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MEMS Fabrication Resources from a Working U.S. Foundry
These MEMS fabrication resources are written by the process engineers who run our fab, not by a marketing team. Every guide, spec, and case study on this page comes out of daily work on a production line in Medford, Oregon, where Rogue Valley Microdevices has processed customer wafers since 2003.
Nothing here is gated. No form, no download wall. If you are choosing between two processes, sizing a film stack, or checking whether a device is manufacturable before you commit to a mask set, the answer should be one click away. When you want a number that is specific to your design, our engineers will give it to you directly through our MEMS foundry and wafer services teams.
Start With a Process Comparison
Most fabrication questions are really choices between two viable options.
Our MEMS process guides take those head-on, with the trade-offs stated plainly and a recommendation for when each option wins.
- Thermal Oxide vs PECVD OxideWhen the thermal budget allows a furnace oxide, and when a low-temperature deposited oxide is the only option.
- LPCVD Nitride vs PECVD NitrideStress control and conformality against deposition temperature and metal compatibility.
- DRIE vs Wet Silicon EtchVertical sidewalls and high aspect ratios against crystallographic angles and batch throughput.
- TMAH vs KOH Silicon EtchChoosing an anisotropic wet chemistry when CMOS compatibility or mask selectivity drives the decision.
- Metal Lift-Off vs Metal EtchHow to pattern a metal layer, including the cases where lift-off is the only route.
- E-Beam Evaporation vs Sputter DepositionStep coverage, film stress, and which materials each method handles well.
- Spin Coat vs Spray Coat PhotoresistCoating flat wafers against coating topography and deep features.
- Photolithography MethodsContact, proximity, and projection exposure, and what each costs you in resolution.
Reference material sits alongside the comparisons: the thermal oxide color chart, thermal anneals for MEMS, and dopant rings on silicon wafers.
Real Numbers, Published Openly
Adjectives do not help you design a device.
Our guides carry the same process numbers our engineers work to every day, so you can check feasibility before you call us. A sample of what is documented for our Medford line:
| Process | Documented capability |
|---|---|
| PECVD oxide | Up to 5µm standard; up to 6µm on 100mm and 150mm by customer need; 1µm maximum at 300mm. ±7% above 1,000Å; refractive index 1.46 ±0.02 at 632.8 nm |
| LPCVD low-stress nitride | Under 250 MPa tensile, ±50 MPa run to run; deposited at 820 to 850 °C |
| Wet thermal oxide | 1,000Å to 10µm; ±5%; approximately 320 MPa compressive, ±50 MPa run to run |
| DRIE | 15:1 aspect ratio, depth to feature; minimum critical dimension 3µm or greater; 3mm edge exclusion at 200mm |
| Film uniformity | PECVD ±7% within wafer; thermal oxidation ±5%; e-beam and sputter ±10% |
Every figure above is drawn from our documented process records. Where a number depends on your stack, your substrate, or your thermal budget, we will say so rather than quote a best case.
Case Studies: Process Choices That Reached Production
A guide tells you how two processes differ. A case study shows which one a real device needed and what happened next. Ours follow the full arc, from the first process conversation to wafers moving in production.
eMagin
Silicon nitride membrane shadow masks for OLED microdisplay manufacturing.
Read the case study →See all customer case studies, or the wider set of companies we build for on our customers page.
Why These Resources Come from a Fab, Not a Blog
- Written by process engineers: the people who own the recipes write the guides, so the trade-offs are the real ones.
- In-house across the flow: thermal oxidation, LPCVD, PECVD, e-beam evaporation, sputtering, DRIE and RIE, contact lithography, wet processing, and metrology all run under one roof, so the guides compare processes we actually operate.
- ITAR registered: Rogue Valley Microdevices is International Traffic in Arms Regulations (ITAR) registered, supporting customers who need a domestic supply chain. See our ITAR-registered foundry page.
- Ungated, always: no forms, no gated PDFs, no lead capture between you and a specification.
- Prototype through mid-volume: we process customer-supplied wafers from R&D and prototyping through pilot and mid-volume production, and offer MEMS design services when a device is still on the drawing board.
News, Events, and Perspective
Our blog covers MEMS, photonics, packaging, and where the semiconductor industry is heading. News and events cover company announcements and the conferences where you can find us in person, including progress on our second fab in Palm Bay, Florida, which is under construction and will add 200mm and 300mm capacity.
Talk to a MEMS Foundry
If a guide gets you close but not all the way, the next step is a conversation, not another download. Tell us what you are building and which processes you are weighing, and an engineer from our team will work through it with you.