JPS639153A - Charge coupled element device and method for driving the same - Google Patents

Abstract

PURPOSE:To manufacture a charge coupling element device with excellent production yield and efficient distribution of signal charge from vertical shift register groups to horizontal shift Register by a method wherein the channel potential below a horizontal shift register isolation region is lowered than the channel potential below barrier electrodes of the horizontal shift registers. CONSTITUTION:Vertical shift registor groups 1-5 by charge coupling element, a transfer gate electrode 31 adjoining one end of the groups 1-5, the first and the second horizontal shift registers 11, 12 by two phase driving charge coupling element arranged rectangularly to the charge transfer direction of adjoining vertical shift register groups 1-5 and mutually adjoining through the intermediary of an isolation region 41 are provided. On the other hand, the charge transfer electrode 61-70 per two electrodes of the second horizontal shift registers 12 electrically independent from one another are covered with a part of isolation region 41 to form the charge transfer channels 71-73 coupling the active regions of horizontal shift registers 11, 12 with each other. Furthermore, the channel potential below the horizontal shift register isolation region 41 including the charge transfer channels 71-73 is lowered than the channel potential below electrodes 87 94 of the horizontal shift registers 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a charge-coupled device device having a plurality of vertical shift registers and two rows of horizontal shift registers, and a method for driving the same.

(Prior Art) In recent years, charge-coupled devices (hereinafter referred to as COD) have been researched and developed in a wide range of fields against the backdrop of advances in integrated circuit technology, and are being applied to solid-state imaging, analog delay lines, field memories, etc. Became.

In particular, solid-state imaging devices using CCN have many features such as small size, light weight, low power consumption, and high reliability, and their development has been active in recent years. There are various structures of such CCD solid-state image sensing devices, but a recent trend that stands out is the emergence of structures suitable for increasing the number of pixels and increasing the density. For example, FIG. 4 is an embodiment described in "Charge-coupled device and method for driving the same" (Japanese Patent Application No. 59-070433), which is written by the same inventor as the present invention, and shows the connection between a vertical shift register and a horizontal shift register. A plan view of the section is shown.

In this example, by arranging two horizontal shift registers in parallel, the horizontal element pitch is relaxed, increasing the number of pixels and increasing the density. In the same figure, 101 to 105
charge transfer channel of vertical shift register group, 111.
112 is the charge transfer channel of the first and second horizontal shift registers, 121 is the final transfer electrode of the vertical shift register group, 131°141 is the first and second transfer gate electrode, 151 to 60 are the horizontal shift registers. Covering horizontal transfer electrodes 161-163 are charge transfer channels coupling the first and second horizontal shift registers, 171-188Fi
For example, a potential barrier region formed by ion implantation is shown. FIG. 5 is a diagram showing an example of a driving method for the CCD solid-state image sensor shown in FIG. 4, and shows the timing of driving pulses applied to each electrode during the horizontal blanking period of a television signal. . In the figure, φv4 is a pulse applied to the final transfer electrode 121 of the vertical shift register group, φτG3 . φteG, respectively, are the first. a pulse applied to the second transfer gate electrode 131.141;
φ1. φ is a pulse applied to the horizontal transfer electrodes 151 to 160, respectively. FIG. 6 shows the potential distribution inside the element along the single-dot chain MB-B' in FIG. 4 at each time in FIG. 5. Here, the operation of the CCD solid-state image sensor shown in FIG. 4 will be explained using FIGS. 5 and 6. First, time t. At this point, the horizontal charge transfer operation of the pulses φI and φn is stopped, and a horizontal blanking period begins. At this time, the pulse φVaF! The signal charges that are in the on state and have been transferred downward through the vertical shift register groups 101 to 105 are accumulated under the final transfer electrode 121 of the vertical shift register group. Next, at R time tIs, pulse φma, kaoff, pulse φ? G1 When transitioning to the ion state, the signal charge is transferred to the agate electrode 13 of the first transformer 7.
1 and is accumulated under the transfer gate electrode 131 at time "I2. At time t, the pulse φ↑
Gl is off, and the pulse φ1 applied to one transfer electrode of the horizontal shift register is turned on, and at time t14, some of the signal charges are transferred in the vertical shift registers 101, 103, 105 corresponding to φ1. The signal charge 191 accumulated under the gate electrode 131 is transferred and accumulated under the horizontal transfer electrode 152, 156°160, corresponding to φ of the first horizontal shift register 111. At this time, the pulse φ? applied to the transfer gate electrode 131? Even though J is in the off state,
Since the pulse φ is in the off state and the potential barrier region 171 exists, the vertical shift register 102 .
The signal charge from 104, for example 192, remains under transfer gate electrode 131. Next time “l”
Pulse φ at it tH! 1m is off, pulse φ? G1
is turned on, the signal charge 191 becomes φ! Il
is transferred and accumulated from the horizontal transfer electrode to which the voltage is applied to below the second tiger/sphere gate electrode 141. At this time,
The signal charge 192 is directly accumulated under the first transfer gate electrode 131. Next time “IYl
``At 1M, the pulse φ!
It is transferred below horizontal transfer electrodes 154° and 158 corresponding to φ12. At the same time, the signal charge 192 from the vertical shift register 102, 104 corresponding to φH2
is transferred from below the first transfer gate electrode 131 to below the horizontal transfer electrode 154°158 corresponding to φ of the first horizontal shift register 111. In this way, the signal charges for every two columns of the vertical shift register group are distributed to the two horizontal shift registers.

