SiGeSn is a promising group IV semiconducting alloy to advance the field of silicon photonics. The bandgap of the alloy can be tuned by varying its' Si and Sn concentrations for developing devices in the near infrared (NIR) range. The growth of the material using a cost-effective process is still challenging due to various obstacles. In this work, a simplified in-house assembled plasma enhanced chemical vapor deposition (PECVD) reactor was used to deposit SiGeSn films. Plasma allows for the use of commercially available precursors (GeH4, Si2H6 and SnCl4) while providing high dissociation and deposition growth rates. Polycrystalline films were deposited at susceptor temperatures in the range of 350 C-450 C to study the effect of process temperature on the Sn segregation and Sn incorporation in the films. Selective area growth (SAG) of SiGeSn films was also achieved by depositing films on patterned silicon substrates. The composition of the films was characterized by Rutherford Back Scattering while the structural and optical properties of the films were analyzed using X-ray diffraction and Raman spectroscopy. Selectively grown films were fabricated into basic test photodiodes and evaluated for electrical performance under NIR illumination.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials