阅读说明：本技术 具有增透膜的多谱段tdiccd结构 (Multi-spectrum TDICCD structure with antireflection film ) 是由 杨洪 白雪平 姜华男 李金� 翁雪涛 于 2020-04-01 设计创作，主要内容包括：本发明公开了一种具有增透膜的多谱段TDICCD结构,包括多个谱段,每个谱段均包括级数选通栅和多个像元,每个像元的左端和右端均设有沟阻,每个所述像元均包括增透膜开窗区域和垂直CCD区域,在所述增透膜开窗区域的上端和下端均设有沟阻,在所述增透膜开窗区域履盖有增透膜,所述垂直CCD区域履盖有复合栅介质,所述复合栅介质履盖有垂直CCD驱动栅。本发明提出了一种新的TDICCD结构,通过采用增透模开窗结构大大减少了垂直CCD驱动栅的覆盖面积,在开窗区域内增大了光线的透射率；级数选通栅CSS引线和垂直CCD驱动栅引线采用分区走线的结构,提高了像元占空比,改善了器件的量子效率。(The invention discloses a multi-spectrum TDICCD structure with an antireflection film, which comprises a plurality of spectrum sections, wherein each spectrum section comprises a series gating grid and a plurality of pixels, the left end and the right end of each pixel are respectively provided with a channel resistor, each pixel comprises an antireflection film windowing region and a vertical CCD region, the upper end and the lower end of the antireflection film windowing region are respectively provided with a channel resistor, the antireflection film windowing region is covered with an antireflection film, the vertical CCD region is covered with a composite grid medium, and the composite grid medium is covered with a vertical CCD driving grid. The invention provides a novel TDICCD structure, which greatly reduces the coverage area of a vertical CCD driving grid by adopting an anti-reflection mode windowing structure, and increases the light transmittance in a windowing area; the series gating CSS lead and the vertical CCD driving grid lead adopt a structure of zone routing, so that the pixel duty ratio is improved, and the quantum efficiency of the device is improved.)

1. A multi-spectral band TDICCD structure with an antireflection film comprises a pixel array, and is characterized in that the pixel array comprises a substrate and a plurality of spectral bands arranged on the substrate at intervals, each spectral band comprises at least one series gating grid and a plurality of pixels, the left end and the right end of each pixel are provided with channel resistors, each pixel comprises an antireflection film windowing region, the antireflection film windowing region is covered with the antireflection film, and the upper end and the lower end of the antireflection film windowing region are provided with the channel resistors; a vertical CCD area is arranged on one side of the anti-reflection film windowing area, the vertical CCD area is covered with a composite gate medium, the composite gate medium is covered with a vertical CCD driving gate, and the vertical CCD driving gate comprises at least two driving phases; in the vertical direction, the same driving phases of the vertical CCD driving gates of the same row of pixels are connected through a vertical CCD driving gate lead; and each series gating grid is electrically connected with a driving phase at the lower end of the vertical CCD driving grid of the pixel at the series adjusting position through a series gating grid CSS lead wire.

2. The multi-spectral TDICCD structure with an antireflective film of claim 1, wherein the antireflective film and the composite gate dielectric each comprise a silicon dioxide layer and a silicon nitride layer.

3. The multi-spectral band TDICCD structure with an antireflection film according to claim 1, wherein a transverse anti-blooming gate covering the antireflection film is arranged in the middle of the vertical CCD drive gate along the vertical direction, and a first contact hole is formed at each position of the vertical CCD drive gate corresponding to each transverse anti-blooming gate; in the vertical direction, the transverse antihalation grids of adjacent pixels are communicated with each other.

4. The structure of claim 3, wherein the lateral anti-blooming gate is made of primary polysilicon, and the vertical CCD drive gate is made of secondary polysilicon and tertiary polysilicon; the CSS lead of the series gating grid adopts third-time polycrystalline silicon and is electrically connected with the third-time polycrystalline silicon of the corresponding vertical CCD driving grid driving phase.

5. The structure of the multi-spectral TDICCD with an antireflection film according to claim 4, wherein the vertical CCD drive gate comprises four drive phases, namely a vertical CCD drive gate CI1 phase, a vertical CCD drive gate CI2 phase, a vertical CCD drive gate CI3 phase and a vertical CCD drive gate CI4 phase, the vertical CCD drive gate CI1 phase and the vertical CCD drive gate CI3 phase are made of secondary polysilicon, and the vertical CCD drive gate CI2 phase and the vertical CCD drive gate CI4 phase are made of tertiary polysilicon.

