Integration of Ultrathin Device Utilizing Capillary Force and a Magnetic-Field-Based Pick-and-Place Method

In this paper, we present a heterogeneous integration of ultrathin III-V semiconductor devices onto a silicon-based host substrate using fluidic self-assembly (FSA) and magnetic-field-based pick-and-place technique. With a thin nickel layer in device metallization step, ultrathin devices can be picked up by a properly magnetized needle tip. This also provides the transportation and coarse alignment of the devices onto their binding sites of a host substrate. Due to the capillary force in FSA, devices can be released from the needle tip enabling the precise self-alignment of thin-film devices onto the binding sites. A thin-film low-temperature grown GaAs inverted metal-semiconductor-metal (MSM) photodetector (PD) was successfully integrated onto a SiO
₂
/Si substrate using the proposed integration method. Dark current and photocurrent of the integrated PD were measured to verify the electrical contact between the thin-film device and its host substrate. With the help of advanced automation/robotics strategies, the proposed integration method can be further developed to offer efficient integration and compatibility required for multi-material/functional hybrid microsystems.