USA As Represented by Secretary of the Navy

Ming-Jey Yang

Brian R Bennett

Chia-Hung Yang

Walter Kruppa

John Bradley Boos

Doewon Park

J Brad Boos

A heterostructure comprising: a buffer layer; a bottom barrier layer formed on the buffer layer; a quantum well layer formed on the bottom barrier layer; a top barrier layer formed on the quantum well layer; and a p-doped cap layer formed on the top barrier layer; wherein a portion of the cap layer is etched to form conducting electrons in the quantum well layer below the etched portion of the cap layer. A method of etching comprising the steps of: providing a heterostructure; providing an etchant solution comprising acetic acid, hydrogen peroxide, and water; and contacting the etchant solution to the heterostructure to etch the heterostructure.

Nanofabrication of InAs/A1Sb heterostructures

Nanofabrication for InAs/AlSb heterostructures

This invention pertains to more sensitive and more stable electronic devices which can sense electrical and magnetic fields. The devices are characterized by InAs channels confined on both sides thereof by a wide band gap AlSb material; protective layers above the AlSb material; modulation doping above the AlSb material; and layers of the InAs channel material containing 1 to 99 mol percent antimony, with the channel material being deposited in the form of alternating monolayers of InSb and InAs, of a ternary mixture of InAsSb.

Modified InAs hall elements

Heterostructure field-effect transistors (HFETs) and other electronic devs are fabricated from a series of semiconductor layers to have reduced impact ionization. On to a first barrier layer there is added a unique second subchannel layer having high quality transport properties for reducing impact ionization. A third barrier layer having a controlled thickness to permit electrons to tunnel through the layer to the subchannel layer is added as a spacer for the fourth main channel layer. A fifth multilayer composite barrier layer is added which has at least a barrier layer in contact with the fourth channel layer and on top a sixth cap layer is applied. The device is completed by adding two ohmic contacts in a spaced apart relationship on the sixth cap layer with a Schottky gate between them which is formed in contact with the fifth barrier layer. The second subchannel layer and the fourth main channel layers are made of materials which have the proper respective energy gaps and ground state energies such that during use the transfer of hot electrons from the main channel into the subchannel is made probable to reduce impact ionization in the main channel. In the preferred AlSb/InAs-based HFETs, the use of an Is InAs subchannel layer under the main InAs channel improves the performance of the HEMTs particularly for gate lengths in the deep-submicron regime. The devices exhibit higher transconductance, lower output conductance, reduced gate leakage current, higher operating drain voltage, and improved frequency performance.

Channel design to reduce impact ionization in heterostructure

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Silver Spring, MD, United States of America

Ming-Jey Yang