Model forforecasting the reliability of nanosized field-effect transistors considering possible influence of cosmic rays

Abstract

Purpose . Within the framework of this work the following purposes were set: study of physical mechanisms of degradation of performance of nanosized field-effect transistors caused by interruptions of Si-H; study of possible influence of cosmic rays on the reliability of nanosized field-effect transistors; development of a model to forecast the reliability of nanosized field-effect transistors considering possible influence of cosmic rays. To achieve the above listed purposes it was necessary to analyze: modern models used to forecast the reliability of nanosized field-effect transistors; data of the scope and intensity of cosmic-ray flux depending on energy. Results and Conclusion . According to the results of work, the most relevant physical model used to forecast reliability is the Bravais model which considers the following mechanisms of degradation of performance of nanosized field-effect transistors: - single Vibration Excitation - SVE, when the interruption of Si-H is initiated by one carrier with enough energy; - electron - Electron Scattering - EES, when the interruption is initiated by the carrier which received some energy from another carrier as the result of collision ionization, and thereafter having enough energy to interrupt the connection; - multi Vibration Excitation - MVE, when the Si-H interruption is initiated by a sequential bombing of connection by the carriers having energy not enough to interrupt the connection. It has been shown that cosmic-ray protons having high initial energy can penetrate through the structure of a field-effect transistor, losing a part of their initial energy by ionization losses, and achieve a Si/Si02 boundary. When achieving the boundary protons may have energy sufficient for the initiation of dissociation of Si-H connections by two mechanisms: single Vibration Excitation of Si-H affected by a proton - SVEp is when a single proton having enough energy for interruption runs into a hydrogen atom, and initiates the Si-H dissociation; collision ionization by analogy with the electron - electron scattering described in the Bravais model, in this case there may be the Proton-Electron Scattering - PES. The Bravais model served as the basis for the development of the model to forecast the reliability of nanosized field-effect transistors that considers possible influence of cosmic rays, and helps to give a more accurate forecast of reliability of electronic devices based on nanosized field-effect transistors. This work reflects modern ideas of forecasting the reliability of nanosized field-effect transistors, describing main physical mechanisms of degradation of performance of nanosized field-effect transistors. This article shows that the reliability forecasting models developed for field-effect transistors with a long channel are not suited to modern nanosized devices due to differences in degradation mechanisms. Within the frameworks of this work it was shown that there is a probability of cosmic rays influence on degradation. As the result a model was developed to forecast the reliability of nanosized filed-effect transistors that shall consider such influence.