Thermal reaction of nickel and Si0.75Ge0.25 alloy
Pey, Kin Leong
Choi, W. K.
Zhao, H. B.
Fitzgerald, Eugene A.
Antoniadis, D. A.
Lee, Pooi See
Date of Issue2002
School of Materials Science and Engineering
The interfacial reactions and chemical phase formation between nickel and ultrahigh vacuum chemical vapor deposited Si0.75Ge0.25 alloy have been studied within the temperature range of 300–900 °C for forming low resistive and uniform silicide films for future application in SiGe based metal–oxide–semiconductor field effect transistor devices. The silicided films were characterized by the x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, transmission electron microscopy, and micro-Raman microscopy techniques. Smooth and uniform nickel monogermanosilicide NiSi0.75Ge0.25 films have been observed for samples annealed at around 400–500 °C. For annealing temperatures of 500 °C and above, Ge-rich Si1−zGez grains where z>0.25 were found among Ge deficient Niy(SiwGe1−w)1−y grains where w<0.25 and the Niy(Si1−wGew)1−y phase is thermally stable up to an annealing temperature of 800 °C. We found that the Ni/SiGe reaction is mainly diffusion controlled with Ge and Ni as the dominant diffusing species compared to Si during the annealing process. In addition, Ge has been found to promote agglomeration especially above 700 °C, leading to an abrupt increase in the sheet resistance.
Journal of vacuum science & technology A
© 2002 American Vacuum Society. This paper was published in Journal of Vacuum Science & Technology A and is made available as an electronic reprint (preprint) with permission of American Vacuum Society. The paper can be found at DOI: [http://dx.doi.org/10.1116/1.1507339]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.