Physics. [DOI:10.1063/1.3176498]