Thermal treatment of a semiconductor wafer in the fabrication of integrated circuits including MOS transistors and ferroelectric capacitors, including those using lead-zirconium-titanate (PZT) ferroelectric material, to reduce variation in the electrical characteristics of the transistors. Thermal treatment of the wafer in a nitrogen-bearing atmosphere in which hydrogen is essentially absent is performed after formation of the transistors and capacitor. An optional thermal treatment of the wafer in a hydrogen-bearing atmosphere prior to deposition of the ferroelectric treatment may be performed.

Non-volatile memory cells including complimentary metal-oxide-semiconductor transistors and embedded ferroelectric capacitor and methods of forming the same are described. In one embodiment, the method includes forming on a surface of a substrate a gate level including a gate stack of a MOS transistor, a first dielectric layer overlying the MOS transistor and a first contact extending through the first dielectric layer from a top surface thereof to a diffusion region of the MOS transistor. A local interconnect (LI) layer is deposited over the top surface of the first dielectric layer and the first contact, a ferro stack including a bottom electrode, a top electrode and ferroelectric layer there between deposited over the LI layer, and the ferro stack and the LI layer patterned to form a ferroelectric capacitor and a LI through which the bottom electrode is electrically coupled to the diffusion region of the MOS transistor.

The disclosed technology generally relates to ferroelectric materials and semiconductor devices, and more particularly to semiconductor memory devices incorporating doped polar materials. In one aspect, a capacitor comprises a crystalline polar layer comprising a base polar material substitutionally doped with a dopant. The base polar material comprises one or more metal elements and one or both of oxygen or nitrogen. The dopant comprises a metal element of one of 4d series, 5d series, 4f series or 5f series that is different from the one or more metal elements, such that a ferroelectric switching voltage of the capacitor is different from that of the capacitor having the base polar material without being doped with the dopant by more than about 100 mV.

Disclosed is a capacitor having a high dielectric constant and low leakage current and a method for fabricating the same, wherein the capacitor may include a first conductive layer, a second conductive layer, a dielectric layer stack between the first conductive layer and the second conductive layer, a dielectric interface layer between the dielectric layer stack and the second conductive layer, and a high work function interface layer between the dielectric interface layer and the second conductive layer.

A semiconductor device includes a random access memory (RAM) structure and a dielectric layer. The RAM structure is over a substrate and includes a bottom electrode layer, a ferroelectric layer over the bottom electrode layer, and a top electrode layer over the ferroelectric layer. The dielectric layer is over the substrate and laterally surrounds a lower portion of the RAM structure. From a cross-sectional view, the bottom electrode layer of the RAM structure has a lateral portion and a vertical portion, and the vertical portion upwardly extends from the lateral portion to a position higher than a top surface of the dielectric layer.

A device structure comprises a first conductive interconnect, an electrode structure on the first conductive interconnect, an etch stop layer laterally surrounding the electrode structure; a plurality of memory devices above the electrode structure, where individual ones of the plurality of memory devices comprise a dielectric layer comprising a perovskite material. The device structure further comprises a plate electrode coupled between the plurality of memory devices and the electrode structure, where the plate electrode is in direct contact with a respective lower most conductive layer of the individual ones of the plurality of memory devices. The device structure further includes an insulative hydrogen barrier layer on at least a sidewall of the individual ones of the plurality of memory devices; and a plurality of via electrodes, wherein individual ones of the plurality of via electrodes are on a respective one of the individual ones of the plurality of memory devices.

1. Various embodiments of the present disclosure are directed towards a ferroelectric random-access memory (FeRAM) cell or some other suitable type of memory cell comprising a bottom-electrode interface structure. The memory cell further comprises a bottom electrode, a switching layer over the bottom electrode, and a top electrode over the switching layer. The bottom-electrode interface structure separates the bottom electrode and the switching layer from each other. Further, the interface structure is dielectric and is configured to block or otherwise resist metal atoms and/or impurities in the bottom electrode from diffusing to the switching layer. By blocking or otherwise resisting such diffusion, leakage current may be decreased. Further, endurance of the memory cell may be increased.

A device structure comprises a first conductive interconnect, an electrode structure on the first conductive interconnect, an etch stop layer laterally surrounding the electrode structure; a plurality of memory devices above the electrode structure, where individual ones of the plurality of memory devices comprise a dielectric layer comprising a perovskite material. The device structure further comprises a plate electrode coupled between the plurality of memory devices and the electrode structure, where the plate electrode is in direct contact with a respective lower most conductive layer of the individual ones of the plurality of memory devices. The device structure further includes an insulative hydrogen barrier layer on at least a sidewall of the individual ones of the plurality of memory devices; and a plurality of via electrodes, wherein individual ones of the plurality of via electrodes are on a respective one of the individual ones of the plurality of memory devices.

The disclosed technology generally relates to ferroelectric materials and semiconductor devices, and more particularly to semiconductor memory devices incorporating doped polar materials. In one aspect, a semiconductor device comprises a capacitor, which in turn comprises a polar layer comprising a crystalline base polar material doped with a dopant. The base polar material includes one or more metal elements and one or both of oxygen or nitrogen, wherein the dopant comprises a metal element that is different from the one or more metal elements and is present at a concentration such that a ferroelectric switching voltage of the capacitor is different from that of the capacitor having the base polar material without being doped with the dopant by more than about 100 mV. The capacitor additionally comprises first and second crystalline conductive or semiconductive oxide electrodes on opposing sides of the polar layer, wherein the polar layer has a lattice constant that is matched within about 20% of a lattice constant of one or both of the first and second crystalline conductive or semiconductive oxide electrodes. The first crystalline conductive or semiconductive oxide electrode serves as a template for growing the polar layer thereon, such that at least a portion of the polar layer is pseudomorphically formed on the first crystalline conductive or semiconductive oxide electrode.

Ferroelectric stacks are disclosed herein that can improve retention performance of ferroelectric memory devices. An exemplary ferroelectric stack has a ferroelectric switching layer (FSL) stack disposed between a first electrode and a second electrode. The ferroelectric stack includes a barrier layer disposed between a first FSL and a second FSL, where a first crystalline condition of the barrier layer is different than a second crystalline condition of the first FSL and/or the second FSL. In some embodiments, the first crystalline condition is an amorphous phase, and the second crystalline condition is an orthorhombic phase. In some embodiments, the first FSL and/or the second FSL include a first metal oxide, and the barrier layer includes a second metal oxide. The ferroelectric stack can be a ferroelectric capacitor, a portion of a transistor, and/or connected to a transistor in a ferroelectric memory device to provide data storage in a non-volatile manner.