光电化学腐蚀条件对多孔硅阵列的影响

Effect of Photo-electrochemical Etching Method on Porous Silicon Arrays

采用光电化学腐蚀的方法在腐蚀电压为1.3 V,腐蚀液配比为HF(40%):C2H5OH(99%):H2O=1:7:1(体积比)和卤素灯为光源的条件下获得了结构整齐、孔道均匀的多孔硅阵列。研究表明,随着电压的增大,孔壁侧蚀严重,孔壁有分叉现象;随着HF浓度的增加,制备的多孔硅阵列孔深增加,腐蚀速度增加;光源的不同会导致孔道内部均匀程度的不同。最后得出了最佳的刻蚀参数条件,得到了长径比大于50,孔道结构外壁均匀光滑的多孔硅阵列。

The porous silicon array with orderly structure and uniform channels was obtained by photochemical etching with a corrosion voltage of 1.3 V, a corrosion solution ratio of HF(40%):C2H5OH(99%):H2O=1:7:1(volume ratio) and a halogen lamp as the light source. The results showed that with the increase of voltage, the holes wall had serious side erosion and bifurcation. With the increase of HF concentration, the holes depth and corrosion rate of the prepared porous silicon were increased. The different light source will lead to the different degree of uniformity inside the channel. Finally, the optimum etching parameters were obtained, and a porous silicon array with aspect ratio greater than 50 and a uniform and smooth outer wall of the channel structure was obtained.