JPS5826714B2 - Denkatenso Ichijigen Kankou Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a charge transfer photosensitive device, and more particularly to a charge transfer dimensional photosensitive device that can be increased in density without deteriorating the characteristics of the device.

In a conventional charge transfer-dimensional photosensitive device, a structure is known in which a photosensitive portion and a charge transfer portion for transferring charges accumulated in the photosensitive portion are provided on both sides of the photosensitive portion.

This structure is described in ``Journal Vacuum Science Technology - 1972, Volume 9, No. 6 (Jour
nalVacuum 5science Technology
ogy Vo19, 44) J, page 1174, page 21.

However, in such a conventional device, increasing the number of picture elements to a high density increases the number of transfer stages, and even if the transfer loss at each stage is the same, the overall transfer loss increases.

For this reason, it has been difficult to increase the number of picture elements in the photosensitive area in conventional devices.

The purpose of the present invention is to be able to increase the number of pixels in a photosensitive pixel section without increasing the number of transfers, and to transfer multiple pieces of information at the same time by applying the same transfer pulse to multiple channels. An object of the present invention is to provide a charge transfer-dimensional photosensitive device that does not cause variations in signals distributed to channels.

According to the present invention, a first transfer array is provided on both sides of a one-dimensional photosensitive array having a large number of photosensitive parts arranged one-dimensionally,
A second transfer array is provided further outside the first transfer array, and a temporary storage array having the same number of elements as the photosensitive array is provided between the first transfer array and the second transfer array. and means for transferring and accumulating signal charges generated in the photosensitive section from the photosensitive array to the temporary storage array via the first transfer array, and controlling from the temporary storage array to the first transfer array and the second transfer array. means for transferring and accumulating using electrodes; means for sequentially transferring charges accumulated in the transfer array section along the transfer array section; means for reading the transferred charges; and means for extracting the read charges. A charge transfer-dimensional photosensitive device is obtained, which is characterized by comprising:

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows a one-dimensional charge transfer photosensitive device showing an embodiment of the present invention, in which a charge medium 10 (a third
A plurality of one-dimensionally arranged photosensitive arrays S (St, S2 r S3t) each accumulate signal charges generated according to the intensity of incident light.
S4 y"', 84m-5rS4rn-2? S4
rn -'1 t S4 m) The separation layer 31 is separated from each other, and the first transfer arrays 21 and 21' are provided below and above the -dimensional photosensitive array S section, respectively.
are provided, and second transfer arrays 22 and 22' are provided on the outside thereof, respectively.

Lower transfer arrays 21, 22 and upper transfer arrays 21', 2 of signal charges integrated in the -dimensional photosensitive array section S
Transfer to 2' is controlled by transfer gate electrodes 23 and 23'.

Further, an electrode 24 for temporarily accumulating charges between the first and second transfer arrays (21°, 22 points and between 21' and 22')
and 24' control electrode 25 for controlling the charge transfer of the lower first transfer array 21 and the temporary storage electrode 24. A control electrode 26 for controlling charge transfer between the lower second transfer array 22 and the temporary storage electrode 24. A control electrode 27 for controlling charge transfer between the upper first transfer array 21' and the temporary storage electrode 24'.
Upper second transfer array 22' and temporary storage electrode 24'
a control electrode 28° for controlling charge transfer; a plurality of transfer electrodes 13a that constitute one transfer element with four electrodes;
, 14a, 15a, 16a, 13b.

14b, 15b, 16b, -”13m, 14m.

15m, 16m and 13a', 14a', 15a'.

16a', 13b', 14b', 151j',
16b'・-・・-13rr(, 14rrf, 14m
', 15rr/, 16rr/.

Means 29 for reading out the signal charges transferred in each transfer array in the correct order and means 30 for converting the read signal charges into electric signals corresponding to the charges are provided, and each transfer electrode is provided with an upper and a lower The same transfer pulse is commonly applied to every four electrodes, that is, transfer electrodes 13a, 13b, .
...13m and 13a', 13b't"'13m
' is the first transfer pulse φ1 from terminals 17 and 17'.
．． Transfer electrode 14a.

