Office of Technology Transfer – University of Michigan

Direct growth of nanowire optoelectronic devices on silicon CMOS

Technology #6786

Semiconductor-based lighting and light sensors are growing in popularity as the need for smaller, lower power systems grow to fulfill demands from wireless sensor networks and implantable biosensors. However, a challenge remains in integrating optimal optoelectronic semiconductors such as GaAs with CMOS chip semiconductors based on silicon. Current integration methods essentially require creating two separate devices joined by complicated and expensive bonding steps that also increase packaging size. This challenge can now be solved using a new technology for growing nanowire-based optoelectronic devices directly on silicon CMOS chips.

Conducting polycrystalline film on CMOS allows low temperature nanowire growth

The process starts by sputtering a polycrystalline film such as indium tin oxide on a fabricated but un-packed CMOS device. III-V semiconductor nanowires such as GaAs can then be grown using molecular beam epitaxy. This process can be performed at or below 400°C to avoid damage to the CMOS device. Experiments demonstrated effective photoluminescence with doped and undoped samples. As the process is driven by the oxide layer, it can be extended to any substrate.

Applications

  • Integrated optoelectronics on silicon CMOS chips
  • Low cost optoelectronic devices

Advantages

  • Creates smaller devices than current methods
  • Reduces manufacturing steps and costs for integrating optical devices with logic circuits
  • Low temperature fabrication increases available applications
  • Method can be applied to any surface