JP2002084556A - Method for evaluating solid-state image pickup element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for evaluating solid-state image pickup element with which charge transfer faults can be detected with high accuracy, without erroneously recognizing a white line as a charge transfer fault. SOLUTION: After the output levels a-h of each R pixel and G pixel in a RED row in the vertical transfer direction are detected, by irradiating solid-state image pickup elements in a Bayer arrangement with RED light, the difference (a-b), (c-d) (e-f) and (g-h) between the output levels of the R pixel and succeeding G pixel are calculated. Consequently, the output component W of the white which is the object of erroneous detection is eliminated. In addition, the differences (a-b), etc., between the output levels of the R pixel and succeeding G pixel are added vertically to each other for, for example, with 100 lines in the vertical transfer direction, and the added results are compared with each other. Thus only the output component T of a charge transfer fault in the RED row is detected easily, without erroneously evaluating the white line as a charge transfer fault.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating a solid-state imaging device, and more particularly to an evaluation method for detecting a charge transfer defect in a solid-state imaging device.

[0002]

2. Description of the Related Art In general, a solid-state image pickup device in which R (red) pixels, G (green) pixels, and B (blue) pixels are arranged mainly includes vertical transfer and horizontal transfer as types of charge transfer. There is. One of the evaluation items of such a solid-state imaging device is evaluation of charge transfer defects. First, charge transfer defects in a conventional solid-state imaging device will be described with reference to a solid-state imaging device in which R, G, and B pixels are arranged in a Bayer array as shown in a schematic plan view of FIG.

In the solid-state image pickup device of the Bayer arrangement shown in FIG. 6, each R pixel along the XY line of a RED (red) column in which R pixels and G pixels are alternately arranged in the vertical transfer direction. The output level of each G pixel is as shown in FIG.

That is, when there is no charge transfer defect in the RED column of the solid-state imaging device, as shown in FIG. 7A, the output level of each R pixel and each G pixel is the output level a in a normal state. Becomes

If there is a charge transfer defect in the RED column, as shown in FIG. 7B, the output level of the defective pixel indicated by a circle in the figure and the output level of the subsequent pixels are reduced. Will change. That is, R in which a charge transfer defect has occurred
Since the signal is trapped by the charge transfer defect, the output level b of the pixel decreases to a level lower than the output level a in a normal state. In addition, subsequent G
As for the output level c of the pixel, the trapped signal remains to be transferred, so that the output level increases by that amount.

Next, a conventional evaluation method for detecting a charge transfer defect in the solid-state imaging device having the Bayer array shown in FIG. 6 will be described with reference to FIG. Here, FIG. 8 is a schematic cross-sectional view taken along the line XY showing the output level of each R pixel and each G pixel in the RED column in the vertical transfer direction when the solid-state imaging device having the Bayer array shown in FIG. 6 is irradiated with RED light. It is.

First, in order to increase or decrease the signal in the Bayer array solid-state image pickup device shown in FIG.
Irradiate ED light. The irradiation of the RED light is for evaluating charge transfer defects in the RED column in the vertical transfer direction. Therefore, when evaluating a charge transfer defect in a BLUE (blue) column in which B pixels and G pixels are alternately arranged, the BLUE light is irradiated.

The output level of each R pixel and each G pixel in the RED column obtained by the irradiation of the RED light is as shown in FIG. That is, when there is no charge transfer defect in the RED column, as shown in FIG.
The output level of the pixel becomes the output level a in a normal state. On the other hand, the output level of each G pixel becomes an output level b which is extremely lower than the output level a of the R pixel (b << a) because the RED light is irradiated.

When there is a charge transfer defect in the RED column, as shown in FIG. 8B, a signal is trapped in the output level of the R pixel having the charge transfer defect due to the charge transfer defect. Therefore, the output level becomes lower than the normal output level a shown in FIG. 8A and becomes the output level c (c <a).

On the other hand, the output level of the G pixel subsequent to the R pixel having the charge transfer defect is higher than the output level b shown in FIG. Therefore, the output level becomes d (d> b). At this time, paying attention to the output level of the G pixel, the change amount (db) of the output signal of the G pixel is detected as the output component T of the charge transmission defect (T = db).

