A method for inspecting a grating biochip comprises the steps of
irradiating a grating biochip using a light beam, measuring a diffracted
light using a photodetector, selecting a plurality of parameters of the
grating biochip, and optimizing the parameters to enhance the detection
sensitivity, wherein the diffracted light is generated by the light beam
passing the grating biochip. The grating biochip comprises a grating
structure including a semiconductor substrate, a grating positioned on
the semiconductor substrate and a dielectric layer covering the grating
and the semiconductor substrate. The sample of the biochip is positioned
on the grating structure.