Characteristics of dielectric layers grown on Ge by low temperature vacuum ultraviolet-assisted oxidation

Abstract

The growth of thin dielectric layers on (100) Ge samples at temperatures lower than 450 °C by photoassisted oxidation with vacuum ultraviolet radiation emitted by a Xe silent discharge lamp has been investigated. The thickness of the grown layers increased with both the oxidation time and processing temperature. Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy (XPS) indicated that the layers are mainly stoichiometric GeO2. XPS investigations also indicated the presence of a several-nanometer-thick substoichiometric oxide layer at the interface region for samples irradiated for short periods of time. Capacitance– and current–voltage measurement showed that layers thicker than 15 nm exhibited good electrical characteristics.

In situ synchrotron radiation photoelectron spectroscopy study of the oxidation of the Ge(100)-2 × 1 surface by supersonic molecular oxygen beams

“…6 cm was used in this study. The surface preparation was performed by chemical treatment and in situ treatment in the UHV apparatus.…”

“…16 It is well known that core-level photoelectron spectroscopy is a powerful tool to give detailed information about the chemical environment and oxidation states of oxides at solid surfaces. [5][6][7][8][9][23][24][25][26][27] Schmeisser et al 28 and Kuhr and Ranke 29 reported Ge 3d core-level spectra for various oxygen exposures to a Ge(100) surface. Two chemically shifted components of Ge 3d, corresponding to Ge atoms with one or two oxygen ligands, were debated.…”

“…1 In the development of Gebased MISFET devices, controlled formation of the surface oxide in a wide variety of ways is important for precise fabrication of dielectric/Ge interfaces. [2][3][4][5][6][7][8][9][10][11][12][13] Therefore, atomic-level understanding of the oxidation of Ge surfaces, especially in the monolayer or sub-monolayer region, is a key research issue. However, the fundamental aspects of the oxidation reaction of Ge surfaces are not well understood, which is in strong contrast to Si surfaces.…”

Fermi level pinning on Si0.83Ge0.17 surface by inductively coupled plasma treatment

“…The Gibbs free energy change for the formation of each oxide is as follows: namely, −⌬G͑700°C͒ in the reaction of Si +2O 2 → SiO 2 is 728.9 kJ/ mol, 9 which is larger than 482.3 kJ/ mol of Ge+ 2O 2 → GeO 2 . 10 Thus, the surface became Si deficient as the ICP-induced oxides were removed through the HF etching.…”

Processing of germanium for integrated circuits

“…Novel processes have been investigated, i.e. sulphur passivation [42], high pressure thermal oxidation [53,54], vacuum ultraviolet-assisted oxidation [55], plasma oxidation [56,57], radical oxidation [58,59], direct neutral beam oxidation [60], plasma postoxidation [61], and thermal molecular oxidation [62].…”