Graphene for More Moore and More Than Moore applications

摘要

Graphene has caught the attention of the electronic device community as a potential future option for More Moore and More Than Moore devices and applications. This is owed to its remarkable material properties, which include ballistic conductance over several hundred nanometers or charge carrier mobilities of several 100.000 cm²/Vs in pristine graphene. Furthermore, standard CMOS technology may be applied to graphene in order to make devices. Integrated graphene devices, however, are performance limited by scattering due to defects in the graphene and its dielectric environment [1, 2] and high contact resistance [3, 4]. In addition, graphene has no energy band gap (Figure 1) and hence graphene MOSFETs (GFETs) cannot be switched off, but instead show ambipolar behaviour [5]. This has steered interest away from logic to analog radio frequency (RF) applications [6, 7]. This talk will systematically compare the expected RF performance of realistic GFETs with current silicon CMOS technology [8]. GFETs slightly lag behind in maximum cut-off frequency FT,max (Figure 2) up to a carrier mobility of 3000 cm²/Vs, where they can achieve similar RF performance as 65nm silicon FETs. While a strongly nonlinear voltage-dependent gate capacitance inherently limits performance, other parasitics such as contact resistance are expected to be optimized as GFET process technology improves.