Solid state imaging device comprising hydrogen supply film and antireflection film

• US 8,110,885 B2
• Filed: 09/01/2005
• Issued: 02/07/2012
• Est. Priority Date: 09/03/2004
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Watanabe, Takanori, Iida, Satoko
• Primary Examiner(s): Gebremariam, Samuel
• Assistant Examiner(s): ARENA, ANDREW OWENS
• Application Number:
  US11/216,006
• Publication Number:
  US 20060061674A1
• Time in Patent Office: 2,350 Days
• Field of Search: 257/431, 257/436, 257/437, 257/E31.119, 257/290, 257/291, 257/292, 257/294, 257/432, 257/E27.122, 257/E27.127, 257/E27.128, 257/E27.129, 257/E27.13, 257/E27.131, 257/E27.132, 257/E27.133, 257/E27.134, 257/E31.12, 257/E31.121, 257/E31.122, 257/E31.123, 438/69, 438/72
• US Class Current: 257/437
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/1463 Pixel isolation structures
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216

Abstract

Provided is a MOS type solid state imaging device, including a semiconductor substrate, a plurality of pixels arranged on the semiconductor substrate, each pixel having a light receiving element for generating a signal charge due to incident light, and a MOS transistor for reading the signal charge, and a hydrogen supply film arranged on the semiconductor substrate over the plurality of pixels and having a region corresponding to the light receiving element at least a part of which has a film thickness greater than the other part of the region.

Claims

1. A MOS type solid state imaging device, comprising:

a semiconductor substrate; and

a plurality of pixels arranged on the semiconductor substrate, each pixel including;

a light receiving element for generating a signal charge due to incident light,

a gate electrode for reading the signal charge,

a gate insulation film, which covers the whole surface of the light receiving element, and which is formed by an oxide film,

an element isolation portion, which is provided adjacent to the light receiving element, and which is formed by an oxide film,

a hydrogen supply film having a convex shape in a region corresponding to the light receiving element for condensing the incident light onto the light receiving element, wherein the hydrogen supply film is a silicon nitride film formed by a plasma CVD process, such that a concentration of hydrogen in the hydrogen supply film is equal to or greater than 1×

10²¹ atoms/cm³,

an interlayer insulation film arranged below the hydrogen supply film and above the light receiving element,

an antireflection film for reducing reflection of the incident light at a surface of a light incident area, and

a microlens arranged above the hydrogen supply film, wherein

the antireflection film is a silicon nitride film formed by a LPCVD process to have a property different from the silicon nitride film formed by the plasma CVD process and corresponding to the hydrogen supply film, such that the antireflection film is impenetrable by hydrogen from the hydrogen supply film,

the antireflection film is provided above the light receiving element and the antireflection film extends above the gate electrode,

the antireflection film is provided in contact with the gate insulation film at the surface of the light receiving element,

an end of the antireflection film is laterally spaced apart from the element isolation portion, such that the antireflection film is not disposed above an end of the light receiving element adjacent to the element isolation portion,

a region of the light receiving element not covered by the antireflection film is opened to the interlayer insulation film via the gate insulation film,

a region of the gate electrode is not covered by the antireflection film and is in contact with the interlayer insulation film, and

the region of the light receiving element not covered by the antireflection film makes a path for supplying hydrogen to the element isolation portion, and the region of the gate electrode not covered by the antireflection film makes a path for supplying hydrogen under the gate electrode.

2. A MOS type solid state imaging device according to claim 1, wherein:

the light receiving element is isolated by a LOCOS portion; and

the antireflection film is arranged not to cover at least a part of a bird'"'"'s beak that exists at an end of the LOCOS portion.

3. The MOS type solid state imaging device according to claim 1, wherein

the light receiving element has a first conductive type storage region and a second conductive type surface region,

the first conductive type storage region of the light receiving element extends under the gate electrode, and

the second conductive type surface region of the light receiving element is not disposed under the gate electrode.

4. The MOS type solid state imaging device according to claim 1,

wherein each pixel further includes a sidewall, a first impurity diffusing region of a first conductive type, and a second impurity diffusing region of a first conductive type, the second impurity diffusing region having lower impurity concentration than the first impurity diffusing region, and

wherein the sidewall has a laminated structure of the antireflection film and the oxide film.