Sharp Kabushiki Kaisha Corporation

Akira Okutoh

Yasuyuki Itoh

Takeshi Kijima

Kazuya Ishihara

Masaya Nagata

Hironori Matsunaga

Maho Ushikubo

Shun Mitarai

By depositing a diffusion prevention film constructed of an oxide of aluminum containing barium and heat-treating the diffusion prevention film in the atmosphere of a mixed gas of oxygen and carbon dioxide, carbon dioxide is made to adsorb to the barium contained in the diffusion prevention film . The diffusion prevention film can effectively restrain the permeation of hydrogen and has an excellent hydrogen barrier property. By using the diffusion prevention film for a capacitor, a high-yield semiconductor storage device having the capacitor of a stable ferroelectric characteristic or high dielectric characteristic can be obtained.

Diffusion prevention film and a semiconductor storage device

An alloy oxide film of platinum and rhodium is formed as an upper electrode so as to be put in direct contact with a ferroelectric PZT film. Asymmetry of a hysteresis loop characteristic of a dielectric material representing a correlation between a polarization value and an application electric field as well as a deterioration such as an increase in leak current density, when oxide electrode of IrO,, RuO,, RhO,or the like is used, are improved.

Semiconductor memory device prevented from deterioration due to activated hydrogen

In a semiconductor storage device in a stack structure wherein a capacitor section having an upper electrode, a dielectric layer, and a lower electrode is connected with a transistor section by a plug, the lower electrode is formed in contact with the plug. The lower electrode is formed of at least an oxide of a platinum-rhodium alloy. In addition to the oxide of a platinum-rhodium alloy, platinum and/or a platinum-rhodium alloy can be used as materials for forming the lower electrode. The plug is formed of polysilicon or tungsten. When the plug is formed of polysilicon, the lower electrode is formed by sequentially laminating, for example, a film of the oxide of the platinum-rhodium alloy, a film of the platinum-rhodium alloy, and a film of the oxide of the platinum-rhodium alloy on the plug.

Semiconductor storage device having a capacitor electrode formed of at least a platinum-rhodium oxide

A method for manufacturing a ferroelectric thin film having a layered perovskite crystal structure of the general formula: Bi.sub.2 A.sub.m-1 B.sub.m O.sub.3m+3, wherein A is selected from the group consisting of Na.sup.1+, K.sup.1+, Pb.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+ and Bi.sup.3+, B is selected from the group consisting of Fe.sup.3+, Ti.sup.4+, Nb.sup.5+, Ta.sup.5+, W.sup.6+ and Mo.sup.6+, and m represents an integer of 1 or larger, which comprises introducing into a film formation chamber where a substrate is set, gaseous starting materials inclusive of oxygen gas for forming the ferroelectric thin film in which the flow rate of oxygen gas as one component of the gaseous starting materials is controlled to an arbitrary value necessary for the formation of the ferroelectric thin film having a desired orientation while the pressure inside the film formation chamber and the total flow rate of the gaseous starting materials and an optionally introduced carrier gas are maintained constant.

Growing community of inventors

Kobe, Japan

Akira Okutoh