Our nanowire synthesis chamber is a rapid thermal CVD system, consisting of a load lock connected to a large, cold-walled quartz reaction chamber. The system can easily accomodate 4" wafers. Source gasses, which include GeH4, SiH4, SnCl4, HCl, B2H6, and PH3, allow for controlled growth of alloyed and doped group IV nanowires and epitaxial films.
Equipment and Facilities Used
Our group utilizes two ALD chambers, which can accommodate samples up to 3" and 4" silicon wafers. Both chambers permit various precursor chemistries, allowing for deposition of metal oxides such as Ti2O3 and Al2O3. Custom programming allows for precise control of precursor delivery, enabling growth of alloyed structures. Our 3" chamber is outfitted with a state of the art Fujikin precursor delivery system.
Instruments: FEI Titan and FEI Tecnai
The transmission electron microscope uses a high-energy electron beam transmitted through a very thin specimen to image and analyze the microstructure of materials with atomic scale resolution. In scanning TEM (STEM), a fine probe (of less than 0.2 nm) is formed by optically focusing the incident electrons and is then scanned across the sample. The information limit in a TEM is limited by aberrations in the electromagnetic lenses.
Instruments: FEI Helios and FEI DB235
The instrument is an FEI Helios NanoLab 600i DualBeam FIB/SEM, containing both a focused Ga+ ion beam ("Tomahawk") and a high resolution field emission scanning electron ("Elstar") column. Combined with advances in patterning, scripting, and a suite of accessories, these features make milling, imaging, analysis, and sample preparation down to the nanoscale possible as standard applications in the lab.
Instruments: PHI VersaProbe
XPS provides elemental and chemical information about the surface region (first 1- 30 monolayers) of nearly any solid material. XPS is useful for determining the elemental composition on the surface of all non-volatile materials semiquantitatively. It is sensitive to all elements except H and He and also provides some chemical information about the valence state of elements. XPS is sensitive to the top 5 nm of a sample, but it can be used to provide elemental composition as a function of depth by analyzing a sample while removing surface layers by ion etching.
Instruments: PHI 700 Scanning Auger Nanoprobe
Auger Electron Spectroscopy (AES) is an analytical technique that uses a primary electron beam to probe the surface of a solid material. Secondary electrons that are emitted as a result of the Auger process are analyzed and their kinetic energy is determined. The identity and quantity of the elements are determined from the kinetic energy and intensity of the Auger peaks. The nature of the Auger surface analysis process is such that Auger electrons can only escape from the outer 5-50 Å of a solid surface at their characteristic energy.
Instruments: PANalytical X'Pert PRO
High resolution rocking curve analysis, reciprocal space mapping and x-ray topography on (epitaxial) layers on single crystal substrates. Reflectometry on thin layers and substrate materials for thickness determination. Phase analysis of samples with flat or irregular surfaces of thin films.