不同非极性与半极性Ⅲ族氮化物材料物性研究

发布时间：2018-05-10 05:07

本文选题：GaN薄膜 + 二次离子谱　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：GaN基LED(发光二极管)作为一种新型的固态光源,具有低功耗,长寿命,高发光效率等优点,在显示、照明和指示方面发挥着越来越大的作用。GaN及其伴生的三元甚至四元化合物因其可实现覆盖全可见光谱的优势赢得了市场的青睐。目前,市场上用于制备Ga N材料的主流生长设备还是MOCVD(金属有机化合物化学气相淀积),但其不可避免地引入了一些C和O等外来杂质的吸附,这势必会对器件的性能产生较大影响。此外,最近已经有报道称杂质在不同极性薄膜中的结合程度不同,并可能影响其它重要元素(比如In)的吸附。本文就是在此背景下开展研究,采用普通而实用的蓝宝石衬底,依托自主研发的MOCVD设备,进行了一系列不同极性GaN和InGaN薄膜的制备,并比较了不同极性面中C、O等杂质的吸附情况后得出相关结论。此外,还对国际研究热点半极性面In GaN中In的结合效率进行了初步探讨,主要研究工作整理如下:1.在不同极性GaN薄膜中进行了C、H和O等杂质的吸附情况比较,通过二次离子谱等表征手段对元素结合进行了定量分析。发现了Ga面中C的结合要高出N面,表明极性会影响C的结合。根据PL能谱中黄带峰的强弱对比得出非极性a面中的C结合明显高出c面,同时也从原子结构上对此进行了解释。此外,还发现了,C在a面和c面中受温度的影响呈现出相反的变化趋势(在a面中随温度降低而增加;在c面中却减少)。这些结果表明C的吸附受到多种环境因素的影响,极性的选择与温度变化都可能成为主要影响因素。2.通过对比,观察到了O在N面中要高出Ga面近两个数量级,在非极性a面中也明显高出极性Ga面,说明了N面和非极性面对O有着较强的吸附能力。还发现温度对非极性a面样品形貌和结晶质量的影响非常大,同时也对O的吸附产生了较大影响。测试结果表明,随着温度的升高,O的吸附反而降低,这不同于前人已报道的结果。相应的实验结果表明,温度改变引起的形貌差异影响了O的结合,这表明形貌也是影响其结合的一个因素。3.发现了H的结合不受温度的影响,但在半极性面和极性面中H的吸附存在较为明显的变化,表明极性影响H的结合。还发现了Si的结合只受温度的影响,随温度升高,GaN中吸附的Si浓度增大。此外,在含In氮化物材料中,In的结合效率受到H浓度变化的影响。同时还从理论和实验上发现了In在半极性(112)面中的结合效率略高于其在极性(002)面中结合效率。
[Abstract]:GaN based LED (light emitting diode) as a new solid-state light source, has the advantages of low power consumption, long life, high luminous efficiency, etc. Lighting and indication play a more and more important role. Gan and its accompanying ternary or even quaternary compounds have won the market favor for their advantages of covering all visible spectra. At present, MOCVD (Organometallic compounds Chemical Vapor deposition) is the main growth equipment used to prepare gan materials on the market, but it inevitably introduces some foreign impurities such as C and O adsorption. This is bound to have a greater impact on the performance of the device. In addition, it has recently been reported that impurities bind differently in different polar films and may affect the adsorption of other important elements, such as In. Under this background, this paper studies a series of GaN and InGaN thin films with different polarity by using ordinary and practical sapphire substrates and relying on self-developed MOCVD equipment. The adsorption of Con O and other impurities in different polar surfaces was compared and the relevant conclusions were obtained. In addition, the binding efficiency of in in in GaN, an international hotspot, is preliminarily discussed. The main research work is as follows: 1. The adsorption of impurities such as Con H and O in GaN thin films with different polarity was compared. The elemental binding was quantitatively analyzed by means of secondary ion spectrum and other characterization methods. It is found that the binding of C in Ga plane is higher than that in N plane, indicating that polarity affects the binding of C. According to the comparison of the intensity of the yellow band peak in the PL spectrum, it is found that the C binding in the nonpolar a plane is obviously higher than that in the c plane, and the atomic structure is also explained. In addition, it is also found that the effect of temperature on the C plane and a plane is opposite (increasing with the temperature decreasing in the a plane and decreasing in the c plane). These results indicate that the adsorption of C is affected by many environmental factors, and the choice of polarity and the change of temperature may be the main influencing factors. By comparison, it is observed that O is nearly two orders of magnitude higher than Ga surface in N plane and obviously higher than polar Ga surface in non-polar a plane, which indicates that O in N plane and nonpolar face O have strong adsorption ability. It is also found that temperature has great influence on the morphology and crystallization quality of non-polar a-plane samples, and also on the adsorption of O. The results show that the adsorption of O decreases with the increase of temperature, which is different from the previous reported results. The experimental results show that the morphology difference caused by the change of temperature affects the bonding of O, which indicates that the morphology is also a factor affecting the combination of O and O. It was found that the binding of H was not affected by temperature, but the adsorption of H on the semi-polar surface and the polar surface had obvious changes, indicating that the polarity affected the binding of H. It is also found that the bonding of Si is only affected by temperature, and the concentration of Si adsorbed in gan increases with the increase of temperature. In addition, the binding efficiency of in containing nitride is affected by the change of H concentration. It is also found theoretically and experimentally that the binding efficiency of in in in is slightly higher than that in polar plane 002).
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

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