In the detection of the charge transmission defect,
Focusing on the output level of the G pixel instead of the R pixel
This is because focusing on the output level of the pixel makes it easier to grasp the relative change amount than focusing on the R pixel.

[0012] The following description of the algorithm for evaluating the electric charge transmission defect will be made in detail later in comparison with the embodiment of the present invention, as will be apparent from the above description. By irradiating the solid-state imaging device with RED light, and paying attention to the output level of the G pixel in the RED column at that time, the amount of change (db) of the output signal of the G pixel is calculated as the output component T ( = D−b), it was possible to evaluate the charge transmission defect.

[0013]

However, the conventional method for evaluating a charge transmission defect in a solid-state imaging device has the following disadvantages. That is, when a DK white point, a so-called white line, occurs in the vertical transfer portion of the solid-state imaging device, the white line is erroneously recognized as a charge transfer defect.

Hereinafter, a specific description will be given with reference to FIG. Here, FIG. 9 is a schematic XY line sectional view showing the output level of each R pixel and each G pixel in the RED column in the vertical transfer direction when the solid-state imaging device having the Bayer array shown in FIG. 6 is irradiated with RED light. It is.

When the solid-state image pickup device having the Bayer array shown in FIG. 6 is irradiated with RED light, RED in the vertical transfer direction is irradiated.
When there is no charge transfer defect in the column, the output levels of each R pixel and each G pixel in the RED column obtained by irradiation of the RED light are as shown in FIG. 9A. That is, each R
The output level of the pixel becomes the output level a in a normal state,
On the other hand, the output level of each G pixel is extremely lower than the output level a of the R pixel b (b << a). This is the same as the case shown in FIG.

However, if there is no charge transfer defect in the RED column in the vertical transfer direction but there is a white line, FIG.
As shown in FIG. 9, since the output level of the R pixel increases due to the occurrence of the white line, a signal component due to the white line is added to the output level a in the normal state shown in FIG. The output level e becomes larger than that (e> a).

The output level of the G pixel similarly increases due to the occurrence of the white line, and a signal component due to the white line is added to the output level b, so that the output level f is larger than the output level b shown in FIG. (F> b).

For this reason, in the conventional evaluation method which focuses on the output level of the G pixel and detects the amount of change in the output signal of the G pixel as the output component T of the charge transfer defect, the amount of change in the output signal of the G pixel Even when (f−b) is due to a signal component represented by a white line, it is detected as an output component T of a charge transmission defect. That is, the generation of the white line is erroneously recognized as the generation of the charge transmission defect, and the output component of the white line is erroneously detected as the output component of the charge transmission defect.

Therefore, in the conventional evaluation method for detecting a charge transfer defect in a solid-state image pickup device, there is a defect that such a white line is erroneously recognized as a charge transfer defect, so that it is impossible to evaluate a charge transfer defect with high accuracy. was there.

Accordingly, the present invention has been made in view of the above circumstances, and provides an evaluation method of a solid-state imaging device capable of detecting a charge transfer defect with high accuracy without erroneously recognizing a white line as a charge transmission defect. The purpose is to provide.

[0021]

The above object is achieved by a method for evaluating a solid-state imaging device according to the present invention described below. That is, the solid-state imaging device evaluation method according to claim 1, when detecting a charge transfer defect in the solid-state imaging device in which the R pixel, the G pixel, and the B pixel are arranged, the solid-state imaging device has a predetermined color. Each of the first and second pixels of a predetermined column in which predetermined two types of first and second pixels of the R, G, and B pixels are alternately arranged in the vertical transfer direction by irradiating light.
A first step of detecting an output level of the pixel and each second pixel, and a second step of calculating a difference between an output level of the first pixel in the predetermined column and an output level of a second pixel immediately after the first pixel.
And the third step of adding the calculation result in the second step in the vertical transfer direction of the solid-state imaging device, and comparing the addition result in the third step,
A fourth step of detecting an output component of a charge transfer defect in a predetermined column.

When detecting an output component of a charge transfer defect in a RED column in which R pixels and G pixels are alternately arranged in the vertical transfer direction, the solid-state imaging device may be irradiated with RED light. It is suitable.

