Research On MOSFET Noise And Hot Carrier Effect

With the decrease of the MOS devices size ,hot carrier effect failure get more and more heavy,it become one of the main failure mechanisms. In order to assure the reliability of the device,at the same time,decrease their cost,one need a new nondestructive forecast method to substitute traditional electricity parameter method, the new method must be reliable ,fast and low cost.Introduced hot carrier effect and 1/f noise mechanism in this paper, based on it,had a experiment about the relationship of noise and hot carrier. Lots of electricity parameter and noise data before and after hot carrier injecting have been got.The method of characterizing ability of MOS devices to restrain hot carrier is thoroughly studied by analyzing the relationship between 1/f noise and hot carrier effects.The results as follow:Hot carrier injecting in three different gate voltage have been going on.The results demonstrate that in different gate voltage the carrier gain different energy, result in high energy carrier and low energy carrier.In MOS device gate oxide,high energy carrier break Si-Si bond,and low energy carrier break Si-H bond or Si-OH bond.excited oxide trapped charges and deep energy level interface traps,shallow energy level interface traps,and so on.all the defects arose threshold voltage excursion,transconductance degradation and 1/f noise parameter degradation in different degree,even make the device failure.Compare with traditional parameters,noise parameters can reflect hot carrier damage in different gate voltage more sensitivity .and there have some relations between 1/ fγnoise exponentγand distribution of gate defects in MOSFETs.Based on the formation theories of interface traps and oxide traps in Si-SiO2,further more the influences of hot carrier injection on 1/ fγnoise are discussed thoroughly. A method is developed to characterize abilities of anti-hot carrier damages with noise parameter S ? fγ,that are induced by three kinds gate stresses in MOSFETs.The work done above not only proving that the 1/f noise can play a important role in investigate MOSFET hot carrier effects,but also providing a new nondestructive method to estimate MOSFET hot carrier response.