Devices, and methods of forming such devices, having a material that is semimetal when in bulk but is a semiconductor in the devices are described. An example structure includes a substrate, a first source/drain contact region, a channel structure, a gate dielectric, a gate electrode, and a second source/drain contact region. The substrate has an upper surface. The channel structure is connected to and over the first source/drain contact region, and the channel structure is over the upper surface of the substrate. The channel structure has a sidewall that extends above the first source/drain contact region. The channel structure comprises a bismuth-containing semiconductor material. The gate dielectric is along the sidewall of the channel structure. The gate electrode is along the gate dielectric. The second source/drain contact region is connected to and over the channel structure.

A system and method for in-situ characterization of functional devices. The system comprises a vacuum chamber; a pump system coupled to the vacuum chamber for evacuation the vacuum chamber to near ultra high vacuum pressures of about 10.sup.8 mbar or lower; a sample holder for a functional device based on nanostructured materials disposed inside the vacuum chamber and configured to provide electrical connection to the functional device for measuring electrical properties of the functional device; and a source system for exposing a surface/interface of the functional device to a modification species; whereby the system is configured to measure the electrical properties of the functional device in-situ upon the exposure to the modification species.

A switchable array includes: a microstructure of interconnected units formed of graphene tubes with open spaces in the microstructure bounded by the graphene tubes; at least one JFET gate in at least one of the graphene tubes; and a control line having an end connected to the at least one JFET gate. The control line extends to a periphery of the microstructure.

Devices, and methods of forming such devices, having a material that is semimetal when in bulk but is a semiconductor in the devices are described. An example structure includes a substrate, a first source/drain contact region, a channel structure, a gate dielectric, a gate electrode, and a second source/drain contact region. The substrate has an upper surface. The channel structure is connected to and over the first source/drain contact region, and the channel structure is over the upper surface of the substrate. The channel structure has a sidewall that extends above the first source/drain contact region. The channel structure comprises a bismuth-containing semiconductor material. The gate dielectric is along the sidewall of the channel structure. The gate electrode is along the gate dielectric. The second source/drain contact region is connected to and over the channel structure.

Devices, and methods of forming such devices, having a material that is semimetal when in bulk but is a semiconductor in the devices are described. An example structure includes a substrate, a first source/drain contact region, a channel structure, a gate dielectric, a gate electrode, and a second source/drain contact region. The substrate has an upper surface. The channel structure is connected to and over the first source/drain contact region, and the channel structure is over the upper surface of the substrate. The channel structure has a sidewall that extends above the first source/drain contact region. The channel structure comprises a bismuth-containing semiconductor material. The gate dielectric is along the sidewall of the channel structure. The gate electrode is along the gate dielectric. The second source/drain contact region is connected to and over the channel structure.

A method for making a metal oxide semiconductor carbon nanotube thin film transistor circuit. A p-type carbon nanotube thin film transistor and a n-type carbon nanotube thin film transistor are formed on an insulating substrate and stacked with each other. The p-type carbon nanotube thin film transistor includes a first semiconductor carbon nanotube layer, a first drain electrode, a first source electrode, a functional dielectric layer, and a first gate electrode. The n-type carbon nanotube thin film transistor includes a second semiconductor carbon nanotube layer, a second drain electrode, a second source electrode, a first insulating layer, and a second gate electrode. The first drain electrode and the second drain electrode are electrically connected with each other. The first gate electrode and the second gate electrode are electrically connected with each other.

A method for making a metal oxide semiconductor carbon nanotube thin film transistor circuit. A p-type carbon nanotube thin film transistor and a n-type carbon nanotube thin film transistor are formed on an insulating substrate and stacked with each other. The p-type carbon nanotube thin film transistor includes a first semiconductor carbon nanotube layer, a first drain electrode, a first source electrode, a functional dielectric layer, and a first gate electrode. The n-type carbon nanotube thin film transistor includes a second semiconductor carbon nanotube layer, a second drain electrode, a second source electrode, a first insulating layer, and a second gate electrode. The first drain electrode and the second drain electrode are electrically connected with each other. The first gate electrode and the second gate electrode are electrically connected with each other.

A semiconductor device includes a substrate, a first dielectric layer on the substrate, a hard mask layer on the first dielectric layer, a trench in the hard mask layer and the first dielectric layer, a first source/drain electrode layer on a sidewall of the trench, a second dielectric layer on the first source/drain electrode layer in the trench, a second source/drain electrode layer on the second dielectric layer in the trench, a third dielectric layer on the second source/drain electrode layer in the trench, an ILD layer overlying the trench, an nFET disposed over the trench, and a pFET disposed over the trench and spaced apart from the nFET.

A switchable array micro-lattice comprises a plurality of interconnected units wherein the units are formed of graphene tubes. JFET gates are provided in selected members of the micro-lattice. Gate connectors are routed from an external surface of an integrated circuit (IC) through openings in the micro-lattice to permit control of the JFET gates.

Vertically-integrated two-dimensional (2D) semiconductor slabs in Complementary Field-Effect Transistor (FET) (CFET) cell circuits are disclosed. A horizontal footprint of a CFET cell circuit may be reduced in an X-axis dimension by reducing a gate length of the N-type and P-type channel structures. The N-type and P-type channel structures may be formed of 2D semiconductor materials with high carrier mobility and strong on/off control, which allows a gate length of each semiconductor channel structure to be reduced without increasing a leakage current. By employing one or more elongated monolayers of 2D material in each slab, and vertically stacking slabs to form each semiconductor channel structure, a desired CFET drive strength may be adjusted according to a vertical dimension of the CFET cell circuit, while X-axis and Y-axis dimensions of the horizontal footprint are reduced.