When detecting an output component of a charge transfer defect in a BLUE column in which B pixels and G pixels are alternately arranged in the vertical transfer direction, the solid-state imaging device may be irradiated with BLUE light. It is suitable.

As described above, in the method for evaluating a solid-state image pickup device according to the first aspect, for example, when the output component of the charge transfer defect in the RED column is detected, the solid-state image pickup device is set to RED
After irradiating light and detecting the output level of each R pixel and each G pixel in the RED column, the output level of the R pixel and the G level immediately after that are detected.
By calculating the difference between the output level of the pixel and the output level of the pixel, the output component of the white line which is an object of erroneous detection in the conventional method of evaluating a charge transfer defect in the solid-state imaging device is eliminated at this time. For this reason, the difference between the output level of the R pixel and the output level of the G pixel immediately following the pixel is added in the vertical transfer direction, and the addition result is compared. Only the output component of the charge transfer defect in the RED column can be easily detected without erroneous evaluation as a component. Accordingly, appropriate and highly accurate evaluation of the charge transfer defect in the RED column of the solid-state imaging device is realized.

The same applies to the case where the output component of the charge transfer defect in the BLUE column is detected. That is, in this case, the solid-state imaging device is irradiated with BLUE light,
Detecting the output level of each B pixel and each G pixel in the UE column,
The difference between the output level of the B pixel and the output level of the G pixel immediately after the pixel is calculated, and the output component of the white line that is the target of erroneous detection in the conventional method of evaluating a charge transfer defect in a solid-state imaging device is formed. By adding the difference between the output level of the G pixel immediately after that and the vertical transfer direction, and comparing the addition results, the output component of the white line is erroneously evaluated as the output component of the charge transfer defect as in the conventional case. Instead, only the output component of the charge transfer defect in the BLUE column is easily detected.
Therefore, proper and highly accurate evaluation of the charge transfer defect in the BLUE column of the solid-state imaging device is also realized.

In the method for evaluating a solid-state image pickup device according to the first aspect, the solid-state image pickup device is irradiated with light of a predetermined color, and a predetermined two types of R, G, and B pixels are used. Until the first step of detecting the output level of each of the first and second pixels in a predetermined column in which one pixel and the second pixel are alternately arranged in the vertical transfer direction, the charge in the conventional solid-state image sensor is Because it is the same as the transfer defect evaluation method,
When combining with a conventional evaluation method or changing from the conventional evaluation method, there is also an advantage that the response is very easy.

[0027]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. FIG. 1 is a schematic plan view showing a Bayer-arrayed solid-state imaging device from which a charge transfer defect is detected by the method for evaluating a solid-state imaging device according to one embodiment of the present invention, and FIG. FIG. 3 is a schematic cross-sectional view showing the output level of each R pixel and each G pixel in the RED column in the vertical transfer direction when the image sensor is irradiated with RED light, and FIG. 3 shows the output level of the R pixel in FIG. FIG. 4 is a schematic sectional view illustrating a difference from an output level of a G pixel.

First, as shown in FIG. 1, for a solid-state image pickup device in which R, G, and B pixels are arranged in a Bayer array, the R and G pixels are alternately arranged in the vertical transfer direction. RED light is irradiated to detect a charge transfer defect in the existing RED column.

Here, in the solid-state image pickup device having the Bayer array shown in FIG. 1, the following four types of RED strings are assumed. There are four types: a column without charge transfer defects, a column with charge transfer defects, a column with white lines without charge transfer defects, and a column with white lines without charge transfer defects.

When the solid-state imaging device having the Bayer array shown in FIG. 1 is irradiated with RED light, the output levels of each R pixel and each G pixel of the four types of RED columns are as shown in FIG.
It becomes as shown in.

That is, in the column having no charge transfer defect, the output level of the R pixel becomes the normal output level a as shown in FIG. On the other hand, the output level of the G pixel becomes extremely lower than the output level a of the R pixel (b << a) because the RED light is irradiated.

In the column having the charge transfer defect, as shown in FIG. 2B, the output level of the R pixel changes to the level shown in FIG. The output level c is reduced from the output level a in the normal state shown in FIG. Assuming that the signal component trapped by the charge transfer defect, that is, the output component of the charge transmission defect is T, the output level c is c = a-T.

