Hydrogen-enhanced clusterization of intrinsic defects and impurities in silicon

Formation of intrinsic and impurity defect complexes in hydrogenated monocr ystalline silicon is studied. Hydrogen was incorporated into samples by dif ferent ways: either by proton implantation at 80 and 300 K, or by annealing at 1250 degreesC for 30-60 min in a sealed quartz ampoule containing simil ar to 10(-3) ml of distilled water, or by treatment in hydrogen plasma. Rad iation defects were incorporated either during the hydrogen implantation or by additional irradiation with protons or alpha -particles. The measuremen ts were performed by electron paramagnetic resonance (EPR), deep level tran sient spectroscopy (DLTS) and infrared absorption (IR) methods. Essential d ifferences of defect formation processes in hydrogenated samples as compare d with reference samples were detected. The main reasons responsible for th e differences are (i) hydrogen precipitation in a supersaturated solution d uring thermal treatment: (ii) interaction of hydrogen with defects and impu rities and hydrogen-induced formation of defects; (iii) ability of hydrogen to play the role of accelerator of impurities precipitation. These factors result in the formation of vacancy-related, interstitial-related and impur ity clusters which are observed only in the presence of hydrogen. The natur e of the clusters and possible models of their structure are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.