Fluidic Assembly of Thin GaAs Blocks on Si Substrates

We have studied the fluidic assembly technique for heterogeneous integration. In this technique, small device blocks, the size of which ranges from a few tens of microns to a few hundreds of microns, can be assembled into the recesses formed on the Si substrate. First, we used thin disk-shaped GaAs blocks to study the fundamental process of the fluidic assembly. A 100% yield was achieved with an appropriate strength of sonic vibration. The assembled blocks were confirmed to have no strain by using Raman scattering spectroscopy even if they were annealed at 320°C for 30 min. In addition, the effects of the shape of blocks are discussed based on the experimental results for disk- and square-shaped blocks.