本論文旨於探討寬能隙（wide band gap）半導體碳化矽基電容器與塊材受輻射損傷之累增效應（cumulative effects）影響，並加入矽基電容器以做為對照。本研究所採用的游離輻射源包含伽瑪、中子及質子，研究中也使用蒙地卡羅模擬粒子遷移的計算程式 SRIM (Stopping and Range of Ions in Matter) 預測質子照射的縱深及損傷分佈。經由完整的電性與材料特性分析，藉此釐清不同游離輻射所誘發之總游離劑量效應（Total Ionizing Dose, TID）與位移損傷（Displacement Damage, DD）效應對於碳化矽材料與元件所造成的損傷及特性劣化。
本論文輻照實驗係利用國立清華大學同位素館的 60Co 照射場與清華水池式反應器（Tsing Hua Open-pool Reactor, THOR）的中子源及 Leonard Kroko, Inc. 的離子佈植機產生之質子。從電性分析的研究結果可知，游離輻射於介電層內部之游離能量損失會造成氧化層陷阱電荷與介面能態陷阱電荷改變。非游離能量損失所引發之位移損傷則可能會導致基板的自由載子移除與局部傳導帶不連續性，由此也可評估碳化矽基元件的輻射耐受性。此外，由 N-type 氮摻雜與半絕緣碳化矽塊材之輻射損傷的材料分析結果顯示，中子與質子照射所致之位移損傷會於塊材中產生大量的碳與矽的空位缺陷，造成嚴重的晶格損傷，此現象可由能隙值下降、 Urbach Energy 增加、拉曼光譜特徵波峰相對強度、以及氮施體能態發光中心之光致發光強度變化等結果獲得驗證。

This study aims to investigate the cumulative effects of radiation damage on silicon carbide (SiC)-based Metal-Oxide-Semiconductor (MOS) capacitors and materials. The Si-based MOS capacitors were also used for comparison. The ionizing radiation sources used in this study included gamma rays, neutrons, and protons. The Monte Carlo calculation code SRIM (Stopping and Range of Ions in Matter) was also used in the study to predict the depth and damage distributions of proton irradiation. Through a complete analysis of electrical characteristics and material properties, the mechanisms for the influence of Total Ionizing Dose (TID) and Displacement Damage (DD) effects on SiC materials and devices can be clarified.
The gamma and neutron irradiation experiments were carried out using the Co-60 gamma-ray source and the fission neutrons from the Tsing Hua Open-pool Reactor (THOR), National Tsing Hua University (NTHU). The proton irradiation experiments were performed using the ion implanter provided by Leonard Kroko, Inc. The results of the TID effects indicated that the change of oxide trapping charges and interface states inside dielectric layer induced by ionizing radiation can be attributed to ionizing energy loss (IEL). Moreover, the DD effects caused by non-ionizing energy loss (NIEL) would result in the removal of free carriers from bulk materials and lead to a large conduction band offset in energy bandgap. Relying on the results, the radiation tolerance of the SiC-based devices can be assessed. In addition, the radiation damage effects on n-type and semi-insulating 4H-SiC bulk materials were also investigated by variety of optical spectroscopic techniques. The results indicated that displacement damage induced by neutron and proton irradiation would create a large number of carbon and silicon vacancies in bulk materials and lead to severe lattice damage as well. This can be evidenced by the decrease of energy band gap, the increase of Urbach energy derived from absorption spectra, the relative intensity of the characteristic peaks in Raman spectra, and the intensity variation of photoluminescence peaks emitting from the luminescence centers assigned to N-donor states and carbon vacancies.

摘要 i
Abstract ii
致謝 iv
目錄 v
表目錄 viii
圖目錄 ix
第一章 序論 -1-
第二章 文獻回顧 -5-
2.1 輻射環境 -5-
2.2 輻射損傷研究發展 -7-
2.2.1 總游離劑量效應 -7-
2.2.2 位移損傷效應 -10-
2.3 輻射損傷原理 -14-
2.3.1 總游離劑量效應 -14-
2.3.2 位移損傷效應 -18-
第三章 實驗製程與原理 -22-
3.1 電容器製備 -22-
3.2 伽瑪照射 -22-
3.3 中子照射 -23-
3.4 質子照射 -25-
3.5 SRIM 電腦模擬計算程式 -26-
3.6 特性分析 -28-
3.6.1 高頻電容-電壓量測 -28-
3.6.2 紫外光-可見光光譜儀 -31-
3.6.3 拉曼光譜儀 -34-
3.6.4 螢光光譜儀 -35-
3.6.5 二次離子質譜儀 -36-
第四章 結果與討論 -39-
4.1 伽瑪輻照實驗 -40-
4.1.1 電容-電壓特性曲線分析 -40-
4.2 中子輻照實驗 -47-
4.2.1 電容-電壓特性曲線分析 -47-
4.2.2 吸收光譜 -54-
4.2.3 拉曼光譜 -62-
4.2.4 光致發光 -68-
4.3 質子輻照實驗 -73-
4.3.1 SRIM 模擬 -73-
4.3.2 SIMS 縱深分析 -75-
4.3.3 電容-電壓特性曲線分析 -77-
4.3.4 吸收光譜 -92-
4.3.5 拉曼光譜 -96-
4.3.6 光致發光 -100-
第五章 結論與未來工作 -105-
5.1 結論 -105-
參考文獻 -109-

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