Abstract: A semiconductor device includes a substrate having a substrate surface, a transistor stack provided on the substrate surface and including a plurality of transistors stacked on each other along a vertical direction that is perpendicular to the substrate surface. Each transistor in the transistor stack includes a vertical channel structure extending along the vertical direction and having a first vertical sidewall and a second vertical sidewall opposite to the first vertical sidewall, and a ferroelectric gate structure in contact with the first vertical sidewall of the vertical channel structure; and a back gate structure provided on the substrate and in contact with the second vertical sidewall of the vertical channel structure of each respective transistor in the transistor stack.

Abstract: Systems and methods for manufacturing two-dimensional (2D) gas channel for vertical transistors. The system can include a semiconductor device. The semiconductor device can include a channel structure surrounding a first dielectric core. The channel structure can include a first two-dimensional (2D) material and a second 2D material. The semiconductor device can include a source metal surrounding a first portion of the channel structure. The semiconductor device can include a drain metal surrounding a second portion of the channel structure. The semiconductor device can include a gate metal surrounding a third portion of the channel structure.

Abstract: A close-coupled tandem bicycle is described with a shorter wheelbase than a standard tandem bicycle and with the front and rear riders positioned closer together for easier communication and interaction between them. Two pedal cranks drive the rear wheel through a sprocket-and-chain drive. Both the front and rear passenger can steer the bicycle. A main handlebar with long handgrips extends rearward within easy reach of the rear passenger. A secondary handlebar attaches to the main handlebar and extends in front of it for use by the front passenger. The height and forward extension of the secondary handlebar is adjustable independently of the main handlebar so that both passengers can adjust the seat and the handlebars to their liking. The tiding positions can be adjusted to allow two riders of different sizes, such as a child and an adult, to ride together in comfort.