Characteristics Of Charge-coupled Device Research Articles

Temporal evolution characteristics and mechanism analysis of CCD breakdown induced by nanosecond and picosecond pulse lasers

Studies on the interaction between laser irradiation and charge-coupled devices (CCDs) have been reported to potentially bring new opportunities in the field of photoelectric countermeasures. It is known that the complete failure of CCD caused by pulsed laser originates from the destruction of CCD internal structure, but the detailed damage mechanism of laser-induced CCD breakdown is still a dilemma. Here, the thermal-mechanical coupling model of CCD irradiated by laser is established by finite element method, and the damage threshold and damage characteristics of CCD in point damage, line damage, black-and-white split screen and complete damage stages are characterized. The results show that the temperature rise effect of silicon substrate damage is predominant in the lateral direction, which increases by 300–3000 K; while it only increases by 300–400 K in the longitudinal direction. The complete damage threshold of CCD irradiated by nanosecond laser is 509 mJ/cm2; while that irradiated by picosecond laser is 190 mJ/cm2. When the silicon dioxide insulation layer is completely ablated, CCD completely fails due to the clock confusion caused by a short circuit between silicon electrodes.

Response non-uniformity of beam profiling cameras at near-infrared laser wavelengths.

The response non-uniformities of laser beam profiling cameras were investigated experimentally at near-infrared laser wavelengths. A uniform-irradiance light source with near-infrared laser wavelengths, and also a visible wavelength as comparison, was constructed for testing several different commercially available beam profiling cameras. The response signals of all charge-coupled device (CCD)-type sensors showed a strong dependence on the irradiant wavelength. The pixel-to-pixel non-uniformity of CCDs at 1064 nm increased rapidly with the reduction of exposure time, whereas that of CMOS sensors was maintained independently of these parameters. The characteristics of CCDs were discussed in terms of charge leakage effect, which is a likely source of these phenomena.

Physical characterization of a high-resolution CCD detector for mammography

The physical characteristics of charge-coupled device (CCD) mammography detector with 16-bit dynamic range and 27 µm detector element size were investigated. The detector, with an active area of 1 cm × 20 cm is suitable for slot-scanning systems. We evaluated the detector resolution by measuring the modulation transfer function (MTF) using a tilted edge. We also measured the noise power spectra (NPS) and detective quantum efficiency (DQE) using tungsten spectra filtered with 3 mm Al. We carried out measurements in two modes of operation: the frame mode where the detector is stationary and the scan mode where the detector operates in a slot-scanning configuration. The specific beam qualities and exposure ranges employed were 30 kVp, HVL 1.4 mm Al, 1.24 µC kg−1 to 12.44 µC kg−1, and 40 kVp, HVL 2.1 mm Al and 3.26 µC kg−1 to 16.64 µC kg−1. The product of the normalized noise power spectrum and exposure was also computed to evaluate the quantum limited characteristic of the detector. The detector MTF was 12% at 15 lp mm−1. The product of the noise power spectra and exposure was independent of exposure level, indicating a quantum limited detector. The DQE in the scan and frame modes near zero frequency was 40% and 60%, respectively. Our results show that the slot-scanning configuration was less efficient than the performance capabilities of the detector. This detector is comparable to other digital mammography sensors evaluated in the literature.

Development and Testing of a 2-D Transfer CCD

This paper describes the development, operation, and characterization of charge-coupled devices (CCDs) that feature an electrode structure that allows the transfer of charge both horizontally and vertically through the image area. Such devices have been termed two-dimensional (2-D) transfer CCDs (2DT CCDs), as opposed to the conventional devices, which might be called one-dimensional transfer CCDs, but in other respects are the same as conventional CCD devices. Batches of two different 2DT CCD test devices, featuring different electrode structures but with identical clocking operation in each case, were produced and tested. The methodology of 2-D charge transfer in each of the device types is described, followed by a presentation of test results from the new CCDs. The ability of both 2DT CCD transfer electrode schemes to successfully transfer charge in both horizontal and vertical directions in the image section of the devices has been proven, opening up potential new applications for 2DT CCD use.

The impact of low energy proton damage on the operational characteristics of EPIC-MOS CCDs

The University of Tübingen 3.5 MeV Van de Graaff accelerator facility was used to investigate the effect of low-energy protons on the performance of the European Photon Imaging Camera, metal-oxide-semiconductor, charge-coupled devices (CCDs). Two CCDs were irradiated in different parts of their detecting areas using different proton spectra and dose rates. Iron-55 was the calibration source in all cases and was used to measure any increases in charge transfer inefficiency (CTI) and spectral resolution of the CCDs. Additional changes in the CCD bright pixel table and changes in the low X-ray energy response of the device were examined. The Monte Carlo code Stopping Range of Ions in Matter was used to model the effect of a 10 MeV equivalent fluence of protons interacting with the CCD. Since the non-ionising energy loss function could not be applied effectively at such low proton energies. From the 10 MeV values, the expected CTI degradation could be calculated and then compared to the measured CTI changes.

Device design with automatic simulation system for basic CCD characteristics

A simulation system has been developed to automatically analyze basic electrical characteristics of a charge-coupled device (CCD) image sensor from a process simulation result. This system shortened the simulation period to approximately 1/10 by getting rid of complicated repetitious procedures. A high-performance new cell technology has been developed successfully with improving impurity distribution in shorter development time by using this system. This technology has been realized as a CCD cell pixel with CCD charge quantity of 1.8 times, effective transfer efficiency of over 99%, no image lag for driving read-out pulse voltage in comparison with conventional technology. A 1/4-in 330 K square pixel progressive-scan CCD was fabricated with this technology. These results are described to demonstrate the effectiveness of the automatic simulation system.

Evaluation of deep states in amorphous-silicon/silicon-nitride system from charge-coupled device characteristics : S SEKINE, S NAKAMURA, S ODA, M MATSUMURA (Dept. of Electr. & Electron. Eng., Tokyo Inst. of Technol., Japan) Jpn. J. Appl. Phys. 2, Lett. (Japan), vol. 27, no. 7, pp. 1337–1339 (July 1988)

Evaluation of deep states in amorphous-silicon/silicon-nitride system from charge-coupled device characteristics : S SEKINE, S NAKAMURA, S ODA, M MATSUMURA (Dept. of Electr. & Electron. Eng., Tokyo Inst. of Technol., Japan) Jpn. J. Appl. Phys. 2, Lett. (Japan), vol. 27, no. 7, pp. 1337–1339 (July 1988)

Charge-Coupled-Device X-Ray Detector Performance Model

We describe a model that predicts the performance characteristics of charge-coupled-device (CCD) detectors being developed for use in x-ray imaging. The model accounts for the interactions of both x rays and charged particles with the CCD and simulates the transport and loss of charge in the detector. Predicted performance parameters include detective and net quantum efficiencies, split-event probability, and a parameter characterizing the effective thickness presented by the detector to cosmic-ray protons. The predicted performance of two CCDs of different epitaxial layer thicknesses is compared. The model predicts that in each device incomplete recovery of the charge liberated by a photon of energy between 0.1 and 10 keV is very likely to be accompanied by charge splitting between adjacent pixels. The implications of the model predictions for CCD data processing algorithms are briefly discussed.