JP2713674B2 - Method for manufacturing solid-state imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solid-state image pickup device capable of selectively manufacturing any type of solid-state image pickup device dedicated to erect image, erect image / mirror image, and mirror image only.

[0002]

2. Description of the Related Art There are three types of solid-state imaging devices: solid-state imaging devices dedicated to erect images, solid-state imaging devices for both erect and mirror images, and solid-state imaging devices for mirror images only.

FIG. 4 shows a solid-state image pickup device dedicated to an erect image.
The signal charges photoelectrically converted by the photodiode PD are transferred from the vertical transfer units (VCCD) 1, 1,.
D) and then transferred to and detected by the charge detection unit 3 connected to one end of the horizontal transfer unit 2 by a two-phase drive horizontal transfer pulse applied to the horizontal transfer electrodes H1 and H2. You.

FIG. 5 shows a solid-state image pickup device for both erect image and mirror image. This solid-state image pickup device includes 4
Two independent horizontal transfer electrodes H1, H1B, H2, H2B
And the horizontal transfer electrodes H1, H1B, H2, H
With the combination of 2B, a video signal of both an erect image and a mirror image is obtained. That is, when the transfer pulses applied to the four horizontal transfer electrodes H1, H1B, H2, and H2B are driven in two phases with H1 = H1B and H2 = H2B, the signal charges photoelectrically converted by the photodiode PD are transferred to the vertical transfer unit. Are transferred to the horizontal transfer unit 2 and then transferred in the horizontal transfer unit 2 in the direction shown by the broken line in the figure, whereby the video signal of an erect image similar to the solid-state imaging device shown in FIG. Is obtained.

On the other hand, four horizontal transfer electrodes H1,
The transfer pulse applied to H1B, H2, H2B is
= H2B, H2 = H1B, and the two-phase drive is performed, the transfer direction in the horizontal transfer unit 2 in this case is opposite to that in the above-described case, so that the signal charge flows in the horizontal transfer unit 2 in the direction indicated by the solid line in the figure. And detected by the charge detection unit 3 as a mirror image signal.

[0006] Figure 6 shows yet another example of a conventional solid-state image pickup element for erecting image-mirror and. The solid-state imaging device includes a charge detection unit 3A at one end of the horizontal transfer unit 2 for detecting a video signal of an erect image, and a charge detection unit at the other end of the horizontal transfer unit 2 for detecting a video signal of a mirror image. 3B. Also, 4
Two independent horizontal transfer electrodes H1, H1B, H2, H2B
It has.

The driving of the solid-state image pickup device is performed as follows. That is, similarly to the solid-state imaging device shown in FIG. 5, when two-phase driving is performed under the conditions of H1 = H1B and H2 = H2B, the signal charges are transferred in the direction of the broken line as described above.
In this driving method, an image signal of an erect image is detected by the charge detection unit 3A.

On the other hand, H1 = H2B, H2 = H1
When two-phase driving is performed under the condition B, the signal charges are transferred in the horizontal transfer unit 2 in the solid line direction opposite to the above, so that in this driving method, the mirror image signal is detected by the charge detection unit 3B.

[0009]

By the way, the type of this kind of solid-state imaging device is determined by the user side, and even a user who needs a solid-state imaging device with a mirror image function, such as an in-vehicle camera or a surveillance camera, is required. If you have a camera integrated VTR
Some users require a solid-state imaging device dedicated to an erect image, such as described above.

Here, both types of solid-state imaging devices differ in the configuration of the horizontal transfer section and the charge detection section as described above, and their manufacturing processes generally include formation of a diffusion region for a PN junction, ion implantation, Since it is performed by a series of wafer processing steps such as formation of an oxide film, each type of solid-state imaging device needs to be manufactured as a completely different device by a dedicated process. In this regard, the same applies to a solid-state imaging device dedicated to a mirror image.

For these reasons, conventionally, it has been necessary to manufacture the solid-state imaging device by different manufacturing processes for each type, so that the cost is increased and the process management is complicated.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and only by changing a wiring mask for forming a horizontal transfer electrode, there are three types, erect image only, erect image / mirror image combined use, and mirror image exclusive use. Solid-state imaging device can be selectively manufactured,
As a result, it is an object of the present invention to provide a method for manufacturing a solid-state imaging device capable of greatly reducing costs and simplifying process management.

