JPS62235888A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To increase the number of elements capable of photoelectrically transferring and to improve the resolution by providing a photosensitive area and a photosensitive transfer area. CONSTITUTION:In a photosensitive part, the photosensitive area 14 consisting of photodetecting element groups formed by longitudinally arranged photoelectric transfer elements as shown by a rectangle of dotted lines and the photosensitive transfer area 15 provided in parallel to this photosensitive area 14 are formed and the plural photosensitive areas 14 and the photosensitive transfer areas 15 are horizontally and alternately disposed. On the surfaces of the respective photodetecting elements of the photosensitive area 14, red filters Ra, Rb and blue filters Ba, Bb are alternately disposed by making the two photodetecting elements disposed vertically (direction crossing said horizontal direction) a pair. The photosensitive transfer area 15 consists of a self-scanning type image pickup device having photosensitive storage and transfer functions. On the surface of this photosensitive transfer area 15, a stripe shape green filter G is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION A solid-state imaging device according to claim 5, characterized in that:

(7) The channel length of the storage section in the transfer direction is shorter than the channel length of the photosensitive transfer section in the transfer direction, and the width of the channel of the storage section in the transfer direction is made wider than the width of the channel for the photosensitive transfer section. A request for a response to the outpost god, which is characterized by the fact that
The solid-state imaging device according to item 5.

3, , $! DETAILED DESCRIPTION OF EMBODIMENTS (INDUSTRIAL APPLICATION FIELD) This %Q relates to a solid-state imaging device, and particularly relates to a solid-state imaging device with improved configurations of a light receiving section and a transfer section.

(Conventional Example) Conventional solid-state imaging devices are known to use a frame transfer method or an interline method.

The former, as shown in FIG.
are formed separately. The photosensitive section 1 consists of a plurality of photosensitive areas a1 to an arranged in the horizontal direction, each consisting of a self-traversing type image sensor that performs photosensitive storage and transfer operations, and a mosaic color filter or the like is provided on the surface of each photosensitive area a to an. has been established. On the other hand, the charge storage section 2 consists of COD shift registers b0 to bn formed following each of the photosensitive areas a1 to an, and the surface thereof is shielded from light by an aluminum film or the like. In addition, a readout shift register 3 consisting of a horizontal COD shift register is provided at the end of the COD shift registers b1 and bn.
is connected.

The signal charge generated in the photosensitive section l is controlled by a predetermined transfer drive signal and transferred to the charge storage section 2, and after temporarily accumulating the signal charge for one image from the photosensitive section 1, the signal charge is transferred to the subsequent shift register. 3, the signal charges for one row are sequentially and repeatedly outputted from the output terminal 4.

As shown in FIG. 5, the latter interline type solid-state imaging device is provided with a plurality of light-receiving elements 5 separated from each other and each light-receiving element 5 consisting of a photodiode or the like provided with a specific color filter on its surface. The signal charges generated are transferred to the transfer shift register 7 through the transfer gate 6, and after this movement, the transfer shift register 7 sequentially transfers the signal charges for each row, and the signal charges for each row are transferred. The charges are further sequentially outputted via a readout shift register 8 consisting of a horizontal COD shift register, so that signal charges for one image are outputted from an output terminal 9.

Here, the surface of the transfer shift register 7 is shielded from light by an aluminum film or the like to prevent noise components caused by external light from being mixed with the signal charges.

(Problem to be solved by Weir Opening) However, in such a solid-state imaging device, in the case of a frame transfer method, the photosensitive part l is not used for the integration of signals generated by photoelectric conversion and for the integration of signals. Since it has two functions of transferring a mass of signal charges to the charge storage section 2, it is not possible to lengthen the effective signal charge integration time, making it difficult to improve sensitivity.

On the other hand, in the case of the interline transfer method, a light-shielded transfer shift register exists within the light receiving section.
It is difficult to improve the light integration efficiency, and the presence of the light-shielding portion poses a problem in that the resolution in the horizontal direction is reduced.

(Means for Solving the Problems) The present invention has been made in view of the above problems, and an object of the present invention is to provide a solid-state imaging device with improved sensitivity and resolution.

In order to achieve this object, the present invention includes a photosensitive area in which a plurality of light receiving elements having a photoelectric conversion function are formed in a predetermined direction, and each light receiving element is formed via a transfer gate and individually has a photoelectric conversion function. By providing a photosensitive transfer area such as a photosensitive transfer element that transfers signal charges between each other under predetermined transfer drive control, the number of elements capable of receiving light and the area capable of receiving light are expanded. , the technical key point is that we have achieved improvements in sensitivity and resolution.

(Embodiment) Figure 1 is a schematic diagram of a solid-state imaging device according to an embodiment of Hondabar. For simplicity, they are shown as individual blocks.

The photosensitive section 10 includes a photosensitive area 14 consisting of a group of light receiving elements formed of photoelectric conversion elements arranged vertically as shown by the dotted rectangle in the figure, and a photosensitive area 14 arranged in parallel with the photosensitive area 14.
A photosensitive transfer area 15 is formed 4, and a plurality of photosensitive areas 14 are formed.
and photosensitive transfer areas 15 are provided alternately in the horizontal direction (left and right directions in the figure).

On the surface of each light receiving element in the photosensitive area 14, a pair of two light receiving elements arranged in the vertical direction (direction perpendicular to the horizontal direction) are provided with red filters Ra and Rb.
and blue filters Ba and Bb are provided alternately.

As shown by the dotted rectangle in FIG. 1, the photosensitive transfer area 15 consists of photosensitive transfer elements arranged in the vertical direction so as to correspond to each light receiving element in the photosensitive area 14, and each photosensitive transfer element has a photoelectric effect. A CCD (charge coupled
device). That is, the photosensitive area 15 is a self-scanning imaging device with photosensitive storage and transfer functions.

A striped green filter G is provided on the surface of this photosensitive transfer region 150.

The charge storage section 1) has a number of COD shift registers equal to the number of photosensitive transfer areas 15 formed in the horizontal direction, and stores signal charges from a specific photosensitive transfer area 15 to a specific COD shift register.
The signals are arranged to be stored in the OD shift register.

Between the photosensitive section 10 and the charge storage section 1), there is a first horizontal COD shift register for transferring signal charges in the horizontal direction.
Further, the first horizontal charge transfer means 12 is connected on both sides to the photosensitive section 10 and the charge storage section 1) via a transfer gate TgltTg2.

The terminal end of the charge storage section 1) is connected to the side end of the second horizontal charge transfer means 13 via the transfer gate Tg3, and the second horizontal charge transfer means 13 is a horizontal COD shifter that transfers signal charges in the horizontal direction. It is made up of registers.

Next, the configuration of the photosensitive section 10 will be explained based on FIG.

The area surrounded by the dotted line is a channel stopper 16 formed on the silicon substrate, and the light receiving element of the photosensitive area 14 is formed in the area surrounded by the channel stopper 16, and red filters Ra, Rb are provided on the surface of the light receiving element. and blue filters Ba and Bb are provided alternately.

A photosensitive transfer area 15 is formed between the photosensitive areas 14 and surrounded by channel stoppers 16 and provided with a green filter G on its surface. That is, the transfer electrodes 18 and 19 are made of polysilicon layers extending in the horizontal direction.

20 and 21 are formed alternately in the vertical direction, and the transfer electrodes 1
The channel portions at the bottom of 8°19, 20, and 21 correspond to the photosensitive transfer elements. The portion corresponding to the horizontal direction of the transfer electrodes 18 and 19 is defined as the A field, and the portion corresponding to the horizontal direction of the transfer electrodes 20 and 21 is defined as the B field, making it possible to perform interlaced scanning in television applications, etc., which will be described later. ing.

That is, the relationship between the light-receiving elements of the photosensitive area 14 and the color filters is such that in the vertical direction, one color filter corresponds to two light-receiving elements, while in the horizontal direction, the color filters correspond to the light-receiving elements and the color filters in the photosensitive transfer area 15. Along with the transfer element, one color filter corresponds to one pitch for one element,
The A field is handled by an element provided with filters Ra, Ba above the red filter and blue filter and a green filter G corresponding to the filters Ra, Ba, and the B field is handled by the element provided with the filters Ra, Ba above the red filter and blue filter, and the green filter G corresponding to the filters Ra, Ba. side filters Ra, Rb and the filters Ra, B
The element provided with the green filter G portion corresponding to a is responsible for this.

A transfer gate 22 is provided in a part of the channel stopper 16 for separating the photosensitive region 14 and the photosensitive transfer region 15 to control the movement of signal charges generated in a portion of each light receiving element toward the photosensitive transfer region 15 side. It is provided.

Although not shown, the transfer electrodes 18, 19, 20
.

The polysilicon layers 21 are overlapped so that the portions that are separated from each other are not electrically conductive, and a recessed portion is provided so as not to cover the light receiving element in the photosensitive area 14.

FIG. 3 shows a part of the structure of the charge storage section 1).

