In this paper, an a-Si solar cell using metallic fishnet nanostructures simultaneously as Schottky contact and light trapping structures is presented. The photogenerated carrier could be collected more efficiently when the metal line spacing is engineered to be less than minority carrier diffusion length. Since no heavily doped regions are used in the device, the Shockley-Read-Hall recombination saturation current density could be two orders of magnitude lower than that of p-i-n a-Si solar cell, which will substantially reduce the device loss. The fishnet structure design is optimized through numerical simulation. Improved light absorption inside intrinsic a-Si layer is observed, especially at the wavelength of 632 nm. The detailed device fabrication results are presented.