太赫兹HEMT器件基础研究

InP-based materials have outstanding properties, such as high carrier mobility, rich band structures, easier band tailoring. The devices based on them have the highest frequency performances in the modern semiconductor technology and are the ideal materials for terahertz HEMT. Based on our previous research on InP-based HEMT, taking full advantages of InP-based materials, we make researches on the epitaxial layer of THz HEMT, device processing, and circuit design to make insigt into the challenges present in improving the cut-off frequency of InP-based HEMT from GHz- to THz-range. By means of investigating the scientific problems and key technologies of the atomic regulating and growth kinetics of THz InP based HEMTs epitaxial layer structure, and the mechanism of carrier transport and behavior law of the THz InP based HEMTs devices, the scientific problems and technical bottlenecks will be solved multi-level and adjectively from the point of view of microelectronics, and a series of frontier achievements of proprietary intellectual property will be obtained. The epitaxial layer with carrier mobility more than 12000 cm2/Vs, the InP based THz HEMTs with sub-50 nm gate length and cut-off frequency of terahertz, and the validation of THz circuit design method will be actualized, which could realize the breakthrough of the THz devices and circuits and accordingly promote the development of the THz devices and circuits in our country.

InP基材料具有载流子迁移率高、材料能带丰富、能带易于剪裁等优点，是现有半导体器件中频率最高的材料体系，是太赫兹HEMT器件的理想材料。项目在已有的研究基础上，针对InP基HEMT的频率特性从吉赫兹提高到太赫兹面临的挑战，充分利用InP基材料的优点，开展太赫兹HEMT外延材料、太赫兹HEMT器件工艺以及太赫兹器件的电路验证研究。通过对太赫兹InP基HEMT外延材料的原子级调控与生长动力学、太赫兹InP基HEMT器件的载流子输运机理与行为规律等科学问题和关键技术的深入研究，从微电子学角度多层次、综合性地解决科学问题和技术瓶颈，取得一批自主知识产权的前沿性成果，研制出迁移率大于12000 cm2/Vs的外延材料，栅长亚50 nm的InP基太赫兹HEMT器件，将InP基HEMT器件的截止频率提高到太赫兹，并验证太赫兹电路的设计方法，实现太赫兹器件和电路的突破，推动我国太赫兹器件和电路的发展。

针对InP基HEMT器件频率特性从吉赫兹提高到太赫兹面临的挑战，从外延材料、关键工艺及电路验证三个方面开展了工作。通过GMBE生长技术，揭示了外延材料的组份、失配度、厚度、掺杂浓度、界面质量等因素对载流子迁移率和二维电子气浓度的影响规律；实现了高掺杂、大失配InP基外延材料的原子级调控技术，解决了影响沟道质量和迁移率提高的关键问题，实现了迁移率大于12000 cm2/Vs的外延材料。从物理结构和等效电路模型两个层面，揭示了器件中金半接触特性、表面电荷和表面态、栅极尺寸、外延结构和二维电子气特性等因素对器件性能的影响规律，明确了器件寄生效应和短沟道效应的对应物理结构和行为规律，对器件的载流子输运机理与行为规律形成了整体的认识。开发了器件关键工艺，实现了fmax超过1.0 Thz的InP基HETM器件。基于InP基材料提出了新型HDL-TFET和MSDG-TFET等太赫兹器件。采用场路结合方法以及基于BCB介质的微带工艺，设计和实现了太赫兹放大器电路芯片，在305GHz获得5.7 dB增益，另外提出了一种基于多点谐振的带宽扩展及噪声抑制技术，设计和实现了1~32 GHz五倍频程超宽带低噪声放大器MMIC。实现了太赫兹InP基HEMT器件和太赫兹电路设计方法的验证。项目的研究实现了太赫兹器件和电路的突破，推动了我国太赫兹器件和电路的发展。