标题: 藉由双闸极制程改善成长于碳化矽基板上氮化铝镓/氮化镓高速电子迁移率电晶体元件之线性度
Study of Device Linearity Improvement for the AlGaN/GaN HEMTs on Silicon Carbide Substrate by Using Double-Gates Process
作者: 苏焕富
Su Huan-Fu
张翼
Edward Yi-Chang
材料科学与工程学系所
关键字: 双闸极电晶体;氮化镓电晶体;线性度;Double gate transistor;GaN transitor;Linearity
公开日期: 2015
摘要: 近年来,随着无线通讯的快速发展,从卫星、汽车雷达、蓝芽传输到多媒体娱乐,无线传输已经被广泛的利用。然而在大量的使用者情形下,可用的低频带已经过度拥挤。为了要降低在开发高频段上的花费,如何在最小的频带下,达成最大的资讯传输量,已经成为资讯传输技术中关键的课题。利用调变技术虽然可以在有限的频带下达到最大的资讯传输量,但也会造成杂讯的产生。因此对于无线传输系统,射频功率放大器的线性度就成为一个重要性的指标。由于三五族氮化镓材料的高电子迁移率以及高崩溃电场,氮化镓高电子迁移率电晶体已在高频及高功率应用方面展现极大潜力。
本研究先利用非线性电路模型来分析三阶截断点(IP3)与转导值的关系式,分析制程对于元件特性的改善,以期能在线性度上的提升。接下来依据模拟结果,利用双闸极制程,透过电子束写系统,成功的制作出较高转导跨压的氮化镓高电子迁移率电晶体,使元件展现出高线性度的特性。此研究比较了在低操作偏压下(VDS=10V)使用此先进制程技术的氮化镓双闸极场效电晶体与未使用此制程的同等线宽元件,发现透过这些先进制程步骤,能使元件有展现更高的崩溃电压、更高的转导值、较佳饱和电流,以及较高的三阶截断点。
In recent years, wireless communication has rapid development, from satellite, automotive radar, bluetooth transmission to multimedia entertainment, the practice of wireless transmission has become widespread.
However, due to a large number of users, the available frequency spectrum is over-crowed. In order to reduce the cost in the frequency spectrum, the maximum data transfer rate in minimum bandwidth is necessary. By using complex modulation, we can achieve maximum data transfer rate, but it also cause noise signal.
Therefore the linearity of the RF power amplifiers is the one of the important parameters in the modern wireless communication system. GaN material have high electron mobility and high breakdown field which make it show a great potential in high frequency and high power application. In this study, first, using nonlinear circuit model to analyze relationship between the third-order intercept point (IP3) and transconductance. Then, analyzing the process to improve the element characteristics, with a view to enhance the linearity.
Next, based on the relationships, the use of double gates process, through the electron beam lithography system, successfully producing a high linearity GaN high electron mobility transistors. This study compared this advanced process technology GaN double gates field effect transistor with the traditional devices with same gate length at low bias (VDS = 10V), found that through these advanced process steps, double gates devices can achieve the higher breakdown voltage, higher transconductance value, better saturation current, and high third-order intercept point (IP3).
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT070251536
http://hdl.handle.net/11536/127752
显示于类别:Thesis