Excess Noise and Deep Levels in GaAs Detectors of Nuclear Particles and Ionizing Radiation

Experimental results on various electric noises in the Al/GaAs structures with Schottky barriers and the AlGaAs/i-GaAs heterostructures that are employed in GaAs detectors of high-energy nuclear particles and ionizing radiation are reviewed. Methods for the study of the parameters of deep levels (DLs) are described. The systematization of DLs that are formed in GaAs barrier structures and heterostructures in the presence of various impurities and defects of crystal lattice is performed. The results on the effect of DLs on the 1/f noise of the detectors and the data on radiation stability under the action of high-energy electrons and gamma radiation are presented. Practical recommendations on the type and production technology of a detector with the minimum level of the 1/f noise are proposed. The method for the measurement of the 1/f noise of the detectors based on the Al/i-GaAs barrier structures is recommended for evaluation of the radiation stability and the breakdown voltage of high-voltage detectors.