物理化学学报 >> 2016, Vol. 32 >> Issue (3): 787-792.doi: 10.3866/PKU.WHXB201512183

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蓝宝石衬底上化学气相沉积法生长石墨烯

刘庆彬,蔚翠,何泽召,王晶晶,李佳芦,伟立,冯志红*()   

  • 收稿日期:2015-09-28 发布日期:2016-03-04
  • 通讯作者: 冯志红 E-mail:ga917vv@163.com
  • 基金资助:
    国家自然科学基金(61306006)

Epitaxial Graphene on Sapphire Substrate by Chemical Vapor Deposition

Qing-Bin LIU,Cui YU,Ze-Zhao HE,Jing-Jing WANG,Jia LI,Wei-Li LU,Zhi-Hong FENG*()   

  • Received:2015-09-28 Published:2016-03-04
  • Contact: Zhi-Hong FENG E-mail:ga917vv@163.com
  • Supported by:
    the National Natural Science Foundation of China(61306006)

摘要:

化学气相沉积(CVD)法是制备大面积、高质量石墨烯材料的主要方法之一,但存在衬底转移和碳固溶等问题,本文选用蓝宝石衬底弥补了传统CVD法的不足。利用CVD法在蓝宝石衬底上生长石墨烯材料,研究生长温度对石墨烯表面形貌和晶体质量的影响。原子力显微镜(AFM)、光学显微镜(OM)、拉曼光谱和霍尔测试表明,低温生长有利于保持材料表面的平整度,高温生长有利于提高材料的晶体质量。研究氢气和碳源对蓝宝石衬底表面刻蚀作用机理,发现氢气对蓝宝石衬底有刻蚀作用,而单纯的碳源不能对衬底产生刻蚀效果。在1200 ℃下,直径为50 mm的晶圆级衬底上获得平整度和质量相对较好的石墨烯材料,室温下载流子迁移超过1000 cm2·V-1·s-1

关键词: 石墨烯, 蓝宝石, 化学气相沉积法, 生长温度, 刻蚀机理

Abstract:

Epitaxial graphene by chemical vapor deposition (CVD) is one of the main methods to fabricate high-quality wafer-scale graphene materials. However, CVD-grown graphene on metal substrates has some disadvantages, such as the need for a transfer process and carbon atoms dissolved into the metal substrate. In this work, we evaluate sapphire substrates to overcome those disadvantages. The morphology and crystal quality of the samples grown at different temperatures were characterized by atomic force microscopy (AFM), optical microscopy (OM), Raman spectroscopy, and a Hall measurement system. To ease the etching process of carbon atoms to the substrate, we adopt a very low carbon concentration of 0.01%. AFM and Raman results show that the surface morphologies of samples grown at lower temperatures were smoother, whereas the quality of samples grown at higher temperatures was better. The sapphire substrate was etched in an H2 environment, while it was not etched only by carbon source without H2 environment. Epitaxial graphene with flat surface morphology and good crystal quality was prepared on a c-plane sapphire substrate (diameter: 50 mm) at a growth temperature of 1200 ℃. The carrier mobility is above 1000 cm2·V-1·s-1 at room temperature.

Key words: Graphene, Sapphire, Chemical vapor deposition, Growth temperature, Etching mechanism

MSC2000: 

  • O646