High-Quality Nanocrystalline Silicon (nc-Si:H) Thin Film With Mixed-Phase and Its Application of Circulating Tumor Cell DEP Biochip

This paper proposes the light-induced dielectrophoresis (DEP) biochip prepared by 40.68-MHz very high-frequency plasma-enhanced chemical vapor deposition (VHFPECVD) and post- microwave annealing treatment. The biochip can screen circulating tumor cells without using any antibodies and biomarkers. Therefore, the biochip's high efficiency and high purity are goals for effectively conducting the whole genome sequencing (WGS) analysis. The quality, uniformity, and electrical properties of the prepared silicon thin films affect the performance parameters of the biochip. High-quality nanocrystalline silicon (nc-Si:H) thin film is the core technology in the biochip. High-density nc-Si:H thin films can be well prepared using 40.68 MHz VHFPECVD and post-treatment microwave annealing. Microwave annealing improves the crystallinity and reduces the defects in the nc-Si:H thin films discovered by Fourier-transform infrared spectroscopy (FTIR). The prepared thin film with a crystallinity of 5% enhanced 38.3%, surface roughness of 10.93 nm, and a photo/dark current of 7.1 × 103 with a power density of 60mW/cm2 was obtained. The biochip showed a recovery rate of 81.3%, purity of 78.6%, and survival rate of 91% for applying to the circulating tumor cells (CTCs).