20nm SiNWs transducers have been fabricated by means of simple in-house fabrication method. A low cost, simple top-down
approach has been successfully used for the fabrication of very sensitive SiNWs. The fabrication was done without using costly deep reactive
ion etching (DRIE) or reactive ion etching (RIE). The process started by patterning wire marked through photoresist and the
marked resist was deepened into buffered oxide etch (BOE) for 30mins to etch away the oxide present on the polysilicon surface leaving
the photoresist masked portion un etched. Wires of <3µm were obtained with 6 buffered thermal re-etch processes. The wire pattern was
trimmed to 20nm using dry etching with constant 5% reduction at 1100°C for 40/5 minutes for Oxidation/BOE respectively. Electrical
characterization conducted has shown an increase in sensitivity with the reduction in size while resistance increases at constants 70V
supply, the characterized device was surface modified and tested on real sample. The device shows a very good response to the concentration
of molecular species in the sample and surface morphology of the device was verified using high powered microscope (HPM) and
scanning electron microscope (SEM) for the size reduction. Moreover, the technique can be easily employed for different semiconductor
materials without any additional complexity. Hence, a novel and simple approach for fabricating SiNWs as sensors in nanosized with
high uniformity is demonstrated.
Keywords: Fabrication, Lab on chip, RIE, Characterization, HPM, ASEM, Buffered thermal re-etch.
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Published on: 30 June, 2013
Page: [543 - 551]