KR-20260065349-A - Image Sensing Device

Abstract

The present invention relates to an image sensing device comprising: a first pixel comprising first and second DCG transistors that change the capacitance of a first floating diffusion region shared by a plurality of pixels included in a first pixel group; and a second pixel comprising third and fourth DCG transistors that change the capacitance of a second floating diffusion region shared by a plurality of pixels included in a second pixel group disposed on one side of the first pixel group, wherein the gate of the first DCG transistor and the gate of the second DCG transistor are disposed offset from the center of the first pixel toward the second pixel, and the gate of the third DCG transistor and the gate of the fourth DCG transistor are disposed offset from the center of the second pixel toward the first pixel.

Inventors

• 최성호
• 김희동
• 이현정
• 임현수
• 권효준
• 백다예

Assignees

• 에스케이하이닉스 주식회사

Dates

Publication Date

20260508

Application Date

20241101

Claims (20)

1. A first pixel comprising first and second DCG (Dual Conversion Gain) transistors that change the capacitance of a first floating diffusion region shared by a plurality of pixels included in a first pixel group; and A second pixel comprising third and fourth DCG transistors that change the capacitance of a second floating diffusion region shared by a plurality of pixels included in a second pixel group disposed on one side of the first pixel group; Includes, An image sensing device in which the gate of the first DCG transistor and the gate of the second DCG transistor are positioned offset from the center of the first pixel toward the second pixel, and the gate of the third DCG transistor and the gate of the fourth DCG transistor are positioned offset from the center of the second pixel toward the first pixel.
2. In paragraph 1, A first DCG electrical wiring that electrically connects one terminal of the first DCG transistor and one terminal of the third DCG transistor; and A second DCG electrical wiring that electrically connects one terminal of the second DCG transistor and one terminal of the fourth DCG transistor; An image sensing device further comprising
3. In paragraph 2, An image sensing device, wherein the first pixel each includes first and second photoelectric conversion elements that generate a photocharge in response to incident light, and the second pixel each includes third and fourth photoelectric conversion elements that generate a photocharge in response to the incident light.
4. In paragraph 3, A pixel separation structure disposed between the first and second photoelectric conversion elements and between the third and fourth photoelectric conversion elements; An image sensing device further comprising
5. In paragraph 3, An image sensing device in which the gate of the first DCG transistor overlaps with the first photoelectric conversion element, the gate of the second DCG transistor overlaps with the second photoelectric conversion element, the gate of the third DCG transistor overlaps with the third photoelectric conversion element, and the gate of the fourth DCG transistor overlaps with the fourth photoelectric conversion element.
6. In paragraph 3, The first pixel includes a first transfer transistor that transfers a photocharge generated by the first photoelectric conversion element to the first floating diffusion region and a second transfer transistor that transfers a photocharge generated by the second photoelectric conversion element to the first floating diffusion region. An image sensing device comprising: a second pixel further comprising a third transfer transistor that transfers a photocharge generated in the third photoelectric conversion element to the second floating diffusion region and a fourth transfer transistor that transfers a photocharge generated in the fourth photoelectric conversion element to the second floating diffusion region.
7. In paragraph 1, The first pixel group further includes a first driving transistor that amplifies an electrical signal corresponding to a photocharge stored in the first floating diffusion region, and An image sensing device comprising a second driving transistor that amplifies an electrical signal corresponding to a photocharge stored in the second floating diffusion region, wherein the second pixel group described above further comprises the second pixel group.
8. In Paragraph 7, The first pixel group further includes a first selection transistor that outputs an electrical signal amplified by the first driving transistor, and An image sensing device comprising a second selection transistor that outputs an electrical signal amplified by the second driving transistor, wherein the second pixel group further comprises the second selection transistor.
9. In paragraph 1, The first pixel group includes a first reset transistor that resets the first floating diffusion region, and An image sensing device comprising a second pixel group including a second reset transistor that resets the second floating diffusion region.
10. In paragraph 1, A third DCG electrical wiring that electrically connects the one terminal of the first DCG transistor and the other terminal of the second DCG transistor; and A fourth DCG electrical wiring that electrically connects the one terminal of the third DCG transistor and the other terminal of the third DCG transistor; An image sensing device further comprising
11. In paragraph 1, An image sensing device in which the first floating diffusion region is electrically connected to the other terminal of the first DCG transistor, and the second floating diffusion region is electrically connected to the other terminal of the third DCG transistor.
12. A first pixel comprising first and second photoelectric conversion elements that generate photocharges in response to incident light; A second pixel comprising third and fourth photoelectric conversion elements that generate photocharges in response to the incident light, and in contact with one side of the first pixel; A third pixel comprising fifth and sixth photoelectric conversion elements that generate photocharges in response to the incident light, and in contact with the other side of the first pixel; and A fourth pixel in contact with the third pixel, comprising seventh and eighth photoelectric conversion elements that generate photocharges in response to the incident light; Includes, An image sensing device, wherein the first pixel comprises first and second DCG transistors that change the conversion gain of each of the first and second pixels and are positioned closer to the third pixel from the center of the first pixel, and the third pixel comprises third and fourth DCG transistors that change the conversion gain of each of the third and fourth pixels and are positioned closer to the first pixel from the center of the third pixel.
13. In Paragraph 12, An image sensing device in which one terminal of the first DCG transistor and one terminal of the third DCG transistor are electrically connected, and one terminal of the second DCG transistor and one terminal of the fourth DCG transistor are electrically connected.
14. In Paragraph 13, An image sensing device, wherein the first pixel comprises a first floating diffusion region that stores the photocharge generated in the first photoelectric conversion element and the second photoelectric conversion element, and the second pixel comprises a second floating diffusion region that stores the photocharge generated in the third photoelectric conversion element and the fourth photoelectric conversion element.
15. In Paragraph 14, The other terminal of the first DCG transistor is electrically connected to the first floating diffusion region, and An image sensing device in which the other terminal of the third DCG transistor is electrically connected to the second floating diffusion region.
16. In Paragraph 14, One terminal of the first DCG transistor is electrically connected to the other terminal of the second DCG transistor, and An image sensing device in which one terminal of the third DCG transistor is electrically connected to the other terminal of the fourth DCG transistor.
17. In Paragraph 12, When the first to fourth DCG transistors are all in the turn-off state, the first and second pixels have a high conversion gain, When the first DCG transistor is in a turned-on state and the second to fourth DCG transistors are in a turned-off state, the first pixel and the second pixel have an intermediate conversion gain, An image sensing device in which the first pixel and the second pixel have low conversion gain when all of the first to fourth DCG transistors are in a turned-on state.
18. In Paragraph 17, An image sensing device in which the above intermediate conversion gain is twice the above low conversion gain.
19. In Paragraph 17, An image sensing device in which the above high conversion gain is eight times the above low conversion gain.
20. In Paragraph 17, When the first to fourth DCG transistors are all in the turn-off state, the third and fourth pixels have a high conversion gain, When the third DCG transistor is in the turned-on state and the first, second, and fourth DCG transistors are in the turned-off state, the third and fourth pixels have an intermediate conversion gain, An image sensing device in which, when all of the first to fourth DCG transistors are in a turned-on state, the third and fourth pixels have a low conversion gain.