[0013]

According to the method of manufacturing a solid-state image pickup device of the present invention, it is possible to selectively manufacture any type of solid-state image pickup device dedicated to erect image, erect image / mirror image, and mirror image only. In the method of manufacturing a solid-state imaging device, the first horizontal transfer electrode, the second horizontal transfer electrode, the third horizontal transfer electrode, and the fourth horizontal transfer electrode provided in the erect image-dedicated, erect-image / mirror-image, and mirror-image-dedicated solid-state imaging devices, respectively. Horizontal transfer electrode 4
A step of selecting a type-specific wiring mask provided for wiring the horizontal transfer electrodes according to the selected type of solid-state imaging device, and the wiring corresponding to the erect image-dedicated solid-state imaging device When a mask is selected, the first horizontal transfer electrode and the second horizontal transfer electrode, and the third horizontal transfer electrode and the fourth horizontal transfer electrode are electrically connected using the wiring mask, and While one horizontal transfer electrode and the third horizontal transfer electrode are taken out as external terminals, if a wiring mask corresponding to the solid-state imaging device for both erect image and mirror image is selected, the first and second horizontal transfer electrodes are used to form the first and second horizontal transfer electrodes. The horizontal transfer electrode, the second horizontal transfer electrode, the third horizontal transfer electrode, and the fourth horizontal transfer electrode are taken out as external terminals, and when a wiring mask corresponding to the solid-state imaging device dedicated to the mirror image is selected, the wiring is removed. Using a mask, the first water Electrically connecting the transfer electrode to the fourth horizontal transfer electrode, the second horizontal transfer electrode to the third horizontal transfer electrode, and using the first horizontal transfer electrode and the third horizontal transfer electrode as external terminals. And selectively performing a wiring step to take out, thereby achieving the above object.

[0014]

According to the above-described process, three types of solid-state imaging devices dedicated to erect image, combined erect image / mirror image, and mirror image can be obtained by merely changing the wiring process of the horizontal transfer electrode using different wiring masks. Can be made.

[0015]

Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 shows a solid-state image pickup device exclusively manufactured for an erect image manufactured by the method of the present invention. The configuration of this solid-state imaging device is the same as the configuration of the conventional erect image / mirror image solid-state imaging device shown in FIG. 5 except that the wiring structure of the horizontal transfer electrode is different.

First, the schematic configuration of the solid-state imaging device will be described together with the operation. This solid-state imaging device is an interline transfer type (ILT) solid-state imaging device. A plurality of vertical transfer units (VCC
D) are formed, and C constituting the vertical transfer unit 1
Photodiodes PD, PD... Serving as a light receiving portion are provided in a portion adjacent to the electrode of the CD.

A horizontal transfer section (HCCD) is provided at one end of each of the vertical transfer sections 1, 1,..., And the signal charges photoelectrically converted by the photodiodes PD, PD,. Are transferred to the horizontal transfer unit 2 and then to the charge detection unit 3 connected to one end of the horizontal transfer unit 2 by a two-phase drive horizontal transfer pulse applied to the horizontal transfer electrodes H1 and H2. Thus, the video signal of the erect image is detected.

Here, the horizontal transfer electrodes H1 and H2 are formed after a series of wafer processing steps such as formation of a diffusion region for PN junction, ion implantation, and formation of an oxide film on an N-type silicon single crystal substrate. It is manufactured by a wiring process using a dedicated wiring mask.

Specifically, when a solid-state image pickup device dedicated to an erect image is selected, a dedicated wiring mask is prepared. When the wafer processing is completed, an N-type silicon single crystal substrate is formed using the wiring mask. To four horizontal transfer electrodes H1, H1
B, H2, and H2B are wired so that the horizontal transfer electrodes H1 and H1B and H2 and H2B are electrically connected inside the solid-state image sensor, and the horizontal transfer electrodes H1 and H2 can be taken out as external terminals.

Since such a wiring structure is employed, in the solid-state imaging device of this embodiment, as shown in FIG. 1, only H1 and H2 eventually become horizontal transfer electrodes, and the horizontal transfer electrodes H
1. By the two-phase driving horizontal transfer pulse applied to H2, the image signal of the erect image similar to the solid-state imaging device dedicated to the erect image shown in FIG. 4 is transferred to the charge detection unit 3 and detected.

(Embodiment 2) FIG. 2 shows a solid-state imaging device for both erect image and mirror image manufactured by the method of the present invention. This solid-state imaging device has the same configuration as the solid-state imaging device of the first embodiment except that the wiring structure is different. The wiring structure is manufactured using a dedicated wiring mask different from the wiring mask of the first embodiment.

That is, when the solid-state image pickup device for both erect image and mirror image is selected, a dedicated wiring mask is prepared, and four independent horizontal transfer are performed on the N-type silicon single crystal substrate using the wiring mask. The electrodes H1, H1B, H2, and H2B are wired. These horizontal transfer electrodes H1, H1B, H2, H
2B are respectively connected to four bonding pads so as to be taken out as external terminals, whereby the solid-state imaging device for both erect image and mirror image of this embodiment is manufactured.

According to the solid-state imaging device of the present embodiment, the charge detection unit 3 can detect the erect image and the mirror image video signal by the two-phase driving method similar to the conventional solid-state imaging device shown in FIG.

As described above, the solid-state imaging device of the present embodiment has the same configuration as the solid-state imaging device of Embodiment 1 except that the wiring structure is different. Therefore, the N-type silicon single crystal which has been subjected to the same wafer processing step is used. By a wiring process using a dedicated wiring mask different from the wiring mask of Example 1 on the substrate, a solid-state imaging device that can be used for both erect image and mirror image can be manufactured.

