JPS58161474A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To increase the number of picture elements included in a photodetection area and to improve the resolution without increasing the photodetection area, by forming the photodetection section and the transfer section on separate semiconductor substrates, and incorporating both substrates solidly, relating to a one-dimension or two-dimension solid-state image pickup device. CONSTITUTION:The 1st semiconductor substrate 1' where a Schottky picture element electrode 2 is provided is separated from the 2nd semiconductor substrate 1 where a CCD shift register is provided. Thus, the 1st substrate 1' uses different material from the 2nd substrate 1. For example, in using a P type Germanium (Ge) as the 1st substrate 1', the photosensing wavelength of the Schottky barrier formed through the contact between the Ge and nickel (Ni) is around 10mum, and the light far longer than the photosensing wavelength of 1.2-4.6mum is detected.

Description

[Detailed description of the invention] (a) Technology of the invention Public funding The present invention relates to a one-dimensional or two-dimensional integrated imaging device,
In particular, the present invention relates to those in which the pixels constituting the light-receiving element have a 71-key barrier configuration.

(b) Background of the technology Among solid-state imaging devices, especially infrared one-dimensional or two-dimensional imaging devices, the light receiving element is made of silicon (81), for example.
For example, platinum (Ft) or gold (
There is a so-called seat key barrier (1) optical sensor which is constructed by depositing a film (U). This type of optical sensor or imaging device is used, for example, in the Journal of 8o1
id -8tate C4rouitsVO1,80-
11, No, L February, 197LP
, 189-146, of which -
Taking a dimensional sensor as an example, a sectional view of a main part of the sensor, that is, an integrated imaging device, is as shown in FIG. 61.

In FIG. 1, for example, Plil's semiconductor substrate (
For example, at a predetermined location on one main surface of 8i)1, there is a shimato key pixel electrode 2 made of todoroki or noodles as described above.
At a low temperature, for example, 77@, a Schottky barrier with a degree of α26 m is formed on the semiconductor surface directly below the pixel electrode 2, for example, in the combination of 6 and Plil. A depletion layer 8 is formed. However, 8 is an insulating film.

When infrared rays are made incident in the direction of arrow A from the rear surface la side -b) of substrate l at this point ξ, the infrared rays are transmitted through the silicon substrate of, for example, PmI, and are incident on the cut key barrier portion. In this way, when the above-mentioned infrared rays pass through as shown by the arrow, the photoelectric conversion that takes place in the cylindrical barrier part creates pairs of electrons and holes in the cylindrical pixel electrode 2. The holes flow away in the direction of the arrow across the depletion layer 8, and as a result, electrons are left behind and accumulated in the pixel electrode 2.

However, since the pixel electrode 2 is electrically connected to the substrate and the reverse conductivity n-doped layer 6 formed adjacent to the diagonal electrode 2, the electrons increased in the pixel electrode 2 are (negative charges) flow into the impurity doped layer, but equivalently, these electrons flow into the impurity doped layer 6.
and the depletion layer capacitance Cd of the depletion layer 9 formed between the base W1 and the base W1, and the depletion layer capacitance Cd of the depletion layer 9 formed between the
This will accumulate in the depletion layer capacitance CI in the key barrier section.

When the foot voltage Vt is applied to the transfer gate 6 via the terminal 18, the accumulated electrons flow in the two directions of the arrows because a channel is generated directly under the transfer gate 6, and the electrons flow in the charge transfer device (hereinafter referred to as 00D). The transfer voltage dat flows into the depletion layer 10 or the potential well just below the transfer electrode 7 of the COD and is applied via the terminal 14. direction and read out.

(0) Prior Art and Problems By the way, in a solid-state imaging device that is equipped with a light-receiving section made up of such a shift register pixel electrode 2 and a charge transfer section made up of a COD that works as a shift register, the transfer section is connected to the light-receiving section. Since the same semiconductor surface 1ζ is disposed on the same semiconductor surface as 1ζ, there is a drawback that the actual light-receiving area is limited and reduced. For that reason, for example, if the pixel electrode material is Ft, the photosensitive wavelength of the VW Watt pixel is 1.2 to 4.
This causes the inconvenience of being limited to 4s11.

