本篇論文主要探討氮化鋁鎵/氮化鎵高電子遷移率電晶體之鈍化，此鈍化方式為利用過氧化氫(雙氧水)使氮化鋁鎵發生氧化反應，於氮化鋁鎵表面生成原生氧化層做為鈍化層。
為了瞭解原生氧化層的 (一)表面粗糙度、(二)化學組成、(三)薄膜的縱深分析狀況與(四)鈍化層薄膜對二維電子雲的影響，因此在研究中使用了 (一)原子力顯微鏡、(二)化學分析電子儀與(三)霍爾量測。其中在原子力顯微鏡觀察中，比較未經過雙氧水處理、雙氧水處理七分三十秒、與雙氧水處理十分鐘。在觀察中發現表面粗糙度分別為: 0.6065 nm，0.2822 nm，1.2699 nm。在化學分析電子儀中比較未經處理與雙氧水處理七分三十秒，此二者間的差異，發現鎵的3d電子殼層的電子束縛能由19 eV下降至18.2 eV; 鋁的2p電子殼層的電子束縛能由73.1 eV上升至74.1 eV; 氮的1s電子殼層的電子束縛能由396.48 eV下降至396.2 eV。因此可斷定原生氧化層的材料主要為氧化鋁，再利用化學分析電子儀的縱深分析系統得知原生氧化層厚度大約為13 nm。在霍爾量測中，比較未經過雙氧水處理與雙氧水處理七分三十秒，此二者之間的差異，發現片電子濃度與電子遷移率的乘積分別為1.33×1016 /V-s與1.56×1016 /V-s。
在瞭解原生鈍化層的化學組成、表面與縱深狀況後，進一步將此一鈍化技術應用於高電子遷移率電晶體的製造上。首先，比較不同的過氧化氫處理時間在直流電的轉移特性上之差異。在研究中挑選了五個時間: 未處理、二分三十秒、五分鐘、七分三十秒、十分鐘。在此比較中發現七分三十秒的有最顯著的特性提升，其最大汲極電流值提升41%、最大轉導值提升47%，因此在接下來的直流電性與微波電性比較中皆採用未經雙氧水處理與雙氧水處理七分三十秒，並比較此二者之間的數據。再者，在崩潰電壓的量測上發現經雙氧水鈍化處理提升53%，在閘極電壓擺幅上經雙氧水鈍化處理七分三十秒提升22%。而在變溫量測中發現鈍化後的元件有較佳的熱穩定性。為瞭解元件在高頻應用的狀況，而進行微波特性的量測，發現在截止頻率與最大震盪頻率各有36%與20%的提升。在功率表現上，功率增益效率在2.4GHz的狀況下，經雙氧水鈍化後的元件由原本的23.03%提升至30.21%，而在5.8GHz的狀況由原本的9.7%上升至12.08%。在雜訊表現上元件經過鈍化處理可明顯改善雜訊強度。在高頻雜訊的部分，2.4GHz 的條件下最小雜訊指數由原本的2.53dB下降至1.86dB，5.8GHz的條件下最小雜訊指數由原本的5.06dB下降至4.15dB。在低頻雜訊部分，線性區的虎格係數由2.3×10-3進步至2.56×10-4，而在飽和區的虎格係數由原本的4.33×10-3進步至5.33×10-4。這種簡易、安全、快速與低成本的鈍化方式能夠有效提升氮化鎵高電子遷移率電晶體的特性，並使其應用更加廣泛。

The research is mainly investigated on passivation for AlGaN/GaN high electron mobility transistors (HEMT). The passivation approach is to use hydrogen peroxide (H2O2) to make AlGaN occur oxidation reaction, the approach makes the surface of AlGaN form native oxide as passivation layer.
In order to know (1) surface roughness, (2) chemical composition, (3) depth profile, and (4) the passivation layer affect on two-dimensionl electron gas concentration (2DEG) of native oxide layer, the (1) atomic force microscopy (AFM), (2) electron spectroscopy for chemical analysis (ESCA), and (3) Hall measurement were required to used in the research. The observation of AFM compare without H2O2 treatment with H2O2 treatment 7 minutes 30seconds and 10minutes, and their surface roughness were 0.6065 nm, 0.2822 nm, and 1.2699 nm, respectively. The observation of ESCA compare without H2O2 treatment with H2O2 treatment 7 minutes 30 seconds. The data show that the binding energy of Ga 3d shell decreases from 19 eV to 18.2 eV, the binding energy of Al 2p shell increases from 73.1 eV to 74.1 eV, and the binding energy of N 1s shell decreases from 396.48 eV to 396.2 eV. Thus the data demonstrates that the composition of native oxide is AlOx. The result of using depth profile analysis of ESCA shows that the thickness of AlOx is about 13nm. The Hall measurement compare without H2O2 treatment with H2O2 treatment 7 minutes 30seconds, the electron sheet concentration multiplied by electron mobility were 1.331×1016 /V-s and 1.56×1016 /V-s, respectively.
After knowing the chemical composition, surface and depth profile of native passivation layer, moreover, the passivation technique was applied to the fabrication of high electron mobility transistors. First, the article compared DC transfer characteristics in the different H2O2 treatment time: without treatment, 2minutes 30seconds, 5 minutes, 7minutes 30seconds, and 10 minutes, respectively. In this comparison, H2O2 treatment time for 7minutes 30 seconds improved significantly, maximum drain current improved 41%, and maximum transconductance improved 47%. Hence, the following texts will demonstrate comparisons of DC characteristics of devices without H2O2 treatment and with H2O2 treatment for 7 minutes 30seconds and comparisons of microwave characteristics of devices without H2O2 treatment and with H2O2 treatment for 7 minutes 30seconds. The breakdown voltage was improved 53% and gate voltage swing (GVS) was improved 22% after H2O2 treatment 7minutes 30seconds. During the temperature–dependent characteristics measurement, the devices with passivation have better thermal stability was observed. In order to know the condition of devices operated under high frequency, microwave characteristics measurement is required. During microwave characteristics measurement cutoff frequency and maximum oscillation frequency were observed to be improved 36% and 20%, respectively. Power characteristics demonstrated that power added efficiency was improved from 23.03% to 30.21% at 2.4GHz and it was also improved from 9.7% to 12.08% at 5.8GHz. Noise characteristics showed that the devices with passivation can obviously improve noise level. For high frequency noise characteristics, minimum noise figure improved from 2.53dB to 1.86dB at 2.4GHz, and from 5.06dB to 4.15dB at 5.8GHz. For low frequency noise characteristics, Hooge’s coefficient in the linear region was improved from 2.3×10-3 to 2.56×10-4, and Hooge’s coefficient in the saturation region was also improved from 4.33×10-3 to 5.33×10-4. The simple, safe, fast, and low-cost passivation approach can effectively improve the characteristics of GaN HEMTs and make its applications more comprehensive.

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