Capacitor fabrication methods and capacitor constructions

Abstract

A capacitor fabrication method may include atomic layer depositing a conductive barrier layer to oxygen diffusion over the first electrode. A method may instead include chemisorbing a layer of a first precursor at least one monolayer thick over the first electrode and chemisorbing a layer of a second precursor at least one monolayer thick on the first precursor layer, a chemisorption product of the first and second precursor layers being comprised by a layer of a conductive barrier material. The barrier layer may be sufficiently thick and dense to reduce oxidation of the first electrode by oxygen diffusion from over the barrier layer. An alternative method may include forming a first capacitor electrode over a substrate, the first electrode having an inner surface area per unit area and an outer surface area per unit area that are both greater than an outer surface area per unit area of the substrate. A capacitor dielectric layer and a second capacitor electrode may be formed over the dielectric layer. The method may further include forming rugged polysilicon over the substrate, the first electrode being over the rugged polysilicon. Accordingly, the outer surface area of the first electrode can be at least 30% greater than the outer surface area of the substrate without the first electrode including polysilicon.

Description

TECHNICAL FIELD [0001] The aspects of the invention relate to capacitor fabrication methods including forming conductive barrier layers and capacitor constructions having conductive barrier layers. BACKGROUND OF THE INVENTION [0002] Capacitors are common devices used in electronics, such as integrated circuits, and particularly semiconductor-based technologies. Two common capacitor structures include metal-insulator-metal (MIM) capacitors and metal-insulator-semiconductor (MIS) capacitors. One important factor to consider when selecting a capacitor structure may be the capacitance per unit area. MIS capacitors may be advantageous since a first electrode as the semiconductor may be formed of hemispherical grain (HSG) polysilicon that exhibits a higher surface area in a given region compared to a planar surface of amorphous silicon. The higher surface area provides more capacitance per unit area occupied by a capacitor. [0003] However, a high K factor (also known as dielectric constan...

AI Technical Summary

Problems solved by technology

Use of other oxygen containing high K dielectric materials has proved to create similar problems.

Unfortunately, silicon nitride exhibits a K factor of only about 7, less than the K factor of some high K factor dielectrics that are desirable.

Accordingly, even the silicon nitride barrier layer reduces the effective dielectric constant of the capacitor.

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