A method to relieve 3D NAND flash stress

Abstract

The HfO2 thin film solution provided by this invention offers a different approach: instead of passively mitigating stress, it actively alleviates stress through structural means. By precisely controlling the deposition process of the HfO2 thin film, strong, designable compressive stress can be generated within it, directly offsetting the inherent tensile stress in the dielectric stack. This solution offers two advantages: firstly, the HfO2 layer can be used as a barrier layer in the process without requiring additional space, improving reliability without sacrificing storage density; secondly, HfO2 possesses high modulus and high hardness, providing robust support in stress concentration areas, significantly reducing structural deformation, and ensuring process consistency and long-term device reliability under ultra-high-layer stacking.

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