Collaborative Research: Non-Conventional Etching and MOCVD Regrowth for Beta-GaO/AlGaO 3D HEMTs

合作研究：Beta-GaO/AlGaO 3D HEMT 的非常规蚀刻和 MOCVD 再生长

• 批准号: 1809946
• 负责人: Xiuling Li
• 金额: $ 24.85万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1809946&HistoricalAwards=false
• 关键词: Collaborative; Research; Non; Conventional; Etching

Gallium oxide represents a promising semiconductor material for electronic devices concerning size scaling and performance enhancement especially for applications in high voltage, high temperature, and high frequency components. Both materials development and device fabrication based on this new semiconductor material is still at its infancy. This project explores the material growth and device processing to achieve a highly scalable radio frequency device with performance beyond the current device technology based on other semiconductor materials such as silicon, gallium nitride or silicon carbide. This project seeks to address the rising challenges in the etching and material growth process due to the complex atomic structure of this oxide semiconductor. Understanding of the fundamental etching mechanisms and materials growth process is critical to fully utilize the advantages offered by this emerging material system. A successful execution of this research is expected to provide a knowledge foundation to electronics industry with positive impacts on the US economy. The research is integrated with educational activities and outreach to benefit the broader community. The proposed education plans focus on integration of research and education, curriculum development, and student training. The results obtained from the proposed research will provide inspiring teaching materials and laboratory projects, to provide training of our next generation workforce for embracing emerging technologies. This project trains two graduate students in the areas of advanced semiconductor materials synthesis, material characterization, and device design and fabrication. The principal investigators (PIs) are strongly committed to promoting the participation of underrepresented groups including women in science and engineering, by creating an inclusive environment, active mentoring, and leading by examples. The proposed outreach activities focus on high school girls and teachers. Both PIs will continue to actively lead or be involved in existing education and outreach programs including the NSF Research Experience for Undergraduates (REU) and Research Experience for Teachers (RET) programs, local and IEEE Women in Engineering programs.Gallium oxide (Ga2O3; GaO), with high breakdown field strength, represents an emerging ultrawide bandgap semiconductor beyond silicon carbide and gallium nitride. The goal of the proposed research is to demonstrate a three-dimensional (3D) GaO/AlGaO high electron mobility transistor (HEMT) using a 3D channel formed by a non-conventional damage-free anisotropic etching technique (meta-assisted chemical etch; MacEtch) followed by metalorganic chemical vapor deposition (MOCVD) epitaxial regrowth of AlGaO. The scope of the research includes: i) realizing high aspect ratio Ga2O3 3D channel structures using the non-destructive MacEtch technology; ii) developing MOCVD growth, doping, and regrowth of AlGaO on the MacEtch-produced non-planar Ga2O3 structures; iii) characterizing the MacEtched Ga2O3 surfaces and the regrown GaO/AlGaO hetero-interfaces chemically, structurally, optically, and electrically; and iv) demonstrating GaO/AlGaO HEMTs with non-planar 3D channels. The proposed GaO/AlGaO HEMT structure, with the non-planar 3D topology and the complex monoclinic crystal structure, provides a unique platform to explore the crystal orientation dependent etching, growth rate, AlGaO composition, GaO/AlGaO interface defects, and dopant/impurity incorporation. The intellectual significance of the project will establish fundamental understanding of the carrier generation and mass transport properties in MacEtch of Ga2O3 as a function of metal catalyst pattern and its alignment with surface orientation, crystal doping concentration, and ultra-violet light illumination wavelength and intensity, as well as the etching mechanism for wide bandgap oxide semiconductors in general. Surface and interface characterization will provide insights in the contributing and limiting factors in vacancy and other defects related traps and establish control process for different device architecture requirements. Beyond the proposed program, the platform and innovative concepts to be explored can also be used for many other types of devices for size scaling and performance enhancement, including optoelectronics devices such as solar blind ultraviolet (UV) detectors and high temperature flame sensors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

