Agree with Mamun. Sputtered metal generates an apron on the edge. Try e-beam
or thermal evaporation.

Another suggestion is in step10, to soak your sample overnight before try
ultrasonication. If possible, avoid ultrasonication.

Jie

2010/5/15 Gonca ARAS 

>

> Hi all,
>
> I want to make lift off by using positive resist AZ5214.
>
> My problem is the defects at the edge of my figure (from 1 um width to 10
> um width) after the liftoff process.
>
> My recipe:
> 1. step cleaning and dehydration bake
> 2. step 4000 rpm 40 sec HMDS
> 3. step 4000 rpm 40 sec AZ5214
> 4. step soft bake 110 oC 55 sec
> 5. step exposure 5mW 75 sec (soda lime mask,Karl Süss MJB3)
> 6. step 10 min chlorobenzene soak
> 7. step blow off  chlorobenzene with N2
> 8. step develop AZ 400K:DI=1:4 70 sec ,rinse with DI, blow dry with N2
> 9. step Cr sputter 100 nm (hard mask during the reactive ion etcing
> process)
> 10. step lift off ultrasonic bath
>
> best regards
>
> Gonca Aras
> [email protected]

*  Zou Jie (Jay)
*  Department of Physics
*  University of Florida
*  Tel: +1-352-846-8018
*  Email: [email protected]
*  Homepage: http://plaza.ufl.edu/zoujie/