中国物理B ›› 2012, Vol. 21 ›› Issue (8): 87304-087304.doi: 10.1088/1674-1056/21/8/087304

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

Formations and morphological stabilities of ultrathin CoSi2 films

朱志炜a, 高歆栋b, 张志滨b, 朴颖华a, 胡成a, 张卫a, 吴东平a   

  1. a State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China;
    b Solid-State Electronics, the Ångström Laboratory, Uppsala University, Box 534, 75121 Uppsala, Sweden
  • 收稿日期:2011-12-22 修回日期:2012-03-19 出版日期:2012-07-01 发布日期:2012-07-01
  • 基金资助:
    Project supported by the "China National Science and Technology Major Project 02" (Grant No. 2009ZX02035-003), the National Natural Science Foundation of China (Grant No. 61176090), and the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning.

Formations and morphological stabilities of ultrathin CoSi2 films

Zhu Zhi-Wei (朱志炜)a, Gao Xin-Dong (高歆栋)b, Zhang Zhi-Bin (张志滨)b, Piao Ying-Hua (朴颖华)a, Hu Cheng (胡成)a, Zhang David-Wei (张卫)a, Wu Dong-Ping (吴东平 )a   

  1. a State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China;
    b Solid-State Electronics, the Ångström Laboratory, Uppsala University, Box 534, 75121 Uppsala, Sweden
  • Received:2011-12-22 Revised:2012-03-19 Online:2012-07-01 Published:2012-07-01
  • Contact: Wu Dong-Ping E-mail:dongpingwu@fudan.edu.cn
  • Supported by:
    Project supported by the "China National Science and Technology Major Project 02" (Grant No. 2009ZX02035-003), the National Natural Science Foundation of China (Grant No. 61176090), and the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning.

摘要: In this paper we investigate the formations and morphological stabilities of Co-silicide films using 1-8-nm thick Co layers sputter-deposited on silicon (100) substrates. These ultrathin Co-silicide films are formed via solid-state reaction of the deposited Co films with Si substrate at annealing temperatures from 450 ℃ to 850 ℃. For Co layer with a thickness no larger than 1 nm, epitaxially aligned CoSi2 films readily grow on silicon (100) substrate and exhibit good morphological stabilities up to 600 ℃. For Co layer thicker than 1 nm, polycrystalline CoSi and CoSi2 films are observed. The critical thickness below which epitaxially aligned CoSi2 film prevails is smaller than the reported critical thickness of Ni layer for epitaxial alignment of NiSi2 on silicon (100) substrate. The larger lattice mismatch between CoSi2 film and silicon substrate is the root cause for the smaller critical thickness of the Co layer.

关键词: silicide, epitaxial alignment, ultrathin film

Abstract: In this paper we investigate the formations and morphological stabilities of Co-silicide films using 1-8-nm thick Co layers sputter-deposited on silicon (100) substrates. These ultrathin Co-silicide films are formed via solid-state reaction of the deposited Co films with Si substrate at annealing temperatures from 450 ℃ to 850 ℃. For Co layer with a thickness no larger than 1 nm, epitaxially aligned CoSi2 films readily grow on silicon (100) substrate and exhibit good morphological stabilities up to 600 ℃. For Co layer thicker than 1 nm, polycrystalline CoSi and CoSi2 films are observed. The critical thickness below which epitaxially aligned CoSi2 film prevails is smaller than the reported critical thickness of Ni layer for epitaxial alignment of NiSi2 on silicon (100) substrate. The larger lattice mismatch between CoSi2 film and silicon substrate is the root cause for the smaller critical thickness of the Co layer.

Key words: silicide, epitaxial alignment, ultrathin film

中图分类号:  (Surface double layers, Schottky barriers, and work functions)

  • 73.30.+y
68.35.Dv (Composition, segregation; defects and impurities) 85.40.Ls (Metallization, contacts, interconnects; device isolation)