Abstract
The silicon thin films have been deposited using VHF (60 MHz) plasma enhanced chemical vapor deposition (PECVD) process. The influence of the power (10–50 W), used during the deposition, on the silicon thin films properties was studied. The structural transition (different crystalline fraction) along with their variable grain distribution within amorphous silicon matrix has been discussed with the help of optical, electrical and structural measurements. Raman characterization along with photoluminescence (PL), UV-VIS spectroscopy, micro-ellipsometry spectroscopy and Field emission scanning electron microscopy (FESEM) have been performed to recognize the transitions in deposited silicon films including the microstructure mainly related with crystallite fraction and optical constants. FESEM was used to investigate the characteristics and variation in the microstructure. From Raman results, the structural transition from amorphous to micro/nanocrystalline growth occur as indicated by narrow band at 515 cm−1 observed at 10 W applied power deposited film. From these results, it was found that with increasing power, the crystallinity increases and the films are highly crystalline (Xc > 50%) in nature above 20 W applied power. The contribution of nano-sized crystallites increases the crystalline volume fraction from 32 to 84%. The peak observed nearly at 2.0 eV in photoluminescence emission spectra (PL) confirms the presence of nanocrystallites in the deposited films which is well correlated with the band gap values observed from UV-VIS spectroscopy. However, red shift in PL peak energy and decrease in PL intensity observed and are explained in terms of grain boundaries. The shift in refractive index (n) and extinction coefficient (k) were also observed at different power variation. The investigation of spectroscopic ellipsometry result explains the microstructure of deposited film with changes in crystallite sizes and their volume fractions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
