New RAM-bus Memory System with Interchip Optical Interconnection

A new optical RAM-bus (ORAM-bus) memory system has been proposed. The ORAM-bus memory has a number of optical interconnections to connect many memory chips. Data transfer using the guided optical interconnections is performed through the optical coupling flip-flop (OC-FF) circuit of the optical coupling sense amplifiers. The ORAM-bus memory test chips were fabricated using 2 µm complementary metal-oxide-semiconductor (CMOS) technology. The light-emitting diodes (LEDs) were successfully bonded onto the silicon test chips using the newly developed microbonding technology. The optical writing operation for ORAM-bus memory was demonstrated using the test chip.