Prolonged Storage of Electrons in Monos-Structures

Abstract

ABSTRACTThe transient process of the accumulation of charge in the Silicon Nitride by applying a positive voltage pulse to MONOS structure is investigated with the help of the experimental and theoretical methods (monopolar injection of electrons). The mathematical model of charge carriers transport in an amorphous nitride thin films in MONOS structures at the high electric fields has been developed. The essential peculiarity of this modelis that the injected carriers from the contact are captured by a quasi - continuous spectrum of states that there are traps, having an exponential distribution of densityin the nitride band gap and by the monoenergetic positively charged deep centers. The positive traps are made by the negative correlation energy defects. These defects are formed by the weak quasi- hydrogenous bonds Si-H-Si the changes of ones in consequences of a migration of hydrogen stipulate for the degradation processes in the nitride. It is established that the quasi - distributed traps are answered for the prolonged relaxation of current in the external circuit when t≫Tg in which the exponent α of function J∼t-α is determined by the parameter of the energy distribution of traps and by the applied voltage on the structure that is in agreement with experimental results and corresponds to the dispersive transport of carriers.