Electric field directed assembly of an InGaAs LED onto silicon circuitry

In this letter we demonstrate an electrophoretic process for assembling ver y small devices on a silicon circuit. A 20-mu m diameter InGaAs LED was fab ricated and then released from the substrate by etching a sacrificial layer underneath the diode structure. The diode, placed into a buffer solution o ver the silicon circuit, was positioned onto the circuit's tin/lead contact electrodes by biasing the contacts to establish. an electrophoretic curren t in the buffer solution, Following removal from the buffer solution, the a ssembly was heated to reflow the solder, Circuit formation and LED activati on is demonstrated by forward biasing the LED using the silicon circuit's c ontacts.