14b, -, 14m and 14a', 14b',...
.

14rrl' is the second transfer pulse φ2 from the terminals 18 and 18'; transfer electrodes 15a, 1sb, . Transfer pulse φ3. Furthermore, transfer electrodes 16a, 16b, +++, 16m and 16a
'.

The fourth transfer pulse φ4 is supplied from the terminals 20 and 2σ to the terminals 16b', . . . , 16tr/, respectively.

Transfer gate electrodes 23 and 23' are connected to each other and the same pulse φb is applied to them.

Storage electrodes 24 and 24' are also connected to each other and the same DC voltage φg is applied thereto.

Pulse φa to control electrode 25; pulse φa to control electrode 26;
Charge transfer is controlled by applying a pulse φe to the control electrode 27 and a pulse φf to the control electrode 28, respectively.

Each picture element section S1 of the photosensitive array section S. S2. S3. S4゜・
The signal charges accumulated in yS4m are sequentially transferred to the upper second transfer array 22' as indicated by arrows in FIG.

Upper first transfer array 21' Lower first transfer array 21
, lower second transfer array 22. . . . are transferred to each transfer array in units of four picture elements, and then transferred within each transfer array by applying a transfer pulse to the latter transfer electrode.

Next, referring to FIG. 3 which shows a cross section seen from A-A' in FIG. The transfer of signal charges from the photosensitive picture element portion S3 to the first transfer array 21 will be described with reference to FIG. 4 showing a cross section.

Referring also to FIGS. 1 and 2, in this embodiment, a dielectric material 11 of silicon dioxide is coated on the surface of a charge storage medium 10 of a P-type silicon substrate, and a photosensitive electrode 12. Transfer gate 23. Transfer electrode 14a (
Figure 3) 16a (Figure 4) and control electrodes 25 and 2
6 storage electrodes 24 are arranged, respectively.

Further, a separation band 31 is provided in the silicon substrate 10 so that the signal charges of the photosensitive picture element portions are not transferred to the transfer array on the non-corresponding side.

Solid lines 33, 34, 35 shown in the substrate 10 are photosensitive electrodes 1
2° represents the substrate surface potential of each substrate when a pulse is applied to the transfer electrode 14a (Fig. 3 L16a (Fig. 4),
A solid line 36 represents the substrate surface potential when a DC voltage φg is applied to the storage electrode 24.

The closer to the surface, the higher the potential.

When a pulse φa is applied to the photosensitive electrode 12, as shown in FIGS. 3a and 4a, (
Potential wells are formed in the photosensitive picture element portions S4, S3).

When light is irradiated, electron-hole pairs are generated, and electrons, which are fractional charges, are accumulated in the potential well.

The symbol "e'' in the figure indicates an integrated signal charge.

During the period when signal charges are accumulated in the photosensitive array S,
Each transfer pulse is applied such that charge transfer in the transfer array takes place, so that the potential wells between the photosensitive array and the transfer array, and the first
There must be separation between the second transfer array 21 and the potential wells of the storage array, and between the second transfer array 22 and the potential wells of the storage array.

For this purpose, the voltages applied to the transfer gate 23 and control electrodes 25, 26 are kept low (nearly zero volts) during the transfer period.

This lowers the surface potential in the substrate directly under these electrodes.

Although not shown in the figure, it goes without saying that it is desirable to shield the surface on the light incident side from light except for the photosensitive picture element portion.

Photosensitive pixel section S3. When transferring the signal charges accumulated in S4 to the transfer array, the voltage applied to the transfer electrodes 13a and 15a connected to the terminals 17 and 19 is set to a low state (
At the same time as the pulse φa applied to the photosensitive electrode 12 is removed, a transfer pulse φb is applied to the transfer gate electrode 23, and the transfer pulse φb is connected to the terminals 18 and 20 so as to overlap with the transfer pulse φb. A pulse is applied to the transfer electrodes 14a and 16a.