After this distribution, at time t1°, the horizontal blanking period ends, and the pulse φ8. starts a charge transfer operation in the horizontal direction, so each signal charge is transferred in the horizontal direction.

(Problems to be Solved by the Invention) However, the above-mentioned COD solid-state image pickup device has the drawback that irregular vertical stripes are likely to occur in reproduced images.

This is due to the fact that signal charges are not transferred efficiently from the vertical shift register group to the horizontal shift registers. In particular, since the pulse φ〒G applied to the transfer gate electrode 141 in FIG. The dispersion of the channel potential under these charge transfer channels, which is caused by the inability of the channels 161 to 163 and the transfer electrodes 152, 156, and 160 covering the transfer channels to be self-aligned, reduces the transfer efficiency in signal charge distribution. This is a major cause of deterioration.

Further, in the above-mentioned COD solid-state image element flat shift register section, the transfer electrodes of different phases are often short-circuited, resulting in a disadvantage that the manufacturing yield tends to decrease. In this case, the transfer gate electrode 141 is formed from the first polysilicon layer, and the transfer electrodes 152, 154, 156, 158, and 160 of the horizontal shift register are formed from the second polysilicon layer, and these electrodes are orthogonal to each other. Since the second polysilicon layer is not etched and remains under the transfer gate electrode 141, this causes a short circuit between the transfer electrodes.

The present invention eliminates the above-mentioned conventional drawbacks, and its purpose is to efficiently separate signal charges from a group of vertical shift registers to a horizontal shift register;
Another object of the present invention is to provide a charge-coupled device device and a method for driving the same, which also has a high manufacturing yield.

(Means for Solving the Problems) According to the first invention of the present application, there is provided a plurality of columns of vertical shift register groups using charge-coupled devices, and a transfer gate electrode arranged adjacent to one end of the vertical shift register group. and,
A first and a first two-phase pivoting charge-coupled device are arranged adjacent to the transfer gate electrode in a direction perpendicular to the charge transfer direction of the vertical shift register group and are arranged adjacent to each other with a horizontal shift register separation region interposed therebetween. 2 horizontal shift registers, and 2 horizontal shift registers of the second horizontal shift register.
A charge transfer electrode for each electrode is formed to be electrically independent from other electrodes, and the charge transfer electrode covers a part of the horizontal shift register isolation region to control the activation of the first and second horizontal shift registers. A charge-coupled device device comprising a charge transfer channel coupling between regions, wherein a channel potential under the horizontal shift register isolation region including the charge transfer channel is applied to a barrier between the first and second horizontal shift registers. A charge-coupled device device is obtained, which is characterized in that the channel potential is lower than the channel potential under the electrode.

