Graphene FETs with Low-Resistance Hybrid Contacts for Improved High Frequency Performance.
This work proposes a novel geometry field effect transistor with graphene as a channel-graphene field-effect transistor (GFET), having a hybrid contact that consists of an ohmic source/drain and its extended part towards the gate, which is capacitively coupled to the channel. The ohmic contacts are used for direct current (DC) biasing, whereas their capacitive extension reduces access region length and provides the radio frequency (RF) signal a low impedance path. Minimization of the access region length, along with the paralleling of ohmic contact's resistance and resistive part of capacitively coupled contact's impedance, lower the overall source/drain resistance, which results in an increase in current gain cut-off frequency,fT. The DC and high-frequency characteristics of the two chosen conventional baseline GFETs, and their modified versions with proposed hybrid contacts, have been extensively studied, compared, and analyzed using numerical and analytical techniques.
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, USA. calam003@fiu.edu.
Chowdhury
C
Al-Amin
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, USA. mkara006@fiu.edu.
Mustafa
M
Karabiyik
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, USA. pvabb001@fiu.edu.
Phani Kiran
PK
Vabbina
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, USA. rsinh001@fiu.edu.
Raju
R
Sinha
Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, USA. npala@fiu.edu.
Nezih
N
Pala
access resistance; capacitive coupling; current-gain cut-off frequency; graphene field-effect transistor (GFET); radio frequency