关于石墨烯上Ge/Au/Ni/Au欧姆接触的对比研究

Superior graphene-metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method （TLM） is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing （RTA） at different temperatures as a post-processing method is studied to improve graphene-metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10^-5 Ω· cm^2 after RTA, and that 350 ℃ is optimum annealing temperature for the contact of graphene-Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices.     

基于反向平行二极管对管的高性能W波段谐波混频器

文章采用砷化镓反向平行二极管对管,提出了一款W波段高性能谐波混频器。二极管对管是由实验室砷化镓工艺线制作而成,并且二极管对管的模型显示具有极高的截止频率和低的串联电阻特性,所以适用于W波段。基于此二极管对管,设计、制作并测试了石英衬底上的W波段谐波混频器。结果显示在80到100GHz的频率范围内,谐波混频器的变频损耗为9.2到12dB,并且所需要的本振功率仅为6dBm,能够很好地减少对本振源的需求。