At this time, the output level of the G pixel is
The trapped signal is left untransferred and increases by that amount, resulting in the output level d. Assuming that the signal component trapped by the charge transfer defect, that is, the output component of the charge transmission defect is T, the output level d is d = b + T.

In a column having a white line without a charge transfer defect, as shown in FIG. 2C, the output level of the R pixel increases to the output level e due to the occurrence of the white line. Assuming that the signal component increased by the white line, that is, the output component of the white line is W, the output level e is e = a + W.

The output level of the G pixel at this time is also
Similarly, the output level f increases due to the occurrence of the white line. That is, the output level f becomes f = b + W.

In a column having a charge transfer defect and a white line, as shown in FIG. 2D, the output level of the R pixel decreases while a signal is trapped by the charge transfer defect. , The output level g. That is, the output level g
Is a state in which FIG. 2B and FIG. 2C are combined, and g = a−T + W.

The output level of the G pixel at this time is
In addition to the trapped signal increasing as a transfer residual, the signal also increases due to the occurrence of a white line, and the output level h
Becomes That is, this output level h is also the same as that shown in FIGS.
(C) and h = b + T + W.

The R of the RED sequence in each state as described above
The output levels a to h of the pixel and the G pixel are summarized as follows. a: Output level of R pixel in normal case b: Output level of G pixel in normal state c: Output level of R pixel in the presence of charge transfer defect (c = a−T) d: Charge transfer defect The output level of the G pixel in a certain case (d
= B + T) e: Output level of R pixel when there is no charge transfer defect and white line (e = a + W) f: Output level of G pixel when there is no white line and no charge transfer defect (f = b + W) g: Electric charge Output level of R pixel in the presence of transfer defect and white line (g = a−T + W) h: Output level of G pixel in the presence of charge transfer defect and white line (h = b + T + W)

Next, in each state, the output level of each R pixel in the RED column and the output level of the G pixel immediately after it, that is, the output level of each R pixel in FIG. 2 and the G level adjacent to the right side (X direction side). The output level of the pixel is compared, and the difference is calculated. The result is as shown in FIG.

That is, in the column having no charge transfer defect, as shown in FIG. 3A, the difference between the output level a of the R pixel and the output level b of the G pixel immediately after it is (a−
b).

Further, in the column having the charge transfer defect, as shown in FIG. 3B, the difference between the output level c of the R pixel and the output level d of the G pixel immediately after it, that is, (c−
d) becomes cd = (a-T)-(b + T) = (ab) -2T.

As shown in FIG. 3 (c), in the column where there is no charge transfer defect and there is a white line, the difference between the output level e of the R pixel and the output level f of the G pixel immediately after it,
That is, (ef) is as follows: ef = (a + W)-(b + W) = ab

In a column having a charge transfer defect and a white line, as shown in FIG. 3 (d), the difference between the output level g of the R pixel and the output level h of the G pixel immediately after it,
That is, (gh) is as follows: gh = (a−T + W) − (b−T + W) = (ab)
−2T.

The R in the RED column in each state as described above
The difference between the output level of the pixel and the output level of the G pixel immediately after it is summarized as follows. ab: Difference in output level between R pixel and G pixel in normal case cd: Difference in output level between R pixel and G pixel in case of charge transfer defect, where cd = (a− b) -2T ef: Difference in output level between R and G pixels when there is no charge transfer defect and there is a white line. However, ef = abgh: When there is a charge transfer defect and a white line. R pixel and G
Difference in output level from pixel where gh = (ab) −2T

From the above, the difference between the output level of the R pixel in the RED column in each state and the output level of the G pixel immediately after the difference is obtained. At that time, the evaluation of the charge transfer defect in the conventional solid-state imaging device is made. It can be seen that in the method, the white line output component W which is the target of the erroneous detection disappears.

Next, the difference between the output level of each R pixel and the output level of the G pixel immediately after it is vertically added in the vertical transfer direction. The reason for performing this vertical addition is that the difference between the output level of each R pixel and the output level of the G pixel immediately after it is very small. To do that. The number of lines to be added can be changed as appropriate.

