Title :
Enhancement of graphene field-effect transistor by surface treatment
Author :
Fahad Chowdhury, Sk ; Li Tao ; Banerjee, Sean ; Akinwande, Deji
Author_Institution :
Microelectron. Res. Center, Univ. of Texas at Austin, Austin, TX, USA
Abstract :
We report the enhancement of electrostatic transfer characteristics of fabricated graphene field-effect transistor (FET) by hexamethyldisilazane (HMDS) surface treatment. Charge carrier mobility increases by over 50% on average for both electron and hole. Impurity concentration also reduces by over 50% on average and charge neutrality point usually moves towards zero gate voltage. Electrostatic transfer characteristics of as fabricated FET show small variation with temperature resulting in weakly temperature sensitive carrier mobility. However, there is significant variation in characteristics between room temperature and 77 K after HMDS treatment and charge carrier mobility at 77K is almost two times the mobility at room temperature. We attribute the performance enhancements upon HMDS treatment to removal or modification of various contaminants present on graphene surface after device fabrication, which results in reduced carrier scattering. Dielectric screening of charged impurities may also contribute towards performance enhancements.
Keywords :
carrier mobility; field effect transistors; graphene; FET; HMDS surface treatment; carrier scattering reduction; charge carrier mobility; device fabrication; dielectric screening; electrostatic transfer characteristics; graphene field-effect transistor; hexamethyldisilazane surface treatment; impurity concentration; performance enhancements; weakly temperature sensitive carrier mobility; zero gate voltage; Electrostatics; Field effect transistors; Graphene; Impurities; Logic gates; Temperature; Temperature measurement; FET; graphene; hmds; mobility;
Conference_Titel :
Nanotechnology (IEEE-NANO), 2014 IEEE 14th International Conference on
Conference_Location :
Toronto, ON
DOI :
10.1109/NANO.2014.6968125