Facilities
The Caltech Nanofabrication Group uses the world-class cleanroom facilities at Caltech’s Kavli Nanoscience Institute, a 1500 square foot cleanroom comprising three separate laboratories for optical lithography, electron beam lithography, and thin film processing. We also maintain a full line of additional fabrication, characterization and testing equipment in our own laboratories on campus. Below, you can find information about some of our equipment, although the list is far from comprehensive.
- Imaging:
- FEI Tecnai TF-20
- A scanning transmission electron microscope (STEM) with a point-to-point resolution of 0.27nm and a 200kV field emission source. This system can be used for analytical electron microscopy on traditional thin-sections, as well as reflection electron microscopy for the evaluation of surface morphologies with nanometer resolution. This system is optimized to integrate chemical analysis tools such as energy dispersive x-ray analysis, energy loss spectroscopy, and energy filtered imaging for enhanced contrast.
- FEI Tecnai TF-20
- Deposition:
- Dual-gun metal sputter system
- Dual-chamber dielectric sputter system
- 2x Edwards 306 Thermal Evaporator
- The BOC Edwards Auto 306 Thermal Evaporator is used for the deposition of thin films of precious metals including: Au, Ag, Au/Ge, Au/Zn, etc. The system is evacuated by a direct drive mechanical pump and a diffusion pump which can reach a base pressure in the high 10-7 torr range. Evaporation is performed by resistively heating a tungsten or tungsten/alumina boat using a manually controlled high amperage supply and is monitored by a quartz crystal deposition monitor.
- E-beam evaporator
- This custom-built electron beam evaporator is built around an MDC 6kW electron beam supply and e-Vap 4000 multi-pocket source. The system is evacuated by a Varian ion pump in addition to a turbo pump for the sample loadlock which allows for very clean operation in the low 10-7 torr range. Deposition is measured by a quartz crystal thickness monitor.
- Fluoride evaporator
- Etching:
- Oxford ICP180
- Outside of the KNI, we maintain an additional load-locked, inductively coupled plasma – reactive ion etching (ICP-RIE) system dedicated for III-V semiconductors. This tool has a temperature controlled stage cooled with chilled water, a 1000W ICP source and 300W RIE supply, and is capable of processing 4″ samples. The system is configured with halogen chemistries (chloride and iodide) optimized for the processing of III-V compound semiconductors, including GaAs, InGaAsP, InP, GaN, AlGaInP, and GaAlInAs. Available gases include Cl2, HI, C4F8, Ar, O2 and N2.
- CAIBE
- Our chemically-assisted ion beam etcher (CAIBE) is an argon-based ion-beam etching system with a 3cm Kaufman ion-source enabling deep, vertical etching for various III-V material systems including InP, GaAs, and InGaAsP. An added-on heated stage together with chlorine gas flow can boost chemical reactions in those material systems by forming InClx or GaClx, resulting in highly anisotropic etching profiles in sub-micron sized pillars and holes.
- Ion Mill
- This is a custom built argon-based ion beam miller with a high power 10cm Kaufman ion source enabling highly anisotropic, deep, high speed mill etching of a wide variety of materials. The chamber is equipped with a residual gas analyzer, sample loadlock, and a Varian diffusion pump.
- Oxford ICP180
- Metrology:
- Optical probe stations
- The group maintains a couple optical probe stations which are typically built on microscope stages set on optical tables and typically feature multiaxis stage and probe control, laser and broadband sources, current and voltage sources, and digital cameras and spectrometers. These stations allow us to quickly determine device performance and tune parameters to characterize our devices immediately after fabrication.
- Semiconductor probe stations
- The group maintains a couple electrical probe stations which are typically built around microscope stages and feature multi-axis stage and probe control, various current and voltage sources, and digital cameras. Characterization of electrical performance may be performed by a current/voltage readers or one of our semiconductor parameter analyzers. Characterization of luminescence of LEDs and lasers may be performed by an optical spectrum analyzer to perform spectral analyses. The 4155C Semiconductor Parameter Analyzer can be used to measure the current-voltage or capacitive characteristics of a wide variety of semiconductor devices. The system has 10fA/2microV measurement resolution and 20microsecond time resolution. Measurement data can be displayed graphically, can be mathematically manipulated, and can be saved as a numerical data file.
- UV-Vis spectrometers
- Optical probe stations