Hi Steven,

Two things that jump out at me are your exposure lamp, and developing
step.

1. I'm not sure about the MA8, but our MA6 had a 1000W lamp in it, and it
was *WAY* too hot for exposing 5214. We had to retrofit a 350W bulb into
it, to make any use out of the system. Has a process been established for
your system yet?

2. I assume your developer is AZ 400K. If that's so, it needs to be
diluted in water ( 1 part AZ400K to 4 parts water), or it will remove
unexposed photoresist as well. You don't indicate any dilution in your
process description.

By the way, I second that oxygen plasma removes HMDS rather quickly and
effectively.

Jesse Fowler




"Steven Yang"  writes:

hi all
I am using AZ5214E as postive PR for the lift-off process. However,
the PR is keeping strip from sub during the development. My procedure
is

(Si sub with 1 micron PECVD SiO2 deposited and pre-cleaned with
actone, IPA, rinse with DI water, dry with N2 flow)

1) Dehydration: hot plate 150C 10 mins
    (no HDMS because I need the sub surface hydrophilic for the later
function)
2) Spin coat: AZ5214E 5000RPM 1000R/s 30s
3) Softbake: 95C 1min
4) Expouse 7s @ 900W (MA8)
5) Develop (AZ developer 30s)
6) Rinse in DI water (30s)
7) Rinse with flow DI water and Dry with N2 flow

The situation is worst when I develop the sample immediately after
expouse, but getting better if I do a hardbake after exposure. But I
am not sure whether this hardbake will make later liftoff difficult or
not?

So, I would appreciate if you guys could give some suggestion on my
procedure. thanks a lot in advance!

Regards,
Steven