Memory device and method of forming the same

A method of forming a device, comprising:

• forming an interconnection structure over a substrate;
• forming a multilayer stack over the interconnection structure;
• patterning the multilayer stack to form trenches;
• conformally forming an oxide semiconductor layer in the trenches, wherein the oxide semiconductor layer is formed by depositing a material represented by formula 1:
• InxSnyTizMmOn [formula 1]
• wherein in formula 1, 0<x<1, 0≤y<1, 0<z<1, 0<m<1, 0<n<1, and M represents at least one metal;
• forming a dielectric material over the oxide semiconductor layer to fill the trenches;
• patterning the dielectric material to form second trenches in the dielectric material;
• and
• forming conductive pillars in the second trenches, wherein the conductive pillars are in contact with the oxide semiconductor layer.

A method of forming a device, comprising:

• forming a transistor structure over a substrate, wherein forming the transistor structure comprises:
• forming a conductive line over the substrate;
• forming a ferroelectric layer over the conductive line;
• forming a first channel material represented by formula 1 over the ferroelectric layer,
• InxSnyTizMmOn [formula 1]
• wherein in formula 1, 0<x<1, 0≤y<1, 0<z<1, 0<m<1, 0<n<1, and M represents at least one metal;
• performing a thermal annealing process on the first channel material at a temperature of 1000° C. to 1600° C. to transform the first channel material to a crystalline state;
• and
• forming source and drain electrodes over the first channel material.