Specific Process Knowledge/Etch/Etching of Polymer/Etch of Photo Resist using RIE

For a general introduction to RIE at Danchip see RIE (Reactive Ion Etch)

Etching of polymer using RIE should only be done if you have no other options. The reason for this is that we want to keep our RIE's as clean as possible. However it can be used for stripping your resist after an etch if you need to keep your sample clean or you need to remove a very thin layer of resist before a RIE etch - like a descum. The process for etching away photoresist or other polymers involves an O2 plasma.Our standard cleaning recipe has been tested for a load of 50% resist on a wafer.

Some RIE recipes for etching of silicon nitride:

Name	O2 flow	N2 flow	Pressure	Power
clean05	99 sccm	20 sccm	300 mTorr	100 W

Expected result using the above RIE recipes for etching of photoresist:

You should be aware that the result can deviate quit a lot from what is written here depending on ex. the mask loading.

Name	Tested with mask load:	Etch rate	Comments
Clean5 on RIE1	50%	~645 nm/min	After the resist has been exposed to 4 min of a Si etch
Clean05 on RIE2	50%	~740 nm/min	without being exposed to RIE before the photoresist etch