On the fabrication and characterization of amorphous silicon ultra-violet sensor array

In this work we present the design and fabrication of a 16 × 16 ultraviolet sensor array, deposited by Plasma Enhanced Chemical Vapor Deposition on glass substrate, suitable for label-free DNA parallel analysis. Each pixel is constituted by two back-to-back series connected coplanar amorphous silicon/amorphous silicon carbide n–i–p diodes. One junction acts as photosensor (with 1.4 × 1.8 mm2 area) and the other as switching diode (with 200 × 200 µm2 area).The array performances have been optimized as a trade-off between the competitive requirements of the photosensor and of the switching element that have the same n–i–p stacked layers, since they have been deposited during the same deposition run. A responsivity around 60 mA/W in the ultraviolet range and an ON/OFF dark current ratio of six orders of magnitude have been achieved for the photodiode and the switching element, respectively.