N型GaAs上AuGeNi/Au歐姆接觸特性研究

Study on ohmic contact to n-GaAs with AuGeNi/Au

王正強(Cheng-Chiang Wang)

指導教授 ： 溫武義

中原大學/工學院/電子工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300329

摘要

中文摘要

由於通訊產業的蓬勃發展，GaAs 的應用變的日漸重要，整體而言砷化鎵較矽元件除了電子遷移速度高，在高頻使用的雜訊低，元件SIZE小，適合用於通訊之外，另外也具備抗輻射性，不易產生訊號錯誤情況，故產品穩定度高，特別是可應付用於衛星通訊時暴露於太空中所產生的輻射問題。
本文主要是以n型砷化鎵作為Substrate, 利用AuGeNi/Au針對各種不同濃度和氣體回火來做歐姆接觸並加以分析其特性及電性，同時進一步探討製程上的變異對電性之影響。
經由實驗結果的驗證，我們可以分別使用2×1018cm-3 和5×1017cm-3 不同濃度之GaAs出良好的歐姆接觸 ，在回火溫度400℃的條件下，以N2 回火作出之歐姆接觸點其最小特徵電阻為2.19×10-5 Ω-cm2 而在H2 回火400℃下其最小特徵電阻為3.78×10-5Ω-cm2。

關鍵字

歐姆接觸 ； 砷化鎵 ； 掃瞄式電子顯微鏡 ； 特徵電阻

並列摘要

Abstract
Gallium Arsenic（GaAs）device applications have become very critical due to the requirement for global communication industrial growth. In general, GaAs devices have the merit of the higher electric mobility speed than Si devices, As a result, the signal to noise ratio of GaAs devices is relatively low for high frequency applications. Also for artificial satellite communication application, the working devices have to expose in the outer space and face highly radiative environment.In other respect, GaAs related devices can present good performance due to their radiation.

The purpose of this study is to optimize the process for ohmic contact to N-type GaAs by comparing the characteristics of ohmic contacts fabricated to GaAs with different concentrations 5×1017cm-3 and 2×1018 cm-3. The influence of contact annealing temperature, time duration and gas ambient are also system actially investigated.

From this study, it is concluded that the ohmic contacts to n-GaAs can be successfully fabricated by alloying AuGeNi / Au to GaAs. The minimum specific resistances ρC of ohmic contract attained are 2.19×10-5Ω-cm2 and 3.78×10-5Ω-cm2 with annealing temperature 400°C, annealing time duration around 3 min, and in ambients of N2 and H2, respectively.

並列關鍵字

N-type GaAs ； ohmic contact ； SEM ； specific resistance.

參考文獻

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