That is, the portion indicated by dotted lines and diagonal lines in the figure is the channel stop horn 16, and the transfer electrodes 23, 24, made of polysilicon layers arranged vertically in parallel on the surface of the layer between the channel stoppers 16. By forming 25 and 26, a COD shift register is formed.

The width W2 in the horizontal direction of the channel portion composed of each transfer electrode 23 , 24 , 25 , 26 is equal to
and the horizontal width Wl of the photosensitive transfer area 15, and each transfer electrode 18, 19 of the photosensitive section 10
.

The channel length L2 of each transfer electrode 23, 24, 25, 26 of the charge storage ill is made narrower than the channel length L1 of 20, 21. Each COD shift register is connected to each pair of photosensitive area 14 and photosensitive transfer area 15 in a dependent manner. This allows the vertical width of the charge storage section 1) to be narrower than the vertical width of the photosensitive section 10.

The first horizontal charge transfer means 12 shown in FIG. 1 is formed between the photosensitive section 10 and the charge storage section 1) shown in FIGS. 2 and 3, and the transfer gates Tgl and Tg2 have predetermined By applying a gate voltage and turning it on, the signal charge of the photosensitive section 10 is transferred to the charge storage section 1) via the first horizontal charge transfer means. Note that the first horizontal charge transfer means 12 is connected to each photosensitive transfer area 15.
The same number of channel portions connecting the corresponding COD shift registers n of the charge storage portions 1) are formed in the horizontal direction. Therefore, by turning on both transfer gates Tgl=Tg2, signal charges can be transferred from the photosensitive section 10 to the charge storage section 1), while turning off both transfer gates Tg□ and Tg□. By operating and causing the first horizontal charge transfer means 12 to perform a shift operation, signal charges can be output from the output terminal device.

Similarly, the second horizontal charge transfer means 13 also stores charge ff.
The same number of channel parts corresponding to the COD shift register r of part 1) are formed in the horizontal direction, and the transfer gate 'r
By turning on g3, signal charges from the charge storage section 1) are accepted, and signals are sequentially output from the output terminal 30 by shifting in the horizontal direction.

Next, a case will be described in which the operation of the solid-state imaging device having such a configuration is applied to an electronic camera.

First, when an optical image of the subject is formed on the photosensitive section 10 by shutter exposure, red and blue color signal charges are generated in the photosensitive element of the photosensitive area 14, and green signal charges are generated on the photosensitive transfer element of the photosensitive transfer area 15. Color signal charges are generated. Note that during this shutter exposure, the transfer gate 22 and the transfer gate T
gl and Tg2 are closed. Therefore, specific color signal charges are accumulated as a lump in each light receiving element and photosensitive transfer element.

Next, the transfer gate Tgl sTg2 is turned on and opened, and a four-phase clock-driven pulse signal φ71. φ72. φ73. φv
4 is applied to transfer the green color signal charge in the photosensitive transfer region 15 to the charge storage section 1). In this case, pulse signals φvl+φV2+φ73. which are also synchronized with the transfer electrodes 23, 24, 25, and 26 of the charge storage section 1). Since φv4 is applied, the green color signal charges in the photosensitive transfer region 15 are transferred to the charge storage section 1) in the same arrangement.

Next, transfer gate 'rg1. Tg2. Tg3 is turned off and closed, and transfer gate 22 is turned on and opened. As a result, the red and blue color signal charges of the photosensitive element in the photosensitive area 14 are transferred to the photosensitive transfer element in the photosensitive transfer area 15.

Next, transfer gate Tgz, 22 is closed, and transfer gate 'rg1. 'rgs is opened and four-phase pulse signals φv1 to φ74 are applied to the photosensitive section 10 and the charge storage section 1)0 transfer electrodes 18 to 21, 23 to 26, so that one field in the horizontal direction of the photosensitive transfer area 15 is At the same time, the green color signal charges of one field in the horizontal direction of the COD shift register n are transferred to the second horizontal charge transfer means 13. Transfer to. Then, by applying a synchronized drive signal to the first horizontal charge transfer means 12 and the second horizontal charge transfer means 13 to perform a shift operation, the red, blue, and green color signal charges are transferred from the output terminals 29 and 30. A corresponding synchronized color signal is output. - When the transfer of the field color signal charge is completed, the first
, the color signal charges for one field are transferred to the second horizontal charge transfer means 12 and 13, and by repeating such control operations, a video signal for one image generated on the photosensitive section 10 is outputted, and further, By repeating shutter exposure, a video signal for the next image can be obtained.

The control of the drive signals and transfer gates described above is realized by a control means (not shown), as described in A above.

