Transient analysis of signal charge transfer in long diffused regions of spectroscopic image sensors

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1086-1091
Author(s):  
David A. B. Dobson ◽  
Savvas G. Chamberlain
Keyword(s):  
Charge Transfer ◽  
High Performance ◽  
Image Sensor ◽  
Image Sensors ◽  
Oxide Semiconductor ◽  
Transfer Time ◽  
Experimental Image ◽  
Experimental Side ◽  
Flow Through ◽  
Effect Transistor

This paper presents the results of a study of charge transfer time in long doped semiconductor regions. These regions are used to collect and store charge in high performance image sensors. The effect of dopant concentration on charge transfer time was studied using a novel two-dimensional device simulation tool. It was found that the delay associated with the long storage region only becomes significant for doping concentrations that are not degenerate. The effect of storage diffusion length on charge transfer time was also studied for degenerately doped structures. For these structures, it was found that the delay is much less than the conventional belief that the delay is proportional to the square of the diffusion dimension the electrons traverse. It was also found that the diffusion dimension affects the charge transfer time indirectly through the back biasing of the transfer metal oxide semiconductor field effect transistor (MOSFET). Shorter diffusions initially cause a larger back biasing of the transfer MOSFET, decreasing the maximum current flow through the device. On the experimental side, novel image sensor devices were designed that incorporate some of the results discussed above. Experimental image sensor structures were analyzed to study charge transfer time and relate the results to the computer simulations.

scholarly journals Ab initio perspective of ultra-scaled CMOS from 2D-material fundamentals to dynamically doped transistors

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Aryan Afzalian
Keyword(s):  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
High Mobility ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Grand Challenge ◽  
Gate Length ◽  
Delay Performance ◽  
Effect Transistor

AbstractUsing accurate dissipative DFT-NEGF atomistic-simulation techniques within the Wannier-Function formalism, we give a fresh look at the possibility of sub-10-nm scaling for high-performance complementary metal oxide semiconductor (CMOS) applications. We show that a combination of good electrostatic control together with high mobility is paramount to meet the stringent roadmap targets. Such requirements typically play against each other at sub-10-nm gate length for MOS transistors made of conventional semiconductor materials like Si, Ge, or III–V and dimensional scaling is expected to end ~12 nm gate-length (pitch of 40 nm). We demonstrate that using alternative 2D channel materials, such as the less-explored HfS2 or ZrS2, high-drive current down to ~6 nm is, however, achievable. We also propose a dynamically doped field-effect transistor concept, that scales better than its MOSFET counterpart. Used in combination with a high-mobility material such as HfS2, it allows for keeping the stringent high-performance CMOS on current and competitive energy-delay performance, when scaling down to virtually 0 nm gate length using a single-gate architecture and an ultra-compact design (pitch of 22 nm). The dynamically doped field-effect transistor further addresses the grand-challenge of doping in ultra-scaled devices and 2D materials in particular.

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 Super Field-of-View Lensless Camera by Coded Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1329 ◽  
Author(s):  
Tomoya Nakamura ◽  
Keiichiro Kagawa ◽  
Shiho Torashima ◽  
Masahiro Yamaguchi
Keyword(s):  
Imaging System ◽  
Complementary Metal Oxide Semiconductor ◽  
Image Sensor ◽  
Image Sensors ◽  
Computational Imaging ◽  
Field Of View ◽  
Oxide Semiconductor ◽  
Back Side ◽  
Cmos Image Sensors ◽  
Rich Information

A lensless camera is an ultra-thin computational-imaging system. Existing lensless cameras are based on the axial arrangement of an image sensor and a coding mask, and therefore, the back side of the image sensor cannot be captured. In this paper, we propose a lensless camera with a novel design that can capture the front and back sides simultaneously. The proposed camera is composed of multiple coded image sensors, which are complementary-metal-oxide-semiconductor (CMOS) image sensors in which air holes are randomly made at some pixels by drilling processing. When the sensors are placed facing each other, the object-side sensor works as a coding mask and the other works as a sparsified image sensor. The captured image is a sparse coded image, which can be decoded computationally by using compressive sensing-based image reconstruction. We verified the feasibility of the proposed lensless camera by simulations and experiments. The proposed thin lensless camera realized super-field-of-view imaging without lenses or coding masks and therefore can be used for rich information sensing in confined spaces. This work also suggests a new direction in the design of CMOS image sensors in the era of computational imaging.

