Why deterministically implant ions?

Many quantum devices are based on single impurity atoms (or defects) in a solid-state host. These single impurity atoms/defects must be positioned with ~nm precision. When done accurately, these atoms/defects can be used as qubits, which exhibit long coherence times, CMOS compatibility and scalability. To do this successfully at scale, we require a level of spatial and fluence control that conventional ion implantation does not offer.

Deterministic Requirements :

Spatial precision

  • Beam spot size 1
  • Device alignment 1
  • Patterning 1
  • Implant straggle 2

Number precision

  • Poisson statistics 3
  • Detection efficiency 3

1 Largely solved with conventional FIB technology.
2 Well understood but little to no control for given ion species, target material and energy.
3 New issues to address for reliable single ion implantation

The SIMPLE implanters:

  • Deterministic Ion Implantation facility
    SIMPLE – Single Ion Multispecies Positioning at Low Energy
  • “Q-one” by Ionoptika
  • Based on focused ion beam
  • Engineered for quantum devices
  • 2 tools 🡪 2 different ion sources
  • Liquid metal (alloy) ion source
  • Duoplasmatron source for gases

 

Main features:

  • Versatile to multiple ion species
  • 10-25 kV sub-surface implantation
  • Isotope selection – mass filtering
  • fA-nA beam currents
  • High spatial resolution ~10-100 nm
  • Single ion detection
  • UHV