Application of Plasma-Doping (PLAD) Technique to Reduce Dark Current of CMOS Image Sensors

Purpose Radioluminescence microscopy can visualize the distribution of beta-emitting radiotracers in live single cells with high resolution. Here, we perform a computational simulation of 18F positron imaging using this modality to better understand how radioluminescence signals are formed and to assist in optimizing the experimental setup and image processing. Methods First, the transport of charged particles through the cell and scintillator and the resulting scintillation is modeled using the GEANT4 Monte-Carlo simulation. Then, the propagation of the scintillation light through the microscope is modeled by a convolution with a depth-dependent point-spread function, which models the microscope response. Finally, the physical measurement of the scintillation light using an electron-multiplying charge-coupled device (EMCCD) camera is modeled using a stochastic numerical photosensor model, which accounts for various sources of noise. The simulated output of the EMCCD camera is further processed using our ORBIT image reconstruction methodology to evaluate the endpoint images. Results The EMCCD camera model was validated against experimentally acquired images and the simulated noise, as measured by the standard deviation of a blank image, was found to be accurate within 2% of the actual detection. Furthermore, point-source simulations found that a reconstructed spatial resolution of 18.5 μm can be achieved near the scintillator. As the source is moved away from the scintillator, spatial resolution degrades at a rate of 3.5 μm per μm distance. These results agree well with the experimentally measured spatial resolution of 30–40 μm (live cells). The simulation also shows that the system sensitivity is 26.5%, which is also consistent with our previous experiments. Finally, an image of a simulated sparse set of single cells is visually similar to the measured cell image. Conclusions Our simulation methodology agrees with experimental measurements taken with radioluminescence microscopy. This in silico approach can be used to guide further instrumentation developments and to provide a framework for improving image reconstruction.

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“…Like the photon shot noise, the dark current noise

I_{{normale}^{-}, D}

due to the random arrival of the generated electrons is modeled by a Poisson process with mean

I_{{normale}^{-}, D, mean}

and variance

{italicσ}_{d}^{2} = I_{e^{-}, normalD, normalmean}

I_{{normale}^{-}, D} \sim P o i s s o n false(I_{e^{-}, normalD, normalmean} false) .

…”

Section: Methodsmentioning

confidence: 99%

“…Like the photon shot noise, the dark current noise I e À ; D due to the random arrival of the generated electrons is modeled by a Poisson process with mean I e À ;D; mean and variance r d 2 ¼ I e À ;D; mean 26,27 I e À ; D $ PoissonðI e À ; D; mean Þ:…”

Section: D Emccd Camera Modelmentioning

confidence: 99%

Performance evaluation of ¹⁸F radioluminescence microscopy using computational simulation

et al. 2017

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“…3,4 Applications for biomaterials as well as for hardening of austenitic stainless steels have been reported, too. 1,2 Thus restrictions of beamline rastering or target manipulation encountered in conventional beamline ion implantation are circumvented.…”

Section: Introductionmentioning

confidence: 99%

Simulated plasma immersion ion implantation processing of thin wires

Lejars¹,

Manova

Mändl

et al. 2010

Journal of Applied Physics

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Particle-in-cell simulation of an electron shock wave in a rapid rise time plasma immersion ion implantation process Phys. Plasmas 12, 043503 (2005); 10.1063/1.1872894Numerical simulation of metal plasma-immersion ion implantation and deposition on a cone Simulation of sheath dynamics and current nonuniformity in plasma-immersion ion implantation of a patterned surface In plasma immersion ion implantation, the dependencies of sheath expansion and ion flux density on substrate geometry are well established. However, effects of extreme diameter variations have not been investigated explicitly. Using an analytical simulation code assuming an infinite mean free path, the sheath expansion, ion flux density, and resulting substrate temperature are explored down to wire diameters of 150 m. Comparing the results for planar substrates and cylindrical, thin wires, a reduction in the sheath width up to a factor of 10, a faster establishing of a new equilibrium sheath position, and an increase in the ion fluence by a factor of 100 is encountered. The smaller plasma sheath allows for a denser packing of wires during the treatment than for planar substrates. Additionally, the implantation time is reduced, allowing a fast wire transport through the chamber, further increasing the throughput.

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“…Recent studies report abnormally large leakage current through junctions and/or transistors attributed to the presence of STI dislocations in the depletion region. [7][8][9] The problem was conventionally treated by p-type implantation to surround STI and screen the defective sidewalls and edges from the depletion region of the photodiodes. 4,5 To reduce the aspect ratio, a T-shaped STI was proposed a few years ago.…”

Section: Introductionmentioning

confidence: 99%

Low-k dielectrics for trench isolation in nanoscaled complementary metal oxide semiconductor imagers

Irrera¹,

Puzzilli²,

Ricci³

et al. 2009

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Articles you may be interested inIntegration of perovskite oxide dielectrics into complementary metal-oxide-semiconductor capacitor structures using amorphous TaSiN as oxygen diffusion barrier Shallow trench isolation stress modification by optimal shallow trench isolation process for sub-65-nm low power complementary metal oxide semiconductor technology Chemical mechanical polishing of shallow trench isolation using the ceria-based high selectivity slurry for sub-0.18 μm complementary metal-oxide-semiconductor fabrication Integration of unit processes in a shallow trench isolation module for a 0.25 μm complementary metal-oxide semiconductor technology

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Application of Plasma-Doping (PLAD) Technique to Reduce Dark Current of CMOS Image Sensors

Cited by 33 publications

References 12 publications

Performance evaluation of ¹⁸F radioluminescence microscopy using computational simulation

Performance evaluation of ¹⁸F radioluminescence microscopy using computational simulation

Simulated plasma immersion ion implantation processing of thin wires

Low-k dielectrics for trench isolation in nanoscaled complementary metal oxide semiconductor imagers

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Application of Plasma-Doping (PLAD) Technique to Reduce Dark Current of CMOS Image Sensors

Cited by 33 publications

References 12 publications

Performance evaluation of 18F radioluminescence microscopy using computational simulation

Performance evaluation of 18F radioluminescence microscopy using computational simulation

Simulated plasma immersion ion implantation processing of thin wires

Low-k dielectrics for trench isolation in nanoscaled complementary metal oxide semiconductor imagers

Contact Info

Product

Resources

About

Performance evaluation of ¹⁸F radioluminescence microscopy using computational simulation

Performance evaluation of ¹⁸F radioluminescence microscopy using computational simulation