%0 Journal Article %1 8401800 %A Das, B. %A Schulze, J. %A Ganguly, U. %D 2018 %J IEEE Transactions on Electron Devices %K iht j.schulze.iht journal %N 8 %P 3414-3420 %R 10.1109/TED.2018.2846360 %T Transient Phenomena in Sub-Bandgap Impact Ionization in Si n-i-p-i-n Diode %U https://ieeexplore.ieee.org/document/8401800/ %V 65 %X Sub-bandgap (SBG) impact ionization (II) enables steep subthreshold slope that enable devices to overcome the thermal limit of 60 mV/decade. This phenomenon at low voltage enables various applications in logic, memory, and neuromorphic engineering. Recently, we have demonstrated sub-0.2-V II in n-i-p-i-n diode experimentally primarily based on steady-state analysis. In this paper, we present the detailed experimental transient behavior of SBG-II in n-i-p-i-n. The SBG-II generated holes are stored in the p-well. First, we extract the leakage mechanism from the p-well to show two mechanisms: 1) recombination–generation and 2) over the barrier (OTB), where OTB dominates when barrier height<inline-formula><tex-math notation="LaTeX">$_b&lt;0.59~eV$</tex-math></inline-formula>. Second, we analytically extract the SBG-II current (<inline-formula><tex-math notation="LaTeX">$I_II$</tex-math></inline-formula>) at 300 K from the experimental results. The drain current (<inline-formula><tex-math notation="LaTeX">$I_D$</tex-math></inline-formula>), electric field (<inline-formula><tex-math notation="LaTeX">$E-field$</tex-math></inline-formula>), and<inline-formula><tex-math notation="LaTeX">$I_II$</tex-math></inline-formula>are plotted in time. We observe that<inline-formula><tex-math notation="LaTeX">$I_II$</tex-math></inline-formula>increase as<inline-formula><tex-math notation="LaTeX">$E-field$</tex-math></inline-formula>reduces which indicates that<inline-formula><tex-math notation="LaTeX">$E$</tex-math></inline-formula>-field does not primarily contribute to<inline-formula><tex-math notation="LaTeX">$I_II$</tex-math></inline-formula>. Furthermore,<inline-formula><tex-math notation="LaTeX">$I_D$</tex-math></inline-formula>shows two distinct behaviors: 1)<inline-formula><tex-math notation="LaTeX">$I_II (I_D$</tex-math></inline-formula>) is constant at the beginning and 2) eventually “universal”<inline-formula><tex-math notation="LaTeX">$I_II (I_D$</tex-math></inline-formula>) is linear, i.e.,<inline-formula><tex-math notation="LaTeX">$I_II=kI_D$</tex-math></inline-formula>where<inline-formula><tex-math notation="LaTeX">$k = 10^-3$</tex-math></inline-formula>; we also show that the electrons primarily contributing to<inline-formula><tex-math notation="LaTeX">$I_D$</tex-math></inline-formula>are directly incapable of II due to insufficient energy (<inline-formula><tex-math notation="LaTeX">$&lt; E_g$</tex-math></inline-formula>). Fischetti’s model showed that SBG-II is primarily caused by “hot” electrons that accept energy in an Auger-like process from “cold” drain electrons to enable SBG-II. We speculate that if<inline-formula><tex-math notation="LaTeX">$I_D$</tex-math></inline-formula>electrons “heat-up” the cold drain electrons, which would further energize the hot electrons to produce the observed<inline-formula><tex-math notation="LaTeX">$I_II(I_D$</tex-math></inline-formula>) universal dependence.

@article{8401800, abstract = {Sub-bandgap (SBG) impact ionization (II) enables steep subthreshold slope that enable devices to overcome the thermal limit of 60 mV/decade. This phenomenon at low voltage enables various applications in logic, memory, and neuromorphic engineering. Recently, we have demonstrated sub-0.2-V II in n-i-p-i-n diode experimentally primarily based on steady-state analysis. In this paper, we present the detailed experimental transient behavior of SBG-II in n-i-p-i-n. The SBG-II generated holes are stored in the p-well. First, we extract the leakage mechanism from the p-well to show two mechanisms: 1) recombination–generation and 2) over the barrier (OTB), where OTB dominates when barrier height<inline-formula><tex-math notation="LaTeX">${\phi }_{b}&lt;\textsf {0.59}~\textsf {eV}$</tex-math></inline-formula>. Second, we analytically extract the SBG-II current (<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}$</tex-math></inline-formula>) at 300 K from the experimental results. The drain current (<inline-formula><tex-math notation="LaTeX">${I}_{D}$</tex-math></inline-formula>), electric field (<inline-formula><tex-math notation="LaTeX">${E}{-}\textsf {field}$</tex-math></inline-formula>), and<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}$</tex-math></inline-formula>are plotted in time. We observe that<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}$</tex-math></inline-formula>increase as<inline-formula><tex-math notation="LaTeX">${E}{-}\textsf {field}$</tex-math></inline-formula>reduces which indicates that<inline-formula><tex-math notation="LaTeX">${E}$</tex-math></inline-formula>-field does not primarily contribute to<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}$</tex-math></inline-formula>. Furthermore,<inline-formula><tex-math notation="LaTeX">${I}_{D}$</tex-math></inline-formula>shows two distinct behaviors: 1)<inline-formula><tex-math notation="LaTeX">${I}_{\textit {II}} ({I}_{D}$</tex-math></inline-formula>) is constant at the beginning and 2) eventually “universal”<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}} ({I}_{D}$</tex-math></inline-formula>) is linear, i.e.,<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}={k}\times {I}_{D}$</tex-math></inline-formula>where<inline-formula><tex-math notation="LaTeX">${k} = \textsf {1}\textsf {0}^{-\textsf {3}}$</tex-math></inline-formula>; we also show that the electrons primarily contributing to<inline-formula><tex-math notation="LaTeX">${I}_{D}$</tex-math></inline-formula>are directly incapable of II due to insufficient energy (<inline-formula><tex-math notation="LaTeX">$&lt; {E}_{g}$</tex-math></inline-formula>). Fischetti’s model showed that SBG-II is primarily caused by “hot” electrons that accept energy in an Auger-like process from “cold” drain electrons to enable SBG-II. We speculate that if<inline-formula><tex-math notation="LaTeX">${I}_{D}$</tex-math></inline-formula>electrons “heat-up” the cold drain electrons, which would further energize the hot electrons to produce the observed<inline-formula><tex-math notation="LaTeX">${I}_{\textsf {II}}{(}{I}_{D}$</tex-math></inline-formula>) universal dependence.}, added-at = {2018-08-09T15:51:05.000+0200}, author = {Das, B. and Schulze, J. and Ganguly, U.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/228dfdf191bcf85f90203ad6cb1f6273e/ihtpublikation}, doi = {10.1109/TED.2018.2846360}, interhash = {3748427b2044969493d1ee414fb7bc8e}, intrahash = {28dfdf191bcf85f90203ad6cb1f6273e}, issn = {0018-9383}, journal = {IEEE Transactions on Electron Devices}, keywords = {iht j.schulze.iht journal}, month = aug, number = 8, pages = {3414-3420}, timestamp = {2018-09-05T07:10:43.000+0200}, title = {Transient Phenomena in Sub-Bandgap Impact Ionization in Si n-i-p-i-n Diode}, url = {https://ieeexplore.ieee.org/document/8401800/}, volume = 65, year = 2018 }