spacer etch filmstack

# Spacer Etch Filmstack

Spacer 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 conformal nitride film over an oxide liner is directionally etched back to leave sidewall spacers. The stack is conformal around topography, not a simple flat blanket stack. The basic self-aligned etchback typically needs no new PR pattern; block masks can exist in more complex integrations.

## What to verify

Check spacer width, horizontal clearing, liner loss and silicon recess.

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

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

## Source and scope

[Selective nitride spacer etching](https://plasma.oxinst.com/assets/uploads/documents/3182_PT_Process_News_Mar2015_Low_res_Spreads.pdf). The diagram is an original teaching schematic. Layer choices and process families describe an example rather than a universal manufacturing recipe.