Method for manufacturing a ferroelectric capacitor having improved polarization characteristics and a method for manufacturing a ferroelectric memory device incorporating such capacitor
AssigneeTexas Instruments Incorporated
InventorsKatsuhiro Aoki, Yukio Fukuda, Ken Numata
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Abstract
The purpose of this invention is to provide a method for manufacturing capacitors free of polarization fatigue even when the treatment is performed at a low temperature. Amorphous layer 32 made of lead zirconate titanate and containing excess lead is formed on lower electrode 13 made of iridium. The amorphous layer is crystallized by a heat treatment to form PZT film 14. Structural transition layer 33 containing excess Pb formed on the surface of PZT film 14 during the aforementioned crystallization is removed by means of dry etching. In this way, a PZT capacitor is obtained.
Claims19
A method for manufacturing a ferroelectric capacitor with a ferroelectric film and a second electrode laminated sequentially on a first electrode comprising the following steps:
- forming a PZT layer containing an excess amount of lead on the first electrode;
- crystallizing the PZT layer by heat treatment at a temperature of no more than substantially 600° C. to form the ferroelectric film, said crystallizing step forming a structural transition layer on a surface of said crystallized PZT;
- and
- removing the structural transition layer.
A method for manufacturing a ferroelectric capacitor by sequentially laminating a ferroelectric film and a second electrode on a first electrode comprising the following steps:
- forming a PZT ferroelectric material layer containing an excess amount of lead on the first electrode;
- crystallizing the ferroelectric material by heat treatment at a temperature of no more than substantially 600° C. to form the ferroelectric film;
- forming an insulating layer on the surface including the surface deposit mainly composed of lead and generated on the surface of the ferroelectric film during the crystallization process;
- and
- removing the prescribed portions of the insulating layer, followed by removing the surface deposit right below the removed portions to expose part of the ferroelectric film.
Dependencies are inferred from the claim text.