Image sensors of today use semi-conductor technologies to a high extent. Be it a camera, transistor or diode, semiconductors are the order of the day. IMEC is a Belgian company who does extensive research on nanoelectronics and is supposed to present their mettle in the workshop on CMOS Image Sensors for High Performance Applications in Toulose in France. They will be presenting a TDI (time-delay-integration) image sensor which has been developed for the sole purpose of observing earth characteristics from space. IMEC has taken utmost efforts to ensure that their developed CCD technology is the most acceptable.
A light sensitive and CCD-based array of TDI pixels are incorporated in the prototype. The image sensor also has CMOS electronics which are readout and light-sensitive in nature. These feats have been achieved with the combination of CMOS and CCD technologies. The CCD pixel arrangement gives low-noise performance on a TDI charge domain, while CMOS technology assists low-power, on-chip assimilation of quick and complex circuitry details.
A TDI imager that is linear in nature can utilize a suave management of the linear scene motion with the similar image being multiple sampled, and in the process enhancing the signal-to-noise ratio. CCDs match well with TDI applications due to their operation in the charge domain, allowing removing excess noise due to charge movements. TDI pixels displays were combined with CMOS circuitry to produce a camera-on-a-chip imager, which lowers the complete system cost and complexity. The CMOS technology allows on-chip readout electronics, like analog-to-digital convertors (ADCs) and clock drivers operating at lower power and higher speeds that is not a possible option with the CCD technology that is in vogue.
“These new devices demonstrate our commitment to provide customers the highest performing image sensors that leverage the most advanced technologies”, said Chris McNiffe, CEO of an imaging company. “Through their features, functionality, and performance, these new products demonstrate the complementary nature of CCD and CMOS devices, and show the importance of having both technologies available in a full-featured product portfolio.”
The 4000 x 3000 and 12 megapixel KAC-12040 Image Sensor is the first of its kind in a family of CMOS devices that glue high frame rates with high image quality with very excellent near-IR sensitivity high frame rate, flexible readout modes for accessing multiple regions of interest – features becoming important in a variety of machining techniques, surveillance applications , and intelligent transportation systems.
The 4/3 optical format, based on a 4.7 micron pixel architecture supports multiple regions of interest (ROI) and different video streams, making this device ideal for applications requiring high frame rates and high resolution. IMEC’s 130 nm process were used to fabricate using the CCD process module. A lossless transport of charges has been ensured in the TDI array, of the order of 99.98%, that guarantees enhanced image quality. IMEC’s specialty imaging platform combines custom design with optimal silicon processing (i.e., specialized pixels, high-performance readout circuits and chip architectures), such as dedicated backside tinning and implants, to achieve specialized images of high-end quality.