負型砷化鎵含銅多層歐姆接觸結構之研究及其應用

Study of multi-layered copper-contained ohmic contact structure on n-type GaAs and its application

謝禎益(Chen-I Hsieh)

指導教授 ： 廖森茂

中原大學/工學院/電子工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700224

摘要

在本論文中，我們使用了傳輸線模型法(TLM)以及表面檢查來研究在N型砷化鎵之上使用含銅之鍺/銅/鎳/金多層金屬結構形成歐姆接觸的可能性，然後將這金屬結構應用於磷化鎵銦/砷化鎵之雙接面太陽能電池。實驗的結果指出為了得到較低的特徵阻值我們需要足夠厚度的銅並且足夠厚度的銅也能使所需要的回火溫度降低，同時太厚的鎳以及鍺將會使歐姆接觸的特性變糟而且對於回火溫度的降低沒有明顯的改善。因此，在鍺/銅/鎳/金的厚度分別在30nm/120nm/40nm/50nm並且回火在435℃一分鐘的時候我們可以得到一個相當低的特徵阻值ρc ~ 5.84×10-6Ωcm2。最後，當我們將這金屬結構應用於磷化鎵銦/砷化鎵雙接面太陽能電池之N型歐姆接觸上時，其所量測到的開路電壓、短路電流、填充因子、效率的值和使用傳統的鎳/鍺/金/鎳/金作為N型歐姆接觸之磷化鎵銦/砷化鎵雙接面太陽能電池所量測到的值大約相等。同時，我們也研究了使用含銅之鍺/銅/鎳/金多層金屬作為歐姆接觸之磷化鎵銦/砷化鎵雙接面太陽能電池的熱穩定特性，並且實驗結果指出此結構有好的熱穩定特性。

關鍵字

銅 ； 歐姆接觸 ； 砷化鎵

並列摘要

The multi-layered Ge / Cu / Ni / Au metal structure is investigated through the TLM method and through surface morphology inspection to study the feasibility of forming an n-type ohmic contact for n-GaAs material and its application in InGaP / GaAs DJ solar cell in this report. Experimental results indicate that enough thickness Cu is essential for obtaining the lower specific contact resistance ρc and keeping the annealing temperature low; while too much Ni and Ge thickness could degrade the ohmic contact quality but having no apparent effect on the annealing temperature for obtaining the best ρc. Additionally, an optimum metallurgical structure of Ge (30nm) / Cu (120nm) / Ni (40nm) / Au (50nm) with a rather low ρc ∼5.84×10−6Ωcm2 can be obtained after annealing at 435℃ for 1 min. Furthermore, this ohmic metal structure Ge / Cu / Ni / Au is deposited for n-type ohmic contact on InGaP / GaAs DJ solar cell. Measurements of the open circuit voltage (Voc), short circuit current (Isc), fill factor (FF) and conversion efficiency (η) are approximately equal to those of device using conventional Ni / Ge / Au / Ni / Au metal contact. Moreover it is also indicated that the solar cell with Ge / Cu / Ni / Au metal contact structure has good thermal stability.

並列關鍵字

Gallium arsenide ； Ohmic contact ； Copper

參考文獻

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