Unraveling BTI in IGZO Devices: Impact of Device Architecture, Channel Film Deposition Method and Stoichiometry/Phase, and Device Operating Conditions
Adrian Chasin, J. Franco, S. Van Beek, H.F.W. Dekkers, Anastasiia Kruv, Pietro Rinaudo, Ying Zhao, Daisuke Matsubayashi, Alexandru Pavel, Yi Wan, Kishor S. Trivedi, Nouredine Rassoul, Jie Li, Yong Jiang, Michiel van Setten, Subhali Subhechha, A. Belmonte, B. Kaczer, Gouri Sankar Kar
Abstract
We study the impact of the device architecture, channel deposition method, stoichiometry and phase, and AC stress on the BTI of IGZO thinfilm transistors fabricated on 300-mm wafers. Two main conclusions are obtained. First, reliability of IGZO based devices is strongly architecture dependent, and therefore reliability solutions are not universal. Second, top-gate (TG) devices are more severely impacted by the abnormal negative <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Delta \mathrm{V}_{\text{th}}$</tex> during PBTI at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{T} > 25^{\circ}\mathrm{C}$</tex>, ascribed to a H-doping process, than back-gated (BG) counterparts. Two remedies for the negative <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Delta \mathrm{V}_{\text{th}}$</tex> are identified: In-poor films (In~5%) and AC stress with duty-cycle< <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$< 25\%$</tex> do not reveal signs of H-doping process within the experimental time window, and thus are promising for reliable product operation.