JPS63142859A - Solid-state image sensing device - Google Patents

Abstract

PURPOSE:To reduce beams projected to a V-CCD channel, and to diminish a smear signal by bringing a light-shielding film into contact with the surface of a photovoltaic element. CONSTITUTION:Light-shielding films 11 consisting of aluminum at the same potential as a semiconductor substrate 7 are brought into contact electrically with a p-type region 9 in an photovoltaic element. According to the constitution, oblique beams projected to V-CCD channels 6 from clearances among the light- shielding films 11 are a semiconductor surface in conventional devices are reflected to the light-shielding films 11 brought into contact with the p-type region in the semiconductor surface, and projected into the photovoltaic element. Consequently, incident oblique beams are not projected directly to the V-CCD channels 6, thus extremely reducing a smear signal.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a solid-state imaging device.

2. Description of the Related Art In recent years, the development of solid-state imaging devices has progressed, and some of them are comparable to or even superior to image pickup tubes in terms of performance.

Among them, an interline transfer type COD solid-state imaging device (hereinafter abbreviated as IT-COD) has particularly excellent characteristics and has been put into practical use.

The configuration of a conventional IT-COD will be described below with reference to the drawings.

FIG. 2 is an overall configuration diagram of IT-COD. In FIG. 2, 1 is a photoelectric conversion element, and 2 is a vertical transfer CCD (hereinafter referred to as V-CC) that transfers the signal charge accumulated in the photoelectric conversion element 1.
3 is a horizontal transfer COD that horizontally transfers the signal charges transferred by the V-CCD 2, and 4 is a charge detection section that detects the signal charges transferred by the horizontal transfer CCD 3.

FIG. 3 is a sectional view taken along the line AB in FIG. 2.

5 is a p-type separation region between the photoelectric conversion element 1 and the V-CCD 2;
6 is a channel region of the V-COD, 7 is a semiconductor substrate, 8 is an n-shade region of the photoelectric conversion element, 9 is a p-shade region on the surface of the photoelectric conversion element, 1o is a polysilicon gate electrode, 11 is an aluminum light-shielding film, 12 is an insulating layer for glabellar insulation and passivation, and 13 is a signal charge generated by photoelectric conversion.

Light that passes through the gap in the light-shielding film and enters the semiconductor generates electrons 13 that become signal charges through photoelectric conversion. Most of the generated electrons are stored in the n-type region 8 of the photoelectric conversion element, and then read out to the channel region 6 of the V-COD by the voltage applied to the polysilicon gate 1o.

Problems to be Solved by the Invention However, in the above configuration, since the light shielding film 11 is floating from the semiconductor surface, a part of the oblique light incident through the gap in the light shielding film 11 is reflected in the V-COD channel. Area 6
It has the disadvantage that a false signal (hereinafter referred to as a smear signal) is generated when the signal is input to the smear signal.

In view of the above-mentioned drawbacks, the present invention has been developed to prevent V-C from the gap in the light shielding film.
The present invention provides a solid-state imaging device that prevents light from entering an OD channel and suppresses the generation of smear signals.

Means for Solving the Problems In order to solve the above problems, the solid-state imaging device of the present invention includes a plurality of photoelectric conversion elements arranged in a matrix and a transfer method for transferring signal charges generated in the photoelectric conversion elements. At least a portion of the surface of the photoelectric conversion element, the surface of the separation region between the photoelectric conversion element and the transfer section, or the surface of the separation region between the photoelectric conversion element and the photoelectric conversion element is in contact with the light shielding film.

Function: With this configuration, the light-shielding film and the semiconductor surface are brought into contact with each other, thereby blocking oblique light that has entered the V-COD channel through the gap between the conventional light-shielding film and the semiconductor surface. Therefore, smear signals generated by photoelectric conversion of oblique light can be extremely reduced.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a photoelectric conversion element and a V-COD region of a solid-state imaging device according to an embodiment of the present invention. An aluminum light shielding film 11 having the same potential as the semiconductor substrate 7 is in electrical contact with the p shadow region 9 of the photoelectric conversion element. With this configuration, oblique light that conventionally entered the V-COD channel 6 through the gap between the light-shielding film 11 and the semiconductor surface is reflected by the light-shielding film 11 that is in contact with the p-shaded region on the semiconductor surface, resulting in photoelectric conversion. The light enters the element and undergoes photoelectric conversion. Therefore, the incident oblique light no longer directly enters the V-COD channel 6, and the smear signal can be extremely reduced. Although this example is an example of a photoelectric conversion element and a transfer section formed on a p-type semiconductor substrate, it is also possible to form a photoelectric conversion element and a transfer section in a p-type semiconductor layer formed on an n-type semiconductor substrate. Even if you do, it will have exactly the same effect.

Effects of the Invention As described above, the present invention can reduce the light incident on the V-COD channel and extremely reduce the smear signal by bringing the light shielding film into contact with the surface of the photoelectric conversion element. There is something big about it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a photoelectric conversion element and a V-COD region of a solid-state imaging device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional I
The overall configuration diagram of T-COD, Figure 3 is the IT-CO in Figure 2.
It is a sectional view of D. 1...Photoelectric conversion element, 2...Vertical transfer CCD (V-CCD), 3---Horizontal transfer CCD
(HCCD) 4... Charge detection section, 6...
...p-type isolation region, 6...channel of V-CCD, 7...semiconductor substrate, 8...n shadow region of photoelectric conversion element, 9... ...P shadow region on the surface of the photoelectric conversion element, 10...polysilicon gate electrode,
11...Aluminum light shielding film, 12...Insulating layer, 13...Signal charge. Name of agent: Patent attorney Toshio Nakao and 1 other person5.
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In AlmusiE (Fig. 3

Claims (1)

[Claims] A plurality of photoelectric conversion elements arranged in a matrix and a transfer part for transferring signal charges generated in the photoelectric conversion elements are provided, and the surface of the photoelectric conversion element or the separation area surface of the photoelectric conversion element and the transfer part is provided. . A solid-state imaging device, wherein at least a part of the surface of the separation region between the photoelectric conversion elements is in contact with a light shielding film.