Dear Chih-Chieh,
                      did you annealed the PECVD Si3N4.If it is not
annealed,then there will be lot of dangling bonds in it.So gold can diffuse
through even at low temp.this may be the reason of increasing leakage current.

bye
jaibir sharma


On Tue, 28 Aug 2007 Chih-Chieh Cheng wrote :
>Hi
>
>We have fabricated MIM structures (Au-PECVD Si3N4-SiCr) and found that the
>leakage current of Si3N4 was incrediblely increased after SU-8 adhesive
>bonding. We used semi-crossed linked SU-8 as the adhesive layer so that we
>can create cavities on the bottom wafer and bond to MIM structure on
>the bottom wafer. The SU-8 layer was right on the top of the Au layer after
>bonding. The bonding temp was ramped up to 150 degree C with the applied
>force 2000 NT over the 4" fused quartz wafer for 1hr. Could anyone share
>with your insightful comments on the degradation of Si3N4 layer?