中国物理B ›› 2013, Vol. 22 ›› Issue (3): 37702-037702.doi: 10.1088/1674-1056/22/3/037702

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

Evidence of GeO volatilization and its effect on the characteristics of HfO2 grown on Ge substrate

樊继斌, 刘红侠, 费晨曦, 马飞, 范晓娇, 郝跃   

  1. School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • 收稿日期:2012-06-18 修回日期:2012-09-19 出版日期:2013-02-01 发布日期:2013-02-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60976068 and 61076097) and the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China (Grant No. 708083).

Evidence of GeO volatilization and its effect on the characteristics of HfO2 grown on Ge substrate

Fan Ji-Bin (樊继斌), Liu Hong-Xia (刘红侠), Fei Cheng-Xi (费晨曦), Ma Fei (马飞), Fan Xiao-Jiao (范晓娇), Hao Yue (郝跃)   

  1. School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • Received:2012-06-18 Revised:2012-09-19 Online:2013-02-01 Published:2013-02-01
  • Contact: Fan Ji-Bin E-mail:jbfan@mail.xidian.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60976068 and 61076097) and the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China (Grant No. 708083).

摘要: HfO2 films are deposited by atomic layer deposition (ALD) using tetrakis ethylmethylamino hafnium (TEMAH) as the hafnium precursor, while O3 or H2O is used as the oxygen precursor. After annealing at 500℃ in nitrogen, the thickness of Ge oxide's interfacial layer decreases, and the presence of GeO is observed at the H2O-based HfO2 interface due to GeO volatilization, while it is not observed for the O3-based HfO2. The difference is attributed to the residue hydroxyl groups or H2O molecules in H2O-based HfO2 hydrolyzing GeO2 and forming GeO, whereas GeO is only formed by the typical reaction mechanism between GeO2 and the Ge substrate for O3-based HfO2 after annealing. The volatilization of GeO deteriorates the characteristics of the high-κ films after annealing, which has effects on the variation of valence band offset and the C-V characteristics of HfO2/Ge after annealing. The results are confirmed by X-ray photoelectron spectroscopy (XPS) and electrical measurements.

关键词: GeO volatilization, H2O-based HfO2, O3-based HfO2, thermal stability

Abstract: HfO2 films are deposited by atomic layer deposition (ALD) using tetrakis ethylmethylamino hafnium (TEMAH) as the hafnium precursor, while O3 or H2O is used as the oxygen precursor. After annealing at 500℃ in nitrogen, the thickness of Ge oxide's interfacial layer decreases, and the presence of GeO is observed at the H2O-based HfO2 interface due to GeO volatilization, while it is not observed for the O3-based HfO2. The difference is attributed to the residue hydroxyl groups or H2O molecules in H2O-based HfO2 hydrolyzing GeO2 and forming GeO, whereas GeO is only formed by the typical reaction mechanism between GeO2 and the Ge substrate for O3-based HfO2 after annealing. The volatilization of GeO deteriorates the characteristics of the high-κ films after annealing, which has effects on the variation of valence band offset and the C–V characteristics of HfO2/Ge after annealing. The results are confirmed by X-ray photoelectron spectroscopy (XPS) and electrical measurements.

Key words: GeO volatilization, H2O-based HfO2, O3-based HfO2, thermal stability

中图分类号: 

  • 77.55.D-
82.80.Pv (Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.))