磁控溅射法制备优质氮化镓衬底生长用缓冲层氧化锌薄膜
发布时间：2018-11-15 08:51
【摘要】：LED衬底决定了LED器件的制造路线,并且会严重影响LED器件的综合性能。开发高质量的自支撑GaN衬底是未来高效大功率LED领域重要发展趋势。然而,GaN衬底很难用常规的单晶生长技术进行制备,而是多采用在蓝宝石衬底上进行外延生长薄膜。异质外延所产生的热膨胀系数差别和晶格失配会大大降低GaN薄膜质量。ZnO和GaN具有相同的六方晶格结构,且晶格常数和热膨胀系数也很相近。因此,高质量的ZnO薄膜能作为GaN薄膜生长的缓冲层。 本文以氧化锌陶瓷靶材为原料,氧气和氩气分别作为反应和溅射气体,根据正交实验原理采用磁控溅射方法在蓝宝石衬底上制备优质GaN薄膜生长用氧化锌缓冲层薄膜,主要研究了溅射温度、所通入氧气与氩气的比例,溅射气压、溅射时间及退火处理对氧化锌薄膜的结晶性能、表面形貌、光致发光性能和薄膜厚度的影响。通过采用SEM、AFM、XRD,PL谱测试仪、台阶仪等仪器来测量表征氧化锌薄膜的性能。 实验结果表明:根据正交试验原理得出,温度变化对氧化锌薄膜的结构和结晶性及光致发光性能影响最大。当温度为250℃的时候,氧化锌薄膜的综合性能较好;比较分析了在空气氛围和氮气氛围下进行退火处理对样品性能的影响,实验表明退火处理能改善氧化锌薄膜的结晶性和光致发光性能,能增强薄膜与基底的结合力;与在氮气氛围条件下进行退火处理相比,在空气氛围条件下退火,ZnO薄膜性能更好。温度为800℃,保温1小时,空气氛围中退火,ZnO薄膜(002)取向性显著提高,FWHM值仅为0.2o,晶粒更加均匀细小;在温度为600℃,保温1h,空气氛围条件下退火,ZnO薄膜的光致发光性能最好。 最后本文得出,磁控溅射法制备高质量的氧化锌缓冲层工艺为:氧氩气体流量比例为O2:Ar=2:1、溅射气压为1Pa、薄膜沉积温度为250℃、薄膜沉积时间为2h,退火气氛为空气,退火温度介于600℃至800℃之间且保温1h。有望在高质量GaN衬底生长用缓冲层领域得到广泛应用。
[Abstract]:LED substrate determines the manufacturing route of LED devices, and will seriously affect the comprehensive performance of LED devices. Developing high-quality self-supporting GaN substrates is an important trend in the field of high efficiency and high power LED in the future. However, GaN substrates are difficult to be prepared by conventional single crystal growth techniques, and epitaxial films are often grown on sapphire substrates. The difference of thermal expansion coefficient and lattice mismatch caused by heteroepitaxial epitaxy will greatly reduce the quality of GaN film. ZnO and GaN have the same hexagonal lattice structure and the lattice constant and thermal expansion coefficient are very similar. Therefore, high quality ZnO film can be used as a buffer layer for GaN thin film growth. In this paper, zinc oxide buffer films were prepared on sapphire substrates by magnetron sputtering with zinc oxide ceramic target as raw material, oxygen and argon as reactive and sputtering gases, respectively, according to the principle of orthogonal experiment. The effects of sputtering temperature, the ratio of oxygen to argon, sputtering pressure, sputtering time and annealing on the crystalline properties, surface morphology, photoluminescence properties and thickness of ZnO thin films were studied. The properties of ZnO films were measured by means of SEM,AFM,XRD,PL spectrometer and step meter. The experimental results show that the effect of temperature on the structure, crystallinity and photoluminescence properties of ZnO films is the greatest according to the principle of orthogonal experiment. When the temperature is 250 鈩，
本文编号：2332816
[Abstract]:LED substrate determines the manufacturing route of LED devices, and will seriously affect the comprehensive performance of LED devices. Developing high-quality self-supporting GaN substrates is an important trend in the field of high efficiency and high power LED in the future. However, GaN substrates are difficult to be prepared by conventional single crystal growth techniques, and epitaxial films are often grown on sapphire substrates. The difference of thermal expansion coefficient and lattice mismatch caused by heteroepitaxial epitaxy will greatly reduce the quality of GaN film. ZnO and GaN have the same hexagonal lattice structure and the lattice constant and thermal expansion coefficient are very similar. Therefore, high quality ZnO film can be used as a buffer layer for GaN thin film growth. In this paper, zinc oxide buffer films were prepared on sapphire substrates by magnetron sputtering with zinc oxide ceramic target as raw material, oxygen and argon as reactive and sputtering gases, respectively, according to the principle of orthogonal experiment. The effects of sputtering temperature, the ratio of oxygen to argon, sputtering pressure, sputtering time and annealing on the crystalline properties, surface morphology, photoluminescence properties and thickness of ZnO thin films were studied. The properties of ZnO films were measured by means of SEM,AFM,XRD,PL spectrometer and step meter. The experimental results show that the effect of temperature on the structure, crystallinity and photoluminescence properties of ZnO films is the greatest according to the principle of orthogonal experiment. When the temperature is 250 鈩，
本文编号：2332816
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