MRI: Acquisition of a Micro-Transfer Printer for Heterogeneous Integration of Electronic/Photonic Microsystems

Micro-transfer printing (µTP) is a recently developed technique that enables the integration of various micro-device technologies that cannot be easily manufactured on a common substrate. For example, laser light sources could be integrated onto a silicon photonics chip rather than fiber coupled. This proposal requests funds for the acquisition of an X-Celeprint (XDC) µTP system well suited for research and development, and prototype fabrication, with the capability of seamless technology transfer to pilot-line or high-volume production using larger XDC automated systems.

The proposed instrument will support next-generation research activities in technology areas such as display devices, computing, energy conversion, quantum photonics, 2D materials, and biosensors. Results from the supported research will provide significant contributions to the literature in relevant and emerging scientific fields. Participants will include graduate and undergraduate student researchers in several disciplines of engineering and science, with a particular emphasis on diversity and inclusion.

The proposed investigations will advance scientific knowledge and support activities that contribute to the betterment of society. These include preparing a diverse workforce for next-generation engineers and scientists, outreach activities with K-12 programs in the Rochester, NY region to promote STEM, and professional development opportunities for high school teachers and industry partners.

Heterogeneous integration involves the combination of separately fabricated micro-devices (e.g., transistors, LEDs, sensors) or device components (e.g., interface layer, porous membrane) at the pre-package stage. The µTP system uses an elastomer stamp typically made of polydimethylsiloxane (PDMS), which is deformable and surface-compliant, transparent, and adhesive; all characteristics needed to transfer devices with precise alignment.

The devices must be singulated and released using an undercut etch of sacrificial material, yet still anchored to the source substrate with one or more tethers at the perimeter. Sacrificial release layers are engineered such that tethers will be overcome by the pickup force, which allows device coupons to be removed from their native substrate. The stamp adhesion is pull-rate sensitive, or kinetically modulated, allowing it to remove anchored or tethered devices using a high pull-rate, and release the same device onto a destination substrate using a low pull-rate.

The formation of local electrical/optical interconnects between mixed-technology devices in close proximity allows them to interact at an intimate level, realizing microsystems that are otherwise not possible. The investigators propose to utilize the µTP system for the heterogeneous integration of device components in several areas of research. These are listed (with specific applications) as follows: Silicon CMOS and thin-film electronics (backplane platforms, back-end devices); display devices (III V and III N micro-LEDs); photovoltaics and power conversion (III V multi junction cells); integrated photonics (lasers, electro-optic materials, modulators); quantum integrated photonics (quantum emitters, single photon detectors, photonic cavities); mixed-dimensional hybrid nanosystems (III-V devices on 2D monolayers); nanoporous biodevices (electrode transfer, sensor arrays).

The µTP system will enable the realization of “monolithic-like” microsystems, with associated advantages in electronic/photonic system performance.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.