阅读说明：本技术 一种成像均匀的tdiccd图像传感器 (TDICCD image sensor with uniform imaging ) 是由 杨洪 白雪平 姜华男 李金� 翁雪涛 于 2020-05-14 设计创作，主要内容包括：本发明公开了一种成像均匀的TDICCD图像传感器,包括TDICCD阵列,所述TDICCD阵列包括若干像元结构,每个所述像元结构均包括衬底和设置在所述衬底上的垂直CCD结构,所述垂直CCD结构用于传输光生信号,两个相邻的垂直CCD结构之间设有抗晕结构；所述垂直CCD结构包括第一垂直CCD驱动相、第二垂直CCD驱动相、第三垂直CCD驱动相和第四垂直CCD驱动相,两个相邻的第四垂直CCD驱动相之间设有阻挡势垒结构,所述阻挡势垒结构围设在所述抗晕结构的四周；所述衬底和垂直结构之间设有非均匀注入埋沟结构,防止光晕现象产生的同时又能有效防止漏电通道的产生,使得TDICCD能够均匀成像。(The invention discloses a TDICCD image sensor with uniform imaging, which comprises a TDICCD array, wherein the TDICCD array comprises a plurality of pixel structures, each pixel structure comprises a substrate and a vertical CCD structure arranged on the substrate, the vertical CCD structure is used for transmitting a photoproduction signal, and an anti-corona structure is arranged between two adjacent vertical CCD structures; the vertical CCD structure comprises a first vertical CCD driving phase, a second vertical CCD driving phase, a third vertical CCD driving phase and a fourth vertical CCD driving phase, a blocking potential barrier structure is arranged between two adjacent fourth vertical CCD driving phases, and the blocking potential barrier structure is arranged around the anti-corona structure; a non-uniform injection buried channel structure is arranged between the substrate and the vertical structure, so that the generation of a halo phenomenon is prevented, meanwhile, the generation of a leakage channel is effectively prevented, and the TDICCD can be used for uniform imaging.)

1. The utility model provides a TDICCD image sensor that imaging is even, includes TDICCD array, TDICCD array includes a plurality of pixel structures, each the pixel structure all includes the substrate and sets up perpendicular CCD structure on the substrate, perpendicular CCD structure is used for transmitting photoproduction signal, its characterized in that: an anti-halo structure is arranged between every two adjacent vertical CCD structures and is used for preventing the halo phenomenon; each vertical CCD structure comprises a first vertical CCD driving phase, a second vertical CCD driving phase, a third vertical CCD driving phase and a fourth vertical CCD driving phase, a blocking potential barrier structure is arranged between every two adjacent fourth vertical CCD driving phases, the blocking potential barrier structure surrounds the periphery of the anti-corona structure, and the blocking potential barrier structure is used for turning off a photoproduction signal on the vertical CCD structure; and a non-uniform injection buried channel structure is arranged between the substrate and the vertical CCD structure and is used for storing and transferring photo-generated signals transmitted by the vertical CCD structure.

2. An imaging uniformity TDICCD image sensor of claim 1, wherein: the anti-corona structure comprises anti-corona potential barriers and anti-corona leakage, the anti-corona potential barriers are located on two sides of the anti-corona leakage, and the anti-corona potential barriers are used for determining the full-well capacity of the pixel structure.

3. An imaging uniformity TDICCD image sensor of claim 1, wherein: the non-uniform injection buried channel structure comprises a filling area and a blank area, and the blank area is positioned below the anti-corona structure.

4. An imaging uniformity TDICCD image sensor of claim 1, wherein: the first vertical CCD driving phase, the second vertical CCD driving phase, the third vertical CCD driving phase and the fourth vertical CCD driving phase are sequentially arranged from top to bottom.

5. An imaging uniformity TDICCD image sensor of claim 1, wherein: an isolation layer is arranged between the non-uniform injection buried channel structure and the vertical CCD structure and used for isolating the vertical CCD structure and the non-uniform injection buried channel structure.

Technical Field

The invention relates to the technical field of image sensors, in particular to a TDICCD image sensor with uniform imaging.

