Metal Lift-Off

What Is the Lift-Off Process?

The lift-off process patterns metal films by first forming a patterned photoresist layer on the wafer. Engineers then deposit a metal film across the entire surface. When the resist dissolves during the lift-off step, it removes the metal that sits on top of the resist while 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 or require precise edge definition.

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

This approach supports many MEMS fabrication flows that require patterned conductive layers, contact pads, and interconnect structures.

Bilayer Resist Lift-Off for Improved Pattern Quality

Our MEMS foundry uses a specialized bilayer resist lift-off process that improves metal adhesion and enables clean removal of unwanted films. This technique creates a controlled resist profile that prevents metal from bridging across resist sidewalls, allowing the resist to release cleanly during the lift-off step.

The result is:

• Smooth metal edges
• Reduced particle generation
• Reliable pattern transfer
• High-quality thin film patterning across the wafer

This process control helps engineers integrate metal layers into complex MEMS device structures without introducing defects or unwanted electrical connections.

Metal Lift-Off Processing for MEMS Fabrication

Precision Metal Lift-Off on Silicon Wafers

Metal lift-off processing enables precise patterning of thin metal films during MEMS and semiconductor device fabrication. At Rogue Valley Microdevices, we apply advanced lift-off techniques to create clean, well-defined metal structures directly on silicon wafers used for sensors, MEMS devices, and microelectronics.

Lift-off provides an effective alternative when conventional etching cannot pattern sensitive metals like platinum or when a subtractive process would damage underlying layers. Our MEMS foundry engineers use optimized photolithography, resist coat, and thin film deposition processes to produce accurate PVD metal patterns while maintaining excellent wafer-level uniformity.

We support customers developing MEMS sensors, photonic devices, RF components, and microelectronic systems that require high-quality metal patterning on silicon substrates.

MEMS Foundry Lift-Off Services

At Rogue Valley Microdevices, lift-off processing operates as part of our integrated MEMS foundry platform. Our engineers combine photolithography, thin-film deposition, and wafer processing expertise to support complex device development and manufacturing.

Fab capabilities include:

• Lift-off patterning for metal thin films
• Integration with MEMS process flows
• Wafer processing for multiple substrate sizes
• Development support for custom device structures
• Production-ready wafer fabrication

By combining process expertise with flexible wafer processing capabilities, we help customers move from prototype devices to scalable manufacturing.

Metals Commonly Patterned with Lift-Off

Our lift-off processing supports a wide range of metals used in MEMS devices, sensors, and semiconductor components, including:

These materials enable the formation of electrical interconnects, electrodes, bonding pads, reflective layers, and functional device structures.

Supported Materials and Wafers Sizes

Applications in MEMS and Sensor Devices

Metal lift-off plays an important role in many MEMS fabrication flows. Engineers use it to create 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.