Measurement of Light Sensitivity of Chromium/Porous Silicon Schottky Diodes Made by Silicon Nitride Masking

Schottky diodes created on a well-defined porous silicon active area are characterized to determine light sensitivity. The conventional Schottky diodes used the normal bulk n-type (or p-type) substrate to build the diode and to use a metal to form a junction called the Schottky junction. We can change the active area to porous silicon (pSi), in place of bulk silicon, we can take advantage of the shift in band. To create a well-defined device, silicon nitride is coated both on the front and back sides of the wafers, and using dry etching, the silicon nitride is selectively removed prior to pore formation. The devices are then metallized using chromium/gold, titanium/gold and tungsten/gold. Barrier heights were measured and then chromium/pSi samples were exposed to light at controlled temperatures.