Background

The TDICCD technology is used as an important branch of the CCD technology, has obvious advantages in the field of satellite application, can improve the light response sensitivity and the signal-to-noise ratio, eliminate the image shift, change the exposure time by selecting TDI series and other functions, is widely used for aerospace remote sensing and high-altitude reconnaissance, is satellite-borne and airborne and is used as a core device for image acquisition and target identification, and TDICCD is mostly adopted by remote sensing satellite reconnaissance cameras and aerial reconnaissance cameras which are in orbit operation and under research in various countries in the world at present.

However, in practical applications, when the TDICCD is irradiated by strong light, a halo phenomenon occurs, that is, a bright spot exists in an imaged image, a white area appears on a display screen and extends to the periphery, and a phenomenon of a column or a line white channel appears, which requires that the TDICCD has an anti-halo structure, thereby realizing an anti-halo function. The anti-corona structure consists of an anti-corona barrier and an anti-corona leakage, but due to the effect of the anti-corona leakage, the height of the anti-corona barrier under the area of the series gating and shutting gate of the TDICCD is pulled to be higher than the turn-off barrier phase potential (about 0V) of the series gating and shutting gate, so that a leakage channel is formed in the area, when the illumination intensity irradiated on the pixel reaches or exceeds the full-well capacity of the pixel determined by the height of the anti-corona barrier of the pixel, one part of generated excessive photogenerated signals is pumped away by the anti-corona leakage, and the other part of generated excessive photogenerated signals enters the next adjacent pixel through the leakage channel, so that the imaging is not uniform.

Disclosure of Invention

The invention aims to provide a TDICCD image sensor which is uniform in imaging and can completely turn off the stage number of a fourth vertical CCD driving phase in the imaging process.

In order to solve the problems, the invention provides a TDICCD image sensor with uniform imaging, which comprises a TDICCD array, wherein the TDICCD array comprises a plurality of pixel structures, each pixel structure comprises a substrate and a vertical CCD structure arranged on the substrate, the vertical CCD structures are used for transmitting photoproduction signals, an anti-corona structure is arranged between every two adjacent vertical CCD structures, and the anti-corona structure is used for preventing the occurrence of a halo phenomenon; each vertical CCD structure comprises a first vertical CCD driving phase, a second vertical CCD driving phase, a third vertical CCD driving phase and a fourth vertical CCD driving phase, a blocking potential barrier structure is arranged between every two adjacent fourth vertical CCD driving phases, the blocking potential barrier structure surrounds the periphery of the anti-corona structure, and the blocking potential barrier structure is used for turning off a photoproduction signal on the vertical CCD structure; and a non-uniform injection buried channel structure is arranged between the substrate and the vertical CCD structure and is used for storing and transferring photo-generated signals transmitted by the vertical CCD structure.

Further, the anti-corona structure comprises an anti-corona barrier and an anti-corona drain, the anti-corona barrier is located on two sides of the anti-corona drain, and the anti-corona barrier is used for determining the full-well capacity of the pixel structure.

Further, the non-uniform injection buried channel structure comprises a filling area and a blank area, and the blank area is positioned below the anti-corona structure.

Further, the first vertical CCD driving phase, the second vertical CCD driving phase, the third vertical CCD driving phase and the fourth vertical CCD driving phase are sequentially arranged from top to bottom.

Furthermore, an isolation layer is arranged between the non-uniform injection buried channel structure and the vertical CCD structure, and the isolation layer is used for isolating the vertical CCD structure and the non-uniform injection buried channel structure.

The invention has the beneficial effects that:

1. by arranging the anti-halo structure between the two adjacent pixel structures, surplus photo-generated signals generated during imaging of the pixel structures are pumped away, so that the generated image is prevented from generating halo and affecting imaging quality;

2. the barrier structure is arranged between two adjacent fourth vertical CCD driving phases, so that the imaging uniformity of the TDICCD image sensor is improved, a leakage channel is prevented from being generated in an anti-corona structure area under the action of anti-corona leakage voltage, and an excessive photo-generated signal enters the next adjacent pixel from the leakage channel;

3. by arranging the non-uniform injection buried channel structure, buried channel injection is not carried out in the blank area, so that the blank area buried channel injection concentration is reduced to improve the potential barrier height of the area, the corona resistant potential barrier of the area is further prevented from being higher than the turn-off potential barrier of the fourth vertical CCD driving phase under the action of corona resistant and leakage voltage, a leakage channel is prevented from occurring, and the generated image has no halo and is uniform in imaging.

