GaN基太赫兹耿氏二极管新结构研究

发布时间：2018-01-24 11:50

本文关键词： GaN耿氏二极管 AlGaN电子发射层超晶格　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：太赫兹技术是近些年来高速发展的新兴学科,是一个国家竞争力和综合实力的重要表现,具有广泛的应用前景,其中关于半导体太赫兹固态源的研究尤其重要。与传统III-V半导体材料相比,GaN具有禁带宽度大、二维电子气浓度高、子带间电子散射快等优点,因此在毫米波大功率电子器件领域受到了广泛的关注。目前比较成熟的耿氏二极管结构有:n+/n-/n+结构、凹槽掺杂结构以及基于AlGaN电子发射层结构等等,其中AlGaN电子发射层的引入是为了发射热电子。为了进一步减小耿氏器件“死区”长度,同时减小AlGaN/GaN异质结中的晶格失配程度,我们进行了耿氏器件的新结构研究,提出了基于AlGaN/GaN超晶格结构的电子发射层、双渐变AlGaN电子发射层以及在欧姆层中加入AlGaN插入层的新结构。并通过仿真实验对器件结构的合理性进行验证,同时提取相关电学参数,说明改进后的器件结构所具有的优势。首先,本文提出了AlGaN/GaN超晶格结构作为耿氏器件的高能热电子发射层。先通过仿真实验选取了合适的直流工作点,从而得到了稳定的自激振荡波形,验证了结构设计的合理性。之后又研究了超晶格周期数目以及偏置电压对于器件的影响,得到了超晶格周期和偏置电压对于器件电特性影响的一般规律,最后根据耿氏器件内的电场分布图像对结论进行了解释和说明。其次,在AlGaN/GaN异质结理论的基础上,针对单渐变Al组分AlGaN电子发射层中的问题,本文提出了双渐变Al组分的AlGaN电子发射层的优化方案。本文先通过伏安特性曲线确定了直流工作点,得到稳定波形,再利用快速傅里叶变换提取了相关参数,对比了双渐变Al组分结构与单渐变Al组分电子发射层结构之间的区别。从而验证了设计的合理性并说明了新结构的优点。最后,针对Notch掺杂结构GaN耿氏二极管中的问题,本文提出了新的优化方案:在GaN耿氏二极管的欧姆接触层中加入AlGaN插入层。首先说明的设计的思想,接着对器件进行了电学仿真,说明新结构设计合理性,最后给出了一般的工艺制造流程图。同时该结构具有很强的移植性,能应用于其他GaN太赫兹器件的研制中。
[Abstract]:Terahertz technology is a newly developed subject in recent years. It is an important manifestation of national competitiveness and comprehensive strength, and has a broad application prospect. The study of semiconductor terahertz solid source is especially important. Compared with traditional III-V semiconductor materials, gan has many advantages, such as wide band gap, high concentration of two-dimensional electron gas and fast electron scattering between subbands. Therefore, in the field of millimeter wave high power electronic devices, wide attention has been paid. At present, the more mature Geng diode structure has a structure of: n / n / n / n. Groove-doped structure and based on AlGaN electron emission layer structure, where AlGaN electron emission layer is introduced to emit hot electrons, in order to further reduce the Gunn device "dead zone" length. At the same time, the lattice mismatch degree in AlGaN/GaN heterojunction is reduced. We study the new structure of Geng device and propose the electron emitter layer based on AlGaN/GaN superlattice structure. The new structure of double gradient AlGaN electron emission layer and AlGaN insertion layer is added to the ohmic layer. The rationality of the device structure is verified by simulation experiments, and the relevant electrical parameters are extracted at the same time. The advantages of the improved device structure are explained. First of all. In this paper, the AlGaN/GaN superlattice structure is proposed as the high-energy thermionic emission layer of Geng device. First, the suitable DC operating point is selected through the simulation experiment, and the stable self-excited oscillation waveform is obtained. The rationality of the structure design is verified. Then the influence of the number of superlattice cycles and the bias voltage on the device is studied, and the general law of the influence of the superlattice period and bias voltage on the electrical characteristics of the device is obtained. Finally, the conclusion is explained and explained according to the electric field distribution image in Geng device. Secondly, based on the AlGaN/GaN heterojunction theory. Aiming at the problem in the electron emitter layer of single graded Al component AlGaN. In this paper, the optimization scheme of AlGaN electron emission layer with double graded Al component is proposed. In this paper, the DC operating point is determined by volt-ampere characteristic curve, and the stable waveform is obtained. Then the parameters are extracted by fast Fourier transform. The differences between the double graded Al component structure and the single gradient Al component electron emitter structure are compared. The rationality of the design and the advantages of the new structure are verified. Finally, the advantages of the new structure are demonstrated. Aim at the problem of Notch doped GaN Gunn diode. In this paper, a new optimization scheme is proposed: AlGaN insertion layer is added to the ohmic contact layer of GaN Gunn diode. First, the design idea is explained, and then the electrical simulation of the device is carried out. The rationality of the new structure design is explained, and the general process flow chart is given at the end of the paper. At the same time, the new structure has strong portability and can be used in the development of other GaN terahertz devices.
【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】：TN31

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