# US 7,407,818 B2 · Method for manufacturing a semiconductor device

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- Number: US 7,407,818 B2
- Document ID: US7407818B2
- Status: Granted
- Kind: B2
- Application number: 11/276,407
- Filed: 2006-02-28
- Published: 2006-09-07
- Granted: 2008-08-05
- Earliest claimed: 2005-03-07
- Assignees: Oki Electric Industry Co., Ltd.
- Inventors: Kousuke Hara; Toshihiko Kamatani; Masaki Yoshimaru; Motoki Kobayashi
- Web page: https://patentgrep.com/patent/US7407818B2

## CPC

- H10P 50/71: {using masks for conductive or resistive materials}
- H10D 1/694: {comprising noble metals or noble metal oxides}
- H10P 50/267: {using plasmas}
- H10P 50/285: {of materials not containing Si, e.g. PZT or Al2O3}
- H10D 1/682: {having dielectrics comprising perovskite structures}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A method for manufacturing a semiconductor device includes the steps of preparing a semiconductor substrate, forming a lower electrode having a laminated film of Ir and IrO2 whose thickness is 100 nm or less over the semiconductor substrate, forming a capacity insulating film comprised of a metal oxide dielectric on the lower electrode, and forming an upper electrode comprised of a precious metal film on the capacity insulating film.

## Claims

### Claim 1

A method for manufacturing a semiconductor device, comprising the steps of:
preparing a semiconductor substrate;
forming a lower electrode which is a laminate comprised of a layer of Ir and a layer of IrO2 over the semiconductor substrate;
forming a capacitor insulating film comprised of a metal oxide dielectric on the lower electrode; and
forming an upper electrode comprised of a precious metal film on the capacitor insulating film,
wherein the Ir film and the IrO2 film have a combined thickness of 100 nm or less so that leakage current of the semiconductor device is reduced, and
wherein the laminate comprising the lower electrode further comprises a hydrogen diffusion barrier film provided proximate to the semiconductor layer and under a lower surface of-the layer of Ir, and a conductive film comprised of a precious metal provided on the layer of IrO2 in contact with the capacitor insulating film which functions to reduce Ir diffusion.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the Ir layer has a thickness of 1 nm or more.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the layer of IrO2 has a thickness of 1 nm or more.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the hydrogen diffusion barrier film is composed of TiAIN.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the precious metal film of the upper electrode consists of Pt.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the precious metal of the conductive film consists of Pt.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the metal oxide dielectric is comprised of one compound selected from the group consisting of a SBT compound, a PZT compound, and a BLT compound.

### Claim 8 (depends on 1)

The method according to claim 1, wherein a laminated film including a layer of TiN and a layer of SiO2 is used as an etching mask in the steps of forming the lower electrode, forming the capacitor insulating film, and forming the upper electrode.

### Claim 9 (depends on 1)

The method according to claim 1, further comprising the steps of forming a field-effect transistor having a diffusion layer on the semiconductor substrate and connecting the diffusion layer of the field-effect transistor with the lower electrode by means of a plug.

### Claim 10

A method for manufacturing a semiconductor device, comprising the steps of:
preparing a semiconductor substrate;
forming a lower electrode over the semiconductor substrate which is a laminate;
comprised of, in the order recited, a TiAlN film provided on the semiconductor substrate, an Ir film, an IrO2 film, and a conductive film consisting of Pt;
forming a capacitor insulating film comprised of a metal oxide dielectric on the lower electrode; and
forming an upper electrode comprised of a precious metal film on the capacitor insulating film,
wherein the Ir film and the IrO2 film each has a respective thickness of 1 nm or more and have a combined thickness of 100 nm or less so that leakage current of the semiconductor device is reduced.

### Claim 11

A method for manufacturing a semiconductor device, comprising the steps of:
preparing a semiconductor substrate;
forming a lower electrode over the semiconductor substrate which is a laminate comprised of, in the order recited, a hydrogen diffusion barrier film provided on the semiconductor substrate, an Ir film, an IrO2 film, and a precious metal film consisting of Pt;
forming a capacity insulating film comprised of a metal oxide dielectric on said lower electrode; and
forming an upper electrode comprised of a precious metal film on said capacity insulating film,
wherein the Ir film and the IrO2 film each has a respective thickness of 1 nm or more and have a combined thickness of 100 nm or less so that leakage current of the semiconductor device is reduced.