Voltage acceleration and t63.2 of 1.6-10 nm gate oxides

摘要

Gate oxide reliability data collected over a considerable period of time were compiled to assess the voltage acceleration and the time to breakdown as function of oxide thickness. These data cover a range from 1.6 to 10 nm and can be used as benchmark for technologies that are still using gate oxide in this thickness range. The data form well-defined bands for each of the voltage acceleration models. The functional dependence of the parameter on oxide thickness depends strongly on the voltage acceleration model. The accuracy of the voltage acceleration parameters determined for the different acceleration models is studied. The time to breakdown at one voltage spans many time-decades if the data covering the entire thickness range are plotted in one graph. Therefore, the use of a model-free value, the voltage to get 63.2% breakdown at a certain fixed time, is proposed for plotting the data taken in the wide oxide thicknesses range, instead of normalizing the time to breakdown to a certain voltage using one of the voltage acceleration models. Based on the results a self-consistent test of the voltage acceleration models is introduced. This parameter also supports the t_(bd) power law and therefore the hydrogen release model when plotting the voltage acceleration parameter of the exp(V)-model versus the inverse model-free gate voltage to get 63.2% breakdown at a fixed time.