Further, according to the second invention of the present application, there is provided a plurality of vertical shift register groups formed of charge-coupled devices, a transfer gate electrode disposed adjacent to one end of the vertical shift register group, and a transfer gate electrode adjacent to the transfer gate electrode. and first and second horizontal shift registers formed of two-phase pivoting charge-coupled devices arranged in a direction perpendicular to the charge transfer direction of the vertical shift register group and arranged adjacent to each other via a horizontal shift register separation region. The charge transfer electrodes for every two electrodes of the second horizontal shift register are formed electrically independent of other electrodes, and the charge transfer electrodes cover a part of the horizontal shift register isolation region. a charge transfer channel coupling between active regions of the first and second horizontal shift registers is formed, and a channel potential under the horizontal shift register isolation region including the charge transfer channel is equal to that of the first and second horizontal shift registers. A method for driving a charge-coupled device device whose channel potential is lower than a channel potential under a barrier electrode of a horizontal shift register, wherein when reading signal charges from the vertical shift register group to the first horizontal shift register, After accumulating signal charges, the voltage applied to the transfer gate electrode is turned off and one transfer electrode covering the first horizontal shift register is turned on to transfer and accumulate signal charges to the horizontal shift register. , when transferring signal charges from the first horizontal shift register to the second horizontal shift register, one transfer electrode storing signal charges of the first horizontal shift register is turned off, and the The charge transfer electrodes of every two electrodes of the second horizontal shift register are turned on to transfer and accumulate signal charges to the second horizontal shift register, and then the signal charges are transferred to the first and second horizontal shift registers. According to the present invention, there is provided a method for driving a charge-coupled device device, which is characterized in that the signal charges are simultaneously read out in parallel in the horizontal direction using the same two-phase drive pulse.

(Function) Uniform transfer pulses are supplied to every two charge transfer electrodes of the second horizontal shift register covering the charge transfer channel from aluminum wiring arranged near the charge transfer electrodes, and these charges are Since the transfer channel is formed in a self-aligned manner by the charge transfer electrodes, signal charges are efficiently transferred from the first horizontal shift register to the second horizontal shift register. In other words, in the COD solid-state image sensor, irregular vertical stripes do not occur in the reproduced image. Furthermore, since the charge transfer electrodes are arranged in parallel with other transfer electrodes, the manufacturing yield will not be reduced due to short circuits between the electrodes.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Figure 1 shows an embodiment in which the present invention is applied to a COD solid-state image sensor, and shows a plan view of a connecting portion between a vertical shift register group and two rows of horizontal shift registers. In the figure, 1 to 5 are charge transfer channels of the vertical shift register group, 11.12 are charge transfer channels of the first and @2 horizontal shift registers, and 21 is a vertical shift channel formed by the first polysilicon layer. Final transfer electrode of register group, 31
are transfer gate electrodes formed by the first and second polysilicon layers; 41 are horizontal shift register isolation regions formed by ion implantation; 51 to 5;
3 is a charge transfer electrode of 2+1η of the second horizontal shift register formed by the first polysilicon layer, 61
~70 are horizontal transfer electrodes of the horizontal shift register formed by the second and third polysilicon layers, 71~73
is formed under the charge transfer electrodes 51 to 53 in a self-aligned manner.
and a charge transfer channel coupling the second horizontal shift registers 11 and 12, a potential barrier region formed by 81-94Vi ion implantation. FIG. 2 is a diagram showing a method of driving the CCD solid-state image sensor of FIG. 1 according to the second invention of the present application, in which the timing of the driving pulses applied to each electrode during the horizontal blanking period of the television signal is It is shown. In the figure, φv4 is the pulse applied to the final transfer electrode 21 of the vertical shift register group, φ〒G is the pulse applied to the transfer gate electrode 31, φ
φH1' is a pulse applied to the horizontal transfer electrodes 61-70, and φH1' is a pulse applied to the charge transfer electrodes 51-53, respectively. FIG. 3 shows the potential distribution inside the element along the dashed line A--M' in FIG. 1 at each time in FIG. 2. The operation of the CCD solid-state imaging device according to the present invention shown in FIG. 1 will now be described with reference to FIGS. 2 and 3. First, at time ■, the pulse φ cap, φF11'+ φH2
The horizontal charge transfer operation is stopped and a horizontal blanking period begins. At this time, the pulse φV is in the on state, and the signal charge transferred downward through the vertical shift register groups 1 to 5 is transferred to the final transfer electrode 2 of the vertical shift register group.
is stored below. Next, time t.