Drawings

Fig. 1 is a schematic structural diagram of a preferred embodiment of a TDICCD image sensor with uniform imaging according to the present invention.

Fig. 2 is a sectional view of the TDICCD image sensor a-a shown in fig. 1.

Fig. 3 is a schematic diagram of a non-uniform implanted buried channel structure of the tdicpcd image sensor shown in fig. 1.

Fig. 4 is a potential distribution diagram of the TDICCD image sensor a-a shown in fig. 1 toward a conventional anti-blooming structure.

Fig. 5 is a potential distribution diagram of the tdicpcd image sensor a-a shown in fig. 1 toward the underlying barrier structure.

Detailed Description

The invention will be further explained with reference to the drawings.

In the description of the present invention, unless otherwise specified and limited, it is to be noted that the term "connected" is to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, or a communication between two elements, or may be a direct connection or an indirect connection through an intermediate medium, and a specific meaning of the term may be understood by those skilled in the art according to specific situations.

Fig. 1 is a schematic structural diagram of a preferred embodiment of the TDICCD image sensor with uniform imaging according to the present invention. The TDICCD image sensor comprises a TDICCD array 1, the TDICCD array 1 comprises a plurality of pixel structures 10, each pixel structure 10 is uniformly arranged, a photosensitive area (not shown in the figure) on each pixel structure 10 generates a light generation signal after being photosensitive, and the light generation signal is sequentially transmitted to a subsequent structure in each pixel structure 10 to be processed, so that imaging is finally realized.

As shown in fig. 2, each of the pixel structures 10 includes a substrate 101 and a vertical CCD structure 102 disposed on the substrate 101, where the substrate 101 is externally connected to a power supply to provide a working power supply for the tdicc image sensor. The vertical CCD structure 102 is used to transmit photo-generated signals.

Each of the vertical CCD structures 102 includes a first vertical CCD driving phase CI1, a second vertical CCD driving phase CI2, a third vertical CCD driving phase CI3, and a fourth vertical CCD driving phase CI4, and the first vertical CCD driving phase CI1, the second vertical CCD driving phase CI2, the third vertical CCD driving phase CI3, and the fourth vertical CCD driving phase CI4 are sequentially arranged from top to bottom. The photo-generated signals are transmitted to the fourth vertical CCD driving phase CI4 in sequence from the first vertical CCD driving phase CI1, so that the transmission of the photo-generated signals is realized, and the imaging of the TDICCD image sensor is completed.

An anti-halo structure 103 is arranged between every two adjacent vertical CCD structures 102, and the anti-halo structure 103 is used for preventing the generation of a halo phenomenon and improving the imaging quality of the TDICCD image sensor. The anti-halo structure 103 comprises an anti-halo barrier 1031 and an anti-halo drain 1032, the anti-halo barrier 1031 is located on two sides of the anti-halo drain 1302, the size of the anti-halo barrier 1031 determines the full-well capacity of the pixel structure 10, and the anti-halo drain 1032 is used for pumping away excess photo-generated signals on the vertical CCD structure 102 and introducing the excess photo-generated signals into the substrate 101, so that the excess photo-generated signals are prevented from overflowing to the adjacent pixel structure 10, and the imaging quality is prevented from being influenced by the halo phenomenon.

A blocking barrier structure 104 is arranged between every two adjacent fourth vertical CCD driving phases CI4, the blocking barrier structure 104 is arranged around the anti-blooming structure 103, and the blocking barrier structure 104 is used for turning off the photo-generated signals on the vertical CCD structure 102, so that the photo-generated signals on the first vertical CCD driving phase CI1, the second vertical CCD driving phase CI2 and the third vertical CCD driving phase CI3 of the vertical CCD structure 102 are turned off and cannot enter the adjacent pixel structure 10, thereby improving the imaging uniformity of the TDICCD image sensor.

