Process for passivating semiconductor laser structures with severe steps in surface topography
AssigneeLucent Technologies Inc.
InventorsRobert Benedict Comizzoli, Mindaugas Fernand Dautartas, John William Osenbach
Life of this patent
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Abstract
The specification describes a process for passivating semiconductor laser structures with severe steps in the surface topography. The technique involves atomic layer deposition to produce the passivating layer which has exceptional coverage and uniformity, even in the case of trench features with trench aspect ratios as large as 5. In addition, the passivation produced by this process has excellent environmental stability, and affords protection against air born contaminant induced degradation.
Claims17
A process for the manufacture of a semiconductor laser comprising the steps of:
- a. forming a layered semiconductor laser structure,
- b. etching said layered semiconductor structure to form a trench along a portion of the layered structure, said trench having a depth at least three times the width, and
- c. coating said etched semiconductor structure with a passivating coating of a passivating compound by the steps of
- i. mounting the etched stacked semiconductor structure in a vacuum chamber,
- ii. evacuating the chamber to a pressure in the range of 1-50 mbar, heating the stacked structure to a temperature in the range 100.degree. C. to 400.degree. C.,
- iii. admitting at least two precursor gases into the chamber in alternate steps, said alternate steps comprising a first step of admitting a flow of a first of said precursor gases, said first of said precursor gases consisting of a source of one part of said passivating compound and a second step of admitting a flow of said second of said precursor gases, said second of said precursor gases comprising a source of an oxidizing agent to form said passivating compound, and continuing to alternate between step one and step two for at least 1000 cycles to produce the desired conformal passivating layer.
A method for the manufacture of an optical device assembly in which the optical device assembly comprises at least one multilayer laser device having a surface topography that includes at least one step feature, said laser device being mounted on a mounting means and additionally including electrical leads for electrically contacting said laser, THE INVENTION CHARACTERIZED BY forming on said optical device assembly a conformal passivating coating by steps comprising:
- a. mounting the optical device assembly in a vacuum chamber,
- b. evacuating the chamber to a pressure in the range of 1-50 mbar,
- c. heating the stacked structure to a temperature in the range 100.degree. C. to 400.degree. C.,
- d. admitting at least two precursor gases into the chamber in alternate steps, said alternate steps comprising a first step of admitting a flow of a first of said precursor gases, said first of said precursor gases consisting of a source of the organometallic precursor of said passivating compound and a second step of admitting a flow of said second of said precursor gases, said second of said precursor gases comprising an oxidizing agent, and continuing to alternate between step one and step two for at least 1000 cycles to produce the desired conformal passivating layer.
Dependencies are inferred from the claim text.