Semiconductor storage device and manufacturing method thereof

• US 7,629,232 B2
• Filed: 08/18/2008
• Issued: 12/08/2009
• Est. Priority Date: 09/30/2005
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanaka, Masayuki, Ishida, Hirokazu
• Primary Examiner(s): Mulpuri; Savitri
• Assistant Examiner(s): Lee; Cheung
• Application Number:
  US12/193,531
• Publication Number:
  US 20080311734A1
• Time in Patent Office: 477 Days
• Field of Search: 438/260, 438/477, 257/E21.179, 257/E21.191, 257/E21.369, 257/E21.466, 257/E21.497, 257/E21.613, 257/E21.662
• US Class Current: 438/476
• CPC Class Codes: H10B 41/30 characterised by the memory core region
• CPC Class Codes: H10B 69/00 Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices

Abstract

A non-volatile semiconductor storage device having a high-dielectric-constant insulator and a manufacturing method thereof suitable for miniaturization are disclosed. According to one aspect of the present invention, it is provided a semiconductor storage device comprising a semiconductor substrate, a plurality of first conductor layers formed on the semiconductor substrate through a first insulator, an isolation formed between the plurality of first conductor layers, a silicon oxide film formed on the first conductor layer, a high-dielectric-constant insulator formed on the silicon oxide film and the isolation and being diffused silicon and oxygen at least in a surface thereof contacting with the silicon oxide film, and a second conductor film formed above the high-dielectric-constant insulator.

Claims

1. A manufacturing method of a semiconductor storage device, comprising:

depositing a first conductor layer on a semiconductor substrate through a first insulator;

patterning the first conductor layer, the first insulator and the semiconductor substrate to form an isolation extending in a first direction;

forming a silicon oxide film on the first conductor layer;

depositing a high-dielectric-constant insulator on the silicon oxide film;

depositing a second conductor film on the high-dielectric-constant insulator;

recovering defects in the high-dielectric-constant insulator by decomposing the silicon oxide film and supplying oxygen and/or silicon to the high-dielectric-constant insulator by a heat treatment; and

patterning the second conductor layer and the high-dielectric-constant insulator to be extended in a second direction orthogonal to the first direction to form a memory cell.

2. The manufacturing method of a semiconductor storage device according to claim 1, wherein the silicon oxide film has a film thickness of 1.5 nm to 4 nm.

3. The manufacturing method of a semiconductor storage device according to claim 1, wherein a relative dielectric constant of the high-dielectric-constant insulator is 5 or greater.

4. The manufacturing method of a semiconductor storage device according to claim 3, wherein the high-dielectric-constant insulator is a laminated film consisting of a plurality of insulators including an insulator whose relative dielectric constant is 5 or greater.

5. The manufacturing method of a semiconductor storage device according to claim 1, wherein the heat treatment for the recovering is performed at a temperature of 500°

C. to 1200°

C.

6. The manufacturing method of a semiconductor storage device according to claim 1, wherein the recovering is carried out between the depositing the high-dielectric-constant insulator and the depositing the second conductor layer.

7. The manufacturing method of a semiconductor storage device according to claim 1, wherein the silicon oxide film is completely decomposed during the recovering.

8. The manufacturing method of a semiconductor storage device according to claim 7, wherein the silicon oxide film has a film thickness of 1.5 nm to 4 nm.

9. The manufacturing method of a semiconductor storage device according to claim 7, wherein a relative dielectric constant of the high-dielectric-constant insulator is 5 or greater.

10. The manufacturing method of a semiconductor storage device according to claim 9, wherein the insulator is a laminated film consisting high-dielectric-constant of a plurality of insulators including an insulator whose relative dielectric constant is 5 or greater.

11. The manufacturing method of a semiconductor storage device according to claim 7, wherein the high-dielectric-constant insulator contains at least aluminum or hafnium.

12. The manufacturing method of a semiconductor storage device according to claim 11, wherein the high-dielectric-constant insulator contains at least an oxide or a nitride of aluminum, hafnium or zirconium.

13. The manufacturing method of a semiconductor storage device according to claim 7, wherein the heat treatment for the recovering is performed at a temperature of 500°

C. to 1200°

C.

14. The manufacturing method of a semiconductor storage device according to claim 7, wherein the recovering is carried out between the depositing the high-dielectric-constant insulator and the depositing the second conductor layer.