RF Gan wafers for GaN-on-Si applications

RF Gan wafers for GaN-on-Si applications tailored on customer needs

Okmetic has succeeded in creating tailor-made products also for GaN-on-Si applications. Okmetic’s customized silicon substrates with special crystal material facilitate growing of high-quality gallium nitride (GAN).  Okmetic has carried out silicon parameter optimization in close co-operation with several industrial players, utilizing all the widely used GaN production processes. 

The tailored substrate simplifies the epitaxial process setup, tuning and ramping-up to production. Full wafer shape analysis is available as part of the substrate tailoring. Used in conjunction with in-situ wafer monitoring the shape analysis enables systematic refinement of the deposition control loop.

Okmetic has further developed optimized BSOI substrate for power electronics applications. GaN layers grown on SOI substrates exhibits lower stress and higher crystalline quality according to x-ray diffraction than the layers grown on standard silicon substrates. 

With these substrates high electron mobility transistors (HEMTs) on GaN-on-SOI combined with trench isolation reduce parasitic inductance and die size.

RF Gan wafer specs and benefits

  • Available in 150 and 200 mm wafer sizes
  • Tailored to match the demanding GaN epi needs
  • High Resistivity: P-, up to ≥ 7000 Ohm-cm resistivity with suitable Oi control, balancing in between the resistivity stability and lattice integrity.
  • On-orientation <111> with tight orientation control. Competing High Resistivity FZ material is very hard to make in <111>.
  • Custom wafer thickness options for reducing wafer bow and warpage (150mm up to 1300µm, 200mm up to 1500µm).
  • Poly and LTO options for the back surface for further stress management
  • Also Double Side Polished wafer available, if needed.
  • SOI based wafer for advanced GaN-on-Si structures

Source: GaN-on-Si HEMTs for wireless base stations - ScienceDirect