Study and applications of plasma-modified Si and porous Si surfaces

• Published in: Applied surface science 2008-04, Vol.254 (12), p.3648-3652
• Main Authors: Gabouze, N., Benzekkour, N., Mahmoudi, Be, Belhousse, S., Cheraga, H., Ghellai, N.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Gas sensors; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Metal-insulator-semiconductor structures (including semiconductor-to-insulator); MIS structures; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photoluminescence; Physics; Porous materials; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Silicon
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2007.10.074

In this work we have studied the electrical, chemical and physical properties of CH x /silicon and CH x /porous silicon (PS). The hydrocarbon (CH x ) layer has been deposited by plasma of methane under argon atmosphere. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy and photoluminescence have been used to characterize the CH x /p-Si, CH x /PS interfaces and, electrolyte/(CH x /p-Si) and CH x /PS/p-Si structures. The results show that in the case of bare silicon, the CH x layers act as a resistant film to HF electrolyte and can be used as a potential tool for ultra-low thickness for masking and patterning. The deposition of CH x layer on PS shows that CH x /PS/p-Si structure presents a rectifying behaviour and can be used for detecting low concentration of large variety of gases. In addition CH x coated PS samples exhibit more intense luminescence than that observed from an uncoated PS surface where red luminescence is shown .In conclusion, the results clearly demonstrate the interest and applications of Si and PS electrodes coated with hydrocarbon groups.