Research On The Relativity Between The Charge Trapping And The Noise In High K Dielectric MOS

As the scaling of MOS devices, the exponential gate leakage increase becomes the limitation of the IC technology development. The substitution of high permittivity dielectric for conventional SiO2 in MOSFET can in a certain extent solve the problem because it has thicker physical thickness when the same equivalent oxide thickness. But a large amount of defects of high k dielectric can deteriorate the performance of the device such as noise increase and mobility degradation because of the charge trapping.Charge trapping in MOS gate dielectric has relativity with the noise.The research of the noise mechanism helps to depress noise and use it as detection tool of traps. So a mount of research work on the traps and noise of high k MOS is done. But these work all only transplants the research method and model of the SiO2 MOS device into high k MOS. In fact, there is a big difference of the trap characteristic, trapping kinetics and noise mechanism between the high k and the SiO2 MOS device.This paper begins with the investigation of the different tunneling mechanisms characteristic and approves the existence of the resonant tunneling in high k MOS device besides the direct tunneling. The calculation of the tunneling transmission coefficient with non equilibrium Green function method and the experiment data of the noise power spectrum prove the existence of the resonant tunneling. And the new tunneling component contribute much more to noise than direct tunneling in certain condition, so the new tunneling mechanism should be considered in the research.This paper proposes the new method with different tunneling mechanisms to investigate the relativity between the noise and the charge trapping because the tunneling mechanisms are the base of the relativity. The relativity between 1/f noise characteristic and tunneling mechanisms is investigated and the dependence model of the noise on the charge trapping mechanisms is proposed and validated.This paper not only points out the different noise component in high k MOS, but also lays a foundation of trap indication and information abstraction in high k dielectric.