pad oxide

# Pad Oxide

Pad oxide is a thin oxide placed between silicon and another process layer, commonly an oxidation or trench hard mask.

## Connect the name to its role

Document whether this film is a target, mask, liner, electrode or temporary layer at the step being discussed. The same material can have different roles in different modules.

## Integration context

In familiar isolation flows it separates silicon from a nitride mask and helps accommodate the interface and stress environment. It is not the same functional layer as the final gate oxide. Removal of the overlying mask and pad oxide belongs to the isolation integration.

## What to verify

Track remaining oxide and silicon surface condition; do not let a pad-oxide strip unintentionally remove protected functional oxides.

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

pad oxide, pad ox. Short abbreviations are local process vocabulary and can have other meanings; use the full module name when searching.

## Source and scope

[Thermal oxide growth and deposited films](https://www.nanofab.ualberta.ca/capabilities/thin-film-deposition/). The diagram is an original teaching schematic. Layer choices and process families describe an example rather than a universal manufacturing recipe.