# US 7,407,862 B2 · Method for manufacturing ferroelectric memory device

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- Number: US 7,407,862 B2
- Document ID: US7407862B2
- Status: Granted
- Kind: B2
- Application number: 11/787,451
- Filed: 2007-04-16
- Published: 2007-10-18
- Granted: 2008-08-05
- Earliest claimed: 2006-04-17
- Assignees: Seiko Epson Corporation
- Inventors: Hiroaki Tamura
- Web page: https://patentgrep.com/patent/US7407862B2

## CPC

- H10B 53/30: characterised by the memory core region
- H10B 53/00: Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors
- H10D 1/682: {having dielectrics comprising perovskite structures}
- H10W 20/056: {by filling conductive material into holes, grooves or trenches}
- H10B: ELECTRONIC MEMORY DEVICES
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A method for manufacturing a ferroelectric memory device includes the steps of forming an active element on a substrate; forming an interlayer dielectric film on the substrate; forming a contact hole in the interlayer dielectric film; forming, in the contact hole, a contact plug that conductively connects to the active element; reacting trimethyl aluminum with the contact plug; applying an oxidation treatment to the contact plug reacted with the trimethyl aluminum; applying an ammonium plasma treatment to the contact plug treated with the oxidation treatment; forming a film of conductive material having a self-orientation property to form a conductive layer on the contact plug treated with the ammonium plasma treatment; and laminating a first electrode, a ferroelectric layer and a second electrode above the conductive layer.

## Claims

### Claim 1

A method for manufacturing a ferroelectric memory device, the method comprising the steps of:
forming an active element on a substrate;
forming an interlayer dielectric film on the substrate;
forming a contact hole in the interlayer dielectric film;
forming, in the contact hole, a contact plug that conductively connects to the active element;
reacting trimethyl aluminum with the contact plug;
applying an oxidation treatment to the contact plug reacted with the trimethyl aluminum;
applying an ammonium plasma treatment to the contact plug treated with the oxidation treatment;
forming a film of conductive material having a self-orientation property to form a conductive layer on the contact plug treated with the ammonium plasma treatment; and
laminating a first electrode, a ferroelectric layer and a second electrode above the conductive layer.

### Claim 2 (depends on 1)

A method for manufacturing a ferroelectric memory device according to claim 1, wherein, in the step of forming the contact plug, tungsten is used as a material for forming the contact plug.

### Claim 3 (depends on 1)

A method for manufacturing a ferroelectric memory device according to claim 1, wherein, in the step of reacting with trimethyl aluminum, the trimethyl aluminum reacts with the contact plug, whereby —O—Al—CH3 bonds are generated on the contact plug.

### Claim 4 (depends on 3)

A method for manufacturing a ferroelectric memory device according to claim 3, wherein, in the step of applying an oxidation treatment, the —O—Al—CH3 bonds generated on the contact plug are changed to —O—Al—OH bonds by the oxidation treatment.

### Claim 5 (depends on 4)

A method for manufacturing a ferroelectric memory device according to claim 4, wherein, in the step of applying an ammonium plasma treatment, the —O—Al—OH bonds generated on the contact plug change to —O—AM—O—NH bonds.

### Claim 6 (depends on 1)

A method for manufacturing a ferroelectric memory device according to claim 1, wherein the step of applying an oxidation treatment includes reacting the contact plug with water.

### Claim 7 (depends on 1)

A method for manufacturing a ferroelectric memory device according to claim 1, wherein, in the step of forming the conductive layer, titanium is used as the conductive material having a self-orientation property.