Reconfigurable NanoFETs: Performance Projections for Multiple-Top-Gate Architectures

In nanowire or nanotube field-effect transistors (nanoFETs) electrostatic doping can be induced by electrical fields originating from multiple independent gates. Therefore, nanoFETs are predestined to explore reconfigurability. Solving the coupled nonlinear Poisson and drift-diffusion differential equations for the three-dimensional electrostatic potential and the one-dimensional channel charge, respectively, we predict the performance of four different reconfigurable (R) nanoFET geometries. The investigated architectures compass FETs with one (1G), two (2G), and three top-gate (3G) terminals with a moderate channel length of half a micrometer. Therefore, the theoretically investigated R-nanoFETs can be manufactured at low costs, allowing to test the performance projections claimed in this paper. The 2G R-nanoFET proved to be the most versatile architecture when no application specific optimization is attempted. However, all considered geometries offer interesting properties. Shortening the program gate with the drain simplifies the local routing and only slightly diminish the performance. A smaller footprint 1G R-nanoFET delivers comparable intrinsic gains at the cost of increased static power dissipation. Finally, a 3G R-nanoFET enables additional dynamic configuration options and faster on/off switching due to a control gate positioned at an increased distance to other metallic contacts.