For this reason, as shown in FIGS. 3 and 4, the photosensitive picture element portion S3. The signal charges accumulated in S4 are transferred to the first transfer array.

Thereafter, by removing the pulse φb applied to the transfer gate electrode 23, the photosensitive picture element portion S3. S4 and transfer array 21 are separated, and pulse φC is applied to control electrode 25.

By simultaneously removing the applied pulses of the transfer electrodes 14a, 16a and the control electrode 25, the temporary storage electrode 24 is pre-applied with a DC voltage φg as shown in FIG. 3C and FIG. 4C.
Charge is accumulated in the

Therefore, the photosensitive pixel portion S3. This means that the signal charge S4 has been transferred from the photosensitive electrode to the temporary storage electrode.

Thereafter, the control electrode 26. Pulses are sequentially applied to the transfer electrodes 14a to transfer the signal charge of the photosensitive picture element portion S4 to the second transfer array, and the pulses of the control electrode 26 are removed to separate the second transfer array.

When a pulse is applied to the photosensitive electrode 12 as shown in FIG. 3d, the accumulation of signal charges in the photosensitive picture element S4 starts again.

The signal charge of the photosensitive pixel portion S3 is transferred to the control electrode 25. as shown in FIG. Pulses are sequentially applied to the transfer electrodes 16a to transfer the data to the first transfer array, and the pulses applied to the control electrodes 25 are removed to separate the first transfer array and the storage array.

The signal charges of the photosensitive picture element sections S3 and S4 are separated into the second transfer array and the first transfer array, respectively, and are sent to the readout means 29 in synchronization with the transfer pulses sequentially applied to the terminals 17 to 20. be transferred.

Above is the photosensitive pixel section S3. Although the signal charge transfer operation in S4 has been described in detail, the overall operation of this embodiment will be further described.

Now, when a pulse is applied to the photosensitive electrode 12, each picture element portion S1. S2゜S3. S4
, S S rn S rn-84rr
A potential well is formed in one substrate, and minority charges generated in accordance with the amount of light irradiated to each picture element portion are accumulated.

After a certain period of time, in order to transfer the accumulated signal charges to each transfer array, the pulse φb is applied to the transfer electrodes 23, 23' at the same time as the pulse application to the photosensitive electrode 12 is removed, and then the terminals 18, 20, 18' and 20' simultaneously, pulses φC2φe are applied to control electrodes 25 and 27, and then terminals 18, 20, 18', 20', transfer electrodes 23, 23', and control electrodes 25 and 27 are simultaneously applied. Except for pulse application, all signal charges are stored in the temporary storage electrodes 24, 24' because the DC voltage φg is applied in advance to the temporary storage electrodes 24, 24'.

As a result, the signal S1. ..., 54m-3
are in the storage array 24' directly below the transfer electrodes 16a', . . . . . , 84m-2 are transmitted to the storage array 24' directly below the transfer electrodes 14a', . . . , 14m'. ....

The signal of 54rn 1 is transferred to the transfer electrodes 16a, ・++, 16m
S4. ..., S4m are stored in the storage array 24 directly below the transfer electrodes 14a, ..., 14m.

In other words, the (4m-3)th (m is a positive integer) and (4m-2:)th signal charges of the photosensitive picture element are stored in the (4m-1)th and 4mth signal charges in the upper storage array 24'. is stored in the lower storage array 24.

From this state, according to the concept of a four-phase drive charge-coupled device, terminals 17°, 18°, 19, and 20 are connected in this order to φ1. φ2. φ3
．． Transfer pulses of φ4 are applied cyclically in this order, and when the pulses are applied to the terminals 18 and 18' in the first cycle, the pulses are applied to the control electrodes 26 and 27, and the pulses are applied to the control electrodes 26 and 27. ..., 54rn-2 signal charges are transferred to the upper first transfer array, and S4. ..., after transferring 84 m of signal charge to the lower transfer array 22, the control electrode 26
．． After that, pulse φ3 is applied to terminals 19 and 19', and pulse φ4 is sequentially applied to terminals 19 and 19'.

