【作者】 张东辉；

【导师】 钟英辉；

【作者基本信息】 郑州大学 ， 电子信息（专业学位）， 2025， 硕士

【摘要】 InP基高电子迁移率晶体管(HEMT)具有高频、低噪声和高增益的优异性能,在高速通信、雷达以及高精度探测等航天领域有着广泛应用。然而太空环境中的高能辐射会引发总剂量效应(TID),这会导致器件的电学性能退化甚至失效。因此系统性地研究总剂量效应对于评估InP基HEMT空间应用可靠性以及设计抗辐射优化策略至关重要。本文通过半导体仿真软件TCAD结合60Co γ源辐照实验的方法来深入研究InP基HEMT器件的总剂量效应物理损伤机制。主要研究内容总结如下:1.利用Sentaurus-TCAD软件对器件的总剂量辐照效应进行探究。首先构建InP基HEMT二维仿真模型,通过优化关键区域网格以及添加合理的物理模型实现仿真结果与实验数据高度吻合。然后结合γ模型和缺陷模型对总剂量辐照引发的性能退化规律进行探究,发现栅槽表面态捕获势垒层载流子主要影响栅调控特性,而异质结界面缺陷则捕获沟道载流子造成阈值电压显著移动。最后对应提出了通过复合沟道提升载流子浓度和栅槽钝化减少表面态的抗辐照结构。2.对未钝化与BCB钝化器件开展了 60Co γ射线总剂量辐照效应实验以及辐照后的室温退火实验。辐照后即时测试结果显示:两种器件均表现为阈值电压负移、跨导和饱和沟道电流增大。室温退火实验结果显示:未钝化器件阈值电压由初期的负移逐渐正移至稳定,跨导和饱和沟道电流也逐渐下降至稳定。稳定后的阈值电压相比于辐照前正移,跨导和饱和沟道电流相比于辐照前降低。然而BCB钝化器件因其优异的抗辐照性能基本恢复到了辐照前。3.对InP基HEMT总剂量辐照效应的损伤机制进行了系统探究。结合对器件关键参数退化的分析与缺陷表征得出:在辐照后,栅下势垒层中产生大量亚稳态施主缺陷,这类缺陷在辐照初期引发了阈值电压的负向漂移。在之后的室温退火过程中,亚稳态施主缺陷逐渐恢复,栅槽表面态缺陷影响显现,这导致了器件阈值电压逐步正向漂移。最后通过在TCAD仿真中调整陷阱参数,得到与实验一致的退化规律,进一步验证了总剂量辐照效应的损伤机制。更多还原

【Abstract】 InP-based high electron mobility transistors(HEMTs)exhibit excellent properties such as high frequency,low noise,and high gain,making them widely used in high-speed communications,radar,and high-precision aerospace applications.However,the high-energy radiation in space environments induces total ionizing dose(TID)effects,leading to device performance degradation or even failure.Therefore,a systematic study of TID radiation effects is crucial for assessing the reliability of InP-based HEMTs in space applications and for developing radiation-hardened design strategies.This study investigates the physical damage mechanisms of TID effects in InP-based HEMTs through a combination of semiconductor simulation using TCAD and irradiation experiments with a 60Co γ-ray source.The main research findings are summarized as follows:1.The total-dose irradiation effects on InP-based HEMTs were investigated using Sentaurus-TCAD software.Initially,a two-dimensional simulation model of the InP-based HEMT was established,achieving excellent agreement between simulation and experimental results by optimizing the mesh density in key regions and incorporating appropriate physical models.Subsequently,degradation behaviors induced by total-dose irradiation were studied using gamma irradiation and defect models.It was found that surface states in the gate recess primarily influenced gate modulation characteristics by trapping carriers in the barrier layer,while defects at the heterojunction interface significantly shifted the threshold voltage by capturing channel carriers.Consequently,an anti-irradiation structure was proposed,employing composite channels to enhance carrier concentration and gate recess passivation to reduce surface states.2.Experiments were conducted on unpassivated and BCB-passivated devices to investigate total-dose effects induced by 60Co gamma-ray irradiation and subsequent room-temperature annealing after irradiation.Immediate post-irradiation measurements revealed negative threshold voltage shifts accompanied by increases in transconductance and saturation drain current for both device types.During subsequent room-temperature annealing,the threshold voltage of unpassivated devices gradually shifted positively from its initial negative displacement until reaching stability,while transconductance and saturation drain current progressively decreased and stabilized.After stabilization,the threshold voltage exhibited a net positive shift relative to pre-irradiation values,and both transconductance and saturation drain current decreased below their initial levels.However,due to their excellent radiation tolerance,BCB-passivated devices essentially recovered to their original pre-irradiation performance.3.The damage mechanism of total-dose irradiation effects in InP-based HEMTs was systematically investigated.Through analyzing key device parameter degradation and defect characterization,it was found that a large number of metastable donor defects generated in the barrier layer beneath the gate region led to an initial negative shift of threshold voltage immediately after irradiation.During subsequent room-temperature annealing,these metastable donor defects gradually recovered,while the influence of gate-recess surface-state defects became prominent,causing a progressive positive shift in threshold voltage.Finally,by adjusting trap parameters in TCAD simulations,degradation trends consistent with experimental results were obtained,further validating the proposed damage mechanism of total-dose irradiation effects.更多还原