Typical DLTS spectrum for majority carrier (hole) emission for as-grown MOCVD GaAs diode taken under reverse bias and filling pulse voltage . Measured emission rate signatures for the levels HM1 and HSA are shown in the inset.
-corrected Arrhenius plots of the deep level HM1 as obtained from DDLTS measurements at various junction electric fields. Arrow indicates direction of increasing field.
Pulse filling hole-capture data for the level HM1 after edge-region correction. Inset shows the raw data (points) used for the edge-region correction (straight line).
Temperature dependence of the hole capture cross section for the level HM1. The solid line shows the fit with multiphonon capture model, yielding a capture barrier of 0.11 eV and for the deep level, as indicated.
Variation of the concentration of deep level HM1 with alpha particle fluence. The straight line is the least-squares fit to the data.
Annealing behavior of the deep levels, HM1 (circles) and HSA (triangles). Solid symbols with solid lines exhibit the annealing behavior of the levels in unirradiated samples, while the open symbols with solid lines show the annealing behavior of the same levels in alpha irradiated samples.
Electric field-enhanced emission rate data for the level HM1 at different temperatures. The vs linear fit at higher fields indicates a phonon-assisted tunneling mechanism while the lower field data (inset) show a satisfactory fit with following the Poole–Frenkel mechanism.
Variation of characteristic time constant vs reciprocal temperature , showing a good linear fit to experimental data yielding a positive intercept and value of slope close to .
A comparison of emission rate signatures of the level HM1 with the previous reported signatures of the deep levels in the same temperature region. These signatures are taken from Refs. 1, 5–7, and 13 as indicated in the figure. All these signatures are within the spread of signatures of the level HM1 due to the electric field, as observed in this study.
Characteristics of the dominant level in MOCVD -GaAs (this work) and the well-known native defect, EL2, observed in our (-type) material as well as in literature.
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