量產型石墨烯作為紫外光發光二極體透明電流擴散層

Abstract

本研究以鎳金屬為催化劑，以電漿輔助式化學氣相沉積(Plasma-enhanced Chemical Vapor Deposition;PECVD)於基板上生長石墨烯薄膜作為透明電流擴散層。為於目標基板與石墨烯透明電流擴散層之間形成類歐姆接觸，本研究使用原子層化學氣相沉積(ALCVD)於目標氮化鎵基板表面沉積氧化鎳薄膜作為緩衝層，並對兩者進行熱退火合金化，以降低功函數差異造成之能障，藉優化參數實現低接觸電阻、高 UV 穿透之透明電流擴散層。以圓形傳輸線量測(CTLM)，檢視各製程參數對石墨烯透明電流擴散層與紫外光發光二極體表層之 p 型氮化鎵介面特性之影響。最終藉加入氧化鎳緩衝層，使介面間自蕭特基接觸轉為類歐姆接觸。達成具低特徵接觸電阻與類歐姆接觸之介面特性之大面積高品質石墨烯作為紫外光發光二極體透明電流擴散層之應用。In this research, nickel metal was used as a catalyst, and plasma-enhanced chemical vapor deposition (Plasma-enhanced Chemical Vapor Deposition; PECVD)was used to grow a graphene film on the target substrate as a transparent current diffusion layer. In order to form an ohmic contact between the target substrate and the graphene transparent current diffusion layer, we use Atomic Layer Chemical Vapor Deposition (ALCVD) to deposit a nickel oxide film on the surface of the target gallium nitride substrate as a buffer layer, and perform thermal annealing to alloy the two to reduce the energy barrier caused by the difference in work function, and achieve a transparent current diffusion layer with low contact resistance and high UV penetration by optimizing parameters.Using CTLM to examine the effect of various process parameters on the properties of the graphene-GaN interface. Interface characteristics changed from Schottky contact to Ohmic contact. Achieving the application of large-area high-quality graphene with low characteristic contact resistance and ohmic contact characteristics as a transparent current diffusion layer for ultraviolet light-emitting diodes.