The primary difference between the two is the base salt that is used for
development purposes.  AZ300MIF is TMAH based (the MIF stands for "metal
ion free"), and the AZ400K uses KOH.

The information I have received from AZ is that the AZ400K will tend to
develop a little faster, and provide a bit better sidewall performance
(meaning more vertical sidewalls).  I have always tended to use a 1:4
dilution (1 part developer to 4 parts water) to develop AZP4620.

Best Regards,
Chad Brubaker

 -----Original Message-----
From: haixinzhu
Subject: [mems-talk] Question on AZ400k and AZ300MIF

Hello, All,

I have a question on the difference between AZ400k and AZ300MIF developer
used for AZP4620 photoresist. The official website
http://www.az-em.com/products/na/photoresists/thick_film.html shows the
developer is AZ300MIF, but I heard many people are using AZ400k
developer.

Anyone can help me out on this, thanks

Michael