基于石墨烯与超材料结构的太赫兹波调制器件研究

发布时间：2018-06-02 17:35

本文选题：太赫兹波调制器 + 石墨烯　；参考：《电子科技大学》2017年硕士论文

【摘要】：随着超快激光技术和太赫兹探测技术的发展,国内外高校和科研机构纷纷投入到太赫兹功能器件的研发热潮当中,使得太赫兹吸收、滤波、调制等功能器件取得了快速的发展。近年来,石墨烯、超材料等大量的新材料、新结构被引入到太赫兹领域,使得太赫兹波调控技术的发展尤为迅速。本文以此为研究背景,基于背栅晶体管结构和现有的半导体工艺,设计并制备了将石墨烯和超材料结构相结合的太赫兹波调制器,并对其性能进行研究。除此之外,针对调制器的实际应用环境,我们提出了两种基于柔性衬底的太赫兹波调制器。本文首先研究了石墨烯的一般转移工艺,并通过分析转移时遇到的问题,对转移工艺进行优化,获得了质量良好的石墨烯薄膜。接着根据传统的晶体管结构,设计了一种以石墨烯为沟道的背栅晶体管,通过不断调整优化工艺和摸索工艺参数,制备出了性能良好的背栅石墨烯晶体管。然后提出了一种将石墨烯和超材料结构结合的太赫兹波调制器,根据之前制备背栅石墨烯晶体管的经验,成功制备出了具有选频特性的太赫兹波调制器件,通过电学调控,在设计的频点处,获得了6%的调制深度。针对二氧化硅容易击穿的缺点,我们提出了改进方案,即用氧化铝作为栅介质,并优化了超材料结构,最终经过THz-TDS时域光谱系统测试,改进后的调制器的调制深度提升了一倍,达到了13%。最后,我们研究了基于柔性衬底太赫兹波调制器。其中,以PET为衬底的多级太赫兹波调制器,通过控制施加电压的方式,可实现四级调制,最大调制深度高达36%;以PDMS为衬底的薄层硅太赫兹波调制器,在808nm激光作用下实现了透射增强,并通过刻蚀薄层硅,获得了可拉伸的太赫兹波调制器。本论文的研究内容比较前沿,为太赫兹调制器的发展提供了一些新思路、新方向,可做进一步研究。
[Abstract]:With the development of ultra-fast laser technology and terahertz detection technology, universities and scientific research institutions at home and abroad have invested in the research and development of terahertz functional devices, resulting in the rapid development of terahertz absorption, filtering, modulation and other functional devices. In recent years, a large number of new materials, such as graphene and metamaterials, have been introduced into the field of terahertz. In this paper, a terahertz wave modulator combining graphene and metamaterials is designed and fabricated based on the back gate transistor structure and the existing semiconductor technology. The performance of the modulator is studied. In addition, we propose two terahertz wave modulators based on flexible substrate for the practical application of modulator. In this paper, the general transfer process of graphene was studied, and through the analysis of the problems encountered in the transfer, the transfer process was optimized, and the graphene film with good quality was obtained. Then, according to the traditional transistor structure, a kind of back gate transistor with graphene as the channel is designed. By continuously adjusting the process and groping the process parameters, the back gate graphene transistor with good performance is prepared. Then, a terahertz wave modulator which combines graphene with metamaterial structure is proposed. According to the experience of fabricating the back gate graphene transistor, a terahertz wave modulator with the characteristic of frequency selection is successfully fabricated, which is controlled by electricity. A modulation depth of 6% is obtained at the designed frequency. Aiming at the disadvantage of silicon dioxide breakdown easily, we put forward an improved scheme, that is, using alumina as gate medium and optimizing the structure of supermaterial. Finally, the modulation depth of the improved modulator was doubled after THz-TDS time-domain spectrum system test. It has reached 13 points. Finally, we study the terahertz wave modulator based on flexible substrate. The multistage terahertz wave modulator with PET as substrate can realize four-stage modulation by controlling the applied voltage, and the maximum modulation depth is up to 36. The thin layer silicon terahertz wave modulator based on PDMS substrate, The transmission enhancement is realized by 808nm laser, and the extensible terahertz modulator is obtained by etching thin layer silicon. The research content of this thesis is very advanced, which provides some new ideas and new directions for the development of terahertz modulator.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN761

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