Method of manufacturing a semiconductor device using a metal oxide film

• US 10,680,071 B2
• Filed: 03/01/2018
• Issued: 06/09/2020
• Est. Priority Date: 05/19/2017
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Yamaguchi, Tadashi
• Primary Examiner(s): Malek, Maliheh
• Application Number:
  US15/909,980
• Publication Number:
  US 20180337055A1
• Time in Patent Office: 831 Days
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02197 the material having a perovskite structure, e.g. BaTiO3
• CPC Class Codes: H01L 21/02345 treatment by exposure to radiation, e.g. visible light
• CPC Class Codes: H01L 21/02356 treatment to change the morphology of the insulating layer, e.g. transformation of an amorphous layer into a crystalline layer
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 29/40111 the electrodes comprising a layer which is used for its ferroelectric properties
• CPC Class Codes: H01L 29/516 with at least one ferroelectric layer
• CPC Class Codes: H01L 29/6684 with a ferroelectric gate insulator
• CPC Class Codes: H01L 29/78391 the gate comprising a layer which is used for its ferroelectric properties
• CPC Class Codes: H10B 43/30 characterised by the memory core region
• CPC Class Codes: H10B 51/30 characterised by the memory core region
• CPC Class Codes: H10B 53/30 characterised by the memory core region

Abstract

To allow a metal oxide film composed mainly of O and at least one of Hf and Zr to exhibit ferroelectric properties. After deposition of a hafnium oxide film on a semiconductor substrate via an insulating film, the semiconductor substrate is exposed to microwaves to selectively heat the hafnium oxide film. This makes it possible to form a larger number of orthorhombic crystals in the crystals of the hafnium oxide film. The hafnium oxide film thus obtained can therefore exhibit ferroelectric properties without adding, thereto, an impurity such as Si. This means that the hafnium oxide film having a reverse size effect can be used as a ferroelectric film of a ferroelectric memory cell and contributes to the manufacture of a miniaturized ferroelectric memory cell.

Claims

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

(a) depositing a metal oxide film having oxygen and at least one of hafnium and zirconium as a main component on a semiconductor substrate;

(b) depositing a conductor film on the metal oxide film;

(c) subjecting the metal oxide film to microwave heat treatment;

(d) depositing a semiconductor film on the conductor film; and

(e) patterning a semiconductor film, the conductor film and the metal oxide film to form a gate electrode and a ferroelectric film;

wherein the gate electrode and the ferroelectric film configure a ferroelectric memory cell.

2. The method of manufacturing a semiconductor device according to claim 1,

wherein (c) is performed after (a) and before (b).

3. The method of manufacturing a semiconductor device according to claim 1,

wherein (c) is performed after (b).

4. The method of manufacturing a semiconductor device according to claim 1,

wherein (a) comprises:

(a1) forming a first insulating film over the semiconductor substrate; and

(a2) depositing the metal oxide film to cover the first insulating film therewith.

5. The method of manufacturing a semiconductor device according to claim 1,

wherein (a) comprises:

(a1) forming a protrusion which has a portion of the semiconductor substrate and protrudes from the main surface of the semiconductor substrate; and

(a2) depositing the metal oxide film over the main surface of the semiconductor substrate to cover the protrusion.

6. The method of manufacturing a semiconductor device according to claim 5, comprising, after (a1) and before (a2):

forming a second insulating film over the surface of the protrusion.

7. The method of manufacturing a semiconductor device according to claim 1,

wherein the conductor film in (b) has titanium nitride as a main component.

8. The method of manufacturing a semiconductor device according to claim 7,

wherein the conductor film is deposited by RF sputtering.

9. The method of manufacturing a semiconductor device according to claim 1,

wherein at least any one of elements silicon, nitrogen, carbon and fluorine is added to the metal oxide film.

10. The method of manufacturing a semiconductor device according to claim 1,

wherein the frequency of the microwaves in (c) is from 1 GHz to 10 GHz.

11. The method of manufacturing a semiconductor device according to claim 1,

wherein the gate electrode is formed of the semiconductor film and the conductor film, and

wherein the ferroelectric film is formed of the metal oxide film.

12. The method of manufacturing a semiconductor device according to claim 1, comprising:

(f) forming a source region and a drain region in the semiconductor substrate exposed from the ferroelectric film,

wherein the gate electrode, the ferroelectric film, the source region and the drain region configure the ferroelectric memory cell.