Method to determine a complete etch in integrated devices
AssigneeTexas Instruments Incorporated
InventorsPing Jiang, Heungsoo Park
Life of this patent
Estimating the term…
Abstract
In an integrated device, an etch is performed in an intermediate layer to form a via. The via is inspected using a scanning electron microscopy. The scanning electron microscopy detects a level of brightness associated with the via and a background shade. Whether the etch reached an etch-stop layer is determined by comparing the level of brightness associated with the via to the background shade.
Claims28
A method for determining a complete etch in integrated devices, comprising:
- performing an etch in an intermediate layer to form a via;
- inspecting the via using a scanning electron microscopy, the scanning electron microscopy detecting a level of brightness associated with the via and a background shade;
- and
- determining whether the etch reached an etch-stop layer by comparing the level of brightness associated with the via to the background shade.
A method for determining a complete etch in integrated devices comprising:
- performing an etch in the intermediate layer to form a via;
- inspecting the via using an scanning electron microscopy, the scanning electron microscopy detecting a level of brightness associated with the via and a background shade;
- comparing the level of brightness associated with the via to the background shade;
- determining that an incomplete etch does not exist if the level of brightness associated with the via is substantially different from the background shade indicating that the etch has reached an underlying etch-stop layer;
- and
- determining that the incomplete etch does exist if the level of brightness associated with the via is not substantially different from the background shade.
A method for determining a complete etch in integrated devices, comprising:
- performing an etch in an intermediate layer to form a contact;
- inspecting the contact using a scanning electron microscopy, the scanning electron microscopy detecting a level of brightness associated with the contact and a background shade;
- and
- determining whether the etch reached an etch-stop layer by comparing the level of brightness associated with the contact to the background shade.
A method for determining a complete etch in integrated devices, comprising:
- performing a first etch in an intermediate layer to form a via;
- inspecting the via using an scanning electron microscopy to determine whether an incomplete etch exists in the first etch by comparing a level of brightness associated with the via with a background shade;
- performing a second etch to extend the via through an etch-stop layer in response to the brightness associated with the via being greater than the background shade by a predetermined threshold value;
- performing a third etch to verify the completeness of the second etch, the third etch including a wet etch selective to a material below the etch-stop layer;
- and
- inspecting the via to determine whether an incomplete second etch exists by comparing a level of brightness associated with the via to the background shade, the second etch being successfully completed upon verifying that the brightness associated with the via is substantially similar to the background shade.
Dependencies are inferred from the claim text.