SI BAND-GAP SHRINKAGE CAUSED BY LOCAL STRAIN AT SI/SIO2 EDGE

This letter describes Si band-gap shrinkage caused by local strain at the local oxidation of silicon (LOCOS) edge. The local band-gap shrinkage of 20-30 meV is shown to exist at the LOCOS edge by measuring the forward-biased junction current of square n+ regions on a p substrate for various junction sizes. The junction current is observed to be proportional to the peripheral length rather than the area of the square n+ regions at liquid-nitrogen temperatures. It is also likely that the shrinkage would degrade the current gain of bipolar transistors, especially at low temperatures.