Air gaps in memory array structures

A device comprising:

• a semiconductor substrate;
• a first memory cell over the semiconductor substrate, the first memory cell comprising a first transistor, wherein the first transistor comprises:
• a gate electrode comprising a portion of a first word line;
• a first portion of a ferroelectric material, wherein the first portion of the ferroelectric material is on a sidewall of the first word line;
• and
• a first channel region on a sidewall of the first portion of the ferroelectric material;
• a source line, wherein a first portion of the source line provides a first source/drain electrode for the first transistor;
• a bit line, wherein a first portion of the bit line provides a second source/drain electrode for the first transistor;
• a first dielectric material separating the source line and the bit line;
• a first air gap separating the source line and the first dielectric material;
• a second air gap separating the bit line and the first dielectric material;
• and
• a second memory cell over the first memory cell.

A method comprising:

• patterning a first trench extending through a first conductive line;
• depositing a memory film along sidewalls and a bottom surface of the first trench;
• depositing an oxide semiconductor (OS) layer over the memory film, wherein the OS layer extends along the sidewalls and the bottom surface of the first trench;
• depositing a first dielectric material on the OS layer, wherein the first dielectric material fills the remaining portion of the first trench;
• patterning a second trench in the first dielectric material;
• depositing a conductive material in the second trench, wherein the conductive material fills the second trench;
• patterning a third trench in the conductive material;
• depositing a second dielectric material in the third trench;
• and
• implanting the second dielectric material with a dopant, wherein after implanting the second dielectric material, implanted portions of the second dielectric material extend over the third trench and form an air gap within the third trench.