[labnetwork] Piranha & HF no rinse protocols

[Morrison, Richard H., Jr.]

HI,

Here at Draper we regulate the use of 1:1 Sulfuric/H2O2 to one bench and only one bath at a time. The mixture reacts very violently and heats very quickly. In fact one time the mixture caused a small fire as a quartz bath failed and melted down and fire retardant plastic was melted and almost ignited.

After that step there is a rinse in DI followed by the HF. You cannot mix the 1:1 with the HF bath that would be a bad idea, so you need to rinse after that step.  If it is a bare silicon wafer then the wafer sheets off of the wafer but not the wafer cassette or wafer holder so a rinse is needed. I guess you could try to take out the wafer and dry it somehow but that is very risky. HF is very dangerous I do not recommend skipping the rinse step.

Rick


Draper Laboratory
Principle Member of the Technical Staff
Group Leader Microfabrication Operations
555 Technology Square
Cambridge Ma, 02139-3563

www.draper.com
rmorrison at draper.com
W 617-258-3420
C 508-930-3461



From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Errol V. Porter
Sent: Wednesday, February 26, 2014 5:44 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Piranha & HF no rinse protocols

Greetings,

I am trying to get a consensus and feedback from the group on a wet etch process using 1st H2SO4:H2O2 (1:1) and 2nd HF:H2O (10:1) where the water rinse is omitted. If this is an acceptable practice in some special circumstances, what safeguards to you put in place to protect the users.

Regards,

Errol Porter
University of Arkansas / HiDEC
700 W. Research Center Blvd
Fayetteville, AR 72701
Tel. (479) 575-2519
Mobile: (479) 236-0693
Fax (479) 575-2719
email: evporte at uark.edu<mailto:evporte at uark.edu>
http://www.hidec.uark.edu<http://www.hidec.uark.edu/>

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