Hybrid silicon lasers can be used to mass produce optics

The production of semiconductor lasers on silicon wafers has long been the target of the electronics industry, but the manufacturing process has proved extremely challenging. Now, researchers at A * STAR Research Institute have developed a new manufacturing method that is cheap, simple and scalable. Hybrid silicon lasers combine the luminescent properties of III-V semiconductors such as gallium arsenide and indium phosphide with proven silicon fabrication techniques. These lasers have received considerable attention as they can integrate photonic and microelectronic components into a single silicon chip for inexpensive, mass-produced optics. They have a wide range of applications, from short-range data communications to high-speed, long-distance optical transmission. However, in the current production process, lasers were fabricated on separate III-V semiconductor wafers and then individually aligned to each silicon device - a time-consuming and expensive process that limited the number of lasers on the chip. To overcome these limitations, Doris Keh-Ting Ng from A * STAR Data Storage Institute and colleagues developed an innovative method for producing mixed III-V semiconductor and silicon on insulator (SOI) optical microcavities. This greatly reduces the complexity of the manufacturing process and makes the device structure more compact. Bevel Scanning Electron Microscopy Image of a 500 nm Diameter Microdisc. Image courtesy of A * STAR Data Storage Institute "Etching the entire cavity is very challenging," Ng said. "At the moment, there is not a single etch recipe and mask that allows etching across the microcavity, so we decided to develop a new method." The III-V semiconductor films are first attached to a silicon oxide (SiO 2) wafer by first using an SOI interlayer thermal bonding process which results in a strong bond that eliminates the need for oxidizing agents such as piranha etchant or hydrofluoric acid . And by etching into the microcavities of the desired layer using dual hard mask technology, they eliminate the need to use multiple overlay lithography and etch cycles - a challenging process. Ng explains: "Our approach reduces the number of manufacturing steps, reduces the use of hazardous chemicals, and the process requires only one lithography step." For the first time, this work introduced a new heterogeneous nuclear configuration and integrated fabrication process that combines a low-temperature SiO2 interlayer bond with a dual hard mask, single lithography pattern. Ng said: "This process can not only produce heterogeneous nuclear devices, but also greatly reduce the manufacturing process is difficult, and can be used as another hybrid micro-cavity research."