When the pulse φv4 is turned on and the pulse φ〒o transitions to the on state, the signal charge is transferred to the transfer gate electrode 31.
It is transferred downward and accumulated under this transfer gate electrode 31 at time t. At time ts, pulse φ〒G
is off, the pulse φg applied to one transfer electrode of the horizontal shift register turns on, and at time c4, the transfer gate electrode in the vertical shift register 1.3.5 corresponding to φH1 among the signal charges 96 signal charges accumulated under the horizontal transfer electrode 62. 66, 7
Transferred and stored below 0. At this time, although the pulse φTG applied to the transfer gate electrode 31 is in the off state, the pulse φ phantom is in the OFF state and the potential barrier region 81 exists, so that the vertical shift register 2.0 corresponding to the φ phantom. The signal charge from 4, for example 97, remains below the transfer gate electrode 31. of course,
At the time t4, the pulse φm2 is changed to 95 in FIG.
Even if the signal charges 97 are transferred and stored under the horizontal transfer electrodes 64 and 68 corresponding to φH7 of the first horizontal shift register 11 in the on state as shown in FIG. 1, there will be no problem in the subsequent operation. Next, time 1. ．． 1. When the pulse φ is turned off and the pulse φ, t is turned on, the signal charge 96 passes through the charge transfer channel 71.72° 73 to the charge transfer electrodes 51 and 5 of the second horizontal shift register 12.
2.53 Transferred and accumulated below. At this time, the signal charge 97 remains as it is at the transfer gate 'lc1M31.
is stored below.

Incidentally, at this time, the width of the pulse φHI' may be larger than that at other times or other pulse amplitudes. Thereby, signal charges are transferred even more efficiently. Next, at time "tl tl" pulse φH1'
When the signal charge 96 is turned off and the pulse φ is turned on, the signal charge 96 is transferred to the bottom of the horizontal transfer electrode 64, 68 corresponding to φ of the second horizontal shift register 12. At the same time, the signal charge 97 is transferred to the transfer gate 'Ia pole 3
1 below to the horizontal transfer electrodes 64 and 68 corresponding to φI(2) of the first horizontal shift register 11. Through the above-described operation, the signal charges in every second column of the vertical shift register group are transferred to the bottom of the horizontal transfer electrodes 64 and 68 corresponding to After the operation, the horizontal blanking period ends at time t, and the pulses φill+φ餞,′,
Since the φ phantom starts a charge transfer operation in the horizontal direction, each signal charge is transferred in the horizontal direction.

At this time, the channel potential of the horizontal shift register isolation region 41 including the charge transfer channels 71 to 73 is equal to the potential barrier region 87 under the barrier electrode of the horizontal shift register 11.12.
Since it is always lower than the channel potential of ~94, the signal charges transferred through the horizontal shift registers 11 and 12 do not mix.

(Effects of the Invention) As stated above, the present invention provides 1! According to the loading combining element device and its driving method, the number of pixels can be increased.

A charge-coupled device device having a structure suitable for high density can be obtained with a high manufacturing yield, and the occurrence of vertical stripe disturbances due to poor signal charge transfer efficiency can be prevented. In addition, although the embodiments of the present invention have been explained limited to CCD solid-state image sensors, the present invention also applies to CCD analog delay lines, CCD solid-state image sensors, etc.
It can also be applied to CD field memory, etc.

