Methods of fabricating three-dimensional capacitor structures having planar metal-insulator-metal and vertical capacitors therein
Methods of forming a three-dimensional capacitor network may include forming a first horizontal MIM capacitor on a semiconductor substrate and forming a first interlayer insulating layer on the first horizontal MIM capacitor. A first vertical capacitor electrode is then formed in the first interlayer insulating layer and a second horizontal MIM capacitor is formed on the first interlayer insulating layer. This second horizontal MIM capacitor may be formed by forming an upper capacitor electrode and a lower capacitor electrode. The upper capacitor electrode may be electrically connected by the first vertical capacitor electrode to an upper capacitor electrode of the underlying first MIM capacitor. The lower capacitor electrode, which may be formed in the first interlayer insulating layer, may extend opposite the upper electrodes of the first and second MIM capacitors.
1. A method of forming a three-dimensional capacitor network, comprising:
forming a first horizontal MIM capacitor comprising a planar and non-interdigitated upper capcitor electrode and a first capacitor dielectric layer containing a first dielectric material, on a semiconductor substrate, said semiconductor substrate comprising a first plurality of stripe-shaped semiconductor regions and a second stripe-shaped semiconductor region extending between first and second ones of the first plurality of stripe-shaped semiconductor regions;
forming a first interlayer insulating layer on the first horizontal MIM capacitor, said first interlayer insulating layer comprising a second dielectric material having a lower dielectric constant relative to the first dielectric material;
forming first and second vertical capacitor electrodes in the first interlayer insulating layer, said first and second vertical capacitor electrodes electrically connected to the first and second ones of the first plurality of stripe-shaped semiconductor regions, respectively; and
forming a second horizontal MIM capacitor on the first interlayer insulating layer, by:
forming a non-interdigitated upper capacitor electrode electrically connected in parallel by the first and second vertical capacitor electrodes to the upper capacitor electrode of the first MIM capacitor;
forming a lower capacitor electrode in the first interlayer insulating layer that extends opposite the upper electrodes of the first and second MIM capacitors and between the first and second vertical capacitor electrodes, said lower capacitor electrode electrically connected to the second stripe-shaped semiconductor region; and
forming a second capacitor dielectric layer of the second horizontal MIM capacitor on the first interlayer insulating layer and on the lower capacitor electrode of the second horizontal MIM capacitor, said second capacitor dielectric layer comprising a third dielectric material having a higher dielectric constant relative to the second dielectric material;
wherein said forming first and second vertical capacitor electrodes and said forming a lower capacitor electrode in the first interlayer insulating layer comprise filling trenches in the first interlayer insulating layer with electrically conductive materials before said forming the capacitor dielectric layer of the second horizontal MIM capacitor; and
wherein the first vertical capacitor electrode and the second vertical capacitor electrode extend through the first interlayer insulating layer to a greater extent than a portion of the lower capacitor electrode extending between the first and second vertical capacitor electrodes.