When the pulse φ4 is applied to the terminal 20, the control electrode 25
．． Apply a pulse to 28, Sl,...S4 In-3
transfers the signal charge of S3, 10 to the upper array 22'.
．． , 84m-1 of signal charges are transferred to the lower first transfer completion layer 21, and the pulse application to the control electrodes 25 and 28 is excluded.
As a result, the signal of the photosensitive pixel portion S1°..., 54m-3
is transferred to the upper second transfer array 22' directly below the transfer electrodes 16a', 16rr(, , 82, ``*54rn2 signal charges are transferred to the upper first transfer array 22' immediately below the transfer electrodes 16a', 16rt(, Ryo Ray 21' to 83..., 84m
-1 signal charges are transferred to the lower first transfer array 21 directly below the transfer electrodes 16a, . . . , 16m in S4. ..., S4m
This means that the signal charges have been transferred to the lower second transfer completion layer 22 directly below the transfer electrodes 16a, . . . , 16m.

That is, the photosensitive pixel portion S1. S2. S3. S4. ....

This means that the signal charges S4m 3 , 54m-2, 84m-1, and 84m were transferred under the transfer electrodes to which the in-phase pulses of the four columns of transfer arrays were applied.

From the above state, by applying transfer pulses cyclically, the signal charges transferred to the four transfer arrays are transferred in parallel to the readout means 23 in each transfer array.
will be forwarded to.

The signal charges transferred in parallel in the four-column transfer array are read out in the correct order using a readout means 23 consisting of, for example, a four-phase drive charge coupling device similar to the transfer array section, and guided to the exchange means 21. It will be destroyed.

Although four-phase drive has been described above as an embodiment of the present invention, it is also possible to use a two-phase drive charge transfer device, and the concept of four-column transfer is a drive that transfers charges from a photosensitive array to a transfer array. By changing , it can also be applied to a single-phase drive charge transfer device.

Furthermore, the structure of the present invention can be implemented with a surface channel or a buried channel, and can be realized by combining any means as long as the functions in each area of the present invention are sufficient.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a pulse time chart for explaining the operation of the embodiment shown in FIG. 1, and FIGS. It is a sectional view seen from A-& and BB'. In the figure, 10...semiconductor substrate, 11...
...Insulating film, 12...Photosensitive electrode, 13a-13
m, 14a~1.4m, , 15a~15m, 16a
~16m. 13a'~13m', 14a'~14m', 15a
'~15m', 16 a'~16m'... Transfer electrode, 17°18.19, 20.17', 18', 19
', 20'...Transfer pulse terminal, 21, 22, 2
1', 22'... Transfer array, 23, 23'...
...Transfer electrode, 24, 24'... Storage electrode, 25, 26, 27, 28... Control electrode, 29
...Reading means, 30... Conversion means, 31, 32, 32'... Separation band, 81-8
4m... Indicates a photosensitive array.

Claims (1)

[Claims] 1. A first transfer array is provided on both sides of a one-dimensional photosensitive array having a large number of photosensitive parts arranged in one dimension, and a second transfer array is provided further outside the first transfer array, and the first A temporary storage array having the same number of elements as the photosensitive array is provided between the transfer array and the second transfer array, and the signal charge generated in the photosensitive area is temporarily stored from the photosensitive array via the first transfer array. means for transferring and accumulating data in the temporary storage array to a first transfer array and a second transfer array;
means for transferring and accumulating using a control electrode in a transfer array;
It is characterized by comprising means for sequentially transferring charges accumulated in the transfer array section along the transfer array section, means for reading out the transferred charges, and means for taking out the read charges. charge transfer-dimensional photosensitive device.