,Improved interfacial properties of HfGdON gate dielectric Ge MOS capacitor by optimizing Gd content

• 作 者: Lin Zhou Lu Liu Yu-Heng Deng Chun-Xia Li Jing-Ping Xu
• 机 构: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 4
• 出 处: 中国物理B（英文版）
• 发表日期: 2019年12期
• 关键词: Ge MOS devices HfGdON dielectric interface quality leakage current density

High-quality dielectric/Ge interface and low gate leakage current are crucial issues for high-performance nanoscaled Ge-based complementary metal-oxide-semiconductor (CMOS) device.In this paper,the interfacial and electrical properties of high-k HfGdON/LaTaON stacked gate dielectric Ge metal-oxide-semiconductor (MOS) capacitors with different gadolinium (Gd) contents are investigated.Experimental results show that when the controlling Gd content is a suitable value (e.g.,～ 13.16％),excellent device performances can be achieved:low interface-state density (6.93 × 1011 cm-2.eV-1),small flatband voltage (0.25 V),good capacitance-voltage behavior,small frequency dispersion,and low gate leakage current (2.29× 10-6 A/cm2 at Vg =Vfb + 1 V).These could be attributed to the repair of oxygen vacancies,the increase of conduction band offset,and the suppression of germanate and suboxide GeOx at/near the high k/Ge interface by doping suitable Gd into HfON.