| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon substrate controlled in the porosity, pore diameter, distribution width of the pore diameter in the porous silicon region and the shape of the porous silicon and a method for formation thereof relating to the silicon substrate selectively having the porous silicon within the substrate and a method for formation thereof. SOLUTION: This method for formation of the silicon consists in covering the silicon substrate 1 with a partly opened mask layer 3, immersing the substrate into a chemical conversion liquid and impressing chemical conversion current thereon and anodically chemical converting a part of the silicon substrate 1 from the removed part of this mask layer 3, thereby forming the porous silicon 10 to 11 to a band form within the silicon substrate. The chemical conversion current described above is increased according to the growth degree of the porous silicon in such a manner that the current density at the boundary between the front end of the growth of the porous silicon and the silicon substrate 1 in the process of the anodically chemical conversion is made nearly constant. |
