Infrared led device with isolation and method of making

A method of making an infrared LED device;

• providing a first substrate;
• using molecular beam epitaxy, growing a quantum well structure comprising alternating active and injection regions on the substrate;
• growing a thin p-type layer on the quantum well structure;
• etching the mesa area down to the substrate to form a plurality of mesas, each mesa being separated by a separation region of approximately 50 to 100 microns;
• each mesa being from approximately 25 to 500 microns;
• forming electrical contacts;
• deep etching to isolate each of the mesas;
• deposit first indium contacts on the upper surface of the mesas;
• provide a second substrate;
• forming electrically conducting lines and pads;
• deposit second indium contacts on the upper surface of the gold pads;
• bonding the fanout silicon substrate and the GaSb mesa structure such that first indium contacts are in contact with the second indium contacts.

A method of making an infrared LED device;

• providing a substrate;
• using molecular beam epitaxy, growing a quantum well structure comprising alternating active and injection regions on the substrate;
• growing a thin p-type layer on the quantum well structure;
• etching the mesa area down to the substrate to form a plurality of mesas, each mesa being separated by a separation region of approximately 50 to 100 microns;
• each mesa being from approximately 25 to 500 microns;
• using photolithography to make a pattern for anode and cathode contacts;
• etching the silicon nitride layer using dry etching;
• depositing gold metal by electron beam evaporation technique to form the anode and cathode contacts;
• deep etching (approximately 20 microns) to form a trench around the mesas for mechanical stability to form a GaSb mesa structure;
• deposit first indium contacts (approximately 5-10 microns) on the upper surface of the mesas;
• provide a silicon substrate;
• deposit silicon dioxide on the substrate;
• using a photolithographic technique, depositing gold metal to form gold metal lines and pads;
• deposit second indium contacts (approximately 5-10 microns) on the upper surface of the gold pads;
• flip-chip bonding the fanout silicon substrate and the GaSb mesa structure such that first indium contacts are in contact with the second indium contacts;
• applying epoxy in the separation regions;
• curing the epoxy at approximately 70 to 100 degrees Celsius for one to two hours;
• removing a portion of the GaSb layer (up to approximately 475 microns to leave approximately 25 microns;
• chemical etching the remaining 25 microns to isolate the mesas.