Hot Electron Induced Fiber Optic Transistor Beta Degradation, Recovery, and Dynamics of Hydrogen Atoms at the Si-SiO2 interface Iayer

摘要

Hot electron induced beta degradation has been observed from fiber optic transistors after multiple parametric testing. Beta degradation originated from increasing base leakage current due to the multiple testing. Base leakage current increases were directly related to the hot electron phenomenon at Si-SiO2 interface layer. The hot electron effect broke down the trivalent silicon and its hydrogen compounds (≡SisH) at the interface layer, which created mobile interstitial hydrogen atoms (Hi) and trivalent silicon atoms Si~* (interface trap charges) at the same time. Typically, the ≡SisH forms during the post metallization anneal. This paper will outline the following topics: 1.) The generation of mobile hydrogen atoms and trap charges at the Si-SiO2 interface due to the hot electron phenomenon and its relationship to transistor beta degradation. 2.) A quantitative analysis of hydrogen atoms measured by Secondary Ion Mass Speetrometry (SIMS), and a direct relation-ship model between beta degradation and hydrogen profiles at the interface layer. 3.) Experimental result showing transistor beta recover as well as the repopulation of the hydrogen atoms at the interface layer after low temperature annealing (150℃ to 200℃ bake).