Here, for example, vertical addition of 100 lines (for 100 pixels) is performed. In this case, in the column having no charge transfer defect, the result of the vertical addition of the difference between the output level a of the R pixel and the output level b of the G pixel immediately thereafter is (100a-100b).

In a column having a charge transfer defect, the result of the vertical addition of the difference between the output level c of the R pixel and the output level d of the G pixel immediately after it is as follows: 100c-100d = 100a-100b-200T Becomes

In a column where there is no charge transfer defect and there is a white line, the result of the vertical addition of the difference between the output level e of the R pixel and the output level f of the G pixel immediately thereafter is 100e-100f = 100a- 100b.

In a column having a charge transfer defect and a white line, the result of the vertical addition of the difference between the output level g of the R pixel and the output level h of the G pixel immediately after the result is 100g-100h = 100a- 100b-200T.

The R in the RED column in each state as described above
The result of the vertical addition of the difference between the output levels of the pixel and the G pixel immediately after the pixel is as follows. Normal case without charge transfer defect or white line: 100a-100b Case with charge transfer defect: 100c-100d = (100a-100b) -200
T When there is no charge transfer defect and there is a white line: 100e-100f = 100a-100b When there is a charge transfer defect and a white line: 100g-100h = (100a-100b) -200
T

From the above, the difference between the output level of the R pixel in the RED column in each state and the output level of the G pixel immediately after it is compared. Is reduced by twice the output component of the charge transfer defect. When there is no charge transfer defect in the RED column and there is a white line, it is the same as in the normal state, and there is no variation due to the output component of the white line. Furthermore, RED
When there is a charge transfer defect and a white line in the column, the output component of the charge transfer defect is reduced by twice the output component of the normal state, and there is no variation due to the output component of the white line.

Therefore, by comparing the output level difference between the R pixel in the RED column and the G pixel immediately after it in each state with the difference in output level between the normal R pixel and the immediately following G pixel. When there is a charge transfer defect regardless of the presence or absence of a white line in the RED column, only the 200T component is detected. Further, when the value is divided back by twice the number of vertically added lines 100, only the output component T of the charge transfer defect is detected. As a result, it is possible to properly and accurately evaluate only the charge transfer defect without erroneously detecting the output component W of the white line as the output component T of the charge transfer defect and erroneously evaluating the white line as the charge transfer defect. .

Next, a method for detecting a charge transfer defect of the solid-state imaging device according to the present embodiment will be compared with a conventional method for detecting a charge transfer defect using FIGS. 4 and 5. FIG.
Here, FIGS. 4 and 5 are schematic sectional views for explaining a method of detecting a charge transfer defect in a conventional solid-state imaging device, and FIG. 4 is a schematic sectional view showing only the output level of the G pixel in FIG. FIG. 5 is a schematic cross-sectional view showing the result of vertically adding only the output levels of the G pixels in FIG.

In the conventional case, when the RED light is irradiated on the solid-state image pickup device having the Bayer array shown in FIG. 1, FIG.
Regarding the output level of each R pixel and each G pixel in the RED column in the vertical transfer direction shown in (d), the output level of the R pixel is ignored, and attention is paid only to the output level of the G pixel. Therefore, the output levels of the respective G pixels corresponding to FIGS. 2A to 2D are as shown in FIGS. 4A to 4D.

The output levels b to h of the G pixels in the RED column in each state are summarized as follows. b: Output level of G pixel in normal case d: Output level of G pixel in case of charge transfer defect (d
= B + T) f: Output level of G pixel when there is no charge transfer defect and white line (f = b + W) h: Output level of G pixel when there is charge transfer defect and white line (h = b + T + W)

Next, the output level b of such a G pixel
To h are vertically added in the vertical transfer direction. The reason for performing the vertical addition is to make the output component T of the charge transmission defect prominent by adding a plurality of lines because the output component T of the charge transmission defect is very small. The number of lines to be added can be changed as appropriate.

Here, when the vertical addition of 100 lines (for 100 pixels) is performed in correspondence with the above embodiment,
The result of this vertical addition is as shown in FIG. However, here, in general, the solid-state imaging device has a large number of pixels in both the vertical transfer direction and the horizontal transfer direction, and charge transfer defects and white lines are rarely adjacent to each other. In other words, the result of vertical addition is displayed on the assumption that a normal state exists between each charge transfer defect.