6. The structure of claim 1, wherein the CSS leads of the series pass gates and the CSS leads of the vertical CCD drive gates are routed in a horizontal direction and cover the trench resistors at the lower ends of the corresponding windowed regions of the pixel antireflection films; the vertical CCD driving grid lead wires are arranged along the vertical direction and cover all driving phases of the vertical CCD driving grid.

7. The multispectral TDICCD structure with an antireflection film according to claim 6, wherein the width of the connecting part of the vertical CCD driving grid lead wire and the driving part of the vertical CCD driving grid is larger than that of the non-connecting part, and a second contact hole is formed in the middle of the connecting part of the vertical CCD driving grid lead wire and the driving part of the vertical CCD driving grid.

Technical Field

The invention relates to the field of low-light-level imaging, in particular to a multi-spectral-band TDICCD structure with an antireflection film.

Background

At present, a Time Delayed Integration CCD (Time Delayed and Integration CCD) is widely used in the aerospace field, and in order to make an imaging system using the TDICCD image sensor have a high signal-to-noise ratio, the TDICCD image sensor is required to have a high quantum efficiency characteristic. Under the condition that a back light entering mode is not considered, the micro lens can be manufactured in a pixel area to improve the quantum efficiency, but in the field of aerospace, due to the space irradiation environment, the TDICCD image sensor manufactured with the micro lens is easy to form fuzzy images.

Disclosure of Invention

The invention aims to provide a multi-spectral band TDICCD structure with an antireflection film, which can improve the quantum efficiency characteristic of a TDICCD image sensor and meet the signal-to-noise ratio requirement of an imaging system taking the TDICCD image sensor as a core component.

The technical scheme of the invention is as follows:

a multi-spectral-band TDICCD structure with an antireflection film comprises a pixel array, wherein the pixel array comprises a substrate and a plurality of spectral bands arranged on the substrate at intervals, each spectral band comprises at least one series gating grid and a plurality of pixels, the left end and the right end of each pixel are provided with channel resistors, each pixel comprises an antireflection film windowing region, the antireflection film windowing region is covered with an antireflection film, and the upper end and the lower end of the antireflection film windowing region are provided with channel resistors; a vertical CCD area is arranged on one side of the anti-reflection film windowing area, the vertical CCD area is covered with a composite gate medium, the composite gate medium is covered with a vertical CCD driving gate, and the vertical CCD driving gate comprises at least two driving phases; in the vertical direction, the same driving phases of the vertical CCD driving gates of the same row of pixels are connected through a vertical CCD driving gate lead; and each series gating grid is electrically connected with a driving phase at the lower end of the vertical CCD driving grid of the pixel at the series adjusting position through a series gating grid CSS lead wire.

Furthermore, the antireflection film and the composite gate dielectric both comprise a silicon dioxide layer and a silicon nitride layer.

Furthermore, a transverse anti-corona gate covering the antireflection film is arranged in the middle of the vertical CCD driving gate along the vertical direction, and a first contact hole is formed in each position of the vertical CCD driving gate, which corresponds to each transverse anti-corona gate; in the vertical direction, the transverse antihalation grids of adjacent pixels are communicated with each other.

Furthermore, the transverse anti-corona gate adopts primary polysilicon, and the vertical CCD driving gate adopts secondary polysilicon and tertiary polysilicon; the CSS lead of the series gating grid adopts third-time polycrystalline silicon and is electrically connected with the third-time polycrystalline silicon of the corresponding vertical CCD driving grid driving phase.

Further, the vertical CCD driving gate includes four driving phases, i.e., a vertical CCD driving gate CI1 phase, a vertical CCD driving gate CI2 phase, a vertical CCD driving gate CI3 phase, and a vertical CCD driving gate CI4 phase, the vertical CCD driving gate CI1 phase and the vertical CCD driving gate CI3 phase use secondary polysilicon, and the vertical CCD driving gate CI2 phase and the vertical CCD driving gate CI4 phase use tertiary polysilicon.

Furthermore, the series gating CSS lead and the vertical CCD driving grid lead adopt a partition wiring structure, and the series gating CSS lead is wired along the horizontal direction and covers a channel resistor at the lower end of a corresponding pixel antireflection film windowing area; the vertical CCD driving grid lead wires are arranged along the vertical direction and cover all driving phases of the vertical CCD driving grid.

Furthermore, the width of the driving connection part of the vertical CCD driving grid lead and the vertical CCD driving grid is larger than that of the non-connection part, and a second contact hole is formed in the middle of the driving connection part of the vertical CCD driving grid lead and the vertical CCD driving grid.

