歐姆接觸均存在於大多數半導體元件中，如太陽能電池、金氧半場效電晶體(MOSFET)等。隨著摩爾定律(Moore's law)，元件尺寸持續微縮，金屬與半導體的接觸面積也隨之縮小，因此需要更低的特徵接觸電阻率(ρc)。準確量測ρc值對研究歐姆接觸特性相當重要，因此本論文利用TLM法萃取ρc值。
銀漿透過網版印刷塗佈至n+-poly-Si/n-Si後進行燒結，發現775 ℃的燒結溫度其阻值為5.3 Ω，有較好的燒結效果。銀漿燒結後內部玻璃料向下擴散，銀藉由玻璃料擴散至n+-poly-Si層表面並形成晶粒，且銀與n+-poly-Si層不產生反應，TLM法萃取ρc值為2.9E-2 Ω-cm^2。在n+-poly-Si層下方增加2 nm厚的SiO2層可有效降低ρc值，TLM法萃取ρc值為9.7E-3 Ω-cm^2。SiO2層可有效阻擋n+-poly-Si層中摻雜的磷原子向下擴散，因此有較高的載子濃度而降低ρc值。n+-poly-Si層的少數載子生命週期(lifetime)影響太陽能電池元件轉換效率，高lifetime及低ρc值能提供良好的轉換效率。但較高lifetime值的n+-poly-Si層通常造成較大的ρc值，需在兩者間做取捨。lifetime為1211 µs的n+-poly-Si層，其萃取ρc值為1.5E-2 Ω-cm^2為此論文實驗的最佳樣品。利用COMSOL軟體模擬TLM與CTLM法的特徵阻抗萃取準確性，模擬結果顯示銀漿外擴長度為0.001 cm將增加約0.6至0.7%的萃取誤差。ρc值在1E-3至1E-4 Ω-cm^2範圍時，其萃取誤差皆低於3%，能符合太陽能電池產業需求。CTLM法可避免電流擁擠效應，其萃取誤差低於TLM法，且無TLM法在電極長度L與傳輸長度LT接近時的數學近似誤差，ρc值在1E-4至6E-5 Ω-cm^2範圍時，其萃取誤差皆低於3%。

Ohmic contacts are present in many semiconductor devices, such as solar cell and MOSFET. While device size is continuously shrunk with Moore's law, the contact area between metal and semiconductor is also shrunk. Therefore, lower specific contact resistivity is required. Accurate measurement of specific contact resistivity (ρc) is very important to study ohmic contact characteristics. Therefore, this thesis used the transmission line method (TLM) method to extract the ρc value.
The silver paste was patterned on n+-poly-Si/n-Si substrates by screen printing. After sintering at 775 °C in atmosphere, the resistance between Ag electrodes had the lowest resistance of 5.3 Ω. During the sintering process, glass frit diffused downward. Silver diffused through the glass frit and formed Ag grains on the surface of the n+-poly-Si layer and the silver did not react with the n+-poly-Si layer. The ρc value extracted by the TLM method was 2.9E-2 Ω-cm^2. Adding a 2 nm-thick SiO2 layer under the n+-poly-Si layer effectively reduced the ρc value. The ρc value was 9.7E-3 Ω-cm^2. The SiO2 layer effectively prevented the diffusion of phosphorus atoms into the n-Si substrate, so it had a higher carrier concentration and thus reduced the ρc value. Minority carrier lifetime of n+-poly-Si layer affects conversion efficiency of the solar cell, higher lifetime and lower ρc value can provide good conversion efficiency. Higher lifetime of n+-poly-Si layer generally results in larger ρc values. The n+-poly-Si layer with a lifetime of 1211 µs had ρc value of 1.5E-2 Ω-cm^2, which was the best result in this thesis.
COMSOL software was used to simulate the extraction accuracy of specific contact resistivity by TLM and CTLM methods. The simulation results show that the external expansion length of silver paste of 0.001 cm increased the extraction error by about 0.6 to 0.7%. When the ρc value was in the range of 1E-3 ~ 1E-4 Ω-cm^2, the extraction error was less than 3%, which can meet the needs of the solar cell industry. Because the CTLM method can avoid the current crowding effect, its extraction error was lower than that of the TLM method. When the ρc value was in the range of 1E-4 to 6E-5 Ω-cm^2, the extraction error of the CTLM method was less than 3%.

中文摘要 X
ABSTRACT XI
誌謝 XIII
目錄 XIV
圖目錄 XVI
表目錄 XX
第一章 緒論 1
1-1 前言 1
1-2 動機與目的 1
1-3 論文架構說明 2
第二章 基礎理論與文獻回顧 3
2-1 金屬與半導體接觸之特性 3
2-2 特徵接觸電阻率 8
2-3 Transmission Line Method (TLM) 結構與量測方式 13
2-4 Circular Transmission Line Method (CTLM) 結構與量測方式 17
2-5 太陽能電池 20
第三章 實驗步驟與方法 24
3-1 實驗敘述與流程說明 24
3-2 實驗設備 25
3-3 元件製備流程 27
3-4 COMSOL模擬軟體介紹 29
3-5 材料分析 35
3-6 電性分析 36
第四章 結果與討論 39
4-1 銀漿與矽接面分析 39
4-2 萃取ρc值 46
4-3 線寬模擬改善萃取ρc值誤差 52
第五章 結論與未來展望 65
5-1 結論 65
5-2 未來展望 66
參考文獻 67
論文比對 70

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