JPS5868377A - Solid-state image pickup element - Google Patents

Abstract

PURPOSE:To prevent the evil influence of relfection of incident light by blackening or covering at least part of metallic wiring or a light-shielding metallic film formed on a surface of a solid-state image pickup element with a black layer. CONSTITUTION:An Al surface on a storage part 12 and a shift register 13 is dipped in ''TOPIKA-blackey A '' or ''Al-blackey '', etc., to form a black dyed layer 17 on the surface of an Al vapor-deposite film 16. In this case, when the thickness of the Al vapor-deposite film 16 is 1.2mum, the tickness of the black dyed layer is 0.2-0.3mum. Thus, the black dyed layer 17 is formed on the surface of the Al layer 16 for light shielding to prevent light reflection by the Al layer 16, improving the characteristics of the element greatly.

Description

[Detailed description of the invention] The present invention relates to a solid-state image sensor.

Recently, the development of solid-state image sensors has been remarkable, including CCD type, CP D (Charge Priming De
Various types of solid-state imaging devices have been developed, such as those of the vice) type and the 1VIO8 type.

When constructing a practical device (such as a camera) using these solid-state image sensors, it is desirable that the reflectance is zero in areas other than the photosensitive portion.

However, a vapor-deposited film (for example, At) used as an electrode or a light shield has a relatively high reflectance. Therefore, it has been a problem in the past that light is repeatedly reflected between these surfaces and optical systems such as prisms and lenses, which adversely affects incident light.

Hereinafter, the drawbacks of the conventional method will be briefly explained based on FIGS. 1(C) and 1(B).

Figures 1 (5) and (B) show a frame transfer CCD image sensor 1 as an example of a conventional solid-state image sensor.
In FIG. 1, the COD image sensor 1 includes an image section 11 that receives an optical image, a storage section 12 that temporarily stores information from the image section 11, and a storage section 12 that stores information from the storage section 12. It consists of a shift register 13 that sequentially transfers data to an output terminal 14.

FIG. 1(B) shows a cross-sectional view of the COD image + sensor 1, in which a light blocking At layer 1 is provided on the surfaces of the storage section 12 and the shift register 13 via a SiQ 2 insulating film 16.
6 is formed. The reflectance on the surface of this A7 layer 16 is close to 100%, and as described above, if this state is maintained, repeated reflections will occur with optical systems such as lenses, which will adversely affect the incident light.

The present invention prevents the adverse effects of reflection of incident light by blackening at least a portion of the metal wiring or the light-shielding gold elliptical film formed on the surface of such a solid-state image sensor or covering it with a black layer.

(Embodiment 1) FIG. 2 shows a solid-state image sensor according to an embodiment of the present invention, and the same parts as in FIGS. 1(A) and 1(B) showing the conventional example are given the same numbers. A feature of this solid-state image sensor is that a black dye layer 17 is formed on the surface of the At layer 16 for light blocking to prevent the reflection of light from the A7 layer 16.

The manufacturing process 9VC of the solid-state image sensor of the above embodiment will be specifically explained below.

In the manufacturing process of the solid-state image sensor of this example, after the oxidation diffusion process is completed, a contact window is opened, and T is deposited on the entire surface for forming wiring within the device. Dye the entire surface of the pattern black. For example, as shown in FIG. 2, the At surfaces on the storage section 12 and shift register 13 are
A black dye layer 17 is formed on the surface of the At vapor deposited film 16 by immersing it in Plaque (trade name: Audic Co., Ltd.) or the like.

At this time, when the thickness of the At vapor deposited film was 1.2 μm, the thickness of the black dyed layer was 0.2 to 0.3 μm. In addition, the spectral specular reflectance of this black dyed layer was about 4% for direct light in the sample using At as a substrate (reflection angle of 10°,
46°).

(Actual Sister Example 2) Image portion 1 of the solid-state image sensor in Example 2 of the present invention
1 has a structure as shown in FIGS. 3 and 4. A polycrystalline Si electrode 23 and an At electrode 24 are formed on a monoconductive type (for example, p type) St substrate 21 with an SiO2 insulating layer 22 interposed therebetween. These electrodes 23.
A portion 26 not covered by the light incident portion 24 is a light incident portion, and charges are accumulated in the Si substrate 21 above the light incident portion 26 in response to light incidence. Also, inside the Si substrate 21 (facing the surface)
K is a channel stopper 26 of another conductivity type (for example, n-type)
is formed. This channel stopper 26 is provided to prevent charges from entering other lines. Even in such an image part 11, the At electrode 2
The surface of the At electrode 24 becomes a reflective surface, which causes the above-mentioned problem. However, in this embodiment, the surface of the At electrode 24 is coated with a black dye layer 27 in the same process as described above, as shown in FIG. can be prevented.

(Embodiment 3) FIG. 6 is a schematic diagram showing an interline type CCL image sensor 30, in which information charges accumulated in a photosensitive section 31 into which light is incident are transferred to a transfer section 32 and transferred. , and is sent to the output terminal 34 via the output register 33. This interline type COD image sensor 3o
In this case, the VC may blacken the At pattern on the transfer unit 32 and output register 33 shown by diagonal lines in FIG.

As is clear from the explanation of the above examples, 100%
Even if the reflectance of an At electrode in Table 1 is similar to that of the At electrode, if it is dyed black, it is possible to suppress the reflectance to a divisor.

On the other hand, in Example 2, the At wiring pattern is dyed black after the At wiring pattern forming step (in this method, At
(The sides of the pattern can also be dyed black), but after At vapor deposition,
If the black dyeing step is performed immediately, the photoresist pattern will be cut better in the photolithography step when forming the At pattern. In other words, in the past, when a resist was directly coated on the surface of At as deposited, when exposing the At with overlapping masks, the A
I couldn't ignore the reflections from the IUIii, and the resist pattern had a large fog and was not cut well. This method can also be used by Jin Kaede Wiring Co., Ltd. in the manufacture of conventional integrated semiconductor circuits.

As described above, the solid-state imaging device of the present invention can easily provide the effect of preventing VC-TX radiation on the At electrode and the continuous light film surface, which have the largest reflection on the surface of the solid-state imaging device, and the characteristics of the device It can be greatly improved, and has a lot of industrial value.

[Brief explanation of drawings]

Figures 1 (A) and (B) fd are F-view and IE view of a conventional solid-state image sensor, respectively. Figure 2 is a front sectional view of the solid-state image sensor according to the first embodiment of the present invention, FIG. 3 is a front view of the solid-state image sensor according to the second embodiment of the present invention, and FIG. 5 is a front sectional view of the same element, and FIG. 5 is a plan view of a main part of a solid-state imaging element according to a third embodiment of the present invention. 1... Frame transfer method COD image analyzer, 11-... Image part, 12...
Accumulation unit, 13...Shift register, 16...
・SiO insulating layer, 16...A7 layer, 17.27.
... Ceratene membrane. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
figure

Claims (1)

[Claims] A solid-state image sensor that reads out a signal photoelectrically converted in a photoconverter through a storage section or a transfer section, and a wiring metal or a light shielding metal formed in a region of each section that is irradiated with light. 1. A solid-state imaging device characterized in that at least a part of the image is blackened or stored as a black layer.