The Research Of Hot-carrier-effects Reliability And Life Model For NMOS

In recent years , with the rapid development of VLSI and microelectronics technology , it's necessary to implant high integration, high performance and high reliability in complex electric circuits system. That's to say , single MOSFET 's characteristic scale is reduced in order to increase device density on every chip. However, IC reliability is demanded high more and more. Nowadays, reliability problem of IC mainly include technological process,MOS transistor,circuit design. Research findings about semiconductor apparatus' reliability problem are focused on hot carrier injection , negative bias temperature instability , time dependent dielectric breakdown, electrostatic damage and so on. HCI reliability is a significant research interest , which can enhance IC reliability. Hot carrier effect induce MOSFET characteristic degradation and short regular working hours, even impact on electric circuits. How establish HCI model and accurately model hot carrier effect. It's meaningful to take effects on HCI , which suppress hot -carrier-effect on MOSFET device. Doing in that's way, device life can be raised to some degree.In this article, hot carrier injection and generation mechanism on N MOFET are firstly introduced. We discuss physical procedure of hot carrier injection and generation in detail ,otherwise, some classic physical model are analysis.Then research methods which are popular domestic and overseas about HCI are introduced. We emphatically introduced about principle and equipment of Charge Pumping technology , DC current stress experiment. Making full use of resource in our laboratory, we design the measurement system for HCI parameter based on LabVIEW. It is inefficient and error-prone to test devices by hands with apparatus . To solve this problem, based on the theory of the reliability test of hot carriers, An automatic testing system is designed regarding LabVIEW 8.5 as a platform in this paper. The hard/software construction of this system especially software design and its fuctional realization are introduced.The experimental results show that the system works steadily and measures accurately, which can improves the measuring efficiency to a great extent .Lastly it has good extendability in program function.Some usual concepts about MOS failure analysis both in Industrial field and academic realm are referred. Three reliability models of MOS HCI, for example , Hu's model, substrate current model and drain voltage Vd model, have been proposed . Analysis their usage respectively. Extract parameters message. In the last place, samples who's channel width length ratio (W/L) is 20/1.5 in SIMBCD Semiconductor Manufacture Corporation of Shanghai.Several characteristic curves of device ,such as Id-Vg,Id-Vd, are given at diverse stress time and stress conditions. Experiment result shows variation of device parameter with stress time is direct ratio, we can extrapolate life of the same kind device based on the test data files.At the end of article, to restrain the hot carrier injection on device, some valid and feasible method were proposed in technical process.