Two-dimensional (2D) material for oxide semiconductor (OS) ferroelectric field-effect transistor (FeFET) device

A method to form a ferroelectric field-effect transistor (FeFET) device, comprising:

• forming an oxide semiconductor (OS) channel layer of a first doping type;
• forming a two-dimensional (2D) contacting layer over the OS channel layer, wherein the 2D contacting layer is of a second doping type opposite to the first doping type;
• forming a ferroelectric layer over the 2D contacting layer;
• etching to form source/drain contact holes through the ferroelectric layer to expose an ending upper surface of the 2D contacting layer;
• performing a doping process vertically throughout the 2D contacting layer from the ending upper surface of the 2D contacting layer;
• and
• forming a pair of source/drain regions within the source/drain contact holes with a bottom surface reaching on the ending upper surface of the 2D contacting layer and a sidewall surface interfacing a sidewall of the ferroelectric layer.

A method to form an integrated chip, comprising:

• forming an interconnect structure comprising a lower metal layer and an upper metal layer stacked over the lower metal layer;
• and
• forming a ferroelectric field-effect transistor (FeFET) device inserted between the lower metal layer and the upper metal layer, comprising:
• forming an oxide semiconductor (OS) channel layer disposed over the lower metal layer and a first dielectric layer, the OS channel layer having a first doping type;
• forming a two-dimensional (2D) contacting layer on the OS channel layer, wherein the 2D contacting layer has a second doping type opposite to the first doping type,
• forming a ferroelectric layer over the OS channel layer;
• forming a second dielectric layer surrounding and over the ferroelectric layer, the 2D contacting layer, and the OS channel layer;
• etching through the second dielectric layer and the ferroelectric layer to form source/drain contact holes exposing an upper surface of the 2D contacting layer;
• and
• forming a pair of source/drain regions within the source/drain contact holes reaching on the upper surface of the 2D contacting layer.