Package, Process & Microassembly

Despite the widespread use of silicon photonics, fiber coupling remains a major challenge in mass production. Our group has demonstrated integrated microlens couplers (IMCs) as an efficient, broadband, and polarization-insensitive solution for wafer-scale fiber-to-chip coupling, with a previously achieved free-space loss of 0.6 dB.

In this project, we are transitioning from polymer-based to hard-material IMCs, fabricating microlens using SiON and utilizing anisotropic etching to transfer the lens pattern from PR to SiON. By optimizing the oxide-to-nitride ratio, we minimized...

We aim to develop a family of autonomous silicon-based robotic insects that integrate actuation, computation, and power within a single platform. A silicon-on-insulator (SOI) device serves as the foundation, enabling electrostatic actuators that drive silicon linkages fabricated directly in the device layer. Electrostatic actuation provides a key advantage at the microscale, offering low power consumption suitable for energy harvesting and autonomous operation. Computation and communication are enabled by the Single Chip Micro Mote (SCuM, BPN803), while a Zappy2 chip with integrated solar...

This paper introduces a microfluidics platform embedded within a silicon chip implemented in CMOS technology. The platform utilizes a one-step wet etching method to create fluidic channels by selectively removing CMOS back-end-of-line (BEOL) routing metals. We term our technique “subtractive” microfluidics, to complement those fabricated with additive manufacturing. Three types of structures are presented in a TSMC I80-nm CMOS chip: (1) passive microfluidics in the form of a micro-mixer and a 1: 64 splitter, (2) fluidic channels with embedded ion-sensitive field-effect transistors (ISFETs...

We are developing a new MEMS bonding process in which we use extremely carefully controlled resistive heating to make a solder bond with negligible substrate temperature rise and tighter temperature control than in laser bonding; we do this by using the temperature change of the heater resistivity as a temperature sensor for closed-loop control. Previously, we analyzed transient heat flow and showed initial progress toward heater control. Now, we have completed our theoretical analysis with a description of temperature fluctuations due to local inhomogeneities on the chip and how to...