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Topological insulators are unique electronic materials with insulating interiors and robust metallic surfaces. Device applications exploiting their remarkable properties have so far been hampered by the difficulty to electrically tune the Fermi levels of both bulk and thin film samples. Here we show experimentally that single-crystal nanowires of the(More)
A description is given of the design and performance of a diagnostic-accessible, perpendicular-flow, single-wafer deposition reactor for use with 50 mm wafers. The reactor chamber design is based on a simple flow tube, with diagnostic access achieved by replacing sections of the reactor chamber wall with recessed diagnostic ports. Reactor chamber(More)
This work presents a novel method for obtaining surface infrared spectra with sub-second time resolution during atomic layer deposition (ALD). Using a rapid-scan Fourier transform infrared (FT-IR) spectrometer, we obtain a series of synchronized interferograms (120 ms) during multiple ALD cycles to observe the dynamics of an average ALD cycle. We use a(More)
A nondispersive infrared (NDIR) gas analyzer that utilizes a mid-infrared light emitting diode (LED) source was demonstrated for monitoring the metal alkylamide compound tetrakis(dimethylamido) titanium (TDMAT), Ti[N(CH3)2]4. This NDIR gas analyzer was based on direct absorption measurement of TDMAT vapor in the C-H stretching spectral region, a spectral(More)
An all-optical terahertz absorption technique for nondestructive characterization of nanometer-scale metal oxide thin films grown on silicon substrates is described. Example measurements of laser-deposited TiO2 and atomic layer-deposited films of HfO2 are presented to demonstrate applicability to pure Y2O3, Al2O3, and VOx and mixed combinatorial films as a(More)
Metal alkylamide compounds, such as tetrakis(ethylmethylamido) hafnium (TEMAH), represent a technologically important class of metalorganic precursors for the deposition of metal oxides and metal nitrides via atomic layer deposition (ALD) or chemical vapor deposition. The development of in situ diagnostics for processes involving these compounds could be(More)
An in situ gas-phase diagnostic for the metal alkylamide compound tetrakis(ethylmethylamido) hafnium (TEMAH), Hf[N(C(2)H(5))(CH(3))](4), was demonstrated. This diagnostic is based on direct absorption measurement of TEMAH vapor using an external cavity quantum cascade laser emitting at 979 cm(-1), coinciding with the most intense TEMAH absorption in the(More)
A nondispersive infrared (NDIR) gas analyzer was demonstrated for measuring the vapor-phase density of the carbonyl-containing organometallic cobalt precurso μ2-η2-(tBu-acetylene) dicobalthexacarbonyl (CCTBA). This sensor was based on direct absorption by CCTBA vapor in the C≡O stretching spectral region and utilized a stable, broadband IR filament source,(More)
The design and operation of a simple, optically-accessible modular reactor for probing thermal thin film deposition processes, such as atomic layer deposition processes (ALD) and chemical vapor deposition (CVD), is described. This reactor has a nominal footprint of 225 cm(2) and a mass of approximately 6.6 kg, making it small enough to conveniently function(More)
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