Fabrication of MSM photoconductor on porous Si using micromachined silicon mask

An MSM photoconductive detector has been fabricated from porous silicon using a micromachined silicon mask instead of photolithography. This approach allows damage to porous silicon that can be caused by chemical processing to be avoided. The interdigitated pattern of the silicon mask with a finger spacing of approximately 150 mu m and finger width of 50 mu m was made using silicon micromachining. The fabricated MSM porous silicon photoconductive detector, which exhibits responsivities of better than 0.5 A/W at the wavelength of the He-Ne laser (6280 AA) and a dark current of 950 nA at 10 V, is very promising as an optoelectronic device.