Methods for forming ferroelectric capacitors
AssigneeHyundai Electronics Industries Co., Ltd.
InventorKwon Hong
Life of this patent
Estimating the term…
Abstract
Provided are methods for forming ferroelectric capacitors, which prevent decreasing ferroelectric characteristics due to the reaction of a ferroelectric layer with hydroxyl group induced from a inter-layer insulating film which will be formed and contacted with the ferroelectric layer after the formation of the ferroelectric capacitor. After a ferroelectric film such as Pb(Zr,Ti)O3 (PZT) is formed, a ZrO2 film, which is insulator and excellent in diffusion barrier characteristics, is formed so as to enclose the entire ferroelectric layer in order to prevent the damage generated by the reaction. The characteristics of the ferroelectric capacitor are enhanced by the invention.
Claims23
A method for forming a ferroelectric capacitor comprising:
- forming a lower electrode over a semiconductor substrate;
- forming a ferroelectric layer over the lower electrode;
- forming a diffusion barrier layer over the ferroelectric layer to enclose sidewalls and a top surface of the ferroelectric layer, wherein the diffusion barrier layer is formed with material selected from the group consisting of Y2O3, CrO2, CeO2 and ZrN;
- etching the diffusion barrier layer to expose a portion of the top surface of the ferroelectric layer;
- and
- forming an upper electrode on the exposed portion of the ferroelectric layer and a portion of the diffusion barrier layer.
A method for forming ferroelectric capacitor comprising the steps of:
- selectively etching an insulating layer formed over a semiconductor substrate so as to expose said substrate or a predetermined conductive layer, thereby forming a contact hole;
- burying conductive material in the contact hole to form a first conductive layer;
- forming a first diffusion barrier layer over the entire substrate;
- forming a second conductive layer over the first diffusion barrier layer to form a lower electrode over the entire substrate;
- forming a ferroelectric layer over the second conductive layer;
- patterning the ferroelectric layer, the second conductive layer and the first diffusion barrier layer;
- forming a second diffusion barrier layer over the entire substrate so as to enclose the patterned ferroelectric layer, the second conductive layer and the first diffusion layer;
- selectively etching the second diffusion barrier layer to expose a portion of the ferroelectric layer;
- and
- forming an upper electrode on the exposed portion of the ferroelectric layer and a portion of the second diffusion barrier layer.
Dependencies are inferred from the claim text.