JPS63269568A - Image sensor chip of contact-type image sensor - Google Patents

Abstract

PURPOSE:To prevent an output of a picture element at an end part from increasing and the resolution from lowering by a method wherein a part between the end part in a picture-element arrangement direction and the picture element which is nearest to this end part is covered with a light-shielding layer. CONSTITUTION:Picture-element diffusion layers 2 are formed in a semiconductor substrate 1; light-shielding Al layers 4 are formed via an intermediate insulating layer 3; furthermore, a protective layer 5 is formed. The Al layer 4 near an end face 6 is formed in such a way that it completely covers a part between the end face 6 and a picture element 7 which is nearest to the edge face. Accordingly, the light does not reach the inside of the substrate at the end face, the resolution is not lowered, and an output from the picture element 7 at the end face and from another picture element 8 is not increased. The light-shielding layers may be composed of a material other than Al which can be applied to an image sensor chip such as a CCD, a MOS type chip or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glue near image sensor chip, such as a COD or MOS type, which constitutes a contact type image sensor used in an image scanner, a FAX, or the like.

[Summary of the invention]

The present invention prevents the resolution of pixels near the end from decreasing by covering the space between the end of an image sensor chip of a contact type image sensor in the pixel arrangement direction and the pixel closest to this end with a light-shielding layer. It is.

[Conventional technology]

When CCD and MOS type image sensor chips of a contact image sensor are arranged in a straight line, the pixels at the edges are moved as close to the edges as possible to prevent the pixel pitch from becoming large between adjacent image sensor chips. need to be formed.

FIG. 2 is a cross-sectional view showing an example of a conventional pn junction type image sensor chip. Pixel diffusion layer 2 on semiconductor substrate I
A light shielding ΔN 54 is formed via the intermediate insulating layer 3, and a protective layer 5 is further formed. Generally, a plurality of these image forming knobs are formed on a wafer and then cut, so the protective layer 5 is formed inside the cut portion to prevent cracks or the like from occurring during cutting. In addition, in the semiconductor process of -a>, the Aβ layer 4
is formed further inside the protective layer 5.

[Problem that the invention seeks to solve]

In FIG. 2, the light incident on X between the end surface 6 of the image sensor chip and the A1 layer 4 near the end surface 6 passes through the semiconductor W plate l.
and generates electron-hole pairs here. These holes, which are minority carriers, reach the pn junction of the pixel 7 at the edge and the pn junction of the pixel 8 further inside by diffusion. As a result, the output of the pixels 7 and 8 at the edges increases, and the resolution between the pixels 7 and 8 decreases.

[Means for solving problems]

The present invention solves the above problems by covering the space between the end of the image sensor chip in the pixel arrangement direction and the pixel closest to this end with a light-shielding layer.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings. FIG. 1 is a cross-sectional view showing an example of a pn junction type image sensor chip, which is an embodiment of the present invention. A pixel diffusion layer 2 is formed on a semiconductor substrate 1, a light shielding Al layer 4 is formed with an intermediate insulating layer 3 interposed therebetween, and an Ai layer s is further formed. Here, A14 near the end surface 6 is formed so as to completely cover the space between the end surface 6 and the pixel 7 closest to the end surface.

Therefore, since light does not reach the inside of the substrate at the edge, a decrease in resolution and an increase in the output of the pixels 7 and 8 at the edge do not occur. Here, the light-shielding layer does not need to be made of Al, and the present invention can also be applied to image sensor chips such as COD and MOS types.

〔Effect of the invention〕

As explained above, this invention has a simple structure in which a light-shielding layer covers the space between the end of the 11-pixel column and the pixel closest to this end, thereby increasing the output of the pixels at the end and increasing the resolution. It is possible to obtain an image sensor chip in which deterioration is prevented.

[Brief explanation of drawings]

FIG. 1 is a 1tli plan view showing an example of an image sensor chip according to the present invention, and FIG. 2 is a sectional view of a conventional image sensor chip. ■... Semiconductor substrate 2... Diffusion layer 3... Intermediate insulating layer 4... First light shielding layer 5... Protective layer 6... End surface 7... End pixel 8.・Inner pixel

Claims (3)

[Claims] (1) In the image sensor chip of a contact type image sensor in which a plurality of image sensor chips are arranged linearly, the distance between the end of the image sensor chip in the pixel arrangement direction and the pixel closest to this end is An image sensor chip of a contact type image sensor characterized by being covered with a light-shielding layer. (2) The image sensor chip of the contact type image sensor according to claim 1, wherein the image sensor chip is a semiconductor element. (3) The image sensor chip of the contact type image sensor according to claim 1, wherein the light shielding layer is made of Al.