橫向P-N接面的製作與模擬

Abstract

在本論文中，我們提出製作高品質二維橫向P-N 接面的方法，該方法是利用類似場效電晶體結構，於無摻雜質的AlGaAs-GaAs-AlGaAs 量子井磊晶結構中，引發二維電子氣(2DEG)與二維電洞氣(2DHG)，設計的特點是在垂直方向上閘極和源極或汲極之間部分重疊，並以絕緣層隔開。N 型和P 型閘極比鄰放置，於是其下方引發的2DEG 與2DHG 相鄰形成二維的橫向P-N 接面二極體。在論文中，詳述了製程參數與量測方法，並探討元件失效的原因，另外對該元件結構進行數值模擬計算熱平衡下的能帶結構、空乏區長度、接面內電場、接面電容、整流特性和發光區域。由於我們所提出的結構可維持二維電荷通道的磊晶品質，特別適合應用於觀察自旋霍爾效應與表面聲波驅動之單光子源元件中。

In the thesis, we proposed a new method to fabricate high quality lateral P-N junction. Two dimensional electron gases (2DEGs) and two dimensional hole gases (2DHGs) is induced with a structure similar to a field effect transistor on undoped AlGaAs/GaAs/AlGaAs quantum well. The difference is that that the gate overlaps with source/drain in vertical direction with an insulator in between. The n-typed and p-typed gates are placed side by side, and therefore the induced 2DEG and 2DHG underneath form a two-dimensional lateral P-N diode. In the thesis, I stated the fabrication parameters and the characterization method and also discussed the failed factors. In addition, the band diagram under thermal equilibrium, the depletion width, the electric field on the junction, the junction capacitance, the rectify behavior and the radiative recombination area are all calculated by simulation with the device structure. The proposed structure can maintain the epitaxy quality of two dimension carrier channel, so it is particularly useful in the applications in the observation of spin Hall effect and surface acoustic wave (SAW) driven single photon source.