| N-Si channel array with high length/diameter ratio can be obtained by photoelectro chemistry etching , ohmic contact layer and inducing pit is required to be processed at the surface of a silicon wafer before electrochemistry etching. In this thesis, the two kinds of process which are diffussion and injection are applied in silicon surface treatment. Macro-si photoelectron chemistry etching is carried out. The I-V characteristic curves of the corresponding samples are measured. The effects of the different process procedures on the sample structures are contrasted and analysed. Taking these effects into account, the preparation technology of ohmic contact layer and inducing pit is optimized. Finally, diffusion technology is applied in fabrication ohmic contact layer and inducing pit. Metallurgical Microscopy and Scanning Electron Microscope(SEM) are used to observe the morphology of Macro-Si channel array. The effects of process parameters on photoelectron chemistry etching are demostrated. The electrochemistry eching parameters, such as light, corrosion voltage, corrosive liquid mixture ratio, surfactant, stirring, corrosion temperature, are optimized. The optimum corrosion conditions: light is LED(850nm infrared light); Corrosion voltage is 0.4V; the composition and ratio of etching solution is HF(150ml), C2H5OH(200ml), deionized water(2000ml), x-100(2.5ml-5.0ml); corrosion temperature is 23℃; precision timing bi-directional electric mixer. The stucture release methods of the various Si-micro channel array, including mechanical lapping, alkaline corrosion, chemically mechanically polish, slice, cleaning, reaming, laser-processed or drill-press-punched. Finally, the ideal transparent sample of Si-micro channel array is obtained after repeating experiments. |