Electric signals corresponding to the interline arrangement can be obtained from both B fields.

(-Effects of the Invention) As explained above, according to the solid-state imaging device of Tatoshi Kimi, there is a photosensitive region in which a plurality of light-receiving elements having a photoelectric conversion function are formed in a predetermined direction, and a transfer gate for each light-receiving element. The photosensitive region is made up of photosensitive transfer elements, each of which has a photoelectric conversion function, and which transfers signal charges between each other by a predetermined transfer drive.The number of elements capable of photoelectric conversion increases, resulting in improved resolution. Furthermore, since the light-receiving area increases, the sensitivity can be increased. Further, by providing a color filter made of specific color filter elements, it is possible to obtain an image without color shift due to an incline arrangement.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing the structure of an embodiment of a solid-state imaging device according to the present invention, Fig. 2 is a surface view of the main part showing the structure of the photosensitive part in Fig. 1 from the surface, and Fig. 3 is a wc1 FIGS. 4 and 5 are schematic configuration diagrams showing the configuration of a conventional solid-state imaging device. FIGS. 10: Photosensitive section 1): FF load accumulation section 12
: First horizontal charge transfer means 13: Second horizontal charge transfer means 14: Photosensitive area 15: Photosensitive transfer area Tgl,
T62. Tg3, 22: Transfer gate 16: Channel block 18, 19, 20, 21, 23, 24, 2
5, 26: Transfer electrode 27: COD shift register 29. 30: Output terminal Ra, Rb: Red filter G: Green filter No. 4 Figure 1) 5 rM Procedure correction fee 1, Incident indication Patent application No. 1988 78308 Bow 2, Name of the invention Solid-state m-image device 6, Invention increased by correction @=07, Corresponding image of correction:

Claims (7)

[Claims] (1) A photosensitive area formed by forming a plurality of light-receiving elements having a photoelectric conversion function in a predetermined direction, each of the light-receiving elements being formed via a transfer gate, each having a photoelectric conversion function, and having a predetermined transfer drive control. What is claimed is: 1. A solid-state imaging device comprising: a photosensitive transfer region made up of photosensitive transfer elements that transfer signal charges therebetween; (2) The light-receiving element in the photosensitive area and the photosensitive transfer element in the photosensitive transfer area are provided with a mosaic color filter that generates signal charges of at least three primary colors or complementary colors. The solid-state imaging device described in . (3) A first color filter is provided in the photosensitive transfer element of the photosensitive transfer area to generate a first signal charge of three types of primary colors or complementary colors, and at least two light receiving elements in the photosensitive area are One light-receiving element is equipped with a second color filter that generates a second signal charge of three types of primary colors or complementary colors, and the other light-receiving element is equipped with a second color filter that generates signal charges of three types of primary colors or complementary colors. Claim 2, characterized in that third color filters that generate third signal charges are arranged alternately.
The solid-state imaging device described in . (4) A first color filter is provided in the photosensitive transfer element in the photosensitive transfer area to generate a first signal charge of three types of primary color or complementary color signal charge, and at least two light receiving elements in the photosensitive area are A second color filter that generates a second signal charge among the three types of primary color or complementary color signal charges is provided on the surface of the pair, and at least two light receiving elements follow the light receiving element provided with the second color filter. A third element has a pair of light-receiving elements, and generates a third signal charge among three types of primary color or complementary color signal charges on its surface.
color filters are provided, the second and third color filters are arranged alternately, one row of the light receiving elements of the pair of light receiving elements is set as the A field, and the row of the other light receiving elements of the pair of light receiving elements is set as the A field. 3. The solid-state imaging device according to claim 2, wherein: is a B field. (5) a charge storage section that temporarily stores the signal charges generated in the photosensitive transfer area after being transferred by the photosensitive transfer area; Claims 1 to 4 further include a control means for moving the signal charge to the photosensitive transfer region via the transfer gate after the signal charge is transferred to the charge storage section. The solid-state imaging device according to item 1. (6) Independent horizontal charge transfer that outputs the signal charges temporarily accumulated in the accumulation section and the signal charges transferred to the accumulation section and then transferred to the photosensitive transfer area at a predetermined synchronized timing. 6. The solid-state imaging device according to claim 5, comprising a plurality of means. (7) The channel length of the storage section in the transfer direction is shorter than the channel length of the photosensitive transfer section in the transfer direction, and the width of the channel of the storage section in the transfer direction is wider than the width of the channel for the photosensitive transfer section. A solid-state imaging device according to claim 5, characterized in that: