Method for fabricating stacked capacitor having excellent anti-oxidation property
AssigneeNEC Corporation
InventorYoshitake Kato
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Abstract
A stacked capacitor includes a top electrode, a capacitor insulator film made of BST, and a bottom electrode having a hollow cylindrical shape and connected through a contact plug to a diffused region of a silicon substrate. The bottom electrode includes a barrier layer, a first electrode layer and a second electrode layer, wherein the first and the second electrode layers are deposited on the barrier layer, followed by patterning of the second electrode layer for forming a hollow therein. The contact resistance between the bottom electrode and the contact plug is low due to excellent crystalline orientation alignment of the first electrode layer and thus prevention of oxidation of the contact plug during deposition of the BST film.
Claims6
A method for fabricating a stacked capacitor comprising the steps of forming a first dielectric film having therein a contact plug in contact with a diffused region of a semiconductor substrate, depositing a bottom electrode layer on the first dielectric film and the contact plug, selectively etching the bottom electrode layer to form an island bottom electrode in contact with the contact plug, depositing a second dielectric film on the first dielectric film to embed the island bottom electrode, selectively etching the island bottom electrode to form a hollow cylindrical electrode having a closed bottom, depositing a capacitor insulator film on the second dielectric film and inside the hollow cylindrical electrode, and depositing a top electrode on the capacitor insulator film.
Dependencies are inferred from the claim text.