EPROM high-speed erasing scheme

We report a technique for erasing an EPROM using the output from a Cu II laser at 2600 Å. By focusing the laser output on a portion of the chip, reliable erasure of a selected number of memory locations is obtained with an exposure time of approximately 35 ms. With the entire chip illuminated by the unfocused laser output, all memory locations are erased after an exposure time of several seconds. This method affords both high-speed and selective erasure of EPROM memory locations.