Demonstration Of GaAs LEDs On Si Chips Using Epitaxial Liftoff

In this paper we report the integration of GaAs LEDs and Si circuits with very high yields (99.9%). This integration is possible based on a new technique called Epitaxial Lift-off ELO). This technique relies on the fact that a thin film of GaAs can be detached from its substrate and then attached on the top of a Si chips. Films as large as 5 cm by 1 cm showed no cracks and dislocations after they had been transferred on Si circuits by ELO. LEDs made of these films had no performance degradation compared to those that had not been lifted off. On the contrary, efficiency enchancements up to 36 times have been observed on reflective surfaces. The major advantage of EL0 is that Si circuits and GaAs LEDs can be optimized separately and then brought together without effecting the yield and the performance. It is a more reliable method than other monolithic integration techniques such as growth of GaAs on Si by MBE where material defects are still a major consideration. We believe that this integration technique is an important achievement towards the fabrication of reliable optoelectronic integrated circuits (OEICs).