Yangtze Memory Technologies Co., Ltd.

Jie Su

Zongliang Huo

Wei Xu

Bo Xu

Yali Guo

Bin Chen

Simin Liu

Rong Xu

Wenbin Sun

Siliu Zhang

The present disclosure discloses a three-dimensional memory and a fabrication method thereof. The fabrication method comprises: forming a stack structure comprising alternately stacked dielectric layers and sacrificial layers; forming a gate line slit penetrating vertically penetrating the stack structure and extending in a first horizontal direction; and etching portions of the dielectric layers and the sacrificial layers adjacent to the gate line slit to form a plurality of recesses, wherein an aperture of each recess in a vertical direction is greater than a thickness of a corresponding sacrificial layer.

Three-dimensional memory and fabrication method thereof

Embodiments of compositions of a wet etchant and additive thereto for selectively etching silicon nitride to silicon oxide are disclosed. In an example, a composition of an additive to a phosphoric acid etchant includes an inhibitor and a dispersant. The inhibitor is absorbable on a surface of silicon oxide and capable of inhibiting etching of the surface of silicon oxide by the phosphoric acid etchant. The dispersant is capable of reacting with a by-product of a reaction between the phosphoric acid etchant and at least one of silicon oxide and silicon nitride and reducing a viscosity of the phosphoric acid etchant.

Additive to phosphoric acid etchant

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Wuhan, China

Jie Su