Semiconductor lasers on a silicon platform have attracted much attention due to the potential of integration with CMOS integrated circuits. Silicon Raman lasers have been demonstrated, however, they still require external optical pumps. Heteroepitaxy can grow compound semiconductor lasers directly on Si, but the growth temperature (> 400oC) is usually too high for post CMOS processing. To circumvent this issue, electrically-pumped compound-silicon hybrid lasers have been integrated on Si wafers utilizing oxygen plasma-assisted wafer bonding or DVS-BCB-assisted bonding techniques. The low bonding temperature (<300ÂºC) enables post-CMOS integration, however, the silicon layer to which the laser wafer bonds is buried under a thick stack of interconnect layers. Though bonding windows can be opened by etching, the nonplanar topography presents additional challenges for wafer bonding. Besides, low efficient usage of expensive epitaxial compound wafer raises the cost. Therefore, the long term goal of this project is to solve all these issues and achieve low-cost optical/microelectronic integrated circuits based on existing CMOS processes using a low temperature post-CMOS assembly technique.
Project end date: 08/11/09