Has the advantages that: the invention provides a novel TDICCD structure, which greatly reduces the coverage area of a vertical CCD driving grid by adopting an anti-reflection mode windowing structure, and increases the light transmittance in a windowing area; the series gating CSS lead and the vertical CCD driving grid lead adopt a partitioning wiring structure, so that the situations that the duty ratio of a pixel is reduced and the quantum efficiency of a device is reduced due to the fact that the series gating grid shields the pixel are avoided; the connecting part of the vertical CCD driving grid lead is wider than the non-connecting part, and the width of the non-connecting part can be reduced, so that the coverage area of the vertical CCD driving grid is reduced, the pixel duty ratio is improved, and the quantum efficiency of the device is improved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural diagram of a pixel;

FIG. 3 is a schematic sectional view taken along line A-A' of FIG. 2;

FIG. 4 is a schematic structural diagram of a CSS lead of a series gating grid and a vertical CCD driving grid lead;

FIG. 5 is a schematic structural diagram of the secondary polysilicon and the trench resistance and anti-reflection mode windowing regions of the vertical CCD drive gate in FIG. 4;

fig. 6 is a schematic structural view of the triple polysilicon of the stage number gate, the stage number gate CSS lead, and the vertical CCD drive gate in fig. 4.

In the figure, 1, a substrate, 2, a spectrum section, 3, a series gate, 4, a series gate CSS lead, 5, a channel resistance, 6, an antireflection film windowing region, 7, a vertical CCD region, 8, a silicon dioxide layer, 9, a silicon nitride layer, 11, a vertical CCD driving gate CI1 phase, 12, a vertical CCD driving gate CI2 phase, 13, a vertical CCD driving gate CI3 phase, 14, a vertical CCD driving gate CI4 phase, 15, a transverse anti-blooming gate, 16, a first contact hole, 17, a vertical CCD driving gate lead, and 18, a second contact hole are arranged.

Detailed Description

In order to make the technical solutions in the embodiments of the present invention better understood and make the above objects, features and advantages of the embodiments of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in further detail below with reference to the accompanying 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.

As shown in fig. 1, an embodiment of the present invention includes a pixel array including a substrate 1 and a plurality of spectral bands 2 disposed on the substrate 1 at intervals.

As shown in fig. 2 and 3, each spectrum segment 2 includes at least one series pass gate 3 and a plurality of pixels, each pixel includes a trench resistance 5 at the left end and the right end, each pixel includes an antireflection film windowing region 6, the antireflection film windowing region 6 is covered with an antireflection film, the trench resistances 5 are disposed at the upper end and the lower end of the antireflection film windowing region 6, a vertical CCD region 7 is disposed at one side of the antireflection film windowing region, the vertical CCD region 7 is covered with a composite gate dielectric, and the composite gate dielectric is covered with a vertical CCD driving gate; the antireflection film and the composite gate dielectric both comprise a silicon dioxide layer 8 and a silicon nitride layer 9. Because the window opening region 6 of the antireflection film adopts a window opening structure and is not covered by polysilicon, the antireflection effect on ultraviolet incident light and visible incident light with the wavelength of 350-780 nm is realized, and the quantum efficiency of the multi-spectral band TDICCD is improved.

The middle part of the vertical CCD driving gate is provided with a transverse anti-corona gate 15 covering the silicon nitride layer 9 along the vertical direction, and the transverse anti-corona gates 15 of adjacent pixels are communicated with each other in the vertical direction; the transverse anti-corona gate 15 adopts primary polysilicon, and the vertical CCD driving gate adopts secondary polysilicon and tertiary polysilicon; excess photo-generated electrons from the anti-reflection film windowing region 6 and the vertical CCD region 7 can be discharged through the lateral anti-halo gate 15, thereby realizing halo suppression.

The vertical CCD driving gate comprises at least two driving phases; because the full-well characteristic of the four-drive-phase structure is better than that of the two-drive-phase structure and the three-drive-phase structure, the transfer efficiency is higher, and in order to better match the situation that the quantum efficiency is improved after the adoption of the pixel antireflection film windowing structure, preferably, the vertical CCD drive gate of the embodiment comprises four drive phases of a vertical CCD drive gate CI1 phase 11, a vertical CCD drive gate CI2 phase 12, a vertical CCD drive gate CI3 phase 13 and a vertical CCD drive gate CI4 phase 14, the vertical CCD drive gate CI1 phase 11 and the vertical CCD drive gate CI3 phase 13 adopt secondary polysilicon, and the vertical CCD drive gate CI2 phase 12 and the vertical CCD drive gate CI4 phase 14 adopt tertiary polysilicon; and the positions of the vertical CCD driving gate CI1 phase 11, the vertical CCD driving gate CI2 phase 12, the vertical CCD driving gate CI3 phase 13 and the vertical CCD driving gate CI4 phase 14, which correspond to the transverse anti-blooming gate 15, are respectively provided with a first contact hole 16. The polysilicon gate of the vertical CCD driving gate adopts a hollow design, the transverse anti-corona gate 15 below the hollow area is exposed, the hole distribution and routing of the transverse anti-corona gate 15 are facilitated, the resistance of the transverse anti-corona gate 15 can be reduced, and the effective electrical connection of the transverse anti-corona gate 15 is realized.