Description

Image Sensing Device The present invention relates to an image sensing device, and more specifically, to an image sensing device capable of implementing multiple gains. An image sensing device is a device that captures optical images by utilizing the properties of light-sensitive semiconductor materials that react to light. With the advancement of industries such as automotive, medical, computer, and telecommunications, the demand for high-performance image sensing devices is increasing in various fields, including smartphones, digital cameras, gaming devices, the Internet of Things, robots, security cameras, and medical micro-cameras. Image sensing devices can be broadly classified into Charge Coupled Device (CCD) image sensing devices and Complementary Metal Oxide Semiconductor (CMOS) image sensing devices. While CCD image sensing devices provide better image quality compared to CMOS image sensing devices, they tend to be implemented in larger sizes and consume more power. On the other hand, CMOS image sensing devices can be implemented in smaller sizes and consume less power than CCD devices. Furthermore, since CMOS image sensing devices are manufactured using CMOS manufacturing technology, light-sensing elements and signal processing circuits can be integrated onto a single chip, enabling the production of compact image sensing devices at a lower cost. For these reasons, CMOS image sensing devices are being developed for many applications, including mobile devices. FIG. 1 is a block diagram illustrating an image sensing device according to one embodiment of the present invention. FIG. 2 is a plan view exemplarily showing a pixel array of the image sensing device of FIG. 1. FIG. 3 is a circuit diagram modeling the first pixel area or the second pixel area of FIG. 2 as an example. FIG. 4 is a plan view illustrating an exemplary embodiment of the first pixel area of FIG. 2. FIG. 5a is a cross-sectional view exemplifying a cross-sectional plane along the line AA' of FIG. 4. FIG. 5b is a cross-sectional view exemplifying a cross-sectional plane along the BB' line of FIG. 4. FIG. 5c is a cross-sectional view exemplifying a cross-section along the CC' line of FIG. 4. FIG. 6 is a plan view illustrating another exemplary embodiment of the second pixel area of FIG. 2. Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted. FIG. 1 is a block diagram illustrating an image sensing device (1) according to one embodiment of the present invention. Referring to FIG. 1, an image sensing device (1, Image Sensing Device) according to one embodiment of the present invention may include a timing generator (110), a row driver (120), a pixel array (200), a correlate double sampler (130), an analog-digital converter (140), an output buffer (150), and a column driver (160). The timing generator (110) can provide timing signals and control signals to at least one of a row driver (120), a correlated dual sampler (130), an A/D converter (140), an output buffer (150), and a column driver (160). The row driver (120) can activate the pixel array (200) to perform specific operations on the pixels included in the corresponding row based on the timing signals and control signals provided from the timing signal generator (110). In one embodiment, the row driver (120) may supply a signal to control the selection of at least one pixel arranged in at least one row of the pixel array (200) to perform a specific action. The row driver (120) may generate a row selection signal to select at least one row among a plurality of rows. When the row driver (120) selects a specific row among a plurality of rows to perform a specific action, it may prevent the specific action from being performed for rows adjacent to the selected specific row. The pixels of the row selected by the row driver (120) can sequentially transmit an analog reference signal and an image signal to the correlation double sampler (130). The reference signal may be an electrical signal provided to the correlation double sampler (130) when the floating diffusion region of the pixel is reset to the power supply voltage, and the image signal may be an electrical signal provided to the correlation double sampler (130) when the photocharge generated by the pixel is accumulated in the floating diffusion region. The above reference signal may be a signal representing a pixel-specific reset noise value, and the above reference signal and the above image