International Business Machines Corporation

University of Texas System

Emanuel Tutuc

Supratik Guha

Joerg Appenzeller

Ali Afzali-Ardakani

Hendrik F Hamann

Sanjay K Banerjee

Leonard Franklin Register, Ii

Allan MacDonald

George Stojan Tulevski

Cherie Renee Kagan

Dharmendar Reddy Palle

Sudhir Muniswamy Gowda

Luigi Colombo

Hua Chen

Xuehao Mou

Seyoung Kim

Inti Sodemann

A device or class of devices that provides a mechanism for controlling charge current flow in transistors that employs collective magnetic effects to overcome voltage limitations associated with single-particle thermionic emission as in conventional MOSFETs. Such a device may include two or more magnetic stacks with an easy-in-plane ferromagnetic film sandwiched between oppositely magnetically oriented perpendicular magnetization anisotropy (PMA) ferromagnets. Each stack includes two non-magnetic layers separating the easy-plane ferromagnetic film from the PMA layers. Charge current flow through one of these stacks controls the current-voltage negative differential resistance characteristics of the second stack through collective magnetic interactions. This can be exploited in a variety of digital logic gates consuming less energy than conventional CMOS integrated circuits. Furthermore, the easy-in-plane magnetic films may be subdivided into regions coupled through exchange interactions and the in-plane fixed magnetic layers in the input magnetic stacks can be used in non-volatile logic and memory.

Transistor that employs collective magnetic effects thereby providing improved energy efficiency

A semiconductor structure is provided, which includes multiple sections arranged along a longitudinal axis. Preferably, the semiconductor structure comprises a middle section and two terminal sections located at opposite ends of the middle section. A semiconductor core having a first dopant concentration preferably extends along the longitudinal axis through the middle section and the two terminal sections. A semiconductor shell having a second, higher dopant concentration preferably encircles a portion of the semiconductor core at the two terminal sections, but not at the middle section, of the semiconductor structure. It is particularly preferred that the semiconductor structure is a nanostructure having a cross-sectional dimension of not more than 100 nm.

Semiconductor nanostructures, semiconductor devices, and methods of making same

A semiconductor device includes a bonding surface, a semiconducting nanostructure including one of a nanowire and a nanocrystal, which is formed on the bonding surface, and a source electrode and a drain electrode which are formed on the nanostructure such that the nanostructure is electrically connected to the source and drain electrodes.

Method of placing a semiconducting nanostructure and semiconductor device including the semiconducting nanostructure

A bi-layer pseudo-spin field-effect transistor (BiSFET) is disclosed. The BiSFET includes a first and second conduction layers separated by a tunnel dielectric. The BiSFET transistor also includes a first gate separated from the first conduction layer by an insulating dielectric layer, and a second gate separated from the second conduction layer by an insulating layer. These conduction layers may be composed of graphene. The voltages applied to the first and/or second gates can control the peak current and associated voltage value for current flow between top and bottom conduction channels, and interlayer current voltage characteristic exhibiting negative differential resistance. BiSFETs may be used to make a variety of logic gates. A clocked power supply scheme may be used to facilitate BiSFET-based logic.

Bi-layer pseudo-spin field-effect transistor

A method and semiconductor device for forming a uniformly thin dielectric layer on graphene. A metal or semiconductor layer is deposited on graphene which is located on the surface of a dielectric layer or on the surface of a substrate. The metal or semiconductor layer may act as a nucleation layer for graphene. The metal or semiconductor layer may be subjected to an oxidation process. A thin dielectric layer may then be formed on the graphene layer after the metal or semiconductor layer is oxidized. As a result of synthesizing a metal-oxide layer on graphene, which acts as a nucleation layer for the gate dielectric and buffer to graphene, a uniformly thin dielectric layer may be established on graphene without affecting the underlying characteristics of graphene.

Establishing a uniformly thin dielectric layer on graphene in a semiconductor device without affecting the properties of graphene

A method of placing a functionalized semiconducting nanostructure, includes functionalizing a semiconducting nanostructure including one of a nanowire and a nanocrystal, with an organic functionality including a functional group for bonding to a bonding surface, dispersing the functionalized semiconducting nanostructure in a solvent to form a dispersion, and depositing the dispersion onto the bonding surface.

Techniques for ultra-sensitive detection are provided. In one aspect, a detection device is provided. The detection device comprises a source; a drain; a nanowire comprising a semiconductor material having a first end clamped to the source and a second end clamped to the drain and suspended freely therebetween; and a gate in close proximity to the nanowire.

Ultra-sensitive detection techniques

Techniques for combining nanotechnology with photovoltaics are provided. In one aspect, a method of forming a photovoltaic device is provided comprising the following steps. A plurality of nanowires are formed on a substrate, wherein the plurality of nanowires attached to the substrate comprises a nanowire forest. In the presence of a first doping agent and a first volatile precursor, a first doped semiconductor layer is conformally deposited over the nanowire forest. In the presence of a second doping agent and a second volatile precursor, a second doped semiconductor layer is conformally deposited over the first doped layer. The first doping agent comprises one of an n-type doping agent and a p-type doping agent and the second doping agent comprises a different one of the n-type doping agent and the p-type doping agent from the first doping agent. A transparent electrode layer is deposited over the second doped semiconductor layer.

Growing community of inventors

Austin, TX, United States of America

Emanuel Tutuc