Self-aligned V0-contact for cell size reduction
View Patent ↗An FeRAM comprising includes a ferroelectric material sandwiched between a top electrode and a bottom electrode. A V0-contact provides an electrical connection with an underlying CS-contact. The V0-contact is aligned using the bottom electrode. A liner layer covers a sidewall of the bottom electrode and provides a stop to an etch a hole forming the V0-contact. A method is utilized to form a V0-contact in an FeRAM comprising. An Fe capacitor of the FeRAM is encapsulated, a bottom electrode is etched, a liner layer is deposited covering a sidewall of the bottom electrode, and a hole is etched for the VO-contact until the etching is stopped by the liner layer.
1. An FeRAM comprising:
a ferroelectric material sandwiched between a top electrode and a bottom electrode;
a V0-contact for providing an electrical connection with an underlying CS-contact, the V0-contact being formed in a hole and being aligned by the bottom electrode;
a liner layer covering a sidewall of the bottom electrode for providing a atop to an etch of the V0-contact hole; and
an alumina spacer deposited on the walls of the V0-contact hole following etching of the hole so that the alumina spacer extends over substantially the entire walls of the V0-contact hole.