Passivation of semiconductor laser facets

A method of forming and passivating faces of an edge-emitting semiconductor optical device prior to reflective deposition, the method of forming and passivating comprising the steps of:

• cleaving along said faces in ambient air for separating a compound semiconductor substrate into at least one chip having opposed air-cleaved facets between which runs an optical waveguide structure for Generating light at an operating wavelength;
• forming a native oxide layer on said opposed air-cleaved facets from oxidation of said facets with said ambient air;
• placing said chip into a vacuum processing system;
• removing said native oxide layer from each of said facets and hydrogenating said air-cleaved facets by applying hydrogen in said vacuum processing system to form hydrogenated facets;
• applying silicon in said vacuum processing system for hydrogenating silicon with said hydrogen to form hydrogenated silicon;
• and
• coating each of said hydrogenated facets directly with a respective passivation layer of hydrogenated amorphous silicon from deposition of said hydrogenated silicon, wherein the molecular hydrogen is directly bonded to the silicon atoms for providing transparency at said operating wavelength, said coating step being performed after said removing step without between said two steps exposing said chip to a partial pressure of oxygen of greater than a maximum background pressure amount in said vacuum processing system.

A method of forming and passivating faces of an edge-emitting semiconductor optical device prior to reflective deposition, the method of forming and passivating comprising the steps of:

• cleaving along said faces in ambient air for separating a compound semiconductor substrate into at least one chip having opposed air-cleaved facets between which runs an optical waveguide structure for generating light at an operating wavelength;
• forming a native oxide layer on said opposed air-cleaved facets from oxidation of said facets with said ambient air;
• removing said native oxide layer from each of said facets while said facets are exposed to ionized hydrogen having a low energy level in a vacuum processing system and hydrogenating said air-cleaved facets to form hydrogenated facets;
• applying silicon in said vacuum processing system for hydrogenating silicon with said hydrogen to form hydrogenated silicon;
• and
• coating directly each of said hydrogenated facets with a respective passivation layer comprising hydrogenated amorphous silicon from deposition of said hydrogenated silicon wherein the molecular hydrogen is directly bonded to the silicon atoms for providing transparency at said operating wavelength.

A method of forming and passivating faces of an edge-emitting semiconductor optical device prior to reflective deposition, the method of forming and passivating comprising the steps of:

• cleaving in ambient air a compound semiconductor substrate along said faces into at least one chip having opposed air-cleaved facets between which runs an optical waveguide structure for generating light at an operating wavelength;
• forming a native oxide layer on said opposed air-cleaved facets from oxidation of said facets with said ambient air;
• placing said cleaved substrate into a vacuum processing chamber;
• flowing hydrogen through an electron cyclotron resonance (ECR) source into said chamber to form a low energy hydrogen plasma in said chamber at around 1-20 eV.;
• continuing said flowing step a sufficient time to clean said facets through removing said native oxide layer from each of said facets and hydrogenating said air-cleaved facets to form hydrogenated facets;
• after said sufficient time, sputtering a target comprising silicon in said chamber while continuing said flowing step to form an a hydrogenated amorphous silicon layer directly on said hydrogenated facets through deposition of hydrogenated silicon, wherein the molecular hydrogen is directly bonded to the silicon atoms for providing transparency at said operating wavelength.