contact etch filmstack

# Contact Etch Filmstack

Contact Etch Filmstack describes the ordered materials and their roles in this pattern-transfer example.

## Read the interfaces

The stack is listed from the top surface downward in this example. State which films must clear and which must remain. Interface opening, bulk removal and landing can need different process conditions.

## Integration context

A contact opening passes through interlayer dielectric and, where used, a contact etch stop layer before reaching a device contact landing. CESL means contact etch stop layer. Oxide removal and nitride opening may require separate controlled steps; an oxide endpoint does not prove the final landing is exposed.

## What to verify

Check bottom CD, dielectric clearing, landing damage and contact resistance after fill.

Before selecting removal conditions, identify all exposed neighboring materials and the amount of loss each can tolerate. Verify the result using the measurements appropriate to the structure, then check that the surface is suitable for the next deposition, contact or clean step.

## Related terminology

contact etch filmstack, contact etch film stack. Short abbreviations are local process vocabulary and can have other meanings; use the full module name when searching.

## Source and scope

[Reactive ion etching capabilities](https://www.nanofab.ualberta.ca/capabilities/plasma-etch/). The diagram is an original teaching schematic. Layer choices and process families describe an example rather than a universal manufacturing recipe.