The results obtained by vertically adding the output levels b to h of the G pixels in the RED column in each state in the vertical transfer direction are summarized as follows. Normal: 100b Charge transfer defect: 100d = 100b + 10
0T When there is no charge transfer defect and there is a white line: 100f = 10
0b + 100W When there is a charge transfer defect and a white line: 100h = 100
b + 100T + 100W

As described above, when a charge transfer defect or a white line exists in the RED column, the output level increases by an amount corresponding to the output component of the charge transfer defect or the output component of the white line from the output level in a normal state. I understand that

Therefore, in the conventional method of detecting a charge transfer defect, the output level of the G pixel in the RED column in each state is compared with the output level b of the G pixel in a normal state, so that the charge in the RED column is obtained. If there is a transfer defect or a white line, each component of 100T, 100W, 100T + 100W is detected. Further, the number of vertically added lines 100
, Not only the output component T of the charge transfer defect but also the output component W of the white line are detected. As a result, the output component W of the white line is erroneously detected as the output component T of the charge transfer defect, and the white line is erroneously evaluated as the charge transfer defect.

As described above, according to the present embodiment, the solid-state image pickup device in the Bayer array is irradiated with RED light, and the output levels a to G of each R pixel and each G pixel in the RED column in the vertical transfer direction are set.
After detecting h, the differences (ab), (cd) and (e−) between the output level of the R pixel and the output level of the G pixel immediately after it are detected.
f) and (gh) are calculated, and the difference (ab) between the output level of the R pixel and the G pixel immediately after the R pixel and the like are vertically added in, for example, 100 lines (for 100 pixels) in the vertical transfer direction. By comparing the result of the vertical addition, the output component T of the charge transfer defect in the RED column in the vertical transfer direction can be easily obtained without erroneously evaluating the white line as a charge transfer defect as in the conventional case. Therefore, appropriate and highly accurate evaluation of the charge transfer defect can be realized.

Further, the solid-state image pickup device having the Bayer array has an RE.
Until the D light is irradiated and the output levels a to h of each R pixel and each G pixel in the RED column in the vertical transfer direction are detected, a common evaluation algorithm and a common evaluation algorithm for the charge transfer defect in the conventional solid-state imaging device are used. Therefore, when the evaluation method according to the present embodiment is used in combination with the conventional evaluation method, or when the conventional evaluation method is changed to the evaluation method according to the present embodiment, the response is extremely difficult. Can be easier.

In the above embodiment, the case where the charge transfer defect is detected in the RED row in the vertical transfer direction of the solid-state imaging device has been described. However, the present invention is not limited to the RED row, and is not limited to the RED row. The present invention can be applied to a case where a charge transfer defect is detected in a BLUE column in which B pixels and G pixels are alternately arranged in the vertical transfer direction. In this case, after irradiating BLUE light instead of RED light and detecting the output levels a to h of each B pixel and each G pixel in the BLUE column in the vertical transfer direction, the output level of the B pixel and the immediately following The difference between the output level of the G pixel and the output level of the B pixel and the G pixel immediately after the pixel are calculated by vertical addition of a plurality of lines in the vertical transfer direction, and the result of the vertical addition is compared. I just need.

Further, in the above-described embodiment, the case where the charge transfer defect is detected in the solid-state image pickup device in which the R, G, and B pixels are arranged in the Bayer array has been described. Instead, even in a solid-state imaging device in which color pixels having a complementary color relationship with RGB are arranged, a charge transfer defect is detected by using the same evaluation algorithm as that of the present embodiment, and the charge transfer defect is determined to be appropriate and high. Accurate evaluation can be realized.

