Samsung Electronics Co., Ltd.

In-kyung Yoo

Chi-won Chung

Seshu B Desu

Jun-ki Lee

Il-Sub Chung

Wan-in Lee

Il-sub Chung

A ferroelectric capacitor taking a multilayer structure wherein a conductive oxide layer which is formed between a metal electrode and a ferroelectric layer, capable of enhancing the fatigue behavior in addition to reducing the leakage current. The multilayer structure can be fabricated by depositing a silicon oxide (SiO.sub.2) layer, an adhesive layer, a bottom metal layer, a lower conductive oxide layer, a ferroelectric layer, an upper conductive oxide layer and a top metal electrode layer are deposited over a silicon substrate, in sequence.

Method for fabricating a ferroelectric capacitor

A novel ferroelectric random access memory structure which comprises a capacitor consisting of upper and lower plane electrodes and a ferroelectric inserted therebetween, and a transistor comprising a means of inducing the capacitor to polarization and maintaining it, connected with at least one of the electrodes, wherein the electric potential of the upper electrode is equalized with that of the lower electrode, thereby preventing the polarization reversal caused by pyroelectric charges.

Ferroelectric random access memory circuits and structures for

A ferroelectric capacitor structure variously having ceramic lower and upper electrodes, lower and upper insert layers, metal lower and upper electrodes, and a ferroelectric. The ceramic electrode(s) are variously connected with a writing terminal, and the metal electrodes are variously connected with a reading terminal. The use of a combination of metal and ceramic electrodes avoids both fatigue and leakage current.

Ferroelectric capacitor structure

PZT ferroelectric thin films for capacitors comprise a combination of a donor dopant and an acceptor dopant in a total amount of about 0.1 to 8 mole percent of PZT, or Sc alone in an amount of about 0.1 to 5 mole percent. Nb or Ta is employed as a donor dopant, while Sc, Mg or Zn can be used as an acceptor dopant. The presence of a single Sc acceptor dopant, or both an acceptor dopant and a donor dopant, results in increased endurance. Fatigue cycles are increased on the order of about 10.sup.5 relative to dopant-free films. Doping with a single Sc acceptor dopant, or both an acceptor dopant and a donor dopant, reduces coercive field, allowing PZT films to switch at relatively low voltages. PZT thin films of a pure perovskite phase are obtained in which a pyrochlore phase is completely excluded. Pt may be used as an electrode material. The leakage current of PZT films doped with both the acceptor and donor elements are similar to the leakage current level of pure PZT thin films.

Growing community of inventors

Kyungki-do, South Korea

In-kyung Yoo