目前，有越來越多的應用是以氮化鎵材料作為光電元件的趨勢，藍光塑膠光纖通訊是其中的一種可能應用。本實驗主要是研究以氮化銦鎵（InGaN）╱氮化鎵（GaN）為材料且吸收波長為400nm左右的電制吸收調變器（EAM）。在設計方面，因為未來會把電吸收調變器整合到氮化鎵（GaN）的異質接面雙載子電晶體（HBT）成為單晶片，所以會有許多的限制。初步的設計上，我們將P型材料的上層加入ㄧ層4nm N-type穿隧接面 (Tunnel junction)，以便未來在設計時，將該層加厚就可以變成n-p-n異質接面雙載子電晶體。在製程上，我們已經確定可行的製程步驟及參數。量測方面，由電壓-電流關係曲線（I-V curve）可驗證磊晶材料的特性；在光電流頻譜上，由於目前只有405nm的波長雷射光源，所以只得到單一波長的光電流對電壓響應，驗證了電吸收調變器是可行的。

Recently, there are more and more applications based on GaN related optoelectronics and plastic fiber communication happens to be one of the potentials. In this study, InGaN/GaN material was used for the EAM and the absorption edge is about 400nm. Our design is restricted by the consideration of future integration between GaN based Electroabsorption modulator (EAM) and HBTs on a single chip. On top of the p layer, a 4 nm n-type thin tunneling junction is added to improve the p contact. If we increase the thickness of the n-type tunneling layer, the structure could be also shared for npn HBTs. During our study, the processing steps and parameters have been refined and identified. The IV measurement has proved that the EAM does exist a p-n junction. Since there is only a fix wavelength 405nm laser source available, the photocurrent measurement was done only at 405nm and the result showed that the fabricated EAM is capable of modulating.

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