Technologies to improve photo-sensitivity and reduce VOD shutter voltage for CCD image sensors

Murakami, Ichiro; Nakano, T.; Hatano, K.; Nakashiba, Y.; Furumiya, M.; Nagata, T.; Kawasaki, Tadayuki; Utsumi, Hiroaki; Uchiya, S.; Arai, K.; Mutoh, N.; Kohno, A.; Teranishi, Nobukazu; Hokari, Y.

doi:10.1109/16.853032

Cited by 10 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This prevents them from reaching and affecting the response of other pixels. The VOD mechanism was as an electronic GS [15], [16]. The shutter is activated by biasing the sensor substrate so that the potential barrier is removed and a strong punchthrough current drains the stored charge.…”

Section: Fast Vod Shutter a Historymentioning

confidence: 99%

Development of a ToF Pixel With VOD Shutter Mechanism, High IR QE, Four Storages, and CDS

Tadmor

Cohen

Yahav

et al. 2016

IEEE Trans. Electron Devices

View full text Add to dashboard Cite

In this paper we discuss the development of an indirect time-of-flight (ToF) pixel in the 0.11-µm CMOS image sensor technology. The pixel design is based on a pinnedphotodiode structure with a novel vertical overflow drain (VOD) shutter mechanism used for fast modulation. We present the second generation of the pixel, with a greatly improved VOD structure that enables a fast shutter efficiency better than 1:100 and a deeper photodiode collection depth for better quantum efficiency in the near-infrared wavelengths. We present a new 6.7-µm pixel design with four pinned storage diodes (SDs) that feature in-pixel complete charge transfer and enable correlateddouble-sampling readout as well as an almost simultaneous global shutter exposure of up to four interleaved frames to be used for the scene depth computation. The novel design features a low readout noise of 7.5e-and a full-well-capacity of 9500e-per SD (a total of 38 000e-per pixel).Index Terms-CMOS image sensor, time of flight (ToF) imaging, time resolved.

show abstract

Section: Fast Vod Shutter a Historymentioning

confidence: 99%

Development of a ToF Pixel With VOD Shutter Mechanism, High IR QE, Four Storages, and CDS

Tadmor

Cohen

Yahav

et al. 2016

IEEE Trans. Electron Devices

View full text Add to dashboard Cite

show abstract

“…An improvement in spatial resolution can reduce pixel size and increase the scale of the array, but results in a lower signal and deterioration in the signal-to-noise ratio [88,89]. This problem can be eliminated when CCDs are integrated with MLAs to improve the filling factor [90].…”

Section: B Sensingmentioning

confidence: 99%

Fabrication, characterization, and applications of microlenses

et al. 2015

View full text Add to dashboard Cite

Microlenses (MLs) and microlens arrays (MLAs) are assuming an increasingly important role in optical devices. In response to this rapid evolution in technology, emphasis is being placed on research into new manufacturing methods for these devices as well as the characterization of their performance. This paper provides an overview of the fabrication of MLs and MLAs by electrical, mechanical, chemical, and optical methods. As each processing method has distinct advantages and limitations, the most significant characteristic parameters and the measurement of these parameters are discussed for each method. These parameters are then used as indices to evaluate and improve each of the processing methods. Some examples of practical applications of MLAs, especially for micromechanical optoelectronic devices, are also given. This paper aims to summarize the present development and the state of the art in processing technology of MLs and MLAs.

show abstract

“…The electrons cannot diffuse freely to adjacent photodiodes and the blooming phenomenon is prevented. When this structure is combined with a PPD it is possible to use it as a global electronic shutter: increasing the substrate bias voltage to a certain value eliminates the potential barrier between the photodiode and the substrate, and all the electrons stored in the photodiode are drained [16], [17]. Using this mechanism the photodiode can be drained just before the desired exposure period starts.…”

Section: The Vod Shutter Mechanismmentioning

confidence: 99%

Dynamic Multispectral Imaging Using the Vertical Overflow Drain Structure

et al. 2015

View full text Add to dashboard Cite

Multispectral imaging enables discrimination of spectra beyond the 3-D spectral space of human vision. Most multispectral systems are complex and bulky, and simpler monolithic designs usually require several pixels in order to generate one multispectral data point. Here, we use the vertical overflow drain (VOD) structure to enable monolithic multispectral imaging in a single pixel. We show that by controlling the substrate bias voltage it is possible to change the effective depth of the photodiode, thus enabling dynamic tuning of the pixel's spectral response. A small voltage change (<5 V) is shown experimentally to reduce the red light quantum efficiency by ∼40%, while the blue light quantum efficiency is reduced by <10%. Using this effect, we demonstrate an ability to discriminate between different monochromatic illumination sources with 20-nm spectral resolution in a single pixel. In addition, we present an RGB image taken using an off-theshelf charge coupled devices with no color filters by relying solely on the VOD mechanism. Finally, we present process and device simulations suggesting that this mechanism can be implemented in any pinned photodiode pixel with a VOD barrier, including in CMOS image sensors fabricated on n-type starting material.Index Terms-CMOS image sensors, CCD image sensors, multispectral imaging, digital photography.

show abstract

Technologies to improve photo-sensitivity and reduce VOD shutter voltage for CCD image sensors

Cited by 10 publications

References 12 publications

Development of a ToF Pixel With VOD Shutter Mechanism, High IR QE, Four Storages, and CDS

Development of a ToF Pixel With VOD Shutter Mechanism, High IR QE, Four Storages, and CDS

Fabrication, characterization, and applications of microlenses

Dynamic Multispectral Imaging Using the Vertical Overflow Drain Structure

Contact Info

Product

Resources

About