LONG WAVELENGTH VCSEL WITH TUNNEL JUNCTION AND IMPLANT

摘要

A vertical cavity surface emitting laser (VCSEL) (10) having a tunnel junction (14) and emitting long wavelength light (i.e., 1200 to 1800 nanometers, though it is contemplated that the structures and techniques are applicable to other wavelength VCSELs). The tunnel junction (14) may be isolated with an implant (21) down into the top mirror (15) through the tunnel junction (14) and p-layer (13) and a trench (19) around the VCSEL (10) down to at least past the tunnel junction (14). The trench may result in reduced capacitance and D.C. isolation of the tunnel junction (14). The implant (21) is performed after the trench (19) is made. Some of the implant (21) may enter the bottom of the trench (19) into the bottom mirror (11) for some further isolation for the tunnel junction (14) of the VCSEL (10). Further isolation and some current confinement may be provided with lateral oxidation (23) of a layer (13) below the tunnel junction (14). Internal trenches (33) may be made from the top of the VCSEL (10) vertically down to the oxidizable layer (13) below the tunnel junction (14). Oxidation of that layer via these trenches (33) may provide further isolation of the tunnel junction (14). Also, a bonding pad (29) connected to a contact (16) on the VCSEL (10) with a bridge (31) may have an open trench (19) about their periphery for their isolation. Internal trenches (34, 35) may be placed on the pad (29) and its bridge (31) that go down vertically to the oxidizable layer (13). Oxidation via these trenches (34, 35) may provide further isolation for the pad (29) and bridge (31) if the latter is present.