Photolmninescence pre-screening of LEC semi-insulating GaAs substrates for the potential backgating performance of MESFET circuits

The backgating characteristics of oxygen implant isolated, self aligned gate metal-semiconductor field effect transistors (MESFETs) have been correlated with the high spatial resolution, room temperature, scanning photoluminescence (sPL) maps of the LEC semi-insulating (SI) GaAs substrates upon which they were fabricated. Wafers from those boules that backgate strongly exhibit larger sPL contrast between dislocation cell walls and the cell interiors than those that backgate less severely. A model is proposed to explain the correlation, linking the non-radiative recombination center detected by sPL with the hole trap which is associated with the occurrence of backgating.