氮化镓射频器件及氧化镓功率器件的研究

RESEARCH ON FABRICATION AND MECHANISM OF GALLIUM NITRIDE RADIO FREQUENCY DEVICES

葛琪

11930220

硕士

材料工程

汪青

2021-05-19

2021-06-18

南方科技大学

深圳

以氮化镓为代表的第三代半导体材料，具有大的带隙宽度、大击穿场强、耐高温、抗辐射能力强等诸多优良特性，使得氮化镓材料相比于第一代Si基半导体和第二代GaAs半导体在高压、高功率、高频等方面有着更广阔的发展前景。GaN功率和射频器件目前已经广泛应用于5G通讯、电源适配器等领域，并在智能电网、新能源汽车、数据中心及未来6G通讯方面展现出巨大的应用前景。本文研究了氮化镓射频器件制备方法和性能参数，提出了改进氮化镓射频器件频率特性的方法。此外，氧化镓材料由于具有更大的禁带宽度，是未来超高压、超高功率等电子电力领域具有潜力的应用材料之一。本文通过器件仿真加实验，初步的研究了氧化镓功率器件的制备方法和性能参数，提出了通过远场势垒渐变掺杂方法和P型氮化镓栅极方法来实现氧化镓器件输出电流密度增加和氧化镓增强型器件。主要内容有：1.通过实验探究了不同工艺的T型特殊栅极氮化镓射频器件的制备流程，得到了基于钝化层刻蚀方法的T型栅结构制备工艺。 2.通过实验探究了不同栅极长度的T型特殊栅极结构的氮化镓射频器件的最大截止频率fT和最高振荡频率fmax的差异，得到随着栅长减小，器件的射频性能逐渐增大，其最大截止频率fT最高达到30GHz，最高振荡频率fmax最高可达到35GHz。3.提出了一种利用远场势垒渐变掺杂技术来提高氧化镓场效应晶体管的输出电流密度的方法，并通过器件仿真发现，远场势垒渐变掺杂技术的氧化镓器件输出电流相较于常规增加一倍以上。4.提出了一种利用P型氮化镓栅极实现增强型氧化镓器件的方法，并且通过器件仿真发现，P型氮化镓栅极的氧化镓场效应管的阈值电压大于0V，成功实现了增强型氧化镓器件。

Gallium nitride,which has many excellent characteristics such as wide band gap, high breakdown electric field, high temperature resistance and radiation resistance, shows great potential in high voltage, high power, high frequency application.This paper studies the fabrication porcess and device performance of GaN RF devices, and focus on improving the frequency characteristics of GaN RF devices by T-shaped gate. Gallium oxide is one of the most promising materials in the field of ultra-high voltage and ultra-high power eletronic power. In this paper,far-field barrier gradual doping was proposed to increase the output current density of gallium oxide devices.While,the P-type gallium nitride gate was involed to realize the enhanced gallium oxide device.The main contents are:1.By exploring the preparation process of T-shaped gate GaN radio frequency devices with different processes, a T-shaped gate structure is obtained by the passivation layer etching method. 2.Experiments are conducted to explore the variation of the maximum cut-off frequency(fT) and the maximum oscillation frequency(fmax) of T-shaped gate GaN RF devices with different gate lengths. It was demonstrated that the radio frequency performance of the device gradually increases as the gate length decreases. The maximum cut-off frequency(fT) reached up to 30GHz, while the maximum oscillation frequency(fmax) reached up to 35GHz. 3.The far-field barrier gradual doping technology is proposed to improve the output current density of gallium oxide field effect transistors.We found that the output current of the device with the far-field barrier gradient doping technology is doubled than that of the ordinary device through device simulation.4.P-type gallium nitride gate is proposed to realize enhanced gallium oxide device, and the threshold voltage of the gallium oxide field effect transistor with the P-type gallium nitride gate is bigger than 0V through device simulation.

氮化镓射频器件 T型栅 电子束光刻工艺 氧化镓场效应管

Gallium nitride radio frequency device T-shaped gate Electron beam lithography process Gallium oxide field effect transistor

中文

独立培养

南方科技大学

葛琪. 氮化镓射频器件及氧化镓功率器件的研究[D]. 深圳. 南方科技大学,2021.