[0066]

As described in detail above, according to the method for evaluating a solid-state imaging device according to the present invention, the following effects can be obtained. That is, according to the solid-state imaging device evaluation method of the first aspect, when detecting an output component of a charge transfer defect in the RED column, the solid-state imaging device is irradiated with RED light, and each R pixel in the RED column and After detecting the output level of each G pixel, the output level difference between the R pixel and the immediately following G pixel is calculated, and the difference between the output level of the R pixel and the immediately subsequent G pixel is added in the vertical transfer direction. Then, by comparing the addition results, and when detecting the output component of the charge transfer defect in the BLUE column, the solid-state imaging device is irradiated with BLUE light, and each B pixel and each G pixel in the BLUE column. , The difference between the output levels of the B pixel and the G pixel immediately after is calculated, and the difference between the output levels of the B pixel and the G pixel immediately after is calculated in the vertical transfer direction. Comparing the addition results Thus, only the output component of the charge transfer defect in the RED column or the BLUE column can be easily detected without erroneously evaluating the output component of the white line as the output component of the charge transfer defect as in the conventional case. , RED column of solid-state imaging device or BLU
Appropriate and highly accurate evaluation of the charge transfer defect in the E column can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a Bayer-array solid-state imaging device from which a charge transfer defect is detected by the method for evaluating a solid-state imaging device according to one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing output levels of each R pixel and each G pixel in a RED column in a vertical transfer direction when the solid-state imaging device shown in FIG. 1 is irradiated with RED light.

FIG. 3 is a schematic cross-sectional view showing a difference between an output level of an R pixel and an output level of a G pixel immediately after the output level in FIG.

FIG. 4 is a schematic cross-sectional view for explaining a method of detecting a charge transfer defect in a conventional solid-state imaging device for comparison with a solid-state imaging device evaluation method according to an embodiment of the present invention; 3 is a schematic sectional view showing only the output level of the G pixel in FIG.

5 is a schematic cross-sectional view for explaining a conventional method for evaluating a solid-state imaging device for comparison with a method for evaluating a solid-state imaging device according to an embodiment of the present invention; FIG.
FIG. 7 is a schematic cross-sectional view showing a result of vertically adding only output levels of pixels.

FIG. 6 is a schematic plan view showing a conventional Bayer array solid-state imaging device.

7 is a schematic cross-sectional view taken along the line XY showing the output level of each R pixel and each G pixel in the RED column in the vertical transfer direction of the solid-state imaging device having the Bayer array shown in FIG.

8 is a schematic cross-sectional view (part 1) illustrating output levels of each R pixel and each G pixel in a RED column in a vertical transfer direction when the solid-state imaging device illustrated in FIG. 6 is irradiated with RED light.

9 is a schematic cross-sectional view (part 2) illustrating output levels of R pixels and G pixels in a RED column in a vertical transfer direction when the solid-state imaging device illustrated in FIG. 6 is irradiated with RED light.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4M118 AA09 AA10 AB01 BA10 FA06 GC08 GC14 5C061 BB07 CC01 5C065 BB23 CC01 DD02 DD17 EE06 GG15 GG21 GG22 5C072 BA20 CA12 EA04 FA03 QA20 UA18 UA20

Claims (3)

[Claims] When detecting a charge transfer defect in a solid-state imaging device in which a red pixel, a green pixel, and a blue pixel are arranged, irradiating the solid-state imaging device with light of a predetermined color, A predetermined 2 of the green pixel and the blue pixel
A first step of detecting an output level of each first pixel and each second pixel of a predetermined column in which first and second pixels of a type are alternately arranged in the vertical transfer direction; A second step of calculating a difference between an output level of the first pixel and an output level of the second pixel immediately after the first pixel; and a vertical transfer of the calculation result in the second step to the solid-state imaging device. A third step of adding in the direction, and a fourth step of comparing the addition result in the third step to detect an output component of the charge transfer defect in the predetermined column. Evaluation method for solid-state imaging device. 2. The method for evaluating a solid-state imaging device according to claim 1, wherein the light of the predetermined color that irradiates the solid-state imaging device is:
Using red light, the first pixel and the second pixel are a red pixel and a green pixel, respectively, and the predetermined column is a red pixel in which the red pixels and the green pixels are alternately arranged in a vertical transfer direction. A method for evaluating a solid-state imaging device, comprising: 3. The method for evaluating a solid-state imaging device according to claim 1, wherein the light of the predetermined color that irradiates the solid-state imaging device is:
Using blue light, the first pixel and the second pixel are a blue pixel and a green pixel, respectively, and the predetermined column is a blue color in which the blue pixels and the green pixels are alternately arranged in a vertical transfer direction. A method for evaluating a solid-state imaging device, comprising: