scholarly journals Fully Depleted, Trench-Pinned Photo Gate for CMOS Image Sensor Applications

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 727
Author(s):  
Francois Roy ◽  
Andrej Suler ◽  
Thomas Dalleau ◽  
Romain Duru ◽  
Daniel Benoit ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Dynamic Range ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Deep Trench ◽  
Fully Depleted ◽  
Sensor Applications ◽  
Temporal Noise

Tackling issues of implantation-caused defects and contamination, this paper presents a new complementary metal–oxide–semiconductor (CMOS) image sensor (CIS) pixel design concept based on a native epitaxial layer for photon detection, charge storage, and charge transfer to the sensing node. To prove this concept, a backside illumination (BSI), p-type, 2-µm-pitch pixel was designed. It integrates a vertical pinned photo gate (PPG), a buried vertical transfer gate (TG), sidewall capacitive deep trench isolation (CDTI), and backside oxide–nitride–oxide (ONO) stack. The designed pixel was fabricated with variations of key parameters for optimization. Testing results showed the following achievements: 13,000 h+ full-well capacity with no lag for charge transfer, 80% quantum efficiency (QE) at 550-nm wavelength, 5 h+/s dark current at 60 °C, 2 h+ temporal noise floor, and 75 dB dynamic range. In comparison with conventional pixel design, the proposed concept could improve CIS performance.

scholarly journals Low-Cost 2D Index and Straightness Measurement System Based on a CMOS Image Sensor

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5461 ◽  
Author(s):  
Alain Küng ◽  
Benjamin A. Bircher ◽  
Felix Meli
Keyword(s):  
Measurement System ◽  
Degrees Of Freedom ◽  
Low Cost ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Measurement Systems ◽  
Starting Point ◽  
Sensor Properties

Accurate traceable measurement systems often use laser interferometers for position measurements in one or more dimensions. Since interferometers provide only incremental information, they are often combined with index sensors to provide a stable reference starting point. Straightness measurements are important for machine axis correction and for systems having several degrees of freedom. In this paper, we investigate the accuracy of an optical two-dimensional (2D) index sensor, which can also be used in a straightness measurement system, based on a fiber-coupled, collimated laser beam pointing onto an image sensor. Additionally, the sensor can directly determine a 2D position over a range of a few millimeters. The device is based on a simple and low-cost complementary metal–oxide–semiconductor (CMOS) image sensor chip and provides sub-micrometer accuracy. The system is an interesting alternative to standard techniques and can even be implemented on machines for real-time corrections. This paper presents the developed sensor properties for various applications and introduces a novel error separation method for straightness measurements.

A Very Low Dark Current Temperature-Resistant, Wide Dynamic Range, Complementary Metal Oxide Semiconductor Image Sensor

2008 ◽  
Vol 47 (7) ◽  
pp. 5390-5395 ◽  
Author(s):  
Koichi Mizobuchi ◽  
Satoru Adachi ◽  
Jose Tejada ◽  
Hiromichi Oshikubo ◽  
Nana Akahane ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Dark Current ◽  
Dynamic Range ◽  
Complementary Metal Oxide Semiconductor ◽  
Image Sensor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Wide Dynamic Range

scholarly journals An Optical Filter-Less CMOS Image Sensor with Differential Spectral Response Pixels for Simultaneous UV-Selective and Visible Imaging

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 13
Author(s):  
Yhang Ricardo Sipauba Carvalho da Silva ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Visible Light ◽  
Spectral Sensitivity ◽  
Dynamic Range ◽  
Uv Light ◽  
Spectral Response ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Conversion Gain ◽  
Uv Sensitivity

This paper presents a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) capable of capturing UV-selective and visible light images simultaneously by a single exposure and without employing optical filters, suitable for applications that require simultaneous UV and visible light imaging, or UV imaging in variable light environment. The developed CIS is composed by high and low UV sensitivity pixel types, arranged alternately in a checker pattern. Both pixel types were designed to have matching sensitivities for non-UV light. The UV-selective image is captured by extracting the differential spectral response between adjacent pixels, while the visible light image is captured simultaneously by the low UV sensitivity pixels. Also, to achieve high conversion gain and wide dynamic range simultaneously, the lateral overflow integration capacitor (LOFIC) technology was introduced in both pixel types. The developed CIS has a pixel pitch of 5.6 µm and exhibits 172 µV/e− conversion gain, 131 ke− full well capacity (FWC), and 92.3 dB dynamic range. The spectral sensitivity ranges of the high and low UV sensitivity pixels are of 200–750 nm and 390–750 nm, respectively. The resulting sensitivity range after the differential spectral response extraction is of 200–480 nm. This paper presents details regarding the CIS pixels structures, doping profiles, device simulations, and the measurement results for photoelectric response and spectral sensitivity for both pixel types. Also, sample images of UV-selective and visible spectral imaging using the developed CIS are presented.

scholarly journals A 120-ke− Full-Well Capacity 160-µV/e− Conversion Gain 2.8-µm Backside-Illuminated Pixel with a Lateral Overflow Integration Capacitor

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5572
Author(s):  
Isao Takayanagi ◽  
Ken Miyauchi ◽  
Shunsuke Okura ◽  
Kazuya Mori ◽  
Junichi Nakamura ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Incident Light ◽  
Complementary Metal Oxide Semiconductor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Conversion Gain ◽  
Cover Glass ◽  
Low Light ◽  
Light Signals ◽  
Backside Illuminated

In this paper, a prototype complementary metal-oxide-semiconductor (CMOS) image sensor with a 2.8-μm backside-illuminated (BSI) pixel with a lateral overflow integration capacitor (LOFIC) architecture is presented. The pixel was capable of a high conversion gain readout with 160 μV/e− for low light signals while a large full-well capacity of 120 ke− was obtained for high light signals. The combination of LOFIC and the BSI technology allowed for high optical performance without degradation caused by extra devices for the LOFIC structure. The sensor realized a 70% peak quantum efficiency with a normal (no anti-reflection coating) cover glass and a 91% angular response at ±20° incident light. This 2.8-μm pixel is potentially capable of higher than 100 dB dynamic range imaging in a pure single exposure operation.

scholarly journals Analysis of Disparity Information for Depth Extraction Using CMOS Image Sensor with Offset Pixel Aperture Technique

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 472 ◽  
Author(s):  
Byoung-Soo Choi ◽  
Jimin Lee ◽  
Sang-Hwan Kim ◽  
Seunghyuk Chang ◽  
JongHo Park ◽  
...  
Keyword(s):  
Geometric Model ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Image Sensor ◽  
Color Pattern ◽  
Image Sensor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Color Information ◽  
Depth Extraction ◽  
Measurement Results

A complementary metal oxide semiconductor (CMOS) image sensor (CIS), using offset pixel aperture (OPA) technique, was designed and fabricated using the 0.11-µm CIS process. In conventional cameras, an aperture is located on the camera lens. However, in a CIS camera using OPA technique, apertures are integrated as left-offset pixel apertures (LOPAs) and right-offset pixel apertures (ROPAs). A color pattern is built, comprising LOPA, blue, red, green, and ROPA pixels. The disparity information can be acquired from the LOPA and ROPA channels. Both disparity information and two-dimensional (2D) color information can be simultaneously acquired from the LOPA, blue, red, green, and ROPA channels. A geometric model of the OPA technique is constructed to estimate the disparity of the image, and the measurement results are compared with the estimated results. Depth extraction is thus achieved by a single CIS using the OPA technique, which can be easily adapted to commercial CIS cameras.

scholarly journals Compensation for Process and Temperature Dependency in a CMOS Image Sensor

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 870 ◽  
Author(s):  
Shuang Xie ◽  
Albert Theuwissen
Keyword(s):  
Complementary Metal Oxide Semiconductor ◽  
Process Variations ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Temperature Sensors ◽  
Oxide Semiconductor ◽  
Temperature Dependency ◽  
Image Pixels ◽  
On Chip ◽  
Dark Signal

This paper analyzes and compensates for process and temperature dependency among a (Complementary Metal Oxide Semiconductor) CMOS image sensor (CIS) array. Both the analysis and compensation are supported with experimental results on the CIS’s dark current, dark signal non-uniformity (DSNU), and conversion gain (CG). To model and to compensate for process variations, process sensors based on pixel source follower (SF)’s transconductance gm,SF have been proposed to model and to be compared against the measurement results of SF gain ASF. In addition, ASF’s thermal dependency has been analyzed in detail. To provide thermal information required for temperature compensation, six scattered bipolar junction transistor (BJT)-based temperature sensors replace six image pixels inside the array. They are measured to have an untrimmed inaccuracy within ±0.5 ⁰C. Dark signal and CG’s thermal dependencies are compensated using the on-chip temperature sensors by at least 79% and 87%, respectively.

scholarly journals A Stacked Back Side-Illuminated Voltage Domain Global Shutter CMOS Image Sensor with a 4.0 μm Multiple Gain Readout Pixel

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 486
Author(s):  
Ken Miyauchi ◽  
Kazuya Mori ◽  
Toshinori Otaka ◽  
Toshiyuki Isozaki ◽  
Naoto Yasuda ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Sensitivity ◽  
Cmos Image Sensor ◽  
Light Sensitivity ◽  
Image Sensor ◽  
Motion Artifacts ◽  
Oxide Semiconductor ◽  
Storage Capacitor ◽  
Cmos Process ◽  
Back Side

A backside-illuminated complementary metal-oxide-semiconductor (CMOS) image sensor with 4.0 μm voltage domain global shutter (GS) pixels has been fabricated in a 45 nm/65 nm stacked CMOS process as a proof-of-concept vehicle. The pixel components for the photon-to-voltage conversion are formed on the top substrate (the first layer). Each voltage signal from the first layer pixel is stored in the sample-and-hold capacitors on the bottom substrate (the second layer) via micro-bump interconnection to achieve a voltage domain GS function. The two sets of voltage domain storage capacitor per pixel enable a multiple gain readout to realize single exposure high dynamic range (SEHDR) in the GS operation. As a result, an 80dB SEHDR GS operation without rolling shutter distortions and motion artifacts has been achieved. Additionally, less than −140dB parasitic light sensitivity, small noise floor, high sensitivity and good angular response have been achieved.

scholarly journals Reduction of Fluorine Diffusion and Improvement of Dark Current Using Carbon Implantation in CMOS Image Sensor

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1106
Author(s):  
Su-Young Chai ◽  
Sung-Hoon Choa
Keyword(s):  
Dark Current ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
State Density ◽  
Oxide Semiconductor ◽  
Fluorine Concentration ◽  
Current Characteristics ◽  
Minority Carriers

Recently, the demand of a high resolution complementary metal-oxide semiconductor (CMOS) image sensor is dramatically increasing. As the pixel size reduces to submicron, however, the quality of the sensor image decreases. In particular, the dark current can act as a large noise source resulting in reduction of the quality of the sensor image. Fluorine ion implantation was commonly used to improve the dark current by reducing the trap state density. However, the implanted fluorine diffused to the outside of the silicon surface and disappeared after annealing process. In this paper, we analyzed the effects of carbon implantation on the fluorine diffusion and the dark current characteristics of the CMOS image sensor. As the carbon was implanted with dose of 5.0 × 1014 and 1 × 1015 ions/cm2 in N+ area of FD region, the retained dose of fluorine was improved by more than 131% and 242%, respectively than no carbon implantation indicating that the higher concentration of the carbon implantation, the higher the retained dose of fluorine after annealing. As the retained fluorine concentration increased, the minority carriers of electrons or holes decreased by more Si-F bond formation, resulting in increasing the sheet resistance. When carbon was implanted with 1.0 × 1015 ions/cm2, the defective pixel, dark current, transient noise, and flicker were much improved by 25%, 9.4%, 1%, and 28%, respectively compared to no carbon implantation. Therefore, the diffusion of fluorine after annealing could be improved by the carbon implantation leading to improvement of the dark current characteristics.

scholarly journals DENOISING ALGORITHM FOR THE PIXEL-RESPONSE NON-UNIFORMITY CORRECTION OF A SCIENTIFIC CMOS UNDER LOW LIGHT CONDITIONS

2016 ◽  
Vol XLI-B3 ◽  
pp. 749-753
Author(s):  
Changmiao Hu ◽  
Yang Bai ◽  
Ping Tang
Keyword(s):  
Imaging System ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Oxide Semiconductor ◽  
Integrating Sphere ◽  
Light Conditions ◽  
Low Light ◽  
Spatial Uniformity ◽  
High Level

We present a denoising algorithm for the pixel-response non-uniformity correction of a scientific complementary metal–oxide–semiconductor (CMOS) image sensor, which captures images under extremely low-light conditions. By analyzing the integrating sphere experimental data, we present a pixel-by-pixel flat-field denoising algorithm to remove this fixed pattern noise, which occur in low-light conditions and high pixel response readouts. The response of the CMOS image sensor imaging system to the uniform radiance field shows a high level of spatial uniformity after the denoising algorithm has been applied.

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