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US 12,356,698 B2Granted
Method of forming a sealed cavity embedded in a semiconductor wafer
AssigneeAnalog Devices, Inc.
InventorsYingqi Jiang, James G. Fiorenza
Life of this patent
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Abstract
Techniques are described for forming a sealed cavity within a semiconductor wafer, where a conductor wafer includes a structure, such as a T-gate electrode or passive component, formed over a substrate. The sealed-cavity structure may be embedded into the wafer without interfering with any subsequent processes. That is, once the cavity is closed, any subsequent backend processes may continue as usual.
Claims10
A method of forming a sealed cavity within a semiconductor wafer, wherein the semiconductor wafer includes a structure formed over a substrate, the method comprising:
- forming a drain electrode and a source electrode over the substrate;
- forming a first plurality of vias that extend vertically between the drain electrode and a first metal region;
- forming a second plurality of vias that extend vertically between the source electrode and a second metal region;
- patterning a region of a passivation layer;
- removing at least a portion of the patterned region of the passivation layer to form at least one hole;
- removing, through the at least one hole formed in the passivation layer, a portion of an underlying insulating layer around the structure to form a cavity by applying vapor hydrofluoric acid to the insulating layer through the at least one hole,
- retaining a first portion of the insulating layer, wherein the first portion extends vertically and is adjacent to at least one of the first plurality of vias, and
- retaining a second portion of the insulating layer, wherein the second portion extends vertically and is adjacent to at least one of the second plurality of vias, and wherein the first portion and the second portion are adjacent to sides of the cavity;
- and
- covering or sealing the at least one hole in the passivation layer to form the sealed cavity.
7 more elements
Dependencies are inferred from the claim text.