A non-uniform injection buried channel structure 105 is arranged between the substrate 101 and the vertical CCD structure 102, and the non-uniform injection buried channel structure 105 is used for storing and transferring photo-generated signals transmitted by the vertical CCD structure 102, so as to avoid the generation of surface state effect and improve the working efficiency of the TDICCD image sensor.

An isolation layer 10 is arranged between the non-uniform injection buried channel structure 105 and the vertical CCD structure 1026, the isolation layer 106 is used for isolating the vertical CCD structure 102 and the non-uniform injection buried channel structure 105 to avoid the mutual influence of signals between the structures, and the isolation layer 106 is SiO₂An isolation layer.

As shown in fig. 3, the non-uniform implanted buried channel structure 105 includes a filled region 1051 and a blank region 1052, the blank region 1052 being located below the anti-halo structure 103. The blank region 1051 is not subjected to buried channel implantation, so that the buried channel implantation concentration of the blank region 1052 is reduced, the barrier height of the region is increased, and the imaging uniformity of the TDICCD image sensor is further improved.

The working principle of the invention is as follows:

the fourth vertical CCD driving phase CI4 has a function of series gating and turn-off, when the fourth vertical CCD driving phase CI4 on any one of the pixel structures 10 is biased at a certain direct current negative level, the fourth vertical CCD driving phase CI4 is a series gating and turn-off gate CSSx _ Bi, at this time, the photo-generated signals above the series gating and turn-off gate CSSx _ Bi (i.e., the first vertical CCD driving phase CI1, the second vertical CCD driving phase CI2, and the third vertical CCD driving phase CI3) are turned off, and theoretically, the photo-generated signals should not enter the region below the series gating and turn-off gate CSSx _ Bi (i.e., the adjacent pixel structure 10), so that the tdicc image sensor can uniformly image.

As shown in fig. 4, under the conventional anti-halo structure 103, due to the action of the anti-halo drain 1032, the height of the anti-halo barrier 1031 under the region of the stage-wise gate-off gate CSSx _ Bi is pulled higher than the height of the off-barrier of the stage-wise gate-off gate CSSx _ Bi, that is, the potential V1 of the anti-halo barrier 1031 is greater than the off-barrier phase potential V2 (that is, 0V) of the stage-wise gate-off gate CSSx _ Bi, so that the region becomes the leakage channel 107 for signal charges. When the pixels above the stage gating and shutting gate CSSx _ Bi reach or exceed the full well capacity of the pixels determined by the height of the anti-blooming barrier 1031 due to strong light, a part of the generated excess photo-generated signals are pumped away through the anti-blooming drain 1032 and flow into the substrate 101, and the other part of the generated excess photo-generated signals enter the next pixel adjacent to the stage gating and shutting gate CSSx _ Bi through the leakage channel 107 existing under the stage gating and shutting gate CSSx _ Bi, which shows that when the stage gating and shutting gate CSSx _ Bi is at the negative turn-off direct current level, when the light intensity reaches near saturation, the signal charges in the region to be shut off will be injected into the selected stage region through the leakage channel 107, and the stage gating is incomplete, thereby causing uneven image imaging.

As shown in fig. 5, the blocking barrier structure 104 is disposed around the anti-blooming structure 103, and at this time, the potential V1 of the anti-blooming barrier 1031 is equal to the turn-off barrier phase potential V2 of the series gating and turn-off gate CSSx _ Bi, so as to avoid the generation of the leakage channel 107, and completely turn off the photo-generated signals above the series gating and turn-off gate CSSx _ Bi, so that the photo-generated signals cannot enter the adjacent pixels, thereby achieving uniform imaging of the tdicc image sensor.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures made by using the contents of the present specification and the drawings can be directly or indirectly applied to other related technical fields, and are within the scope of the present invention.