Characterization of Strain for High-Performance Metal–Oxide–Semiconductor Field-Effect-Transistor

2008 ◽  
Vol 47 (4) ◽  
pp. 2538-2543 ◽  
Author(s):  
Daisuke Kosemura ◽  
Yasuto Kakemura ◽  
Tetsuya Yoshida ◽  
Atsushi Ogura ◽  
Masayuki Kohno ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Effect Transistor

scholarly journals Modelling and Simulation of Tri-layered (s-Si/s-SiGe/s-Si) Channel Double Gate Nano FET

2019 ◽  
Vol 9 (2S) ◽  
pp. 113-116
Keyword(s):  
High Performance ◽  
Channel Length ◽  
Depletion Region ◽  
Oxide Semiconductor ◽  
Double Gate ◽  
The Past ◽  
Mobility Of Charge Carriers ◽  
Subthreshold Leakage ◽  
Effect Transistor ◽  
Channel Region

The down scaling of Meatal Oxide Semiconductor Field Effect transistor (MOSFET) devices nevertheless the most important and effective way for accomplishing high performance with low power adopted the miniaturization trend of channel length from the past, which is very aggressive. The double gate NanoFET with the incorporation of the strain Silicon technology is developed here on 45nm gate length comprises of tri-layered (s-Si/s-SiGe/s-Si) channel region with varied thicknesses. The induction of strain increases mobility of charge carriers. Two gates are deployed in bottom and up side of strained channel provides better control over the depletion region developed by applying same gate bias voltage. This newly developed double gate NanoFET on 45nm channel length provides 63% reduced subthreshold leakage current, and maximum electron drift velocity in strained channel.

Enabling Wafer Level Processes for CIS Manufacturing

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 002393-002413
Author(s):  
Eric F. Pabo ◽  
Garrett Oakes ◽  
Ron Miller ◽  
Paul Lindner ◽  
Gerald Kreindl ◽  
...  
Keyword(s):  
Image Sensor ◽  
Image Sensors ◽  
Oxide Semiconductor ◽  
Sensor Technology ◽  
Cost Ratio ◽  
Cost Curve ◽  
Back Side ◽  
Wafer Level ◽  
3D Packaging ◽  
Lens Molding

CMOS (Complimentary Metal Oxide Semiconductor) Image Sensors have become ubiquitous, appearing in cars, cell phones, toys and many other devices used in every day life. The primary reason for this increasing presence of CIS (CMOS Image Sensors) is the continual improvement of the performance to cost ratio of these devices. The drivers behind this are the advancements of CMOS image sensor technology such as improved signal to noise ratio as well as advancements in wafer level processing technology related to 3D packaging. Numerous process developments related to both the electrical and optical aspects of 3D packaging of CIS that have enabled this climb up the performance vs. cost curve will be reviewed in this paper with particular attention to:(1) Lens molding – The ability to mold lenses, both spherical and aspherical at the wafer level as well as make full size master stamps from partial masters for lens molding. These lenses can be molded on both sides of a wafer and the lenses aligned to each other;(2) Aligned wafer bonding for optical interconnects consisting of lens stacks and CIS wafer, to allow the thinning of a CIS for BSI (back side illumination), and for electrical interconnects. Together these processes allow the heterogeneous integration of optical and electrical elements at the wafer level and advance the CIS up the performance vs. cost curve.

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