Experimental and theoretical investigation of geometric and compositional factors in improving the off-state breakdown voltage, reliability, and enhancement-mode operation among GaN channel hetero-structure field effect transistors

几何和成分因素在提高 GaN 沟道异质结构场效应晶体管断态击穿电压、可靠性和增强模式操作方面的实验和理论研究

• 批准号: RGPIN-2020-05656
• 负责人: Valizadeh, Pouya
• 金额: $ 2.04万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717789
• 关键词: Experimental; theoretical; investigation; geometric; compositional

More than two decades of research on polar III-Nitride hetero-structure field effect transistors (HFETs) has resulted in rapidly growing markets in the areas of high-frequency power-amplifiers/RF-switches and high-temperature/high-voltage power electronic switches. As the market-share is passing the billion-dollar mark, innovative solutions in-tune with the particulars of these polar hetero-structures for improving their power-handling/heat-management, and for reliable realization of both enhancement- and depletion-modes of operation (i.e. having positive and negative threshold-voltage, respectively) are gaining a more prominent status. With the improvement in techniques of hetero-epitaxy and availability of reliable sources providing the less explored AlInGaN/GaN hetero-structures, taking advantage of lattice-matching to the GaN channel and examining the less-explored compositional and geometric structures towards improving the long-term reliability, enhancing the possibility of achieving stable enhancement-mode operation, and extending the breakdown voltage are all very timely. Combing the now-proven possibilities of shifting the threshold-voltage towards enhancement-mode operation and reducing the self-heating (both realized through modifying the mesa structure of the isolation-feature), with the offered opportunity to tailor the drain-induced electric-field due to the proximity of Fermi-level pinned sidewall facets is expected to not only offer ways to achieve reliable enhancement-mode III-Nitride HFETs, but also to boost their off-state breakdown voltage. While traditionally off-state breakdown voltage is boosted by employing the so-called field-plates (i.e. extensions to the gate electrode and hence capacitance), tailoring the electric-field via the presence of pinned side-wall facets in the close proximity of the channel can partially lift the burden on the frequency response for a higher breakdown voltage. With the help of the previous Discovery grants, PI's team has proudly managed to develop an e-beam lithography process poised for successfully performing the experimental tasks identified in the current proposal. Along with the contributions of the PI to understanding of the aforementioned phenomena, a few other groups are also currently involved in lively technological endeavors in this area. Under the support of the present Discovery grant application, PI intends to continue his groundbreaking work on exploring the aforementioned alternatives for improving the off-state breakdown voltage, long-term reliability, and frequency response among enhancement mode GaN-channel HFETs. The ideas presented in this proposal have the possibility of generating patentable concepts and in the long-term establishing future joint ventures with automobile and telecommunication industries. The latter of which is presently poised to take advantage of III-Nitride HFETs in 5G networks and developing internet of things (IOT) applications.

二十多年来对极性 III 族氮化物异质结构场效应晶体管 (HFET) 的研究已导致高频功率放大器/射频开关和高温/高压电力电子领域的市场快速增长开关。随着市场份额突破十亿美元大关，创新解决方案与这些极性异质结构的细节相一致，以改善其功率处理/热管理，并可靠地实现增强模式和耗尽模式操作（即分别具有正阈值电压和负阈值电压）正在获得更加突出的地位。 随着异质外延技术的改进和可靠来源的可用性，提供了较少探索的 AlInGaN/GaN 异质结构，利用与 GaN 沟道的晶格匹配并检查较少探索的成分和几何结构，以改善长寿命长期可靠性、增强实现稳定增强模式运行的可能性以及延长击穿电压都非常及时。 结合现已证明的将阈值电压转向增强模式操作和减少自加热的可能性（两者都是通过修改隔离功能的台面结构实现的），并提供定制漏极感应电的机会由于费米级固定侧壁面的接近而产生的电场预计不仅可以提供实现可靠的增强型 III 族氮化物 HFET 的方法，而且还可以提高其断态击穿电压。虽然传统上通过使用所谓的场板（即延伸至栅电极并因此延伸电容）来提高断态击穿电压，但通过紧邻场板的存在的固定侧壁面来定制电场通道可以部分减轻频率响应的负担，以获得更高的击穿电压。 在之前的 Discovery 资助的帮助下，PI 的团队自豪地成功开发了一种电子束光刻工艺，准备成功执行当前提案中确定的实验任务。除了 PI 对理解上述现象的贡献外，其他一些团体目前也参与了该领域的活跃技术努力。在目前的 Discovery 拨款申请的支持下，PI 打算继续探索上述替代方案的开创性工作，以提高增强型 GaN 沟道 HFET 的断态击穿电压、长期可靠性和频率响应。 该提案中提出的想法有可能产生可专利的概念，并有可能与汽车和电信行业建立未来的长期合资企业。后者目前准备在 5G 网络和开发物联网 (IOT) 应用中利用 III 族氮化物 HFET。