Cao Group Facilities
Our research laboratories are located on the fourth floor of the Frederick Seitz Materials Research Laboratory (MRL) at the University of Illinois Urbana-Champaign. The group occupies Rooms 413 and 417 (wet chemistry laboratories) and Room 414 (device characterization and testing laboratory).
Our laboratories provide comprehensive capabilities for materials synthesis, device fabrication, characterization, and bioelectronic research. Key equipment and facilities include:
1) Vigor glovebox systems with integrated spin coater
For thin-film deposition and sample processing in a controlled inert atmosphere.
2) Manual probe station (Micromanipulator 450PM-A-HR)
For electrical characterization of devices and circuits on substrates up to 200 mm in diameter. The system includes a stereo-zoom microscope with digital imaging capability and supports probe-card measurements.
3) Cryogenic probe station (Lake Shore CRX 6.5K)
Equipped with a closed-cycle cryogenic refrigerator and high-temperature sample stage, enabling electrical measurements from 10 K to 675 K.
4) Semiconductor parameter analyzer (Keysight B1500A)
Featuring four high-resolution source/measurement units (SMUs) with measurement sensitivity down to 1 fA and 0.5 μV, multi-frequency capacitance measurements from 1 kHz to 5 MHz, and an integrated waveform generator/fast measurement unit with 10 ns programmable resolution.
5) Imaging spectrometer (Horiba iHR320) with high-intensity xenon light source (PowerArc)
For optoelectronic device characterization using monochromatic illumination spanning wavelengths from 180 nm to 2500 nm.
6) Cell culture facility with integrated electrophysiology measurement platform
Supporting bioelectronics and biointerface research.
7) Nitrogen storage cabinet
For controlled storage of air-sensitive materials and devices.
8) Three chemical fume hoods
Supporting chemical synthesis, materials processing, and safe storage of laboratory chemicals.
Shared Facilities
The Cao Group is among the major users of the shared research infrastructure available at the Frederick Seitz Materials Research Laboratory (MRL) and the Holonyak Micro and Nanotechnology Laboratory (HMNTL), two premier interdisciplinary research facilities within The Grainger College of Engineering at the University of Illinois Urbana-Champaign.
These state-of-the-art facilities provide extensive capabilities for nanofabrication, materials synthesis, and advanced characterization. Frequently used resources include:
1) Cleanroom Facilities
MRL and HMNTL collectively provide more than 14,000 square feet of cleanroom space for semiconductor device fabrication and advanced materials processing.
2) Advanced Lithography Tools
We routinely utilize a suite of cutting-edge lithography systems, including Heidelberg MLA 150 Maskless Aligner, Nanoscribe Photonic Professional GT 3D Printer, Raith EBPG5150 100 kV Electron-Beam Lithography System, and Elionix 150 keV Electron-Beam Lithography System. These tools enable fabrication of planar structures with feature sizes down to 7 nm, as well as complex three-dimensional architectures.
3) Plasma-Enhanced Atomic Layer Deposition (PEALD)
This PEALD system was acquired through a National Science Foundation Major Research Instrumentation (MRI) award led by Prof. Cao. The system integrates a remote plasma source, flow-through precursor delivery module, in situ spectroscopic ellipsometry, and glovebox-connected load-lock transfer. These capabilities enable the conformal deposition of dense, pinhole-free metallic, nitride, and oxide thin films with atomic-scale thickness control.
4) Physical Vapor Deposition (PVD) Systems
We have access to a broad range of thin-film deposition tools, including thermal evaporators, electron-beam evaporators, DC magnetron sputtering systems, and RF sputtering systems.
5) Advanced Etching Systems
Available tools include ion milling, inductively coupled plasma reactive ion etching (ICP-RIE), atomic layer etching (ALE), and deep reactive ion etching (DRIE) using the Bosch process for high-aspect-ratio micro- and nanostructure fabrication.
