Deep-Level Transient Spectroscopy of GaAs Nanoridge Diodes Grown on Si Substrates

Monolithically integrated $\mathrm{Ga}\mathrm{As}$ $p$-$i$-$n$ diodes are demonstrated on 300-mm $\mathrm{Si}$ $(001)$ substrates using a nanoridge-engineering approach. Deep-level transient spectroscopy (DLTS) is used to perform defect analysis for nanoridge and planar $\mathrm{Ga}\mathrm{As}$ diodes. The point defect, EL2 with ${N}_{T}\ensuremath{\simeq}3\ifmmode\times\else\texttimes\fi{}{10}^{14}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$, is observed for nanoridge $p$-$i$-$n$ diodes. A methodology is developed to extract the surface-state density (${N}_{\mathrm{SS}}$) directly from the DLTS spectrum. $\mathrm{Ga}\mathrm{As}$ nanoridge diodes show ${N}_{\mathrm{SS}}\ensuremath{\simeq}2\ifmmode\times\else\texttimes\fi{}{10}^{13}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ compared to planar diode approximately $6.5\ifmmode\times\else\texttimes\fi{}{10}^{12}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$. A clear correlation is observed between dark current and defect density. An investigation on the impact of an in situ and ex situ passivation layers on the leakage current reduction is performed for $\mathrm{Ga}\mathrm{As}$ $p$-$i$-$n$ diodes.