Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-24T12:43:42.571Z Has data issue: false hasContentIssue false
  • English
  • Français

Pt Segregation at the NiSi/Si Interface and a Relationship with the Microstructure of NiSi

Published online by Cambridge University Press:  01 February 2011

Haruko Akutsu ,
Hiroshi Itokawa ,
Kazuhiko Nakamura ,
Toshihiko Iinuma ,
Kyoichi Suguro ,
Hiroshi Uchida  and
Masanori Tada
Haruko Akutsu
Affiliation:
[email protected], Toshiba corporation, Process & Manufacturing Engineering Center, 8, Shinsugita-Cho, Isogo-Ku, Yokohama, N/A, Japan, +81-45-776-4709, +81-45-776-4106
Hiroshi Itokawa
Affiliation:
[email protected], Toshiba Corporation Semiconductor Company, 8, Shinsugita-Cho, Isogo-Ku, Yokohama, Japan
Kazuhiko Nakamura
Affiliation:
[email protected], Toshiba Corporation Semiconductor Company, 8, Shinsugita-Cho, Isogo-Ku, Yokohama, Japan
Toshihiko Iinuma
Affiliation:
[email protected], Toshiba Corporation Semiconductor Company, 8, Shinsugita-Cho, Isogo-Ku, Yokohama, Japan
Kyoichi Suguro
Affiliation:
[email protected], Toshiba Corporation Semiconductor Company, 8, Shinsugita-Cho, Isogo-Ku, Yokohama, Japan
Hiroshi Uchida
Affiliation:
[email protected], Toshiba Nanoanalysis Corporation, ., ., ., Japan
Masanori Tada
Affiliation:
[email protected], Toshiba Nanoanalysis Corporation, ., ., ., Japan
Get access

Abstract

Nickel monosilicide (NiSi) is used for lowering the parasitic resistances in source/drain. However, NiSi has a disadvantage of lower thermal instability such as NiSi2 nucleation and agglomeration. We first reported Pt segregation was found at a NiSi/Si interface by Atom Probe (AP) analysis.[6] In this study, we found that the scheme of Ni silicide grain growth and the resultant NiSi crystal shape is strongly affected by the existence of Pt by utilizing AP analysis, TEM and FE-SEM. AP observations were carried on a Ni-Pt as sputterd sample and on a Ni-Pt as annealed sample. The depth profile for the sample after silicidation indicates Pt atoms are segregated at a NiSi surface and NiSi/Si interface. For the analysis of the Pt distribution in the sample after silicidation in more details, we thoroughly analyzed the 3D image as follows: a cylindrical part is extracted from the 3D image; it is divided into 5nm thick slices; and 2D images depicting density-distribution of Pt and As. From these 2D images, we found Pt atoms exist around NiSi grains. The Atom Probe result indicates that Pt atoms segregate at the NiSi surface, grain boundaries and NiSi/Si interface. Plane view TEM and FE-SEM observations were carried out on Ni(Pt) silicide and on Ni silicide without Pt to find the influence of the segregated Pt atoms on the microstructure of NiSi. The spindle shape of NiSi(w/o Pt) grains were observed on the former. On the other hand, we observed on the latter that the Pt addition affected the shape of the NiSi grains and changed NiSi grains to round polygonal shape and the average grain size became smaller. It can be said that the Pt addition suppresses a crystal growth along in a longitudinal direction of a grain. We speculate that fine round shape NiSi grains are formed as a result of the suppression of the anisotropic crystal growth by Pt segregation, and provide the improvement of the thermal stability of the NiSi film.

Keywords

NiSiPt
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1070: Symposium E – Doping Engineering for Front-End Processing , 2008 , 1070-E02-09
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Mangelinck, D., Dai, J.Y., Pan, J. and Lahiri, S.K., Appl. Phys. Let. 75 1736 (1999)Google Scholar
2. Strane, J., et al. International Symposium on VLSI-TSA-Tech 2007 (Hsinchu, 2007) p.140 Google Scholar
3. Detavernier, C., Lavoie, C., Appl.Phys.Let. 84 3549 (2004)Google Scholar
4. Kelly, T.F., Roberts, J., Thompson, K., 7th IWJT 2007, S3-1, p.27 (Kyoto)Google Scholar
5.Properties of Silicon, INSPEC 1988 Google Scholar
6. Akutsu, H. et al., Ext. Abstacts of SSDM, F-3-6L, p. 296 (Tsukuba, 2007).Google Scholar