Tantalum capacitor

About: Tantalum capacitor is a research topic. Over the lifetime, 2432 publications have been published within this topic receiving 26709 citations.

Capacitors, methods of forming capacitors, and DRAM memory cells

Abstract: Capacitors and methods of forming capacitors are disclosed. In one implementation, a capacitor comprises a capacitor dielectric layer comprising Ta 2 O 5 formed over a first capacitor electrode. A second capacitor electrode is formed over the Ta 2 O 5 capacitor dielectric layer. Preferably, at least a portion of the second capacitor electrode is formed over and in contact with the Ta 2 O 5 in an oxygen containing environment at a temperature of at least about 175° C. Chemical vapor deposition is one example forming method. The preferred second capacitor electrode comprises a conductive metal oxide. A more preferred second capacitor electrode comprises a conductive silicon comprising layer, over a conductive titanium comprising layer, over a conductive metal oxide layer. A preferred first capacitor electrode comprises a conductively doped Si-Ge alloy. Preferably, a Si 3 N 4 layer is formed over the first capacitor electrode. DRAM cells and methods of forming DRAM cells are disclosed.

Metal-insulator-metal capacitors’ current instability improvement using dielectric stacks to prevent oxygen vacancies formation

Abstract: Current instability in metal-oxide-semiconductor and metal-insulator-metal (MIM) capacitors has been previously reported to be a potential reliability issue. This letter intends to study a particular way to reduce these current instabilities with time in high-κ MIM capacitors. It consists in the introduction of a stable dielectric layer between the high-κ dielectric and the electrodes in order to prevent oxygen vacancy formation at interfaces. When applied to Ta2O5 capacitors, the deposition of a thin layer of Al2O3 in the range of a few tens of angstroms enables the strong reduction of current instabilities while maintaining good electrical performances.

Semiconductor memory device with a capacitor having a protection layer

Abstract: A semiconductor memory device in which a protection layer is disposed between a silicon storage electrode and a tantalum pentoxide dielectric layer. A conductive material having a larger free energy of oxide formation than that of the tantalum pentoxide is used for forming the protection layer. Therefore, no native oxide film is formed at the interface between the storage electrode and the dielectric layer. As a result, the dielectric constant of the dielectric layer does not decrease even when the dielectric layer is a thin film.

Method for forming a tantalum oxide capacitor

Abstract: A method for forming capacitor using a tantalum oxide (TaO5) layer is disclosed. Tantalum oxide is deposited by an atomic layer deposition ALD process so that the step-coverage of the tantalum oxide layer is improved, and accordingly the electrical characteristics of the capacitor are improved.

Clockwise C‐V hysteresis phenomena of metal–tantalum‐oxide–silicon‐oxide–silicon ( p) capacitors due to leakage current through tantalum oxide

Abstract: Thermal tantalum oxide with a thickness of 620 A was studied. The dc leakage resistance and high‐frequency (1‐MHz) resistance of a metal–tantalum‐oxide–silicon capacitor were found to be on the order of 108 and 1 Ω cm2, respectively. The C‐V behavior of the capacitor, with its initial states being carefully treated, was reproduced and observed to be dependent on the return voltage and hold time (at return point) of the measurement conditions. And only negative charges were observed to be responsible for the conduction current through tantalum oxide. A model with the considerations of the ac equivalent circuit and low‐frequency leakage characteristic of tantalum oxide was proposed for these observations. Theoretical examples, with their parameters being suitably given according to the measured data, were shown, and they explained the experimental observations quite well. It is found that the measurement conditions and effect of the ac resistance of tantalum oxide on the determination of flat‐band capacitance are important and should be carefully considered when one is interpreting the interface charges from C‐V curves.