Liu Meihua, Yang Yang, Chang Changkuan, Li Lei, Jin Yufeng
School of Electronic and Computer Engineering, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan, Shenzhen 518055, China.
Micromachines (Basel). 2021 May 18;12(5):572. doi: 10.3390/mi12050572.
In this paper, a novel method to achieve all-GaN integrated MIS-HEMTs in a Si-CMOS platform by self-terminated and self-alignment process is reported. Furthermore, a process of repairing interface defects by supercritical technology is proposed to suppress the threshold voltage shift of all GaN integrated MIS-HEMTs. The threshold voltage characteristics of all-GaN integrated MIS-HEMTs are simulated and analyzed. We found that supercritical NH3 fluid has the characteristics of both liquid NH3 and gaseous NH3 simultaneously, i.e., high penetration and high solubility, which penetrate the packaging of MIS-HEMTs. In addition, NH2- produced via the auto coupling ionization of NH3 has strong nucleophilic ability, and is able to fill nitrogen vacancies near the GaN surface created by high temperature process. The fabricated device delivers a threshold voltage of 2.67 V. After supercritical fluid treatment, the threshold voltage shift is reduced from 0.67 V to 0.13 V. Our demonstration of the supercritical technology to repair defects of wide-bandgap family of semiconductors may bring about great changes in the field of device fabrication.
本文报道了一种通过自终止和自对准工艺在硅互补金属氧化物半导体（Si-CMOS）平台上实现全氮化镓（GaN）集成金属-绝缘体-半导体-高电子迁移率晶体管（MIS-HEMT）的新方法。此外，还提出了一种利用超临界技术修复界面缺陷的工艺，以抑制全GaN集成MIS-HEMT的阈值电压漂移。对全GaN集成MIS-HEMT的阈值电压特性进行了模拟和分析。我们发现超临界氨流体同时具有液态氨和气态氨的特性，即高渗透性和高溶解性，它能穿透MIS-HEMT的封装。此外，通过氨的自耦合电离产生的NH2-具有很强的亲核能力，能够填充高温工艺在GaN表面产生的氮空位。所制备的器件阈值电压为2.67V。经过超临界流体处理后，阈值电压漂移从0.67V降低到0.13V。我们对超临界技术修复宽带隙半导体家族缺陷的演示可能会给器件制造领域带来巨大变化。
