Record-Low EOT(3.6Å) & Jleak(7×10-8A/cm2@0.8V) HZO by Dielectric-Selective Microwave Annealing

초록

In this work, we present HZO film near the morphotropic phase boundary (MPB) with an EOT of 3.6 Å and a low leakage current density (Jleak @ 0.8 V) of Jleak(7.0 × 10-8A/cm2@ using a microwave annealing (MWA) system. The MWA supplies the energy required for HZO crystallization in both thermal and microwave forms, offering three key benefits: (i) It drastically reduces thermal budget (TB), suppresses interfacial dead layer formation, and enhances endurance (K ∼ 62 at 1012 cycles). (ii) It only affects the HZO film and not the TiN electrodes, making the dipoles inside HZO vibrate. This enables selective and volumetric annealing in high-aspect-ratio DRAM cell capacitors. (iii) It lowers the activation barrier for HZO crystallization compared to typical rapid thermal annealing (RTA). We experimentally verified this by quantifying activation energy (Ea) using electrical measurements under various TBs, finding that the Ea was 0.67 eV/f.u. for MWA, and 0.85 eV/f.u. for RTA.

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