以3ω法量測複合層鑽石薄膜之熱傳導性質

Thermal Conductivity Measurements for Hybrid Granular Structured Diamond Films Using 3ω Method

曾才碩(Tsai-Shuo Tseng)

指導教授 ： 戴念華

國立清華大學/工學院/材料科學工程學系/碩士(2014年)

摘要

本研究使用微波輔助化學氣相沉積法沉積鑽石薄膜於矽基板上，成長的薄膜種類包括單層及雙層複合膜，雙層複合膜是由兩層不同大小的鑽石晶粒所組合而成，而我們期待從這些參數中找出符合我們需求的薄膜，再利用SEM及AFM觀察其表面形貌，以XRD確認晶體結構，並利用TEM觀察微結構及拉曼光譜儀確定薄膜的性質，最後利用三倍頻法量測其熱傳導係數。
　　以3ω法量測本實驗製備的薄膜之熱傳導特性，製造過程為一簡單的黃光微影製程，超奈米晶鑽石薄膜及奈米晶鑽石薄膜均可以順利將π字型的電極圖案完整鍍覆於薄膜表面，然而微米晶鑽石薄膜卻無法以相同步驟作出電極，推測是因為微米晶鑽石薄膜的高低差極大所導致，因此造成金電極容易剝離。
　　在NCD/MCD的試片中，NCD為上層，MCD為底層，當厚度比(下層/上層)從0增加至0.878時，其熱傳導係數由30.34 W/mK提升至41.46 W/mK；在UNCD/MCD的試片中，當厚度比從0提升至0.925時，其熱傳導係數由8.68 W/mK增加至16.94 W/mK。

關鍵字

複合層鑽石薄膜 ； 3ω法 ； 熱傳導性質

並列摘要

In this study, we fabricated the single layer and hybrid granular structured diamond films on silicon wafer by using the microwave plasma enhanced chemical vapor deposition (MPECVD).The hybrid diamond films are composed of two kinds of diamond grain size. We wish we can find the optimized parameter. We observed the morphologies of films by SEM and detected the roughness of surface by AFM. The crystal structure of our samples are analyzed by using X-ray diffractometer and TEM. Also, the bonding properties are characterized by Raman Spectroscopy. In the end, we measure the thermal conductivity by 3ω method.
We deposited NCD film as top layer, and MCD as bottom layer in the NCD/MCD sample. When the thickness ratio (bottom/top) increase from 0 to 0.878, the thermal conductivity get higher from 30.34 W/mK to 41.46 W/mK. When the thickness ratio of UNCD/MCD increase from 0 to 0.925, thermal conductivity increase from 8.68 W/mK to 16.94 W/mK. Furthermore, UNCD/MCD have the smaller roughness than NCD/MCD.

參考文獻

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