标题: 研究藉由多闸极制程改善成长于矽基板上之氮化铝镓/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 Substrate by Using Multi-Gate Process
作者: 黄冠宁
张翼
材料科学与工程学系
关键字: 氮化镓;三阶交叉点;多闸极;八十奈米闸极线宽;lGaN/GaN High Electron Mobility Transistors;GaN;80 nm gate length;multi-gate;third order intermodulation point
公开日期: 2011
摘要: 本实验中,成功的制作出八十奈米闸极线宽的氮化镓高电子移动率电晶体,并且进一步利用创新的多闸极技术,使元件在线性度上有显着的改善。在单闸极八十奈米闸极的氮化镓高电子迁移率电晶体中,元件展现出高饱和电流,高转导性和高电流增截止频率特性。但是因为短通道效应,造成元件有较高的漏电流,此一现象经过讨论是可以进一步藉由闸极蚀刻技术来改善短通道效应和抑制闸极漏电流。
然而,在八十奈米闸极线宽下,由于高电场的因素,使得速度过冲效应很容易产生。在此实验中,成功的制造出多闸极元件,在实验数据的分析与资料的佐证下,发现多闸极可以有效的改善高电场现象,让电子在多闸极区域下,有着较稳定的电子速度,进一步抑制速度过冲效应,使元件可以在较大的VGS范围下,IDS有着稳定的上升率,并且维持平稳的转导值,有效的改善元件线性度,同时具有奈米极线宽元件的特性。经过量测得到元件的三阶交叉点在三闸极结构下,可达30.5dBm的最高值。此外,此研究中还比较了在不同闸极操作偏压下,多闸极与单闸极的三阶交叉点表现,利用分析IDS对VGS的关系式,成功解释多闸极可以在较大的IDSS%范围下,有着高三阶交叉点。由上述分析可知,多闸极技术可以有效的提升元件线性度特性。由此可知,在未来多闸极氮化镓高电子迁移率电晶体可有效地应用在无线通讯系统中的射频功率放大器。
In this study, the 80 nm gate length AlGaN/GaN High Electron Mobility Transistors were successfully fabricated. Moreover, by using the innovative multi-gate technique, the linearity of devices has significant improvement. In the 80nm gate length AlGaN/GaN HEMTs, the devices possessed high saturation current, high transconductance and high current-gain cut-off frequency. However, the short channel effect led to the high leakage current. After the discussion, this phenomenon could be improved by using the gate recess technique to suppress the short channel effect and gate leakage current.
Nevertheless, due to the high electric field under the gate domain, the electron over shoot effect could be observed in 80 nm gate length devices. In this study, the multi-gate devices were successfully fabricated. By the experiment data analysis and paper evidence, it could be found that multi-gate effectively reduced the high electric field. It made the electron possessed a stable electron velocity under the gate domain and further to suppress the velocity overshoot effect. The multi-gate devices could stably increase the drain current and maintain the transconductance value under a larger gate bias region; furthermore, multi-gate devices possessed the electrical characteristic as same as the nanometer gate length device. After the measurement, the maximum third order intermodulation point (IP3) of 30.54 dBm could be achieved in the triple-gate devices. It shown that multi gate could effectively improve the linearity of devices. In addition, the third order intermodulation points of the multi-gate and single gate device under the different gate bias are also compared in this study. By analyzing the function of IDS versus VGS, It could successfully demonstrated that the multi-gate device have the higher IP3 in the larger IDSS % region. Therefore, it could be known that multi gate technique could effectively improve the linearity performance.
In the future, the multi-gate AlGaN/GaN HEMTs have the great potential to be the RF power amplifier applied in the modern wireless communication system.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079818509
http://hdl.handle.net/11536/47348
显示于类别:Thesis


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