多孔硅层湿法腐蚀现象的研究

Study of porous silicon layer treated with wet etching techniques.

阳极氧化法制备的多孔硅层分别经 1% HF、 1% NH3 / H2 O2 和 0 .0 5 % Na OH三种溶液在室温下进行湿法腐蚀 ,并用傅里叶变换红外光谱 (FTIR)和扫描电子显微镜 (SEM)对其变化进行了研究。腐蚀后多孔硅的表面形貌出现明显的刻蚀现象。红外吸收光谱表明 ,在用 1% NH3 / H2 O2 溶液腐蚀时 ,多孔硅层中 Si- O键和 Si- H键的强度增加 ,H- O键的强度下降 ;用 1% HF溶液和 0 .0 5 % Na OH溶液的腐蚀结果正好相反。 0 .0 5 %Na OH溶液对多孔硅层的腐蚀现象类似于强碱性溶液对单晶硅腐蚀表现出的各向异性 ,对多孔硅层厚度的腐蚀速度比 1%

In Chinese. As-prepared p-type porous silicon (PS) layers treated with wet etching techniq ue s are investigated by means of FTIR and SEM. FTIR show that both Si-O bond co nt ent and H-O bond content increase but Si - H bond content decreases when PS la ye rs treated with 1%NH_3/H_2O_2 solution. The contrary, results are obtained a s treat ed with 0.05%NaOH and 1%HF solution. The surface and cross section morphology of PS layers indicate that the rate at which PS layer is etched out in 0.05%NaOH s olution is higher than in 1%HF solution, and PS layer show anisotropic etching p henomena which is similar to that when wafer of single crystalline silicon treat ed with alkaline solution. (16 refs.)