[17a-F206-1~13] 13.3 Insulator technology

△ [17a-F206-11] Optimized post-deposition annealing for improved bias stability of atomic-layer-deposited Al2O3 films

〇Kiyotaka Horikawa¹, Atsushi Hiraiwa^2,4, Satoshi Okubo¹, Taisuke Kageura¹, Hiroshi Kawarada^1,2,3 (1.Waseda Univ., 2.RONLI, Waseda Univ., 3.KMLMST, Waseda Univ., 4.Nagoya Univ.)

Keywords:atomic-layer-deposited Al2O3 films, bias stability, post-deposition annealing

Atomic layer deposition Al2O3 film is promising for gate insulating film in semiconductor elements other than Si. The problem is biased instability (BI). This is a problem that the Al2O3 film is charged due to voltage stress, and as a result, the flat band voltage (Vfb) fluctuates. In this study, we investigated the field equivalent electric field strength (Feo=4 ~ 7 MV/cm), and it was able to estimate the saturation value of the Vfb fluctuation by the complementary KWW function to optimize the PDA temperature for BI reduction. In order to reduce the Al2O3 film BI, it was revealed that it is most effective to perform PDA at 750°C.