Fig. 5: Grayscale nanostructures fabricated using a-PEC etching on undoped GaAs wafers.
From: Anomalous photoelectrochemical etching of undoped semiconductor surfaces
a The spiral with decreasing light intensity from the center outward. b The logo “HUST” (Huazhong University of Science and Technology). c The concentric ring structure separated by two vertical lines. d The grayscale panda-like structure. e The in-house developed holographic lithography system. f The simulated 200 pixels phase mask for holographic imaging. g The fabricated 200 pixels phase mask for holographic imaging. h The holographic imaging results of the 200 pixels phase mask. i The simulated 500 pixels phase mask for holographic imaging. j The fabricated 500 pixels phase mask for holographic imaging. k The holographic imaging results of the 500 pixels phase mask.
