在本文中，我們研究與探討將液相氧化法應用在磷化銦鎵/砷化鎵異質接面雙極性電晶體上。相較於其他的氧化法，此氧化法的系統是一種相當簡單且容易操作並在低溫上(從30℃到70℃)成長出一層表面均勻的氧化層，且該氧化法亦不需要外加任何的能量輔助。另外，我們也針對此氧化層做物理性及化學性的探討，藉由掃描式電子顯微鏡及原子力顯微鏡的分析得知其表面的粗糙度相當均勻，再經由X光光譜及歐傑電子光譜的縱深分析得知此氧化物的成份含有三氧化二鎵及三氧化二砷，之後再將其應用在異質接面雙極性電晶體鈍化層上並探討直流特性之關係。基於此表面氧化法之鈍化層的使用，在較低的基極-射極偏壓中可以有效的壓制基極的電流，即表示能提高直流電流增益，且在低集極電流區域可獲得7倍的增加。另外，在逆向基極-集極的崩潰電壓(23.5伏特)及在較低的基極-射極偏壓中所獲得的基極電流(2×10-12安培)都有明顯的改善。
　　另一方面，我們加入硫化鈍化層的方式和液相氧化法做一比對。在我們的研究中可觀察到氧化法鈍化層有一最高的崩潰電壓且可操作在較寬廣的集極電流區(從8.3×10-11到0.1 安培)，並且達到十倍的改善(從8.1×10-10到8.3×10-11安培)，可提供使用者在低功率電子電路上的應用。

　　Liquid phase oxidation (LPO) method to grow native oxide films on InGaP/GaAs HBTs near room temperature is investigated and characterized. This is a very simple, low-cost and low-temperature (30-70oC) technique to grow uniform and smooth native oxide films. In the liquid phase oxidation system, neither anodic equipment nor assisting energy source is needed. Additionally, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to analyze the surfaces of the grown oxide films. Moreover, from the chemical analysis of x-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES), the oxide films are found to be a composite of the Ga2O3 and As2O3. Since the passivation on the GaAs surface is one of the key issues in III-V materials to reduce the density of surface states, leading to the reduction of the surface recombination velocity and improvement of the device performance, therefore, the implementation of LPO as the surface passivation to improve the InGaP/GaAs heterojunction bipolar transistors (HBTs) performance is also demonstrated. In this work, the current gain of the HBT devices with a native oxide film as the surface passivation increase 7 fold in low collector current regimes. In addition, a larger reverse-bias base-collector breakdown voltage, 23.5 V, and a lower base recombination current, 2×10-12 A, are also obtained.
Furthermore, sulfur solutions are used to compare with the LPO method. It was found that the device with an oxide passivation exhibits the highest breakdown voltage. Additionally, the device with a surface passivation shows wider collector regimes from 8.3×10-11 A to 0.1 A. Moreover, an order of magnitude improve in the current gain from the collector current of 8.1×10-10 A to 8.3×10-11 A. This gives promising implementations to low-power electronics and communication applications.

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