Silicon dioxide films grown by industrial thermal furnace, rapid thermal, and low-pressure thermal methods were measured by x-ray photoelectron spectroscopy, transmission electron microscopy (TEM), spectroscopic ellipsometry, and capacitance–voltage analysis. Based on TEM measurements, the photoelectron effective attenuation lengths in the SiO2 and Si are found to be 2.96±0.19 and 2.11±0.13 nm, respectively. The oxide physical thicknesses (range from 1.5 to 12.5 nm) as measured by all above techniques are in good agreement. The electrical thickness is noted to be slightly thicker than the physical thickness.

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Published by the AIP PublishingArticles you may be interested in InAs channel heterostructurefield effect transistors with InAs/AlSb shortperiod superlattice barriers

We present both theoretical and experimental results on the intersubband resonance in InAs/AlSb quantum wells. From a Kane (k•p) description of the band structure we investigate the effect of the large nonparabolicity and of the high Fermi wave vector on the selection rules and matrix elements. The 1-2 transition in parallel excitation (x) is shown to be very weak from simple parity arguments; in perpendicular excitation (z) the matrix element ͗z͘ is shown to be largely unaffected by nonparabolicity. The 1-3 transition turns out to be very weak in both geometries. Two band-gap engineering approaches to enhancing the parallel excitation of 1-2 are considered but the effect remains small as compared to the conventional z excitation. In z excitation the depolarization field condenses all the oscillator strength into essentially one sharp line despite the broadening expected from the nonparabolicity in the band dispersions. Inclusion of the depolarization field in the theory gives us good agreement with both the experimentally determined line shape and ͗z͘ matrix element.

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