XeF2 process is highly selective to a range of materials including SiO2, Si3N4. This process means that large undercuts of structures can be performed with no degradation in etch rate and a wide range of films including all forms of silicon can be etched.
What is XeF2?
Xenon difluoride is a powerful fluorinating agent with the chemical formula XeF2, and one of the most stable xenon compounds. Xenon difluoride is adense, white crystalline solid.
How does it etch silicon?
The XeF2 adsorbs and dissociates to xenon (Xe) and fluorine (F) on the surface of silicon. Fluorine is the main etchant in the silicon etching process. The reaction between silicon and XeF2 is described as: »» 2 XeF2 + Si → 2 Xe + SiF4
What are the advantages of XeF2 etching?
XeF2 is highly selective to silicon with respect to aluminum, photoresist and silicon dioxide. It has a relatively high etch rate and does not require ion bombardment or external energy sources in order to etch silicon. Since it is isotropic, large structures can be undercut.
How do you get the vapor into the chamber?
memsstar is unique in using a carrier gas method to flow HF or XeF2 into the
process chamber. Called “Controlled Continuous Flow,” this technique is
the bedrock for the process performance.
Large process window to optimize process for any structure.
with silicon nitride and silicon dioxide (<5% 1σ)
Unique process controls deliver tunable etch rates, uniformity and selectivity, with endpoint capability and thermal control of the wafer during etch.
for undercut and blanket Si
For up to 150 mm wafers
XeF2, N2