Properties of polycrystalline silicon films obtained by rapid thermal processing for micromechanical sensors

• Published in: Journal of non-crystalline solids Vol. 343; no. 1; pp. 54 - 60
• Main Authors: Girginoudi, D., Mitsinakis, A., Kotsani, M., Georgoulas, N., Thanailakis, A., Kontos, A.G., Stergiou, V.C., Raptis, Y.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2004; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; S180; M220; M120; Doping; Polycrystals; Mechanical properties; Deposition rate; Phosphorus additions; Micromechanical devices; CVD; Rapid thermal processing; Impurities; Low pressure; Silicon; Sensors; Microstructure; Application; Activation energy
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2004.07.007

The mechanical and structural properties of as-deposited polycrystalline Si films, grown by rapid thermal processing low-pressure chemical vapor deposition at a high deposition rate of 0.4 μm/min on oxidized Si wafer substrates, were investigated using Raman spectroscopy and transmission electron microscopy (TEM) measurements. The effect of high phosphorus doping using a spin-on technique has also been studied for applications in electrically conducting microstructures. The thermal treatment of the samples, with rapid thermal annealing at 1000 and 1050 °C, as well as with furnace annealing at 1000 °C, results in a reduction of the intra-grain defects in the films. Furthermore, spin-on-coated phosphorus was easily incorporated in the films resulting in an effective electrical activation. All films have shown an overall marginal compressive stress of about 20 MPa; however, the SiO 2, in pad form, beneath the SOI structures, introduces a small (about 10 MPa) tensile stress. Finally, cantilever and doubly supported beams, of useful length with a deflection, out of the horizontal plane, of less than 0.1 μm, were fabricated using rapid thermal processing compatible with the standard silicon microelectronics technologies.