FinFET with Constant Transconductance

Many analog FinFET applications, such as amplifiers, would benefit if the transistor provided a constant transconductance (gm=constant).The direct modification of transconductance can be done by tailoring the electric field inside the FinFET transistor. In the current study, we modeled and compared the electrical field profiles, IV characteristics, and transconductances of a conventional FinFET with a wrapped gate forming a single pair of gates, and our novel device with two wrapped gates forming two pairs of gates. We modeled and designed the devices taking into account transverse quantum confinement using the commercial modeling package Silvaco Atlas. We found that the novel FinFET operates with a nearly constant gmover a wide range of gate voltages. The novel device, made from silicon, has two pairs of gates with each gate being 10 nm wide and the two pairs of gates being 20 nm apart. The length of the transistor is 40 nm. The region underneath and between the gates is lightly n-type doped at 1×1015 cm-3 with doping of 7×1018 cm-3 at the source and drain contacts. The fin thickness is 120 and the gate oxide is 17 . The fin height is arbitrary as currents are normalized to the fin height.