Modeling of Joule heating and thermoelectric transport in thin film silicon for SJEM measurement

Scanning Joule Expansion Microscopy;Thermoelectric effect;Joule heating;COMSOL;Thin film Si

Koh, Youngjoon ; King ; William P.

关键词: Scanning Joule Expansion Microscopy;    Thermoelectric effect;    Joule heating;    COMSOL;    Thin film Si;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/49679/Youngjoon_Koh.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis reports the finite element modeling of a quantitative nanometer-scaletemperature distribution along the doped Si devices. The modeling replicates data acquisitiontechnique of Scanning Joule expansion microscopy (SJEM). Time varying heat equations andMaxwell’s equations are solved in frequency domain and applied to commercial finite elementsoftware, COMSOL. Chapter 1 introduces various techniques to obtain nanoscale temperaturedistribution. In Chapter 2, Joule heating and Thermoelectric heating in 1st harmonic and 2ndharmonic signals are analyzed by comparing the terms in governing equations and simulationresults. Chapter 3 optimizes device design of doped Si and experimental conditions for futuremeasurement. The approach used in Chapter 2 is expanded in Chapter 4 to understandthermoelectric behaviors in 500 nm thick boron doped p-type and phosphorus doped n-type Sidevices with doping levels of 1019 cm-3 and 1018 cm-3. PtSi or NiSi Ohmic contacts are formed onthe devices and thermoelectric behaviors are analyzed in conditions either under simultaneous DCand AC excitations, or AC only excitations. The simulation results show that thermoelectriccontribution in heating increases with the product of electrical conductivity and Seebeckcoefficient. Chapter 5 explains the future plan for the device fabrication and platform for contactresistance measurements. The studies in this thesis can extend to Schottky contact devices andfurther complicated structures for understanding heat and thermoelectric transport in specificfrequency.