US 11,685,647 B2 · Nanosheet MEMs sensor device and method of manufacture

Abstract

A nanosheet MEMS sensor device and method are described for integrating the fabrication of nanosheet transistors (61) and MEMS sensors (62) in a single nanosheet process flow by forming separate nanosheet transistor and MEMS sensor stacks (12A-16A, 12B-16B) of alternating Si and SiGe layers which are selectively processed to form gate electrodes (49A-C) which replace the silicon germanium layers in the nanosheet transistor stack, to form silicon fixed electrodes using silicon layers (13B-2, 15B-2) on a first side of the MEMS sensor stack, and to form silicon cantilever electrodes using silicon layers (13B-1, 15B-1) on a second side of the MEMS sensor stack by forming a narrow trench opening (54) in the MEMS sensor stack to expose and remove remnant silicon germanium layers on the second side in the MEMS sensor stack.

Claims21

Dependent claims

A method for forming a semiconductor device comprising:

providing a stack of alternating first and second semiconductor layers on a substrate;
selectively etching the stack of alternating first and second semiconductor layers to form a transistor stack and a sensor stack on the substrate;
and
processing the transistor stack and the sensor stack to form gate electrodes between the first semiconductor layers in the transistor stack and to form cantilever electrodes from the first semiconductor layers in the sensor stack.

1 more element

A method for forming a semiconductor device comprising:

providing a stack of alternating silicon and silicon germanium layers on a substrate;
selectively etching the stack of alternating silicon and silicon germanium layers to form a nanosheet transistor stack and a nanosheet sensor stack on the substrate;
selectively processing the nanosheet sensor stack while masking the nanosheet transistor stack to form silicon fixed electrodes from the silicon layers in the nanosheet sensor stack by forming one or more dielectric layers on a first side of the nanosheet sensor stack which replace a portion of the silicon germanium layers in the nanosheet sensor stack and leave remnant silicon germanium layers in the nanosheet sensor stack;
selectively processing the nanosheet transistor stack while masking the nanosheet sensor stack to form dielectric spacer layers on peripheral sides of the nanosheet transistor stack which replace peripheral portions of the silicon germanium layers in the nanosheet transistor stack and leave remnant silicon germanium layers in the nanosheet transistor stack;
forming doped epitaxial semiconductor regions adjacent to the nanosheet transistor stack and a nanosheet sensor stack;
selectively processing the nanosheet transistor stack while masking the nanosheet sensor stack to form gate electrodes which replace the remnant silicon germanium layers in the nanosheet transistor stack;
selectively processing the nanosheet sensor stack while masking the nanosheet transistor stack to form silicon cantilever electrodes from the silicon layers in the nanosheet sensor stack by forming a narrow trench opening in the nanosheet sensor stack to expose the remnant silicon germanium layers on a second side in the nanosheet sensor stack and selectively removing the remnant silicon germanium layers in the nanosheet sensor stack;
and
depositing one or more dielectric layers over the nanosheet transistor stack and a nanosheet sensor stack to seal the top of the narrow trench opening.

6 more elements

A method for forming a semiconductor device comprising:

providing a stack of alternating silicon and silicon germanium layers on a substrate;
selectively etching the stack of alternating silicon and silicon germanium layers to form a nanosheet transistor stack and a nanosheet sensor stack on the substrate;
processing the nanosheet sensor stack by performing nanosheet sensor stack processing steps to:
form silicon fixed electrodes from the silicon layers in the nanosheet sensor stack by forming one or more dielectric layers in the nanosheet sensor stack which replace a portion of the silicon germanium layers in the nanosheet sensor stack and leave remnant silicon germanium layers in the nanosheet sensor stack, and
form silicon cantilever electrodes from the silicon layers in the nanosheet sensor stack by selectively removing the remnant silicon germanium layers in the nanosheet sensor stack;
and
processing the nanosheet transistor by performing nanosheet transistor stack processing steps to:
form dielectric spacer layers on peripheral sides of the nanosheet transistor stack which replace peripheral portions of the silicon germanium layers in the nanosheet transistor stack and leave remnant silicon germanium layers in the nanosheet transistor stack, and
form gate electrodes which replace the remnant silicon germanium layers in the nanosheet transistor stack.

6 more elements

Dependencies are inferred from the claim text.

Nanosheet MEMs sensor device and method of manufacture

Life of this patent

Nanosheet MEMs sensor device and method of manufacture

Life of this patent

Abstract

Claims21