Film-substrate interaction in Si/Ta and Si/Ta2O5 structures
Abstract
Gravimetric and secondary ion mass spectroscopy (SIMS) analyses of vacuum-deposited Ta films on Si substrates as well as Ta2O5 films obtained by thermal oxidation demonstrate a significant interaction in Si/Ta (Ta2O5) structures well below the usual temperatures required to form TaSi2 or SiO2 on silicon. The interaction begins during deposition of the Ta film, leading to incorporation of silicon in the film. It is suggested that oxygen gettered by tantalum facilitates this process. During oxidation of the Ta film, the silicon in the film is cooxidized, and oxygen diffusing through the already formed oxide enhances the further entry of silicon into the film. Oxygen diffusing through the completely oxidized Ta film further reacts with the silicon substrate during postoxidation heat treatment in oxygen. The results of the present analyses are qualitatively consistent with measured dielectric parameters of the film and observed electronic properties of the Si/Ta2O5 interface.
- Publication:
-
Journal of the Electrochemical Society
- Pub Date:
- October 1976
- DOI:
- 10.1149/1.2132629
- Bibcode:
- 1976JElS..123.1514R
- Keywords:
-
- Metal Films;
- Oxide Films;
- Silicon;
- Substrates;
- Tantalum Oxides;
- Vacuum Deposition;
- Gaseous Diffusion;
- Gravimetry;
- Heat Treatment;
- Mass Spectroscopy;
- Microstructure;
- Oxidation Resistance;
- Oxygen;
- Surface Reactions;
- Temperature Effects;
- Solid-State Physics