[Brief explanation of drawings]

FIG. 1 is a plan view of a connecting portion between a vertical shift register group and a horizontal shift register of a CCD solid-state image sensor, which is an embodiment of a charge-coupled device device according to the first invention of the present application, and FIG. FIG. 3 is a diagram showing the potential distribution inside the device and the flow of signal charges along the dashed line A-A/ in FIG. 1. , FIG. 4 is a plan view of a connection section between a vertical shift register group and a horizontal shift register of a CCD solid-state image sensor, which is an example of a conventional charge-coupled device, and FIG.
FIG. 6 is a timing chart of drive pulses used to drive the CD solid-state image pickup device, and is a diagram showing the potential distribution inside the device and the flow of signal charges along the dashed line BB/ in FIG. 4. In the figure, 1 to 5, 101 to 105 are vertical shift registers, tt*12t 111.112 are horizontal shift registers, 21 and 121 are final transfer electrodes of the vertical shift register group, 319 131.141 are transfer gate electrodes, and 41 Horizontal shift register separation area, 51~
53 is a charge transfer electrode of the horizontal shift register 12, 61-
70, 151-160 are horizontal transfer electrodes, 71-73.1
61 to 163 are charge transfer channels that connect horizontal shift registers, and 81 to 94 and 171 to 188 are potential barrier regions. Agent - Patent attorney Shinsuke Honjo 1, SL shift register 41
Eiyu Shifuhiresuku minute 11 chest area I+, 12
Mizute shift revs 7 51-53 Denpai Oyunshi τ book b21 #JL:i#+tff Yang
s+ ~7o ri14'耘tfJ&31
Transfer gate electrode 1t 71-73
ttff good 1,000 and a half l and 81~94 f (iLP'i
ri0 month
~160 Mizusenpay Ward wo Kaki II+, 112 Mizute Shift Register'' Sufu 161~+63 (葡turnt+IKyoIshi121 48 Final 9?-d,'
+ 2 4 steps 171 ~ + aa f 131, + 41 transfer electrode Fig. 4

Claims (2)

[Claims] (1) A plurality of columns of vertical shift register groups using charge-coupled devices, a transfer gate electrode arranged adjacent to one end of the vertical shift register group, and charge transfer of the vertical shift register group adjacent to the transfer gate electrode. first and second horizontal shift registers formed by two-phase drive charge-coupled devices disposed perpendicularly to the direction and adjacent to each other via a horizontal shift register isolation region; A charge transfer electrode for every two electrodes of the register is formed electrically independent of the electrode of the electrode, and the charge transfer electrode covers a part of the horizontal shift register separation area and is connected to the first and second horizontal shift registers. In a charge-coupled device device formed with a charge transfer channel coupling between active regions of shift registers, a channel potential under the horizontal shift register isolation region including the charge transfer channel is applied to the first and second horizontal shift registers. A charge-coupled device device characterized in that the channel potential is lower than the channel potential under the barrier electrode of the device. (2) A plurality of columns of vertical shift register groups using charge-coupled devices, a transfer gate electrode disposed adjacent to one end of the vertical shift register group, and charge transfer of the vertical shift register group adjacent to the transfer gate electrode. first and second horizontal shift registers formed by two-phase pivoting charge-coupled devices disposed perpendicular to the direction and adjacent to each other via a horizontal shift register isolation region; A charge transfer electrode for every two electrodes of the shift register is formed electrically independent of the other electrodes, and the charge transfer electrode covers a part of the horizontal shift register separation area and connects the first and second electrodes. A charge transfer channel is formed that connects active regions of the horizontal shift register, and the channel potential under the horizontal shift register isolation region including the charge transfer channel is equal to the channel potential under the pariah electrode of the first and second horizontal shift registers. In the method for driving a charge-coupled device device whose potential is lower than the potential, when reading signal charges from the vertical shift register group to the first horizontal shift register, the signal charges are accumulated directly under the transfer gate electrode, and then the signal charges are stored directly under the transfer gate electrode. The voltage applied to the first horizontal shift register is turned off, and one transfer electrode covering the first horizontal shift register is turned on to transfer and accumulate signal charges to the horizontal shift register. When transferring signal charges to the second horizontal shift register, one transfer electrode that stores signal charges in the first horizontal shift register is turned off, and the transfer electrodes of every two electrodes of the second horizontal shift register are turned off. The charge transfer electrode is turned on to transfer and accumulate signal charges to the second horizontal shift register, and then the first and second horizontal shift registers are
A method for driving a charge-coupled device device, characterized in that signal charges distributed to horizontal shift registers are simultaneously read out in parallel in the horizontal direction using the same two-phase drive pulse.