(d) Purpose of the Invention The present invention has been achieved in view of the above-mentioned drawbacks of the conventional technology, and aims to improve resolution by increasing the number of pixels included in the light-receiving area without increasing the area. Another object of the present invention is to provide a novel one-piece imaging device that can be used to change the photosensitive wavelength region by using a material other than 81 for the semiconductor substrate of the light receiving part.

(・) Structure and object of the invention According to the present invention, there is provided a light-receiving section made up of a plurality of light-receiving atoms having a single soto-key barrier structure, and a charge transfer device that transfers the charges generated in the light-receiving section. An integrated imaging device characterized in that the light receiving section and the transfer section are configured on separate semiconductor substrates, and the two substrates are three-dimensionally integrated. This is achieved by providing a number.

g) Examples of the invention Hereinafter, embodiments of the present invention will be briefly described in detail.

FIG. 2 is a WIIW/II diagram showing the structure of a solid-state imaging device according to the present invention.
The same reference numerals as in Fig. 1 are given to the same parts as in Fig. 1. The main difference between the solid-state imaging device of the present invention and the conventional one shown in Fig. The semiconductor substrate 1' is separate from the second semiconductor substrate 1 on which the CCD shift register is disposed, and for the sake of convenience, the substrate 1' is different from the second substrate 1. There are many types using different materials.

For example, if pH germanium (Go) is used as the substrate 1' of the above lit, then nickel (Go) and
The photosensitive wavelength of the shield formed by contact with & is 10 pH degrees, making it possible to detect light with a much longer wavelength than the above-mentioned photosensitive wavelength of 1, 2 to 4.6 microns.

Moreover, the key pixel electrode 2 of the substrate 1' of the turtle 1 is
Since there is no need to dispose a CCD shift register on the main surface of the screen where the light-receiving surface is disposed, it is possible to dispose a larger number of other shift registers on the main surface, which increases the efficiency of use of the light-receiving surface. Significantly improved.

The operation itself of this solid-state imaging device is no different from the operating principle of the conventional device number ζ shown in Fig. 111, but the pixel electrode 2
The increased electric charge (electrons) is transferred to a bump 2 made of, for example, indium (In), which is placed at one corner of the electrode 2.
tm via 2! It flows into the impurity doped layer 6. Then, when a voltage VT is applied to the transfer gate 6 through the terminal 1s of the transfer gate, the COD is transferred in the two directions of the arrows through the channel that is generated directly below the transfer gate 6, and the COD is transferred to the depletion layer immediately below the transfer electrode 7. It flows into the IO, is transferred in the longitudinal direction of the COD, that is, in a direction perpendicular to the plane of the paper, and is scraped out.

Note that the impurity doped layers 20 and 21 provided in $1 and the second substrate 1' and l in FIG.
is the charge increase. Moreover, if the wavelength of one light is 1.2 to 46 μm for the substrate of Ill, it is possible to use 81 as it is as before, and furthermore, gallium intimmonium (Garb) can be used for the first substrate 1'. If used as a light beam, the wavelength of one light should be 1.0 to 1.6 μmsi degrees.

Effects of the Invention As described above in detail, the solid-state imaging device according to the present invention uses Ga, 8i as the first semiconductor substrate 1'.

Since we can freely select materials such as Ga8b, we can not only change the wavelength of the light in various ways, but also increase the efficiency of use of the light-receiving area, thereby increasing the actual detection sensitivity of infrared rays, which has a great practical effect. You can expect good results.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of a conventional Schottky barrier type solid-state imaging device, and FIG. 2 is a diagram showing the structure of a Schottky barrier type solid-state imaging device according to the present invention. In the drawings, ■ and 1' are semiconductor substrates, 2 is a Schottky pixel electrode, 8 is an insulating film, 5 is an impurity doped layer, and 6 is a semiconductor substrate.
is the transfer gate, 7 is the transfer electrode of CCI), 8 is the depletion layer of the Schottky barrier part, 9 is the depletion layer around the impurity doped layer, IO is the depletion layer of the transfer electrode angle F of CCU, 20 and 21
2 represents a charge weir and 22 represents a bump.

Claims (1)

[Claims] In the configuration of an imaging device including a light receiving section configured with a plurality of light receiving elements having a Schottky barrier structure, and a transfer section configured with a wired charge transfer device that transfers charges generated in the light receiving section, the light receiving section What is claimed is: 1. An integrated imaging device characterized in that a transfer section and a transfer section are constructed on separate semiconductor substrates, and the two substrates are three-dimensionally integrated.