Metal Lift-Off Process Services with a Specialized Bilayer Resist
Rogue Valley Microdevices provides metal lift-off process services for MEMS and semiconductor device fabrication. We are experts in depositing thick metal layers, and we developed a specialized bilayer resist process that improves film adhesion and delivers clean, high-quality lift-off.
Lift-off processing operates as part of our integrated U.S.-based MEMS foundry platform, where our engineers combine photolithography, thin-film deposition, and wafer processing expertise to support complex device development and manufacturing.
What Is the Metal Lift-Off Process?
The lift-off process patterns metal films by first forming a patterned photoresist layer on the wafer, then depositing metal across the entire surface. When the resist dissolves during the lift-off step, it carries away the metal sitting on top of the resist, leaving metal only in the desired patterned regions.
Because the process adds material only where needed, lift-off often works better than etching for metals that resist chemical etchants, such as platinum, or when a subtractive process would damage underlying layers.
Key advantages include:
- Clean pattern definition without metal etching
- Compatibility with sensitive materials and multilayer structures
- Precise pattern control for MEMS and semiconductor devices
- Reliable wafer-level repeatability
Our Bilayer Resist Lift-Off Process
Our MEMS foundry uses a specialized bilayer resist lift-off process that improves metal adhesion and enables clean removal of unwanted films. The dual-layer photoresist stack creates a controlled re-entrant (undercut) profile that physically breaks the continuity of the deposited metal film at the resist sidewalls. Because the metal never bridges across the sidewall, the lift-off solvent reaches and dissolves the release layer cleanly, instead of tearing metal away from patterned features.
What that means for your device:
This process control helps engineers integrate metal layers into complex MEMS device structures without introducing defects or unwanted electrical connections.
Metals Commonly Patterned with Lift-Off
Our lift-off processing supports a wide range of PVD-deposited metals used in MEMS devices, sensors, and semiconductor components, including:
- Aluminum
- Chrome
- Copper
- Gold
- Indium
- Nickel
- Platinum
- Silver
- Tin
- Titanium
These materials enable electrical interconnects, electrodes, bonding pads, reflective layers, and functional device structures.
Supported Substrates and Wafer Sizes
We run metal lift-off on 100mm, 150mm, and 200mm wafers. Lithography-based patterning sets the 100mm minimum for lift-off; if your early-stage work uses smaller substrates, our film-only wafer services support wafers down to 50mm. Supported substrate materials include:
| Parameter | Capability |
|---|---|
| Wafer sizes | 100mm, 150mm, and 200mm |
| Substrate materials | Silicon; silicon on insulator (SOI); quartz; sapphire; glass; GaN on silicon; silicon carbide; other specialty substrates |
Applications in MEMS and Sensor Devices
Metal lift-off plays an important role in many MEMS fabrication flows, creating the patterned conductive layers that define electrical and functional device elements. Common applications include:
- MEMS sensor electrodes
- RF MEMS interconnects
- Optical MEMS reflective coatings
- Microheater and microelectrode structures
- Contact pads and bonding interfaces
- Thin-film metallization layers
Our wafer-level processing ensures consistent results across development runs and production manufacturing.
Lift-Off or Metal Etch?
Lift-off adds metal only where the pattern needs it; etching removes metal everywhere the mask leaves it exposed. When your metal stack is compatible with wet etching or dry etching, a subtractive process may be the simpler route. Our metal lift-off vs. metal etch guide compares the two approaches, and our engineers will help you pick the right one for your device.
Request a Quote for Metal Lift-Off Services
Tell us your metal stack, substrate, and pattern requirements, and our engineering team will scope a lift-off process that fits your device. Request a quote to get started.