Semiconductor device with current confinement structure

摘要

The present invention relates to a semiconductor device (1) with one or more current confinement regions (20) and to a method of manufacturing such a device, particularly buried heterostructure light emitting devices such as semiconductor lasers and light emitting diodes. The device comprising a doped semiconductor substrate (2) of a first conduction type, a buried heterojunction active layer (10) above the substrate (2), a current conduction region (4) above the active layer (10), one or more current confinement regions (20) formed over the substrate (2) adjacent the active layer (10), the current conduction region (4) and current confinement region (20) being arranged in use to channel electric current to the active layer (10). Each current confinement region (20) includes a reverse-biased diode junction (9;119) current blocking structure (17,18), and between said structure and the substrate (2) a graded second conduction type current blocking layer (7;107) in contact with the reverse-biased diode structure. The graded second conduction type current blocking layer (7,107) has a dopant concentration that falls from the reverse-biased diode structure (17,18) towards the substrate (2). <IMAGE>