Solid-state imaging device and method for producing the same

• US 20070034981A1
• Filed: 08/07/2006
• Published: 02/15/2007
• Est. Priority Date: 08/09/2005
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Saito, Maki
• Granted Patent: US 7,420,235 B2
• Time in Patent Office: Days
• US Class Current: 257/462
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 31/1122 the device being a CCD device

Abstract

In the solid-state imaging device of the present invention having a photoelectric conversion section and a charge transfer section equipped with a charge transfer electrode for transferring an electric charge generated in the photoelectric conversion section, the charge transfer electrode has an alternate arrangement of a first layer electrode comprising a first layer electrically conducting film and a second layer electrode comprising a second layer electrically conducting film, which are formed on a gate oxide film comprising a laminate film consisting of a silicon oxide film and a metal oxide thin film, and the first layer electrode and the second layer electrode are separated by insulation with an interelectrode insulating film comprising a sidewall insulating film formed by a CVD process to cover the lateral wall of the first layer electrode.

Claims

1. A solid-state imaging device comprising:

a semiconductor substrate;

a photoelectric conversion section;

a gate oxide film comprising a two-layer film containing a silicon oxide film and a metal oxide thin film;

a charge transfer section comprising a charge transfer electrode for transferring an electric charge generated in the photoelectric conversion section,

the charge transfer electrode comprising;

a first electrode comprising a first conductive film; and

a second electrode comprising a second conductive film, the first electrode and the second electrode being disposed on a surface of the semiconductor substrate through the gate oxide film and alternatively arranged; and

an interelectrode insulating film comprising a sidewall insulating film covering the lateral wall of the first electrode, the interelectrode insulating film separating and insulating the first electrode from the second electrode.

2. The solid-state imaging device as claimed in claim 1, wherein the metal oxide thin film has high dielectric constant.

3. The solid-state imaging device as claimed in claim 2, wherein the metal oxide thin film comprises at least one element selected from the group consisting of Al, Ti, Hf, Zr, La and Y.

4. The solid-state imaging device as claimed in claim 2, wherein the metal oxide thin film has low dielectric constant.

5. The solid-state imaging device as claimed in claim 1, wherein the silicon oxide film comprises a silicon oxide film formed by a chemical vapor deposition method.

6. The solid-state imaging device as claimed in claim 1, wherein the silicon oxide film comprises a HTO film.

7. A method for producing a solid-state imaging device, the solid-state imaging device containing:

a photoelectric conversion section; and

a charge transfer section having a charge transfer electrode for transferring an electric charge generated in the photoelectric conversion section, comprising;

sequentially laminating a silicon oxide film and a metal oxide thin film on a semiconductor substrate;

forming a first electrode comprising a first conductive film;

forming a silicon oxide film on the top of the first electrode;

anisotropically etching the silicon oxide film by using the metal oxide thin film as an etching stopper to form a sidewall insulating film on the lateral wall of the first electrode; and

forming a second electrode comprising a second conductive film through the sidewall insulating film so as to be insulated and separated from the first electrode.

8. The method for producing a solid-state imaging device as claimed in claim 7, which comprises:

removing the metal oxide thin film on the gate oxide film after the forming of the sidewall insulating film, the first insulating film being exposed from the sidewall insulating film.

9. The method for producing a solid-state imaging device as claimed in claim 8,

wherein

the second electrode is formed by removing and flattening the second conductive film on the first electrode to separate the second conductive film so that the second electrode can be formed between the first electrodes.

10. The method for producing a solid-state imaging device as claimed in claim 8,

wherein

the forming of the first electrode comprises:

forming the first conductive film;

forming a hard mask comprising an insulting film on the first conductive film; and

selectively removing the first conductive film by using the hard mask.

11. The method for producing a solid-state imaging device as claimed in claim 10,

wherein

the hard mask comprises a two-layer film containing the silicon oxide film and a silicon nitride film, and

the first insulating film is laminated on the hard mask.