本项目面向新一代氮化镓基单片集成太赫兹收发系统核心电子器件的设计和工艺实现，研究与平面工艺全兼容的高电子迁移率晶体管新型太赫兹器件，重点集中在器件的高次谐波调控新机理、新结构和新工艺，旨在实现高功率密度的200-300 GHz信号的产生、调制解调、混频、倍频等核心功能。研究采用肖特基-欧姆接触复合电极结构、非均匀势垒结构和浮空场板结构来调控二维电子气沟道电场，从而控制沟道内电子畴的形态和强度、以及电子温度，结合源漏区掺杂浓度的梯度变化，以增强高电子迁移率晶体管沟道漏极区的空间电荷扰动从而形成电子畴，实现器件的非线性跨导输出特性，以降低基波分量提高谐波分量，有利于高功率混频倍频太赫兹信号的产生。

The project is on the study of novel structural HEMTs that are compatible with planar device fabrication process for terahertz application. The devices will be employed in next generation terahertz systems based on GaN monolithic ICs. The emphasis is put on the new mechanism, structure and process of enhancing harmonic-frequency components of THz devices, aimed at achieving the generation, modulation-demodulation, mixing and frequency multiplication of high power density signals at 200-300 GHz. In Particular, we propose a Schottky-ohmic composite contact instead of traditional ohmic contact for HEMTs which aims to modulate the electric-field in 2DEG channel in order to promote formation and propagation of multiple electron domains, thereby, enhancing the harmonic-frequency components. We also propose a novel device structure in the gate-drain region of HEMTs by using Schottky contact and thickness modulation of barrier layer above 2DEG channel, which aims to enhance the perturbation of spatial charges by means of drastically fluctuating the electric-field in the drain region in order to achieve an extremely non-linear transconductance, thereby, the high component of harmonic in terahertz frequencies.