In the vertical direction, vertical CCD drive gates CI1 phase 11, vertical CCD drive gates CI2 phase 12, vertical CCD drive gates CI3 phase 13 and vertical CCD drive gates CI4 phase 14 of the same column of pixels are respectively connected through a vertical CCD drive gate lead 17, the vertical CCD drive gate lead 17 adopts a metal lead and is arranged along the vertical direction to cover each drive phase of the vertical CCD drive gates, the width of the driving connection part of the vertical CCD drive gate lead 17 and the vertical CCD drive gate is larger than that of the non-connection part, a second contact hole 18 can be arranged in the middle of the connection part of the vertical CCD drive gate lead 17 and the vertical CCD drive gate, so that the connection part of the vertical CCD drive gate lead 17 can be kept wider width to increase the contact area for convenient connection, and the rest parts can be designed to be narrow, thereby reducing the vertical CCD drive gate lead 17 while ensuring effective electrical connection of the vertical CCD drive gate lead 17 For the coverage of the vertical CCD driving gate, the pixel duty ratio is improved, and the quantum efficiency of the image sensor is improved.

Each series gating grid 3 is electrically connected with a vertical CCD driving grid CI4 phase 14 of the pixel at the series adjusting position through a series gating grid CSS lead 4; the CSS lead 4 of the series pass gate adopts triple polysilicon, is wired along the horizontal direction, and covers the channel resistor 5 at the lower end of the anti-reflection film windowing region 6 when passing through the anti-reflection film windowing region 6 of the pixel. For matching the pixel antireflection film windowing structure, vertical CCD polysilicon gates between adjacent pixels in the horizontal direction are mutually independent, are similar to an island and cannot be electrically connected through polysilicon as in the conventional design; therefore, in order to match the antireflection film windowing structure of the pixel, in this embodiment, the stage-number gating grid CSS lead 4 and the vertical CCD driving grid lead 17 adopt a partitioned routing structure, so that the phenomenon that the pixel is shielded when the stage-number gating grid 4 uses a metal lead is avoided, the duty ratio of the pixel is reduced, the quantum efficiency of the device is reduced, and the coverage of the vertical CCD driving grid lead 17 on the vertical CCD driving grid is reduced.

As shown in FIG. 4, the following description will take the case of achieving 1-level adjustability in the spectral band of the 2 × array, but of course, the pixel may also have more than 2 columns and/or more than 3 rows, and the adjustable number of levels may also be adjustable by other number of levels or multiple number of levels, as shown in FIG. 5, the vertical CCD driving gate CI1 phase 11 and the vertical CCD driving gate CI3 phase 13 of the pixel are made of secondary polysilicon, as shown in FIG. 6, CSS lead 4 of the series gating gate and the vertical CCD driving gate CI2 phase 12 and the vertical CCD driving gate CI4 phase 14 of the pixel are made of tertiary polysilicon, the tertiary polysilicon of the vertical CCD driving gate CI4 phase 14 of the pixel in the 1 st row of the pixel in the 1 st column of the pixel in the 2 nd row is electrically connected to the series gating gate 3 through the CSS gate lead 4, the tertiary polysilicon of the vertical CCD driving gate CI4 phase 14 of the pixel in the 2 nd row of the 1 st column of the pixel is electrically connected to the series gating gate 3 of the series gating gate through the series gating gate lead 4 of the series gating gate, and the third polysilicon of the vertical CCD driving gate CI4 phase 14 of the vertical CCD driving gate in the column in the row of the pixel in the row of the row 2 nd row of the pixel in the row of the pixel in the column of the row 2.

In the invention, the primary polysilicon, the secondary polysilicon and the tertiary polysilicon are used for indicating the sequence of the polysilicon production in the production process of the TDICCD, wherein the primary polysilicon indicates the polysilicon firstly produced on the TDICCD, the secondary polysilicon indicates the polysilicon produced for the second time on the TDICCD, and the tertiary polysilicon indicates the polysilicon produced for the third time on the TDICCD.

The undescribed parts of the present invention are consistent with the prior art, and are not described herein.

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.