Subject: Re: Dose for 5% PMMA E-beam
From: James Conway <jwc@snf.stanford.edu>
Date: Wed, 25 Apr 2007 10:33:50 -0700
Wed, 25 Apr 2007 10:33:50 -0700
Hello Arash and Ebeam and RAITH  Users:

On the HL-700 at 30 kV I have found 320 - 340 uC/cm**2 works well for 
patterns to 100 nm. Below that dimension you will have to increase your 
dose markedly.

On the Raith at 10 kV just this week using 5% 950K PMMA - A,  Raith 
Group XXVI has found 140 uC/cm**2 to be a bit too high and 120 uC/cm**2 
just a bit too low for area features to ~ 100 nm. Single pixel lines are 
in the 360 - 420 uC/cm range.

Note that currently their are two blends of 5% PMMA in anisole:
Our normal 5% 495K MW PMMA - A and currently I am testing a batch of 5% 
950K MW PMMA-A which is also in the Ebeam resist tub.

Users are encouraged to report their dose determinations to the email 
lists to aid new users coming onto the system.  You may also wish to 
review other user's doses reported in the RAITH operations log book.  
There is much information to be gleaned from this data.

Best,

James Conway



Arash Hazeghi wrote:
> Hello,
> I am wondering if anyone has used 5% PMMA-A recently with good 
> results. I'd be happy to know what your dose was. last time I used the 
> system with .dos=340 my pattern was severely overexposed.
>
> Thanks,
> Arash
>
>
>
>
>
> --------------------------------------------------------------------------
>
> Arash Hazeghi
>
>
> PhD Candidate
>
> Stanford Center for Integrated Systems,
>
> 420 Via Palou Mall, CIS-X 300
>
> tel: 650-725-0418
>
> mobile: 650-353-1866
>
> http://www.stanford.edu/group/nanoelectronics/index.htm
>
>


Hello Arash and Ebeam and RAITH  Users:

On the HL-700 at 30 kV I have found 320 - 340 uC/cm**2 works well for patterns to 100 nm. Below that dimension you will have to increase your dose markedly.

On the Raith at 10 kV just this week using 5% 950K PMMA - A,  Raith Group XXVI has found 140
uC/cm**2 to be a bit too high and 120 uC/cm**2 just a bit too low for area features to ~ 100 nm. Single pixel lines are in the 360 - 420 uC/cm range.

Note that currently their are two blends of 5% PMMA in anisole:
Our normal 5% 495K MW PMMA - A and currently I am testing a batch of 5% 950K MW PMMA-A which is also in the Ebeam resist tub.

Users are encouraged to report their dose determinations to the email lists to aid new users coming onto the system.  You may also wish to review other user's doses reported in the RAITH operations log book.  There is much information to be gleaned from this data.

Best,

James Conway



Arash Hazeghi wrote:
Hello,
I am wondering if anyone has used 5% PMMA-A recently with good results. I'd be happy to know what your dose was. last time I used the system with .dos=340 my pattern was severely overexposed.

Thanks,
Arash





--------------------------------------------------------------------------

Arash Hazeghi


PhD Candidate

Stanford Center for Integrated Systems,

420 Via Palou Mall, CIS-X 300

tel: 650-725-0418

mobile: 650-353-1866

http://www.stanford.edu/group/nanoelectronics/index.htm