nitride spacer

# Nitride Spacer (SiN)

A nitride spacer uses a silicon-nitride-based film on a feature sidewall.

## Read the retained sidewall

A conformal coating covers both horizontal and vertical surfaces before etchback. The intended final feature is the retained sidewall material, not a uniformly thinned blanket film.

## Integration context

The deposited film is commonly described as SiN or SiNx; its composition and stress depend on the deposition. Directional etchback must clear horizontal surfaces while retaining the intended sidewall material. Selectivity to an oxide liner and exposed silicon constrains the available window.

## What to verify

Check retained width, liner loss, substrate recess and deposition-stress compatibility.

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

nitride spacer, SiN spacer. 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.