Technologies
Vapor-phase HF release
The final release etch is where a MEMS wafer carries its highest accumulated value — and where wet processes can destroy it through stiction. Anhydrous vapor-phase HF removes sacrificial oxide dry, freeing structures without the capillary forces of liquid chemistry.
What it does
Controlled vapor-phase HF chemistry etches sacrificial SiO₂ beneath released structures without liquid contact, eliminating stiction as a failure mode. Process control centres on etch-rate stability, uniformity across cavity geometries, selectivity to exposed materials and residue behaviour.
Evaluation dimensions that decide projects
- Material compatibility
- Every exposed material — metals, nitrides, polymers, bond interfaces — must be catalogued and verified against the chemistry.
- Etch uniformity in real geometry
- Release front progress under wide plates and in narrow channels differs; evaluation must use representative structures.
- Residue control
- Reaction products can condense; their management is a process-design question with yield consequences.
- Endpoint & inspection strategy
- How release completion is verified non-destructively at production rhythm.
- Safety & facility integration
- HF demands rigorous abatement, interlocks and handling discipline — part of the total cost, never a footnote.
Where it is used
Questions worth asking early
When does vapor HF beat wet release?
Whenever stiction risk, structure fragility or material sensitivity makes liquid processing marginal. For robust structures with generous gaps, wet release may remain economical — the comparison belongs in your evaluation, in your geometry.
What does a meaningful release demo look like?
Your structures or agreed proxies, a defined completion criterion, inspection of stiction and residues, and selectivity data on your exposed material set.
Have a structure, film or thermal step to discuss?
Send a short description of your application — device type, material, wafer size and what a good result looks like. An engineer will reply with a concrete next step.