Results for Si etching in the IBE

Made by Kristian Hagsted Rasmussen @ Nanotech <br\>

Best recipe with respect to the etch profile and low redeposition:

Parameter	Best Si etching recipe so fare
Neutalizer current [mA]	450
RF Power [W]	1200
Beam current [mA]	400
Beam voltage [V]	600
Beam accelerator voltage	400
Ar flow to neutralizer [sccm]	6.0
Ar flow to beam [sccm]	6.0
Rotation speed [rpm]	20
Stage angle [degrees]	5
Results	vvv
Etch rate [nm/min]	17-18

Etch results

The silicon etch test was made as a preliminary test of the IBE system, to obtain a felling of the system capabilities and the different parameters influence on etch outcome. A throughout characterization of the wafers was not carried out. However, the most important results are listed here. The table list the best etch definition obtained. The IBE etcher should only be used for silicon etching, if you have a specific need that cannot be accommodated in a RIE tool. This could be excessive amount of metals on the surface or a layer of silicon in a stack of several layers that all must be etched. The corner definition is strongly dependent on both accelerator and beam voltage and of course the incident angle. However, no interactions between parameters seem to influence the angle outcome. The good corner definition will introduce hare ears at the resist edge. Which is best limited by use of thin resist layers only thick enough to mask for the duration of the etch. Be aware that the selectivity between silicon and resist is poor.