Microelectromechanical Systems (MEMS)
MEMS devices live or die at their surfaces. A few nanometers of organic residue on a wafer, a released cantilever or a parylene layer can cause resist lift-off, poor metal adhesion, patchy silane coatings and drifting sensor baselines. Low-pressure air or oxygen plasma removes that residue (roughly 5 nm/min of organic material) and leaves a clean, hydroxylated, high-energy surface ready for the next step, all at near room temperature.
Harrick Plasma benchtop cleaners give MEMS researchers that clean, activated surface right at the bench, between cleanroom steps, without booking time on a shared etch tool. Our technical database of over 8,500 peer-reviewed publications includes about 100 papers in dedicated MEMS journals and conferences, from wafer preparation and microactuator fabrication to cantilever biosensors and wireless resonators.
How plasma treatment is used in MEMS
Wafer and substrate preparation. A short oxygen plasma before spin-coating removes organic residue and raises surface energy, improving the adhesion and uniformity of SU-8 and photoresist on silicon, glass and PDMS. See also: Photoresist: Cleaning, Spinning & Descum.
Thin-film and metal adhesion on polymer layers. Parylene, SU-8, polyimide and PEDOT:PSS are hard to coat. Plasma activation before sputtering, evaporation or electroless plating improves adhesion of aluminum, gold and silver layers in flexible actuators and 3D microstructures.
Microcantilever and resonator sensors. Plasma cleans and hydroxylates silicon, silicon nitride and quartz surfaces so aminosilanes and other linkers bind uniformly, giving cantilever arrays, nanomechanical sensors and acoustic resonators a reproducible starting surface for functionalization.
Anti-stiction and tribological coatings. Fluorosilane (FDTS, PFDTS) and other self-assembled monolayers need a clean, hydroxyl-rich surface to form a dense film. Plasma is the standard pretreatment for anti-stiction and low-friction coatings on silicon MEMS.
Bonding, packaging and flexible MEMS. Plasma activation enables room-temperature bonding of PDMS, glass and ceramics, and improves wetting of electrodes and elastomer layers in flexible pressure, strain and tactile sensors. See also: PDMS Bonding.
Working on a MEMS process? Tell us your materials, sample size and the step you are trying to improve, and we will point you to published conditions from Harrick users and the configuration that fits. Request a Quote or email info@harrickplasma.com.
Microcantilever and Resonator Sensors
Microcantilevers, nanomechanical resonators and acoustic-wave devices turn molecular events into measurable signals: a shift in resonant frequency, a change in surface stress, a bend of a few nanometers. At that scale the sensor surface is part of...
Applications
Life Sciences
Materials
Electronics
Energy
Characterization
Frequently asked questions
Can a benchtop plasma cleaner replace reactive ion etching for MEMS? No. Harrick cleaners produce an isotropic, low-power plasma that is ideal for cleaning, activation and light organic removal. Deep or anisotropic etching still belongs on a cleanroom RIE or DRIE tool.
Does plasma treatment improve SU-8 adhesion to silicon? Yes. A short oxygen plasma (typically 1-5 min) removes organic residue and leaves a hydroxylated surface, which improves SU-8 wetting and adhesion. Coat soon after treatment.
How long does plasma activation last? On silicon and glass it lasts hours if the surface is kept clean; on polymers such as PDMS it fades within hours to days as the surface recovers. Treat shortly before the next step.
Which Harrick model fits MEMS wafers and dies? The Basic Plasma Cleaner suits small dies and chips. The Expanded Plasma Cleaner (6″ chamber) holds wafers up to about 5 in (130 mm) diameter and batches of dies.