STR Software for Different Stages of UV LED Design and Production

Reactor-scale modeling of Al(Ga)N epitaxy with account for effects specific for the growth of Al-rich layers. Typical software applications include:

  • Improvement of reactor productivity and precursor utilization efficiency;
  • Achieving higher thickness and composition uniformity;
  • Mitigating intrinsic carbon doping;
  • Scale-up and process transfer

Modeling of stress, bow, and dislocation dynamics with STREEM AlGaN – specialized software tool for self-consistent modeling of the evolution of epitaxial stress, bow, and dislocation dynamics during the growth and cooling of (0001) III-Nitride heterostructures by MOCVD on silicon, sapphire, SiC, GaN and AlN wafers.

Bandgap engineering of UV heterostructures with SiLENSe:

  • Development of underlayer (UL) for injection improvement. Example: in Li et al., Semiconductor Sci. Technol. 30, 125012 (2015) SiLENSe was used to study the effect of n-AlGaN underlayer on operation of MQW DUL LED. The revealed information on the underlying mechanism was used to build the improved version of the device and compare it to the baseline design in a series of experiments.
  • Optimization of electron blocking layer (EBL). Example: in the works by F. Mehnkle at al., simulations by SiLENSe software demonstrated: inefficient operation of EBL caused by polarization charges as well as correlation between observed parasitic p-side luminescence and EBL parameters controlling the band alignment in the LED structures. Performed optimization of the AlN electron blocking layer (EBL) enabled the increase of the quantum well emission power, significant reduction of long wavelength parasitic luminescence, and suppression of electron leakage  by optimizing the thickness of the AlN EBL, see F. Mehnke et al., Appl. Phys. Lett. 105, 051113 (2014), and Appl. Phys. Lett. 117, 195704 (2015)
  • Polarization doping. Example: utilization of distributed polarization doping for improvement of p-type conductivity in AlGaN, see Yu. Karpov, Proc. SPIE 7939, 79391C (2011), and O. V. Khokhlev et al., Phys. Stat. Solidi A 210, 1369 (2013)

Simulation of current spreading, self heating, and light extraction in UV LED chip with SpeCLED and RATRO