Epitaxial Liftoff and Grafting Technologies for Thin Film Placement

Epitaxial liftoff and grafting technology with photo lithographically-defined interconnects offer new approaches for the development of mult ichip module fabrication. Our approach facilitates improved thermalmanagement, testing, and packaging. As demonstrated already at TACAN Corporation, thin single-crystal semiconductor films can be produced by epitaxial liftoff technology. After grafting to a different substrate, the films which contain integrated devices can be used to improve several features of MCMs and the manufacturing process. Significant advantages of our unique approach are improved thermal management, higher density packaging, lower parasitics, in process testing and repair, applications to electronic mixed-signal and optoelectronic devices, lower manufacturin costs, and applications to flexible or nonplanar packages. Epitaxial liftoff technology can be used to separate the active epitaxial semiconductor layers from their mechanical support substrates. New methods of automated assembly and epitaxial film placement will be investigated. Photo lithographically defined patterned interconnects can be used with epitaxial films to provide electrical interconnection and interim testing as the MCM is assembled. These epitaxial device films can be then used to create polylithically integrated electronic or optoelectronic circuits. These circuits will merge the best qualities of monolithic and hybrid integration methods. The development of epitaxial liftoff and frafting technology will allow increased density of electronic integration by improved thermal dissipation and lead to improved in process testing of multichip modules and optoelectronic devices. It will also facilitate the development of emiconductor electronics and optoelectronics for flexible, nonplanr, or even packages of stacked integrated circuits.