Ingrid Debusschere

A Foveated Retina-Like Sensor Using CCD Technology

A CCD imager whose sampling structure is loosely modeled after the biological visual system is described. Its architecture and advantages over conventional cameras for pattern recognition are discussed. The sensor has embedded in its structure a logarithmic transformation that makes it size and rotation invariant. Simulations on real images using the actual sensor geometry have been performed to study the sensor performance for 2D pattern recognition and object tracking.

Retinalike space variant CCD sensor

The retina is a smart sensor, but in the sense of intelligent design and not on-chip computing power. It uses a unique layout and elementary charge computing elements to implement in hardware a polar-exponential transform on visual data. The final chip includes a large section of photosites arranged in a circular pattern. Further, the pixels grow m size as radial distance increases. The retina also has a fovea (a high resolution area at the chips center) and the computational circuitry. The sensor works and will serve as the key component of a real-time imaging system.

Enabling 3X nm DRAM: Record low leakage 0.4 nm EOT MIM capacitors with novel stack engineering

We report the lowest leakage achieved to date in sub-0.5 nm EOT MIM capacitors compatible with DRAM flows, showing for the first time a path enabling scalability to the 3X nm node. A novel stack engineering consisting of: 1) novel controlled ultrathin Ru oxidation process, 2) TiO<inf>x</inf> interface layer, is used for the first time to achieve record low Jg-EOT in MIM capacitors using ALD Sr-rich STO high-k dielectric and thin Ru bottom electrode. Record low Jg of 10⁻⁶ A/cm² (10⁻⁸ A/cm²) is achieved for EOT of 0.4 nm (0.5 nm) at 0.8 V. Our data is compared favorably (> 100× Jg reduction at 0.4 nm) to previous best values in literature for MIMcaps with ALD dielectrics.

CIVIS sensor: a flexible smart imager with programmable resolution

For time-critical industrial machine vision applications, a dedicated imager has been developed. The camera can be programmed to operate in several resolutions, by binning the signal charges of neighboring pixels on the sensor plane itself. Additionally the readout window was made programmable and an electronic shutter function was implemented. This square 256 X 256 imager was fabricated in a standard 1.5 micrometers CMOS technology. The readout occurs in two phases. After transferring in parallel a row of charges to 256 charge sensitive amplifiers, these signals are coupled to a single output amplifier. By controlling the sequence of addresses and reset pulses of the amplifiers, charges of different pixels are accumulated. This way multiple resolutions can be programmed. The imager is operated at data rates up to 10 MHz providing about 125 full images per second. At lower resolution, even higher frame rates are obtained. The signal to noise ratio is about 35 dB. This paper reports on the fixed pattern noise, response, speed and smear behavior of this imager.

Design and characterization of a space-variant CCD sensor

Arranging the photosensitive elements of an imaging sensor in a log-polar grid automatically samples an image in a logpolar space. The Retina project is a chip with such a spatially varying layout that can produce the advantages of image processing in the new space at real-time speeds. The actual chip is a small part of a complete imaging system. The system is part of a class of imagers called foveal sensors and these sensors have distinct and significant computational savings over conventional imagers as many as 3-10 orders of magnitude improvement in processing time and memory. The design maintains a large region of high-resolution data although it is still only a fraction of the total photosensitive area.

Active machine vision system for surface quality inspection

The realization of an integrated, flexible, and robust CIM vision system, suitable for performing quality-assurance surface inspections is discussed. The optimized combination of advanced optics, optomechanics, and flexible image sensor realizes a high virtual resolution without penalizing the pixel transfer rate. High computation rates are obtained by complementing the fractal inspection algorithm with a dynamic hologram, a modular data flow processor, and the system computer. The integrated vision system is validated for the surface quality inspection of concrete tiles in an industrial environment. The overall system performance is discussed in detail and the potential of the system for other application fields will be addressed.

Development Of A Ccd For Detection Of Gas-Phase Electron Diffraction Patterns

A linear CCD-imager has been developed for detection of gas-phase electron diffraction patterns. The gain of the photosites is calculated and compared with experimental results. The influence of the process modification for optimal electron gain, on optical and electrical characteristics is discussed.

Integrated, dynamic machine vision system with virtual high resolution

A novel active vision system for CIM production and inspection applications has been developed in the framework of ESPRIT II project No. 5194 (CIVIS). The system consists of a unique, integrated combination of novel components: camera head, data acquisition electronics, a custom digital image processor, control hardware and a commercial framestore, all under the direction of control and processing software on a PC-486 platform. The camera head incorporates a fast zoom lens in combination with a pan/tilt mirror system, allowing region-of-interest acquisition. The special 256 X 256 MOS image sensor offers programmable resolution and random pixel access. The unique combination of optics, optomechanics and versatile image sensor has a high `virtual resolution, corresponding to more than 1k X 1k pixels but without the overhead of a high pixel transfer rate. The fast computation of the algorithm employed for the fractal inspection of surfaces is realized with an unusual combination of an electrically switchable hologram (for performing all linear operations at the speed of light in the optical domain), a module-based digital processor and the host computer. In this way, active vision for the inspection of concrete tile surfaces has been implemented by acquiring only relevant image data and elegantly processing them in the most appropriate domain.