積體整合氮化鎵發光二極體與金氧半場效電晶體於光引擎應用

Abstract

本論文提出一種新穎氮化鎵(gallium nitride, GaN)單晶片光電積體電路(optoelectronic integrated circuits, OEICs) 結構，其垂直整合發光二極體(light-emitting diode, LED)與金氧半場效應電晶體(metal-oxide-semiconductor field-effect transistor, MOSFET )，並應用於智慧型照明系統之上。本論文所提出之氮化鎵光電積體電路整合結構優點在於金氧半場效應電晶體是透過標準半導體製程技術，直接製作在經乾蝕刻後的LED晶片，其所裸露出的n-GaN磊晶層之上。此等效電路可視為直接與LED作串接，且無須另行磊晶成長其他電晶體結構層。相較於已發表文獻所提出之氮化鎵單晶片光電積體電路整合結構，例如將電晶體磊晶於LED結構之上，或是將LED磊晶於電晶體結構之上，我們的單晶片整合結構有效地避免在先前結構中，因磊晶材料晶格不匹配或磊晶熱積存(thermal budget)等等問題的產生。最終，我們所製作之光電積體電路結構其金氧半場效應電晶體最大輸出電流為IDS=1050 mA/mm，且其最大轉導數值為Gm=368 ms/mm。此外，雖然 p-GaN之金屬歐姆接觸電極尚未優化，我們所製作出之光電積體電路結構其發光二極體整 (λ=485nm)仍展現出極佳整流特性，伴隨稍為偏高的導通電壓(5.32V) 。最重要的是，無論於金氧半場效應電晶體之閘極調變亦或於發光二極體之注入電流驅動特性與光功率之調變能力，我們所提出之氮化鎵單晶片整合結構均呈現極佳的元件輸出特性, 證明本論文提出之新穎整合結構將可廣泛地應用於智能照明、網路傳輸及光學通訊等相關技術平台。

In this study, we report a novel monolithically integrated GaN-based light-emitting diode (LED) with metal-oxide-semiconductor field-effect transistor (MOSFET). Without additionally introducing complicated epitaxial structures for transistors, he MOSFET is directly fabricated on the exposed n-type GaN layer of the LED after dry etching, and serially connected to the LED through standard semiconductor-manufacturing technologies. Such monolithically integrated LED/MOSFET device is able to circumvent undesirable issues that might be faced by other kinds of integration schemes by growing a transistor oan LED or vice versa. For the performances of resulting device, our monolithically integrated LED/MOSFET device exhibits good characteristics in the modulation of gate voltage and good capability of driving injected current, which are essential for the important applications such as smart lighting, interconnection, and optical communication. In conclusion, we have demonstrated a monolithic integration of optoelectronic (LED) and electronic (MOSFET) devices in the GaN-based platform by using standard semiconductor-manufacturing technologies. The fabricated monolithically integrated LED/MOSFET device exhibits a maximum output current of IDS =1050 mA/mm and a peak transconductance of Gm=368 mS/mm. The LED exhibits a well rectifying behavior with a slightly high turn-on voltage of 5.32V, mainly due to the un-optimized condition of p-contact metal. Most importantly, the monolithically integrated LED/MOSFET device exhibits good gate controllability in the LED’s light output power, and hence is viable and highly promising for a broad range of applications.