Fabrication of injection lasers utilizing epitaxial growth and selective diffusion

Claim 1

A method of making a double heterostructure injection laser of III-V material, the method including the steps of: forming by epitaxial growth a double heterostructure wherein an active layer of semiconductor material is sandwiched between upper and lower layers of higher band-gap semiconductor material, and wherein the upper layer is provided with a p-n junction dividing a lower part having the same conductivity type as that of the active layer and the lower layer from an upper part having the opposite conductivity type; growing a layer of semiconductor material of the opposite conductivity than that of the upper part on upper layer, thereby producing a p-n junction which restricts current flow upon being reverse biased during the operation of the laser; delineating a stripe on the upper surface of the semiconductive material; and diffusing through said stripe a conductivity type determining dopant of the type opposite that of the active layer and of greater mobility than that used in the provision of the three layers of the heterostructure until the region of the p-n junction underlying the stripe is translated downwardly halting at the heterojunction between the active layer and the lower layer.

Claim 2

A method of making a double heterostructure injection laser of III-V material, the method including the steps of: forming by epitaxial growth a double heterostructure wherein an active layer of semiconductor material is sandwiched between upper and lower layers of higher band-gap semiconductor material, and wherein the upper layer is provided with a p-n junction dividing a lower part having the same conductivity type as that of the active layer and the lower layer from an upper part having the opposite conductivity type; growing a layer of semiconductor material of the opposite conductivity than that of the upper part on upper layer, thereby producing a p-n junction which restricts current flow upon being reverse biased during the operation of the laser; delineating a stripe on the upper surface of the semiconductive material; and diffusing through said stripe a conductivity type determining dopant of the type opposite that of the active layer and of greater mobility than that used in the provision of the three layers of the heterostructure until the region of the p-n junction underlying the stripe is translated downwardly halting at the heterojunction between the active layer and the lower layer.