Energy-band parameters of atomic layer deposited Al2O3 and HfO2 on InxGa1−xAs

Abstract

Articles you may be interested inSurface band bending and band alignment of plasma enhanced atomic layer deposited dielectrics on Ga-and N-face gallium nitride X-ray photoelectron spectroscopy ͑XPS͒ combined with reflection electron energy loss spectroscopy ͑REELS͒ were used to determine the energy-band parameters, valence-band offsets ⌬E V , conduction-band offsets ⌬E C , and energy-band gaps E g , of the atomic layer deposited ͑ALD͒ Al 2 O 3 and HfO 2 on In x Ga 1−x As ͑x = 0, 0.15, 0.25, and 0.53͒. Using REELS, E g values of the ALD-Al 2 O 3 and -HfO 2 were estimated to be 6.77 and 5.56Ϯ 0.05 eV, respectively. The ⌬E V 's were determined by measuring the core level to valence band maximum binding energy difference from the XPS spectra. The ⌬E C 's were then extracted from ⌬E V 's and the energy-band gaps of the oxides and In x Ga 1−x As, and are in good agreement with those estimated from the Fowler-Nordheim tunneling. The ⌬E C 's and ⌬E V 's are larger than 1.5 and 2.5 eV, respectively, for all the ALD-oxide/In x Ga 1−x As samples.

Electrical properties of GaAs metal–oxide–semiconductor structure comprising Al2O3 gate oxide and AlN passivation layer fabricated in situ using a metal–organic vapor deposition/atomic layer deposition hybrid system

“…This value was smaller than that of bulk AlN (6.2 eV) 62 and ALD-formed Al 2 O 3 (6.8 eV). 63 As mentioned above, the as-grown AlN layer displays poor bulk properties. The weak bonds in such poor AlN films contributed to the narrowed band gap.…”

Energy barriers at interfaces between (100) InxGa1−xAs (≤x≤0.53) and atomic-layer deposited Al2O3 and HfO2

“…Yet, there is significant uncertainty regarding band offset values at the interfaces of In x Ga 1−x As with oxides: Over seemingly identically fabricated In 0.53 Ga 0.47 As/ HfO 2 structures a variation in the valence band ͑VB͒ offset up to 0.5 eV is reported, 1,2 which substantially exceeds the ϳ0.3 eV VB shift between GaAs and In 0.53 Ga 0.47 As recently reported for the interface with HfO 2 . 3 This uncertainty ͑confusion͒ is likely caused by the insulator charging. 4 An additional problem is associated with incorporation of In into the "native" oxide interlayer ͑IL͒ formed when depositing the insulator, which may cause significant reduction of the interface barrier height as, for instance, is observed at interfaces of Ge and GaAs with Al 2 O 3 and HfO 2 .…”

Complex investigation of multilayer nanostructure of a-Si/SiO1.9 by probe and spectroscopic analysis techniques. Visualization of the band structure. Studying of the band structure of the suboxide border layers

“…Calculations were carried out by a method similar to that described by several authors. [15,16] For a more accurate determination of numerical values the second derivative of the function of electron energy loss was also considered. Summary of the forbidden bandwidth and the position of the peaks of suboxide states [17] are shown in Table 4.…”