Integrated Lasers on Different Surfaces
September 11, 2017 | A*STAREstimated reading time: 1 minute
Fabricating hybrid semiconductor lasers on materials other than the commonly used silicon-on-insulator (SOI) substrates has proved challenging. Now, A*STAR researchers have developed an innovative technique that can integrate the lasers on to a range of different materials.
Hybrid lasers combine the light-emitting properties of group III-V semiconductors like gallium arsenide and indium phosphide, with conventional silicon technologies, offering inexpensive photonic and microelectronic devices for application in optical telecommunication systems.
Their range of applications, however, is limited by the poor light-emitting characteristics of the silicon-on-insulator (SOI) wafers mostly used as substrates in the fabrication process. This spurred Doris Keh-Ting Ng and colleagues from the A*STAR Data Storage Institute to develop an innovative technique for bonding III-V lasers on to other substrates, be it silicon, quartz, or metal alloys.
By using an ultrathin layer of silicon oxide to bond the lasers to a silicon substrate, the researchers developed a simpler, safer and more flexible technique than direct bonding, which relies on chemical bonding between the surfaces.
“The challenge is to produce a smooth, extremely thin layer of silicon oxide on the surface of the substrate,” explains Ng. “By growing the film on the silicon substrate, but not on the III-V substrate, we greatly reduced the complexity of the process and improved the strength of the bond between the two materials.”
After first cleaning the surfaces with an organic solvent, the researchers exposed the surface to an oxygen plasma to increase its adhesive properties. They then initiated the bonding process at ambient temperature by bringing the two substrates slowly together, to reduce the air trapped between them, ensuring a much stronger bond.
The bonding was then completed at relatively low temperatures of around 220 degrees Celsius, allowing the ultrathin layer of silicon oxide to conduct heat between the layers, reducing potential damage to the materials, strengthening the bond and avoiding the need for hazardous chemicals, such as Piranha solution and hydrofluoric acid, used in direct bonding.
The work demonstrates a versatile on-chip laser that can be integrated on to any material platform and could lead to new applications for photonic devices, such as detector-on-chip and modulator-on-chip technologies.
“The low temperature interlayer approach is simpler and much safer than direct bonding, and means that laser manufacturers are not restricted by the choice of substrate,” says Ng.
The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute.
Suggested Items
Indium Corporation to Present, Exhibit at EPP InnovationsFORUM
03/28/2024 | Indium CorporationIndium Corporation is set to present and exhibit at EPP InnovationsFORUM, one of Europe’s premier single-day electronics manufacturing forums, on April 17 in Leinfelden-Echterdingen, Germany. Topic areas for 2024 will include AI, automation, sustainability, and quality.
Indium Corporation, Industry Partners to Showcase Products “Live@APEX”
03/26/2024 | Indium CorporationIndium Corporation®, in cooperation with its industry partners, will feature its proven solder solutions live on the show floor throughout IPC APEX Expo from Apr. 9‒11 in Anaheim, Calif., U.S.
Indium Corporation Experts to Present Throughout IPC APEX EXPO
03/18/2024 | Indium CorporationIndium Corporation’s leading technical experts are set to deliver and participate in a number of presentations and panel discussions throughout IPC APEX Expo, April 9-11, in Anaheim, Calif., U.S. Topics will include sustainability, assembly processes, and EV electronics.
Indium Corporation Celebrates 90 Years of Materials Science Innovation
03/13/2024 | Indium CorporationIndium Corporation will commemorate its 90th anniversary on March 13. Indium Corporation’s innovative products, especially its advanced soldering solutions, are found in many common consumer electronics and high-reliability technologies such as electric vehicles, mobile devices, life-saving medical devices, and emerging 5G technology to name just a few.
Indium Corporation to Showcase Proven EV Products and High-Reliability Alloys at Productronica China
02/28/2024 | Indium CorporationAs a materials pioneer and trusted partner in electric vehicle (EV) and e-Mobility manufacturing, Indium Corporation is proud to showcase its high-reliability alloys and soldering solutions at Productronica China, March 20-22, in Shanghai.