(Embodiment 3) FIG. 3 shows a solid-state image pickup device exclusively manufactured for a mirror image manufactured by the method of the present invention. This solid-state imaging device is different from the first and second embodiments except that the wiring structure is different.
Has the same configuration as that of the solid-state imaging device. The wiring structure is manufactured using a dedicated wiring mask different from the wiring mask of each of the above embodiments.

That is, when a solid-state image pickup device dedicated to mirror image is selected, a dedicated wiring mask is prepared, and the four horizontal transfer electrodes H1, H1B, H2 and H2B are wired so that the horizontal transfer electrodes H1 and H2B and H2 and H1B are electrically connected inside the solid-state imaging device, and the horizontal transfer electrodes H1 and H2 can be taken out as external terminals.

According to the solid-state imaging device having the above wiring structure,
H1 = H2B, H2 = since the two-phase driving in conditions of H1B, video signal mirror image is detected by the charge detection unit 3 at the transfer path shown in solid line in FIG. 5.

Therefore, according to the present embodiment, the solid-state image pickup dedicated to the mirror image is performed irrespective of the fact that only the wiring mask is replaced and the wiring process is changed, and the other structure is the same as that of each of the above embodiments. An element can be manufactured.

In each of the above embodiments, the case where the method of the present invention is applied to the solid-state image pickup device having the structure shown in FIG. 5 has been described. However, it is needless to say that the method can be similarly applied to the solid-state image pickup device having the structure shown in FIG. It is.

As described above, according to the method of manufacturing a solid-state image pickup device of the present invention, three types of solid-state image pickup devices dedicated to erect image, combined erect image / mirror image, and mirror image can be selected simply by changing the wiring mask. It can be manufactured in a special way. Therefore, there is an advantage that the solid-state imaging device according to the demand of the user can be efficiently manufactured.

[0032]

According to the method of manufacturing a solid-state imaging device of the present invention described above, only the erect image and the erect image / mirror image can be used simply by changing the wiring process of the horizontal transfer electrodes using different exclusive wiring masks. And three types of solid-state imaging devices dedicated to mirror images can be manufactured.
There is no need to manufacture these three types of solid-state imaging devices as separate devices. Therefore, a common manufacturing process can be achieved, and efficient manufacturing can be performed according to the demand of the user, so that the cost of the product can be significantly reduced. There is also an advantage that the process management can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a solid-state imaging device dedicated to an erect image manufactured by the method of the present invention.

FIG. 2 is a schematic plan view showing a solid-state imaging device for both erect image and mirror image manufactured by the method of the present invention.

FIG. 3 is a schematic plan view showing a solid-state image pickup device dedicated to a mirror image manufactured by the method of the present invention.

FIG. 4 is a schematic plan view showing a conventional example of a solid-state imaging device dedicated to erect images.

FIG. 5 is a schematic plan view showing a conventional example of a solid-state imaging device for both erect image and mirror image.

FIG. 6 is a schematic plan view showing still another conventional example of a solid-state imaging device that can be used for both an erect image and a mirror image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical transfer part 2 Horizontal transfer part 3 Charge detection part PD Photodiode H1, H1B, H2, H2B Horizontal transfer electrode

Claims (1)

(57) [Claims] 1. A method for manufacturing a solid-state image pickup device, wherein a solid-state image pickup device of any type exclusively for erect image use, for both erect image / mirror image use and mirror image use can be selectively manufactured. A first horizontal transfer electrode and a second horizontal transfer electrode provided in each of the solid-state imaging devices for mirror image and mirror image only;
A wiring mask for each type provided for wiring the four horizontal transfer electrodes of the horizontal transfer electrode, the third horizontal transfer electrode, and the fourth horizontal transfer electrode is selected corresponding to the selected type of solid-state imaging device. And when the wiring mask corresponding to the solid-state imaging device dedicated to the erect image is selected, the first horizontal transfer electrode, the second horizontal transfer electrode, and the third horizontal transfer electrode are used by using the wiring mask. And the fourth horizontal transfer electrode are electrically connected, and the first horizontal transfer electrode and the third horizontal transfer electrode are taken out as external terminals, while wiring corresponding to the upright image / mirror image solid-state imaging device is provided. When a mask is selected, the first horizontal transfer electrode, the second horizontal transfer electrode, the third horizontal transfer electrode, and the fourth horizontal transfer electrode are taken out as external terminals by using the wiring mask, and the mirror image is exclusively used. Compatible with solid-state imaging devices When a wiring mask is selected, the first horizontal transfer electrode and the fourth horizontal transfer electrode, and the second horizontal transfer electrode and the third horizontal transfer electrode are electrically connected using the wiring mask, And the first
Selectively performing a wiring step of taking out the horizontal transfer electrodes and the third horizontal transfer electrodes as external terminals.