中国物理B ›› 2012, Vol. 21 ›› Issue (11): 117701-117701.doi: 10.1088/1674-1056/21/11/117701

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Wet thermal annealing effect on TaN/HfO2/Ge metal–oxide–semiconductor capacitors with and without a GeO2 passivation layer

刘冠洲, 李成, 路长宝, 唐锐钒, 汤梦饶, 吴政, 杨旭, 黄巍, 赖虹凯, 陈松岩   

  1. Department of Physics, Semiconductor Photonics Research Center, Xiamen University, Xiamen 361005, China
  • 收稿日期:2012-05-11 修回日期:2012-07-13 出版日期:2012-10-01 发布日期:2012-10-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176092, 61036003, and 60837001), the National Basic Research Program of China (Grant No. 2012CB933503), the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20110121110025), and the Fundamental Research Funds for the Central Universities, China (Grant No. 2010121056).

Wet thermal annealing effect on TaN/HfO2/Ge metal–oxide–semiconductor capacitors with and without a GeO2 passivation layer

Liu Guan-Zhou (刘冠洲), Li Cheng (李成), Lu Chang-Bao (路长宝), Tang Rui-Fan (唐锐钒), Tang Meng-Rao (汤梦饶), Wu Zheng (吴政), Yang Xu (杨旭), Huang Wei (黄巍), Lai Hong-Kai (赖虹凯), Chen Song-Yan (陈松岩 )   

  1. Department of Physics, Semiconductor Photonics Research Center, Xiamen University, Xiamen 361005, China
  • Received:2012-05-11 Revised:2012-07-13 Online:2012-10-01 Published:2012-10-01
  • Contact: Li Cheng E-mail:lich@xmu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176092, 61036003, and 60837001), the National Basic Research Program of China (Grant No. 2012CB933503), the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20110121110025), and the Fundamental Research Funds for the Central Universities, China (Grant No. 2010121056).

摘要: Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor (MOS) structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage (C-V) and current-voltage characteristics. It is demonstrated that the wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, the wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C-V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of the wet thermal annealing to a certain extent.

关键词: HfO2 dielectric on germanium, X-ray photoemission spectroscopy, wet thermal annealing, metal-oxide-semiconductor capacitor

Abstract: Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor (MOS) structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage (C-V) and current-voltage characteristics. It is demonstrated that the wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, the wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C-V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of the wet thermal annealing to a certain extent.

Key words: HfO2 dielectric on germanium, X-ray photoemission spectroscopy, wet thermal annealing, metal-oxide-semiconductor capacitor

中图分类号:  (For nonsilicon electronics (Ge, III-V, II-VI, organic electronics))

  • 77.55.dj
79.60.Bm (Clean metal, semiconductor, and insulator surfaces) 73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator))