Study of Metal Contamination in CMOS Image Sensors by Dark-Current and Deep-Level Transient Spectroscopies

2010 ◽  
Vol 39 (6) ◽  
pp. 625-629 ◽  
Author(s):  
F. Domengie ◽  
J. L. Regolini ◽  
D. Bauza
Keyword(s):  
Dark Current ◽  
Metal Contamination ◽  
Deep Level ◽  
Image Sensors ◽  
Cmos Image Sensors

Specification of Trace Metal Contamination for Image Sensors

2016 ◽  
Vol 255 ◽  
pp. 309-312 ◽  
Author(s):  
Paul W. Mertens ◽  
Simone Lavizzari ◽  
Stefano Guerrieri
Keyword(s):  
Trace Metal ◽  
Dark Current ◽  
Background Noise ◽  
Metal Contamination ◽  
Image Sensors ◽  
Trace Metal Contamination ◽  
Metal Impurities ◽  
Current Contribution ◽  
Cmos Image Sensors ◽  
Internal Generation

CMOS image sensors can suffer from background noise in absence of any light. In order to suppress this it is important to keep this noise, referred to as dark-current low. This implies that the internal generation current should be very low. Trace metal impurities have been reported to increase the generation current. In this study the trap-assisted generation current contributions due to 7 different metal impurities have been calculated. It was concluded that Cu and Mn impurities yield the highest generation current contribution.

scholarly journals Proximity Gettering Design of Hydrocarbon–Molecular–Ion–Implanted Silicon Wafers Using Dark Current Spectroscopy for CMOS Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2073 ◽  
Author(s):  
Kazunari Kurita ◽  
Takeshi Kadono ◽  
Satoshi Shigematsu ◽  
Ryo Hirose ◽  
Ryosuke Okuyama ◽  
...  
Keyword(s):  
Dark Current ◽  
Image Sensor ◽  
Image Sensors ◽  
Silicon Wafers ◽  
Device Fabrication ◽  
Oxide Semiconductor ◽  
Device Performance ◽  
Molecular Ion ◽  
Cmos Image Sensors ◽  
Ion Implanted

We developed silicon epitaxial wafers with high gettering capability by using hydrocarbon–molecular–ion implantation. These wafers also have the effect of hydrogen passivation on process-induced defects and a barrier to out-diffusion of oxygen of the Czochralski silicon (CZ) substrate bulk during Complementary metal-oxide-semiconductor (CMOS) device fabrication processes. We evaluated the electrical device performance of CMOS image sensor fabricated on this type of wafer by using dark current spectroscopy. We found fewer white spot defects compared with those of intrinsic gettering (IG) silicon wafers. We believe that these hydrocarbon–molecular–ion–implanted silicon epitaxial wafers will improve the device performance of CMOS image sensors.

scholarly journals Random Telegraph Noises from the Source Follower, the Photodiode Dark Current, and the Gate-Induced Sense Node Leakage in CMOS Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5447
Author(s):  
Calvin Yi-Ping Chao ◽  
Shang-Fu Yeh ◽  
Meng-Hsu Wu ◽  
Kuo-Yu Chou ◽  
Honyih Tu ◽  
...  
Keyword(s):  
Dark Current ◽  
Image Sensors ◽  
Integration Time ◽  
X Ray ◽  
Multiple Sampling ◽  
Cmos Image Sensors ◽  
Measurement Results ◽  
Source Follower ◽  
Different Types ◽  
Dark Signal

In this paper we present a systematic approach to sort out different types of random telegraph noises (RTN) in CMOS image sensors (CIS) by examining their dependencies on the transfer gate off-voltage, the reset gate off-voltage, the photodiode integration time, and the sense node charge retention time. Besides the well-known source follower RTN, we have identified the RTN caused by varying photodiode dark current, transfer-gate and reset-gate induced sense node leakage. These four types of RTN and the dark signal shot noises dominate the noise distribution tails of CIS and non-CIS chips under test, either with or without X-ray irradiation. The effect of correlated multiple sampling (CMS) on noise reduction is studied and a theoretical model is developed to account for the measurement results.

scholarly journals CMOS Image Sensors and Plasma Processes: How PMD Nitride Charging Acts on the Dark Current

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5534
Author(s):  
Yolène Sacchettini ◽  
Jean-Pierre Carrère ◽  
Romain Duru ◽  
Jean-Pierre Oddou ◽  
Vincent Goiffon ◽  
...  
Keyword(s):  
Dark Current ◽  
Uv Light ◽  
Degradation Mechanism ◽  
Nitride Layer ◽  
Image Sensors ◽  
Electron Hole ◽  
Cmos Image Sensors ◽  
Depth Analysis

Plasma processes are known to be prone to inducing damage by charging effects. For CMOS image sensors, this can lead to dark current degradation both in value and uniformity. An in-depth analysis, motivated by the different degrading behavior of two different plasma processes, has been performed in order to determine the degradation mechanisms associated with one plasma process. It is based on in situ plasma-induced charge characterization techniques for various dielectric stack structures (dielectric nature and stack configuration). A degradation mechanism is proposed, highlighting the role of ultraviolet (UV) light from the plasma in creating an electron hole which induces positive charges in the nitride layer at the wafer center, and negative ones at the edge. The trapped charges de-passivate the SiO2/Si interface by inducing a depleted interface above the photodiode, thus emphasizing the generation of dark current. A good correlation between the spatial distribution of the total charges and the value of dark current has been observed.

scholarly journals Dark Current Sharing and Cancellation Mechanisms in CMOS Image Sensors Analyzed by TCAD Simulations

2017 ◽  
Vol 64 (12) ◽  
pp. 4985-4991 ◽  
Author(s):  
Olivier Marcelot ◽  
Vincent Goiffon ◽  
Serena Rizzolo ◽  
Federico Pace ◽  
Pierre Magnan
Keyword(s):  
Dark Current ◽  
Image Sensors ◽  
Current Sharing ◽  
Cmos Image Sensors ◽  
Tcad Simulations

Metal Removal Efficiency in High Aspect Ratio Structures

2016 ◽  
Vol 255 ◽  
pp. 313-318 ◽  
Author(s):  
Philippe Garnier ◽  
Hervé Fontaine
Keyword(s):  
Aspect Ratio ◽  
Removal Efficiency ◽  
High Aspect Ratio ◽  
Metal Contamination ◽  
Metal Removal ◽  
Image Sensors ◽  
Flat Surfaces ◽  
Past Work ◽  
Patterned Wafers ◽  
Cmos Image Sensors

An extremely low level of metal contamination is required for specific devices like memories and CMOS Image sensors. Most of past work in the literature has focused on blanket wafer decontamination, since metrology is mostly adapted to flat surfaces. Metal removal efficiency has been compared between blanket wafers versus high aspect ratio deep trenches wafers. Two different metrology technics enable a quantitative and spatial metal removal determination on patterned wafers. Efficient cleaning in high aspect ratio structures requires much longer cleaning recipes than on flat surfaces.

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