SPTS Si DRIE

SPTS Si DRIE

Tool Name	SPTS Si DRIE
Instrument Type	Etch
Staff Manager	Sam Azadi
Lab Location	Bay 2
Tool Manufacturer	SPTS
Tool Model	Rapier
NEMO Designation	{{{NEMO_Designation}}}
Lab Phone	215-898-9748
SOP Link	SOP

Description

SPTS Rapier is an anisotropic dry etch tool. The tool uses Bosch Process to etch silicon with high selectivity and nearly vertical sidewalls. Bosch process consists of two steps: 1) Deposition of a passivation layer, using C4F8 gas. This passivation layer is a polymer that protects the sidewalls from being etched. 2) A nearly vertical plasma etch step using SF6. A bias is applied in the chamber that forces the ions to attack the surface vertically and etch through the passivation layer at the bottom of the trench, exposing the silicon underneath. That Si is then etched within the same step. The passivation layer is also deposited inside the chamber and the etch results in a layer of deposited polymer inside the chamber walls which makes it critical to run a cleaning recipe at the end of each etch run.

Shorter cycle times result in smoother sidewalls while longer cycle times achieve higher etch rate. The tool in QNF is connected to Ar, O2,N2, C4F8, and SF6 gases.

Applications

• Deep etching of Si

Etch masks allowed

• Resist
• SiO2, SiNx, Al2O3, AlN

- No metal is allowed in the chamber!

Post etch sample cleaning procedure

We recommend an O₂ plasma in a barrel asher for removal of residue of the passivation layer as well as remainder of resist mask.

The standard cleaning recipe is a 300 Watt O₂ plasma for 1 hour, with 100 sccm O₂ flow - see DE-02 tool page.

Resources

SPTS Etch Recipe Characterization

Training Part 1, Introduction & Wafer Cleaning

Training Part 2, Operating The Tool

SOPs & Troubleshooting

• QNF SOP