Integrated and Discrete Capacitors Based on Carbon Nanostructures with Capacitance Densities in Excess of 350 nF/​mm2

Com­plete on-chip ful­ly sol­id-state 3D inte­grat­ed capac­i­tors using ver­ti­cal­ly aligned car­bon nanofibers as elec­trodes to pro­vide a large 3D sur­face in a MIM con­fig­u­ra­tion have been man­u­fac­tured and char­ac­ter­ized. The capac­i­tance per device foot­print area has been stud­ied, as well as its behav­ior at dif­fer­ent tem­per­a­tures and fre­quen­cies. Equiv­a­lent series resis­tance (ESR), break­down volt­age and leak­age cur­rent have also been mea­sured. The entire man­u­fac­tur­ing process of the capac­i­tors is com­plete­ly CMOS com­pat­i­ble, and in com­bi­na­tion with the low device pro­file of about 4 µm this makes the devices read­i­ly avail­able for inte­gra­tion on a CMOS-chip, in 3D stack­ing, or redis­tri­b­u­tion lay­ers in a 2.5D inter­pos­er tech­nol­o­gy. Capac­i­tances of ca 350 nF/​mm², ESR of about 100 mΩ, break­down volt­ages of up to 25 V and leak­age cur­rents in the order of 0.004 nA/​nF have been measured.