New dielectric stack for CNF-MIM capacitors boost capacitance density by 230%

The first phase of this pro­ject has now con­cluded suc­cess­fully, demon­strat­ing sig­ni­fic­ant improve­ments over the pre­vi­ous gen­er­a­tion of dielec­tric stacks. The new stack, based on zir­coni­um oxide, will be integ­rated into future gen­er­a­tions of CNF-MIM capa­cit­ors. The pri­or stack, made from hafni­um oxide, was util­ized in the Gen Zero capa­cit­ors.

The newly developed dielec­tric stack is a blend of two oxides: a high‑k oxide to boost capa­cit­ance dens­ity, and an oxide that serves as a bar­ri­er against charge move­ment, thus min­im­iz­ing cur­rent leakage.

Far­z­an Ghavanini, CTO at Smoltek.

Dur­ing the first phase, Smol­tek Semi focused on par­al­lel plate capa­cit­ors, depos­it­ing the dielec­tric stack on flat sur­faces between two par­al­lel elec­trodes. Per­form­ance meas­ure­ments were car­ried out at the wafer level and after the devices were trans­ferred and moun­ted onto PCBs. The res­ults revealed an extraordin­ary 230% improve­ment in capa­cit­ance dens­ity com­pared to the Gen Zero dielec­tric stack, while anoth­er crit­ic­al per­form­ance met­ric, leak­age cur­rent, showed a 50% reduction.

The res­ults have been out­stand­ing, both in terms of per­form­ance met­rics and repro­du­cib­il­ity. I’m par­tic­u­larly excited about the excep­tion­al repro­du­cib­il­ity achieved dur­ing the first phase, where we reached a fab­ric­a­tion yield of 100%.

Far­z­an Ghavanini

The devices moun­ted on PCBs have now been sent to Yageo who is sup­port­ing Smol­tek with reli­ab­il­ity test­ing and fur­ther characterization.