Fluidic self assembly process integrates VCSELs onto silicon wafers

Optoelectronic integrated circuits (OEICs) incorporating vertical-cavity surface-emitting lasers (VCSELs) are attractive devices for many applications. The lasers have low threshold currents and high wall-plug efficiencies and can easily be fabricated into two-dimensional arrays. To create OEICs easily, however, the VCSELs need to be integrated with silicon circuitry.

Fluidic self assembly process integrates VCSELs onto silicon wafers

Optoelectronic integrated circuits (OEICs) incorporating vertical-cavity surface-emitting lasers (VCSELs) are attractive devices for many applications. The lasers have low threshold currents and high wall-plug efficiencies and can easily be fabricated into two-dimensional arrays. To create OEICs easily, however, the VCSELs need to be integrated with silicon circuitry.

Researchers at the University of California at Berkeley adopted a fluidic self-assembly process, in which devices are grown on GaAs substrates and fabricated into trapezoidal blocks that are freed from the substrate into a carrier liquid, to place 980-nm InGaAs VCSELs onto silicon wafers by dispensing the solution over a wafer that has corresponding holes etched into it. Their planar process includes device isolation, bonding, and contacting, giving it advantages over other technologies such as epitaxial liftoff, because precise alignment is not necessary. Further work optimizing the device structure and fluidic self-assembly process is underway. The researchers expect that selective oxidation will improve the device structure.

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