A. G. Korotaev

Radiation effects in photoconductive MCT MBE heterostructures

The first results on a radiation stability investigation of mercury cadmium telluride (MCT) films, grown by molecular beam epitaxy (MBE) are represented. The samples were irradiated by high energy electron beams and gamma rays. Electrophysical and photoelectric parameters of MCT epilayers were measured. Volume material was measured too for the checking with MBE-grown one. MBE epifilms were irradiated on a pulsed electron accelerator with electron energy 1-2 MeV and current density less than 1 μA/cm2 for several fluences. Also MCT epitaxial heterostructures were irradiated by Co60 gamma rays. The same experiments were carried out for volume material. The analysis of dependence of Hall coefficient and conductivity from temperature and magnetic field (B) for p- and n- type samples was made. The irradiation of epilayers and volume MCT in the investigated range of irradiation fluences does not give both creation of electrical active damages in high concentrations and reconstruction of initial defects. Thus, MBE films of MCT have the high radiation stability to an electron and gamma irradiation. The obtained first results allow us to speak about high performance of explored MCT epilayers.

Photoelectric characteristics of PtSi-Si Schottky barrier with heavily boron-doped nanolayer

The photo electric characteristics of Schottky barriers, created by recoil implantation in silicon, are analyzed. Implantation of boron atoms in silicon samples was made by recoil method, inducing Al ion beams bombardment, with current density 4-10 A/cm2 and 30-150keV energy. A SIMS analysis of obtained structures and calculation of their electric parameters show the opportunity of conducting layers formation, with a thickness of 10 nm and carrier concentration higher than 1018 cm-3.

Effect of a boron implantation on the electrical properties of epitaxial HgCdTe with different material composition

In this work the experimental results of investigations of the dynamics of accumulation and spatial distribution of electrically active radiation defects when irradiating epitaxial films of Hg1-xCdxTe (MCT) with different material composition (x). The films, grown by molecular beam epitaxy (MBE) were irradiated by B ions at room temperature in the radiation dose range 1012 -1015 ions/cm2 and with ion energy 100 keV. The results give the differences in implantation profiles, damage accumulation and electrical properties as a function of the material composition of the films.

Energy band diagrams of PtSi-Si barrier with a heavily doped surface nanolayer formed by recoil implantation

The development of Schottky barrier technology for creation of IR-photodetectors is caused by reduction of a potential barrier height used by formation of heavily-doped thin layer near to the semiconductor surface. We propose for this aim to form heavily-doped nanolayer in p-Si by recoil implantation of boron. Boron nm-thick film was deposited on the Si sample surfaces by cathode sputtering. After that the samples were irradiated by high intensity Al+ beams extracted from pregenerated explosion-emission plasma. The samples are examined by secondary ion mass-spectrometry (SIMS). It is experimental established that profile of impurity distribution in surface layer is exponential. The doping concentration at the silicide/silicon interface is 1018-1020 cm-3 and thickness of surface layer is 8 - 12 nm. The energy band diagrams of a PtSi - p- Si Schottky barrier with high-doped surface layer formed by recoil implantation were calculated for different parameters of barrier. It is shown, that effective barrier heights in PtSi-Si with recoil implantation formed surface 10 nm layer at surface concentration order 1020 cm-3 is reduced to 0.13 eV, corresponding to a cutoff wavelength of 9.5 micrometers . Thus, the cutoff wavelength of the PtSi Schottky infrared detectors has been extended to the long wavelength infrared region by incorporating a p+ doping layer with exponential profile of impurity distribution at the silicide/silicon interface.

Formation of heavily boron-doped nanolayer in silicon by powerful ion irradiation

An opportunity of forming heavily doped boron layers in silicon is analyzed in this work for variation of potential barrier height on the metal-semiconductor interfaces. Implantation of boron atoms in silicon samples was made by recoil method, inducing Al ion beams bombardment with current density 4-10 A/cm2 and 30-150 keV energy. An analysis of getting structures by SIMS and calculation of their electric parameters show the opportunity of conducting layers formation with a thickness of 10 nm and carrier concentration more than 1018 cm-3.