Abstract: An improved process for forming a contact on a top electrode of a capacitor is described. The process includes forming an encapsulation layer on at least the top electrode of the capacitor. When the contact hole is etched, the encapsulation layer is not removed. After the contact hole is formed, the resist mask is removed. Since the encapsulation layer remains on the top electrode, the capacitor is protected from hydrogen resulting from the decomposition of the resist material.

Abstract: A capacitor with improved reliability is disclosed. The capacitor includes a bottom electrode, a top electrode, and an intermediate layer therebetween. A contact, which is electrically coupled to the top electrode, is provided. At least a portion of the contact is offset from the capacitor. By offsetting the contact from the top electrode, the etch damage to the top electrode is reduced, thereby reducing or eliminating the need for the anneal to repair the etch damage.

Abstract: A capacitor over plug (COP) structure is disclosed. The COP avoids the step which is created in conventional COP structures, which adversely impacts the properties of the capacitor. In one embodiment, the step is avoided by providing a plug having upper and lower portions. The upper portion, which is coupled to the bottom electrode of the capacitor, has substantially the same surface area as the bottom electrode. A barrier layer can be provided between the plug and bottom electrode to avoid oxidation of the plug material.

Abstract: A memory cell which provides a diffusion path for hydrogen to the transistor is disclosed. The diffusion path is provided by forming a contact in which the upper section overlaps the lower section, thus creating a gap that serve as a hydrogen diffusion path. The hydrogen diffusion path is necessary for annealing the damage to the gate oxide.

Abstract: An improved barrier stack for inhibiting diffusion of atoms or molecules, such as O2 is disclosed. The barrier stack is particularly useful in capacitor over plug structures to prevent plug oxidation which can adversely impact the reliability of the structures. The barrier stack includes first and second barrier layers having mismatched grain boundaries. The barrier layers are selected from, for example, Ir, Ru, Pd, Rh, or alloys thereof. By providing mismatched grain boundaries, the interface of the layers block the diffusion path of oxygen. To further enhance the barrier properties, the first barrier layer is passivated with O2 using, for example, a rapid thermal oxidation. The RTO forms a thin oxide layer on the surface of the first barrier layer. The oxide layer can advantageously promote mismatching of the grain boundaries of the first and second barrier layer.