Vapor HF (Hydrogen Fluoride) Etching

Advanced Dry Release Processing for Current and Next Generation MEMS Devices.

To create a MEMS microstructure, a release etch process is required in order to remove the structural material and leave the mechanical structure with clean and free surfaces. It is essential that removal (etching) of the sacrificial material does not damage or restrict the operation of the MEMS device. To ensure full performance and reliability, the remaining mechanical structure needs to be free from residues, particles and damage, and prepared for the application of an anti-stiction coating or packaging process steps. XERIC™ vapor HF (Hydrogen Fluoride) etching—or vapor phase—sacrificial release etching from memsstar offers many benefits to companies engaged in MEMS development and manufacturing.

XERIC Vapor Phase Dry Release With HF

Using memsstar’s XERIC dry anhydrous HF etching is unique because it eliminates stiction in a single process. The patented process is compatible with the widest wide range of metals—especially Al/alloy and other metals commonly used in MEMS mirrors and electrical contacts.

Sacrificial Oxides:
Thermal oxide, TEOS, SOI bonded oxide, quartz, PECVD oxide, spin-on oxide, low-temperature spin-on glass

Protective Layers:
Aluminum, silicon carbide, Si-rich LPCVD nitride, stoichiometric PECVD nitride

Metal Layers:
Gold, copper, TiW, nickel, aluminum, Ti, TiO2

XERIC Oxide Etch Features
Key characteristics	Large process window to optimize process for any structure Excellent selectivity with silicon nitride and silicon dioxide (<5% 1σ) High selectivity to underlayer and mechanical materials Industry-leading etch rates High etch rates for undercut and blanket Si Excellent uniformity (<5% 1σ) Excellent repeatability (<5% 1σ) No corrosion No stiction In-line controls—etch rate monitor, endpoint, temperature Unique endpoint capability
Application examples	Sensors, RF MEMS, micro bolometer arrays, accelerometers, RF switches, temperature gauges

XERIC Oxide Etch Features

Key characteristics

Large process window to optimize process for any structure
Excellent selectivity with silicon nitride and silicon dioxide (<5% 1σ)
High selectivity to underlayer and mechanical materials
Industry-leading etch rates
High etch rates for undercut and blanket Si
Excellent uniformity (<5% 1σ)
Excellent repeatability (<5% 1σ)
No corrosion
No stiction
In-line controls—etch rate monitor, endpoint, temperature
Unique endpoint capability

Application examples

Sensors, RF MEMS, micro bolometer arrays, accelerometers, RF switches, temperature gauges

memsstar: Vapor HF etching for next generation MEMS devices.