Biomedical Nanoelectronics and Neurotransistor

A "neurotransistor" connects a network of living brain cells wired together to a transistor incorporated on a silicon chip using nanotechnology. An individual neuron is attached to the gate of a neurotransistor and is fed essential nutrients and grows dendrites that branch out and make connections with other neurons attached to the gates of other neurotransistors. As a result each neuron can be recorded and manipulated by the transistor. This novel technology is used in studying the development of living neural networks. This "hybrid" neural network will allow the study of how neurons maintain and change their interconnections with time. It will also enable the study of chemical reactions at the "synapses" for long periods of time.

These biochips are of extremely small size (smaller than the thickness of a hair). A biochip with memory and sensors (just like a computer chip) may mimic the function of neurons in the brain (neurons are brain cells). The chip can be used to replace the damages part of the brain for Alzheimer's and Parkinson's

Silicon-Germanium Based Microwave Low Noise Amplifier

Silicon germanium (SiGe) nanotechnology is being developed for the investigation of low noise amplifiers (LNA) for space communication applications. The overall goal is to obtain a three stage low noise amplifier at the microwave frequencies of 13-15Ghz. Minimum noise figures of less than 1.6dB with an associated gain greater than 22 dB is expected to be achieved. The active device of an LNA is a field effect transistor. High performance n-type-metal-oxide semiconductor modulation doped field effect transistors (MOS-MODFET) are currently being investigated. These are being fabricated on silicon-germanium virtual substrates using Nanotechnology.

Cryogenic Nanoelectronics for Space-Borne Power Applications

Concerns exist regarding the ability of currently available electronics to operate at temperatures below 40 K for deep space probe missions. Therefore, the development of electronics devices and systems which can function and cold restart over the range from 77K down to 20K offers great advantages for future space missions.

The overall objective of the research is twofold. The first objective is to fabricate a DC-DC power converter which is able to operate from 77K to 20K using silicon-germanium (SiGe) nanotechnology. The second objective is to fabricate a digital (AND/NAND) circuit using the same substrate as the DC-DC converter. Currently, the bandgap engineering of SiGe is being investigated to design, fabricate and test n- and p-MOSFETs for 77K to 20K nanoelectronics.

Compound Semiconductor Technology

Research is being conducted to investigate InP and InGaAs based compound semiconductors for heterostructure and quantum well devices (HEMTs, etc) with submicron features. The research involves parallel efforts on MBE/MOCVD grown layers, ion-implantation and rapid thermal annealing, ohmic and Schottky contact technology, deposition of thin film as gate insulator and as encapsulant, use of X-Ray photoelectron spectroscopy (XPS/ESCA) and Auger Electron Spectroscopy (AES), refractory metals deposition, deep UV and electron-beam direct-write lithography techniques.