溅射温度调制氧化镓生长结构及光透射  

Modulation of Ga_(2)O_(3)Growth Structure and Optical Transmittance by Sputtering Temperature

作　　者：刘毅 韦素芬[1] 单婵 吴梦春 陈红霞[1] 刘璟[1] 李明逵 LIU Yi;WEI Sufen;SHAN Chan;WU Mengchun;CHEN Hongxia;LIU Jing;LEE Mingkwei(School of Ocean Information Engineering,Jimei University,Xiamen 361021,China;San'an Optoelectronics CO.,Ltd.,Xiamen 361009,China)

机构地区：[1]集美大学海洋信息工程学院,福建厦门361021 [2]三安光电股份有限公司,福建厦门361009

出　　处：《集美大学学报（自然科学版）》2023年第3期279-288,共10页Journal of Jimei University：Natural Science

基　　金：福建省科技厅高校对外合作项目(2020I0022);福建省自然科学基金青年项目(2020J05151,2020J0515)。

摘　　要：采用射频磁控溅射法,在(0001)蓝宝石衬底上制备了超宽带隙Ga 2 O 3薄膜。在功率200 W、用时20 min、氧气和氩气气氛(氧气2.5%)总流量40 mL/min,以及不同的溅射温度(25℃(室温)、200℃、300℃、400℃、500℃、600℃)下,分别制备了Ga_(2)O_(3)薄膜。发现随着温度从室温到600℃,薄膜结构与溅射温度有强相关关系。扫描电子显微镜(SEM)测试结果显示,当溅射温度在200~300℃,Ga_(2)O_(3)薄膜截面逐渐产生柱状结构,且柱状结构随温度升高而变得更明显,即柱径和边缘间隙随温度升高而减小,当温度升高到400℃及以上,柱状结构开始转变为连续薄膜结构。X射线衍射(XRD)结果显示,升高温度对于柱状结构转变的影响与SEM测试结果一致。用薄膜生长机制模型(SK生长模型)来解释柱状结构的出现、生长、消失的机制,提出光波导的概念来阐释柱状结构在蓝光频段具更高透光性的原因,突显氧化镓作为蓝光LED钝化层的应用优势。The ultra-wide bandgap Ga_(2)O_(3)thin films were deposited on a(0001)sapphire substrate by radio frequency magnetron sputtering.The Ga_(2)O_(3)thin films were prepared at a power of 200 W,a time of 20 min,and a total flow rate of 40 mL/min in an oxygen and argon atmosphere(2.5%oxygen ratio)at the different sputtering temperatures,(25℃(room temperature,RT),200℃,300℃,400℃,500℃and 600℃).Analyzing the results of scanning electron microscopy(SEM)and X-ray diffraction(XRD)at different temperatures,it is observed that the film structure is strongly related to the sputtering temperature as the temperature goes from room temperature to 600℃SEM results show that,when the sputtering temperature is between 200℃and 300℃,the cross-section of Ga 2O 3 film gradually produces the column-like structures.And the growth of Ga_(2)O_(3)column becomes distinguishing with the increase of temperature,that is to say,the column-size and boundary-gap decrease with the increase of temperature.When the temperature further rises to 400℃and above,the column-like structure begins to transform into a continuous film structure.The XRD results show that the effect of temperature increase on the transformation of the column-like structure is consistent with the SEM results.The thin-film formation mechanism model(SK growth model)was used to explain the appearance,the growth and the disappearance of the column-like structure.Then the relationship between the light transmittance and the column-like structure was analyzed.An optical wave guide(OWG)was used to explain well the reason why column-like structure has higher light transmittance in blue light band,highlighting the advantages of Ga_(2)O_(3)as the passivation layer of blue light LED.

关 键 词：薄膜 磁控溅射 氧化镓 柱状结构 溅射温度 光波导 

分 类 号：TN04[电子电信—物理电子学]