氧化镓是一种有前途的电子器件半导体材料，涉及尺寸缩小和性能增强，特别是在高压、高温和高频元件中的应用。基于这种新型半导体材料的材料开发和器件制造仍处于起步阶段。该项目探索材料生长和器件加工，以实现高度可扩展的射频器件，其性能超越基于其他半导体材料（例如硅、氮化镓或碳化硅）的当前器件技术。该项目旨在解决由于这种氧化物半导体的复杂原子结构而导致的蚀刻和材料生长过程中日益严峻的挑战。了解基本蚀刻机制和材料生长过程对于充分利用这种新兴材料系统提供的优势至关重要。这项研究的成功执行预计将为电子行业提供知识基础，并对美国经济产生积极影响。该研究与教育活动和外展活动相结合，以造福更广泛的社区。拟议的教育计划侧重于研究与教育的整合、课程开发和学生培训。拟议研究获得的结果将提供鼓舞人心的教材和实验室项目，为我们的下一代劳动力提供拥抱新兴技术的培训。该项目在先进半导体材料合成、材料表征以及器件设计和制造领域培训两名​​研究生。首席研究员 (PI) 坚定致力于通过创造包容性环境、积极指导和以身作则，促进包括女性在内的弱势群体参与科学和工程领域。 拟议的外展活动重点关注高中女生和教师。两位 PI 将继续积极领导或参与现有的教育和推广项目，包括 NSF 本科生研究体验 (REU) 和教师研究体验 (RET) 项目、本地和 IEEE 女性工程项目。氧化镓 (Ga2O3；GaO) 具有高击穿场强，代表了超越碳化硅和氮化镓的新兴超宽带隙半导体。拟议研究的目标是展示一种三维（3D）GaO/AlGaO高电子迁移率晶体管（HEMT），该晶体管使用由非常规无损伤各向异性蚀刻技术（元辅助化学蚀刻；MacEtch）形成的3D沟道，然后进行AlGaO的金属有机化学气相沉积（MOCVD）外延再生长。研究范围包括：i）利用无损MacEtch技术实现高深宽比Ga2O3 3D通道结构； ii) 在 MacEtch 生产的非平面 Ga2O3 结构上开发 AlGaO 的 MOCVD 生长、掺杂和再生长； iii) 对 MacEtched Ga2O3 表面和再生的 GaO/AlGaO 异质界面进行化学、结构、光学和电学表征； iv) 演示具有非平面 3D 通道的 GaO/AlGaO HEMT。所提出的GaO/AlGaO HEMT结构具有非平面3D拓扑和复杂的单斜晶体结构，为探索晶体取向相关的蚀刻、生长速率、AlGaO成分、GaO/AlGaO界面缺陷和掺杂剂/杂质掺入提供了独特的平台。该项目的智力意义将建立对 Ga2O3 MacEtch 中载流子生成和质量传输特性作为金属催化剂图案及其与表面取向、晶体掺杂浓度、紫外光照射波长和强度的对准的函数的基本理解，以及宽带隙氧化物半导体的一般蚀刻机制。 表面和界面表征将提供对空位和其他缺陷相关陷阱的影响和限制因素的见解，并为不同的器件架构要求建立控制流程。除了拟议的计划之外，待探索的平台和创新概念还可用于许多其他类型的设备，以实现尺寸缩放和性能增强，包括日盲紫外线 (UV) 探测器和高温火焰传感器等光电子设备。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

β -Ga 2 O 3 FinFETs with ultra-low hysteresis by plasma-free metal-assisted chemical etching

通过无等离子体金属辅助化学蚀刻实现超低磁滞的β-Ga 2 O 3 FinFET

• DOI: 10.1063/5.0096490
• 发表时间: 2022
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Huang, Hsien-Chih;Ren, Zhongjie;Anhar Uddin Bhuiyan, A F;Feng, Zixuan;Yang, Zhendong;Luo, Xixi;Huang, Alex Q.;Green, Andrew;Chabak, Kelson;Zhao, Hongping
• 通讯作者: Zhao, Hongping

A Review of Recent Progress in β‐Ga 2 O 3 Epitaxial Growth: Effect of Substrate Orientation and Precursors in Metal–Organic Chemical Vapor Deposition

β-Ga 2 O 3 外延生长最新进展综述：金属有机化学气相沉积中基底取向和前驱体的影响

• DOI: 10.1002/pssa.202200616
• 发表时间: 2022
• 期刊: physica status solidi (a
• 作者: Waseem, Aadil;Ren, Zhongjie;Huang, Hsien-Chih;Nguyen, Kristen;Wu, Xihang;Li, Xiuling
• 通讯作者: Li, Xiuling

Metal-Assisted Chemical Etching of (001) β-Ga2O3

(001) β-Ga2O3 的金属辅助化学蚀刻

• 发表时间: 2021
• 期刊: 2020 Compound Semiconductor Week (CSW
• 作者: Hsien-Chih Huang, Zhongjie Ren

On the Surface Properties of High Aspect Ratio $\beta$-Ga 2 O 3 Fin Structures Formed by I-MacEtch

I-MacEtch形成的高深宽比$eta$-Ga 2 O 3 Fin结构的表面特性

• DOI: 10.1109/iciprm.2019.8819197
• 发表时间: 2019
• 期刊: Compound Semiconductor Week (CSW
• 作者: Huang, Hsien-Chih;Kim, Munho;Zhan, Xun;Chabak, Kelson;Kim, Jeongdong;Zuo, Jian-min;Li, Xiuling
• 通讯作者: Li, Xiuling