中子辐照含氢硅中的与氢有关的深能级缺陷

利用深能级瞬态谱(简称DLTS),恒温下瞬态电容技术及红外吸收光谱,研究了中子辐照氢气氛中生长的n型区熔硅。相应于间隙氢的红外吸收谱带中子辐照后强度减弱。首次观察到未经退火就出现了能级为E_c=0.20eV的一个新的缺陷——Z中心,由于该中心的能级很接近于A中心,而浓度又较A中心低得多,通过改变中子剂量使费密能级处于A中心以下几个kT处,才能精确地测定Z中心的DLTS峰所在的温度。根据实验判断Z中心很可能是氢与空位的复合物,讨论了它的可能电子结构。关键词：

DEEP LEVEL DEFECTS RELATED TO HYDROGEN IN NEUTRON IRRADIATED SILICON CONTAINING HYDROGEN

The interaction between hydrogen and defects in neutron irradiated n-type FZ silicon has been studied with deep level transient spectroscopy, transient capacitance at constant temperature and infrared absorption spectroscopy. It has been observed that the absorption peaks of infrared spectroscopy corresponding to the interstitial hydrogen reduce after neutron irradiation. In the unannealed neutron irradiated n-type FZ silicon grown in hydrogen, a new defect-Z center has been observed for the first time. Because the energy level of the Z center (E_c-0.20 eV) is very close to the energy level of the A center (E_c-0.16 eV) and the concentration of the former is much lower than that of the latter. In order to detect the Z center, neutron dose has been selected so that the Fermi level locates at several kT below the energy level of A center. In all probability the Z center is a hydrogen-vacancy complex. The possible electron structure of this center is discussed.