No abstract

No abstract

A technology of semiconductor surface cleaning has been applied to GaAs surfaces for the preparation of contamination free surfaces. This technique combines a low energy hydrogen ion beam (ion energy <500 eV) with an increased substrate temperature (150 °C). The long term change of the GaAs (001) surface composition under the influence of this process was investigated with in situ x-ray photoelectron spectroscopy and atomic force microscopy. A removal of surface oxides and carbon as well as of surface contaminations due to the hydrogen ion beam treatment could be observed. At an elevated substrate temperature of 150 °C, the hydrogen ion beam produces a contamination-free surface without changes in surface composition (stoichiometry) or surface roughness, whereas room temperature hydrogen exposure results in an As-depleted surface composition. This technique could be used for wafer direct bonding of III–V semiconductors and other processes which require highly efficient quality cleaning procedures.

The anisotropic optical constants of slightly In-rich CuInSe2 are determined on the (112) surface of a naturally grown single-crystal sample with orientation domains using generalized spectroscopic ellipsometry for photon energies between 0.8 and 4.5 eV. Orientation domains within the sample, revealed by electron diffraction investigation, cause biaxial response of the sample surface. The CuInSe2 dielectric functions are extracted at each wavelength rigorously considering orientation domains and surface roughness effects, and improve previous results.

No abstract