Method of making surface-normal semiconductor optical cavity device
AssigneeAT&T Corp.
InventorKeith W. Goossen
Life of this patent
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Abstract
A multi-layer mirror structure included in a surface-normal semiconductor optical cavity is fabricated in a deposition reactor dedicated to that purpose alone. Additional layers of the device are subsequently deposited on top of the mirror structure in a second reactor. In practice, the dedicated reactor produces layers whose thickness variations over their entire extents are considerably less than the thickness variations of layers made in the second reactor. This coupled with the fact that the actual achieved thickness of the mirror structure can be conveniently measured before commencing deposition of a prescribed thickness of the additional layers makes it possible to fabricate a specified-thickness optical cavity within tight tolerances in a high-yield manner.
Claims11
A method for fabricating a semiconductor optical cavity device that includes at least one multi-layer mirror structure that consists only of undoped layers, said method comprising the steps of
- in a first reactor adapted to deposit only undoped layers whose thickness variations over their entire extents are less than the thickness variations over their entire extents of layers deposited in a second reactor, successively depositing the undoped layers that constitute said mirror structure, at least some of the layers of said mirror structure being included in the overall thickness of the optical cavity of the device,
- and, in said second reactor, successively depositing undoped and doped layers that constitute the remainder of the thickness of said optical cavity,
- wherein each of the layers deposited in said first reactor is characterized by thickness variations over its entire extent that are less than the thickness variations of layers deposited in said second reactor.
Dependencies are inferred from the claim text.