Regarding Michael's point below, that cracking in SU-8 is due to
over-exposure:

While intuitively this makes sense, in practice it's not what I've seen. In
my experience, a wide exposure matrix, starting well below the optimal dose,
always shows obvious, macroscopic cracking when *under*exposed. These
disappear entirely when overexposed, even when highly overexposed (though of
course, eventually your features eventually disappear as well...)

Anyone else care to weigh in on this?

- Kevin

On 2/19/08 11:43 PM, "Michael Larsson"  wrote:

> Hi Sonic,
>
> The cracking indicates your layer is under high tensile stress. I would
> guess that the through-thickness cracking is the combined effect of
> over-exposure and/or over-baking (i.e. excess dehydration).


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Kevin Paul Nichols
MESA+ Institute for Nanotechnology
Mesoscale Chemical Systems
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