Fabrication of nano-sheet transistors with different threshold voltages
AssigneeAdeia Semiconductor Solutions LLC
InventorsKarthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
Life of this patent
Estimating the term…
Abstract
A method of forming two or more nano-sheet devices with varying electrical gate lengths, including, forming at least two cut-stacks including a plurality of sacrificial release layers and at least one alternating nano-sheet channel layer on a substrate, removing a portion of the plurality of sacrificial release layers to form indentations having an indentation depth in the plurality of sacrificial release layers, and removing a portion of the at least one alternating nano-sheet channel layer to form a recess having a recess depth in the at least one alternating nano-sheet channel layers, where the recess depth is greater than the indentation depth.
Claims39
A method of forming two or more nano-sheet devices with varying channel lengths, comprising:
- forming at least two cut-stacks including a plurality of sacrificial release layers and at least one alternating nano-sheet channel layer on a substrate;
- removing a portion of the plurality of sacrificial release layers to form indentations having an indentation depth in the plurality of sacrificial release layers;
- removing a portion of the at least one alternating nano-sheet channel layer in a first of the at least two cut-stacks to form a first recess having a first recess depth in the at least one alternating nano-sheet channel layer;
- and
- removing a portion of the at least one alternating nano-sheet channel layer in a second of the at least two cut-stacks to provide two different channel lengths.
A method of forming two or more nano-sheet devices with varying channel lengths, comprising:
- forming a channel stack including a plurality of sacrificial release layers and at least one alternating nano-sheet channel layer on a substrate;
- forming at least two cut-stacks from the channel stack, where each of the at least two cut-stacks includes a plurality of sacrificial release layers and at least one alternating nano-sheet channel layer;
- removing a portion of the plurality of sacrificial release layers to form indentations having an indentation depth in the plurality of sacrificial release layers;
- forming an indentation fill layer in the indentations;
- forming a mask on at least one of the two or more cut-stacks;
- and
- removing a portion of the at least one alternating nano-sheet channel layer to form a recess in the unmasked cut-stacks.
A method of forming two or more nano-sheet devices with varying channel lengths, comprising:
- forming at least two cut-stacks including a plurality of sacrificial release layers and at least one alternating nano-sheet channel layer on a substrate;
- removing a portion of the plurality of sacrificial release layers to form indentations having an indentation depth in the plurality of sacrificial release layers;
- and
- removing a portion of the at least one alternating nano-sheet channel layer to form a recess having a recess depth in the at least one alternating nano-sheet channel layer, wherein the one of the two or more nano-sheet devices has a different threshold voltage, VT, than the other of the two or more nano-sheet devices by altering the length of the at least one alternating nano-sheet channel layer.
A pair of nano-sheet devices on a substrate, comprising:
- a first nano-sheet device comprising a plurality of nano-sheet channel layers contacted on opposite ends by first source/drain regions;
- and
- a second nano-sheet device comprising a plurality of nano-sheet channel layers contacted on opposite ends by second source/drain regions, wherein:
- the first and second nano-sheet devices have substantially the same physical gate length;
- and
- a length of a topmost nano-sheet channel layer between opposing second source/drain regions of the second nano-sheet device is greater than a length of a topmost nano-sheet channel layer between opposing first source/drain regions of the first nano-sheet device.
A pair of nano-sheet devices on a substrate, comprising:
- a first nano-sheet device comprising:
- a first pair of indentation fill regions aligned with and on opposite ends of a first gate electrode region;
- and
- a first topmost nano-sheet channel layer;
- and
- a second nano-sheet device comprising:
- a second pair of indentation fill regions aligned with and on opposite ends of a second gate electrode region;
- and
- a second topmost nano-sheet channel layer, wherein:
- the first and second nano-sheet devices have substantially the same physical gate length:
- the first gate electrode region is directly adjacent to the first topmost nano-sheet channel layer and the second gate electrode region is directly adjacent to the second topmost nano-sheet channel layer;
- and
- a length of the first gate electrode region between opposing first indentation fill regions of the first nano-sheet device is greater than a length of the second gate electrode region between opposing second indentation fill regions of the second nano-sheet device.
Dependencies are inferred from the claim text.