Subject: Re: Double layer PMMA dose
From: James Conway <>
Date: Thu, 29 Jan 2004 16:45:26 -0800

Hi Scott:

Hitachi 30 KeV:

Threshold to clear large areas:  350 uC/cm2
Normal area dose I use:  500 uC/cm2

Line dose to 100 - 150 nm: 650 - 800 uC/cm2   Jing Kong used 900 uC/cm2

You will have to adjust your dose for 10 keV downward divide by 2.5.
10 keV gave me ~ 0.2 um of undercut.

I will be running more samples in late February.

All the best,


Scott D. Andrews wrote:

>Does anyone have recent data on the proper dot and line dose for the
>bilayer PMMA process?  If you also know the undercut you achieved, could
>you let me know that as well?
>Thank you,
>Scott Andrews