Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Group:  List of Projects | List of Researchers

Jerry (Li-Chia) Tai

Alumni
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2020

BPN463: Controlled Nanoscale Doping of Semiconductors via Molecular Monolayers

Johnny C. Ho
2009

One of the major challenges towards scaling down of the electronic devices to the nm-regime is attaining controlled doping of semiconductor materials with atomic accuracy. At such small scales, the various existing technologies suffer from a number of setbacks, including an inability to achieve junction abruptness down to nm range, stochastic distribution of the dopant atoms, crystal damage, and incompatibility with nanomaterials. In this work, We report the formation of sub-5 nm ultrashallow junctions in 4” Si wafers enabled by the molecular monolayer doping of phosphorous and...

BPN501: Patterned Contact Printing with Monolayer for Aligned Nanowire Arrays

Toshitake Takahashi
Kuniharu Takei
Johnny C. Ho
Zhiyong Fan
2010

Large-area, patterned printing of nanowires by using fluorinated self-assembled monolayers (SAM) as the resist layer is demonstrated. By projecting a light pattern on the surface of the monolayer-resist in an oxygen rich environment, sticky and non-sticky regions on the surface are directly defined in a single-step process which then enables the highly specific and patterned transfer of the nanowires by the contact printing process, without the need for a subsequent lift-off step. This work demonstrates a simple route toward scalable, patterned printing of nanowires on substrates by...

BPN386: CMOS-Integrated Nanowire-Based Molecular and Gas Sensors

Karl Skucha
2010

This project first aims to develop a process flow to integrate silicon nanowires onto a CMOS substrate, both via and top-down and bottom-up processes. Then, by carefully designing the underlying circuitry and functionalizing the nanowire transducers, we hope to demonstrate a fully functional integrated sensing platform for various molecular agents and/or gases. The overall goal and application is to create an easy-to-use CMOS-based sensing system for low-cost portable applications.

Project end date: 02/04/10

BPN556: NiO-Based LED Fabrication

Xiaobo Zhang
Kuniharu Takei
2010

NiO is a p-type semiconductor material with band gap about 3.7 eV. It has been fabricated in the form of film by several methods, including electrodeposition[1], pulse laser deposition[2], and ion beam assisted e-beam evaporation[3]. Its applications have been limited to Nickel-ion battery, catalysts and rechargeable batteries. Very little interest and effort was put in its photoelectric applications such as light emission diodes which is primarily due to the poor quality of NiO made by the previously mentioned methods[4]. Here we are to utilize heterostructures made by p-type NiO...

BPN525: Hybrid Core-Multishell Nanowire Forests for Electrical Connector Applications

Rehan Kapadia
2010

Electrical connectors based on hybrid core-multishell nanowire forests that require low engagement forces are demonstrated. The physical binding and electrical connectivity of the nanowire electrical connectors arise from the van der Waals interactions between the conductive metallic shells of the engaged nanowire forests. Specifically, the nanofibrillar structure of the connectors causes an amplification of the contact area between the interpenetrating nanowire arrays, resulting in strong adhesion with relatively low interfacial resistance. The nanowire electrical connectors may...

BPN526: Semiconducting Nanopillars for Photodiodes

Rehan R. Kapadia
Zhiyong Fan
Daniel Ruebusch
2010

The ability to grow high-quality, vertically oriented, single-crystalline nanopillar arrays non-epitaxially enables the fabrication of novel and potentially highly-efficient opto-electronic devices on arbitrary substrates. This project aims to exploit the optical and electronic properties of these structures to fabricate highly sensitive photodiodes on low-cost substrates. In addition, photodiodes will be fabricated from multiple semiconductor materials to explore devices sensitive to different wavelength ranges.

Project end date: 08/09/10

BPN532: Sub-5 nm-wide Junction Formation by Monolayer Doping

Hui Fang
Kuniharu Takei
Johnny Ho
2010

We have previously created a new doping method of semiconductor-monolayer doping (MLD). This method can fulfill the need of the shrinking size of devices by making ultra shallow junctions. More importantly, it causes much less lattice damage in the crystal than conventional ion-implantation technique. In this project, we are going to apply MLD to sub-5 nm-wide patterned lines (by the e-beam lithography), which is very essential to achieve future nanoscale VLSI. The doping profile will be characterized by C-V measurement.

Project end date: 08/10/10

BPN527: Materials Development for Nanopillar Array Photovoltaics

Daniel J. Ruebusch
Rehan R. Kapadia
Zhiyong Fan
Xiaobo Zhang
2010

We have previously demonstrated a first generation solar cell employing an array of vertically oriented and spatially ordered n-CdS nanopillars (NPLs) embedded in a p-CdTe film. The single crystal NPLs are grown by a Au catalyzed vapor-liquid-solid (VLS) process that is compatible with a wide range of materials systems. We seek to expand the design space of our solar cells by developing and integrating promising NPL materials. Successfully grown NPLs will be characterized and ultimately integrated into complete solar cells.

Project end date: 08/11/10

BPN601: Strain Engineering of Epitaxially Transferred, Ultrathin Layers of III-V Semiconductor on Insulator

Hui Fang
Morten Madsen
Kuniharu Takei
Ha Sul Kim
2011

Strain state of ultrathin InAs-on-insulator layers obtained from an epitaxial transfer process is studied. The as-grown InAs epilayer (10¨C20 nm thick) on the GaSb/AlGaSb source wafer has the expected ~0.62% tensile strain. The strain is found to fully release during the epitaxial transfer of the InAs layer onto a Si/SiO2 substrate. In order to engineer the strain of the transferred InAs layers, a ZrOx cap was used during the transfer process to effectively preserve the strain. The work presents an important advance toward the control of materials properties of III-V on insulator...