Selective formation of porous layer on n-type InP by anodic etching combined with scratching

The cross section of porous layer on the scratched area perpendicular to the [1¯10] or [1 1 0] scratching direction had a V-shape, while the cross section of porous layer on the scratched area parallel to the [1¯10] or [1 1 0] scratching direction had a band structure with stripes oriented to the [1¯11] or [11¯1] direction. Moreover, nano-scratching at a constant normal force in the micro-Newton range followed by anodic etching showed the possibility for selective formation of porous wire with a nano-meter width.