SEMICONDUCTOR DEVICE

摘要

The purpose of the present invention is to provide a semiconductor device that can suppress device size shrinkage, reduction in series resistance, and leak current. The present invention ventures to insert into the device structure a layer that generates a difference in electric potential that was unnecessary conventionally for device operation. Even when a semiconductor with a small band gap is exposed on a mesa side surface, this difference in electric potential provides a function that can suppress the amount of drop in electric potential in that part and reduce leak current that is inconvenient for device operation. As a result, obtaining these effects is common to heterostructure bipolar transistors, photodiodes, electroabsorption optical modulators, and other devices. Furthermore, in photodiodes, leak current is relaxed; therefore the device size can be reduced. Not only is operating speed improved by reducing series resistance, but also the advantage of being able to dispose devices in a high density array form arises.