JPS6146061A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To prevent the generation of a narrow channel, and to enable a picture having excellent quality by narrowing a section adjacent to a reading channel reading signal changes to a charge transfer element from a light-receiving element of a channel stop region. CONSTITUTION:A channel stop region 1 is narrowed in sections adjacent to reading channels A reading signals to a register from a light-receiving element. Accordingly, the regions of the reading channels A may be affected by a bird beak, etc. The width of the reading channel regions A reading signals to the register from the light-receiving element can be ensured effectively by a second layer polysilicon electrode 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a solid-state imaging device with an interline transfer structure in which each light receiving element is separated by a channel stop region.

[Prior art]

FIG. 1 is a schematic top view of a conventional solid-state imaging device with an interline transfer structure. As shown in the figure, a solid-state imaging device with an interline transfer structure consists of a line-shaped light receiving element and a parallel array of resistors in a non-irradiated area, and each light receiving element is airtightly separated by one channel stop. ing. The resistor is formed, for example, by a two-layer polysilicon electrode, where 2 is the first layer of polysilicon electrode.

3 is a second layer polysilicon electrode. Figure 2 is a cross-sectional view taken along the line I-I in Figure 1, where 4 is a PM semiconductor substrate, 6 is a P
A photodetector element 7 in an n-type region is formed on the surface of the semiconductor substrate 4, and 7 is a resistor in the 9nu region formed on the surface of the substrate 4. The incident light generates and accumulates charges in the light receiving element 6 according to the amount of light, and the accumulated charges are transferred to the vertical shift register 7 only when the polysilicon electrode 2 is in the on state.
is read out. By the way, in a solid-state imaging device with such an interline transfer structure, when reading signal charges from the light receiving element 6 to the register 7, the second layer polysilicon electrode 3 is used rather than the first layer polysilicon/electrode 2. It has been found that properties such as shading are better when used. This is the second layer of polysilico/electrode 3
This is thought to be because the load capacitance is smaller than that of the polysilicon electrode 2 in the first layer.

However, if readout using the second layer polysilicon electrode 3 is performed using the conventional structure shown in FIG. The width of part A) becomes significantly narrower due to the influence of the bird's peak of the channel stop region l. Due to such a narrow channel effect, signal charge transfer from the light-receiving probe 6 to the vertical register 7 is not completely performed, resulting in image quality deterioration such as afterimage. On the other hand, the gate polysilicon size of the first layer polysilicon electrode 2 is reduced. In order to widen the readout channel A, do not cause a same layer short circuit of the second layer polysilicon electrode 3.
) It causes a significant deterioration of manufacturing yield.

[Purpose of the invention]

The present invention aims to provide a solid-state imaging device that prevents narrow channels and enables high-quality images.

[Structure of the invention]

The present invention provides a solid-state imaging device in which a plurality of light receiving elements and a plurality of charge transfer elements are provided facing each other, and each of the light receiving elements is electrically separated from each other by a channel stop region. It is characterized by a narrow portion adjacent to the read channel that reads signal charges to the transfer element.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 3 is a schematic top view of a solid-state imaging device according to an embodiment of the present invention. In the figures, the same numbers as in FIG. 1 indicate the same things. The feature of the present invention compared to the conventional fixed imaging device (see FIG. 1) is that the channel stop region 1 is narrower in the portion adjacent to the readout channel A that reads signals from the light receiving element to the register. There is a particular thing. As a result, the area of the read channel A is not affected by bird's beak or the like.

Note that, as shown in FIG. 3, the shape of the polysilicon 2 is changed so that the channel width becomes wider. This further reduces the negative effects of narrow channels.

Further, in the embodiment, a case where charge reading is performed using a two-layer polysilicon electrode has been described, but it is clear that the present invention can also be applied to a case where a single-layer polysilicon electrode is used.

〔Effect of the invention〕

As described above, according to the present invention, the width of the readout channel region for reading out signals from the light receiving element to the register can be effectively secured using the second layer polysilicon electrode.

[Brief explanation of drawings]

FIG. 1 is a schematic top view showing a part of a conventional solid-state imaging device with an interline transfer structure. FIG. 2 is a sectional view taken along line II in FIG. 1, and FIG. 3 is a schematic top view of a solid-state imaging device according to an embodiment of the present invention. 1... Channel stop region 2... 1NJth polysilicon electrode 3... 2Rrith polysilicon' ridge electrode 4... Semiconductor substrate 5... Insulating film 6... Light receiving element 7...・Register A...Channel area

Claims (1)

[Claims] A solid-state imaging device in which a plurality of light receiving elements and charge transfer elements are provided facing each other, and each of the light receiving elements is electrically separated from each other by a channel stop region,
A solid-state imaging device characterized in that the channel stop region is narrowed at a portion adjacent to a readout channel for reading signal charges from a light receiving element to a charge transfer element.