Graduation Semester and Year

2007

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Electrical Engineering

Department

Electrical Engineering

First Advisor

Zeynep Celik-Butler

Abstract

A new 1/f noise model has been developed for MOSFET devices with high-? gate stack. To investigate the impacts of nitridation, MOSFETs with nitrided high-? dielectric was used. These devices were provided by Texas Instruments, having four different interfacial layer thicknesses with a stack composition of SiON/HfSiON. The dominant mechanism affecting the noise behavior of these devices was experimentally determined to be correlated number and mobility fluctuation. The impact of remote phonon scattering was investigated in the temperature range of 172K to 300K. It has been observed that the mobility characteristics of these devices were significantly affected by remote phonon scattering. However, the impact of remote phonon scattering was not observed on the flicker noise characteristics. The new model was developed in the frame work of the original Unified Model incorporating two distinct features that distinguish high-? gate stacks from SiO2. The new model considers energy and spatial dependence of trap distribution in the dielectric, thus generates a more realistic trap profile. Furthermore, it incorporates the multi layered structure of the gate stack by considering tunneling of carriers through a double step cascaded barrier. The newly developed model is accordingly called MSUN (Multi Stack Unified Noise) Model, named after the original Unified Model. MSUN Model has been successfully verified with data on MOSFETs having four different interfacial layer thicknesses, in the temperature range of 172K to 300K. The model predictions show very good agreement with data in the bias range of moderate to strong inversion. No specific impact due to nitridation was observed on these devices. The model has been successfully transformed into a compact form which is compatible with leading device simulation package used in the industry.

Disciplines

Electrical and Computer Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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