Hi Suraj,

Remember, we're talking about a positive-working resist here, so
increased UV exposure won't really help, unless you want to
over-expose regions for removal, so less time is required for
dissolution in developer. In any case, this method will diminish
pattern transfer resolution, and even promote peeling of very fine
features - the very thing you want to avoid.

Regards,

Michael



> ---------- Forwarded message ----------
> From: "Suraj Patil" 
> To: "General MEMS discussion" 
> Date: Sat, 16 Aug 2008 21:27:46 -0500
> Subject: Re: [mems-talk] Photolithography - Resist peeling
> Madhav,
>
> A good thing would be to first check for cleaniness of your develop
> and rinse beakers. Also check with any temperature change with the
> hot-plate (is it showing  accurate temperatures), also if the UV lamp
> is getting used-up, its intensity tend to reduce. Check the intensity
> of the lamp.
>
> One of the abve or all of the above reasons may contribute to your probelm.
>
> Check with the integrity of the Photo-resist (expiry date and stuff).
>
> If everything seems alright, then increase the exposure time by couple
> of seconds (depending on your feature size) and increase the
> post-exposure bake temperature by 10-15 C for the same time and try
> developing.
>
> Hope this helps.
>
> Suraj Patil