Herman L. Peek

A frame-transfer CCD color imager with vertical antiblooming

A high-density 604 (H)× 576 (V) frame-transfer CCD color image sensor is realized with a pixel dimension of 10.0 (H) × 15.6 (V) µm2, an image diagonal of 7.5 mm, and a total chip area of 66 mm2. On-chip color filters and the use of a triple read-out register result in separate Cy, G, and Ye output signals. The imager is an n-p-n buried-channel CCD which can handle 125 times overexposure with vertical antiblooming. For the calculation of a suitable dopant distribution in the image, storage, and output sections, a four-step procedure has been developed. This procedure has proved to be successful and is much faster than an approach based exclusively on two-dimensional potential calculations.

A 2.2 M pixel FT-CCD imager according to the Eureka HDTV standard

The first frame transfer CCD (charge coupled device) imager with 2.2 Mpixel, developed for use in HDTV (high-definition television) applications according to the Eureka HDTV standard, is reported with 1250 lines/frame, 1920 pixels/line, 50 fields/sec, aspect ratio of 16:9, and 2:1 interlacing. The image section of the CCD fits an optical system of 1 in., corresponding to a diagonal of 16 mm. The total chip area is 240 mm/sup 2/. This huge HDTV sensor has tackled successfully some typical technological challenges: high RC-value of the poly-silicon CCD gates; the high pixel count resulting in an output rate of 72 MHz; providing the device with a highly sensitive, low-noise, and high-bandwidth output amplifier; and a compact and efficient CCD cell combining the photo conversion, CCD transport, vertical anti-blooming, and electronic charge reset. >

Anomalous behavior of surface leakage currents in heavily doped gated-diodes

Anomalous voltage and doping dependence of surface leakage currents in heavily doped gated diodes is described and explained. By 2-D numerical device simulations, using a recombination model which includes trap-assisted tunneling, a good quantitative description of surface leakage current is obtained. This has resulted in a revision of the conventional description of these currents. Simple design criteria to avoid excessive surface leakage currents are presented. >

A 2/3-in 1187(H)*581(V) S-VHS-compatible frame-transfer CCD for ESP and movie mode

The authors present a high-resolution frame-transfer charge-coupled-device (CCD) suitable for S-VHS camcorders with an additional full-resolution true electronic still picture (ESP) mode of operation. The CCD sensor is composed of an image section, an intermediate readout register, a storage section, and a second readout register. A resolution of 450 TV lines (H) is obtained in color images by applying cyan-green-yellow complementary stripe color filters on the 1187(H)*581(V) pixels. The operation of the sensor in both conventional video and ESP modes is described. Special attention is paid to the 3-D potential calculations required to obtain a design guaranteeing a high-quality picture. Experimental results are presented. >

Frame transfer CCDs for digital still cameras: concept, design, and evaluation

Digital still cameras are becoming a widely used alternative for conventional silver-halide cameras. This paper presents first the concept of frame-transfer CCD imagers designed for consumer digital cameras. Next, the different modes of operation are explained in detail and compared with alternative approaches. Finally, extensive evaluation results on four different imagers using this new concept are presented. It will be demonstrated that the flexible modes of operation, the high dynamic range, and excellent optical properties of FT-CCDs make them very suited for this type of electronic imaging.

Groove-fill of tungsten and poly-Si membrane technology for high performance (HDTV) FT-CCD imagers

Key technologies necessary for the manufacturing of a HDTV Frame Transfer CCD sensor are reported: a groove-fill titanium-tungsten/tungsten shunt wiring technology, directly resulting in a planar surface; non-overlapping poly-Si transfer gate method; very thin poly-Si gate-electrodes (membrane poly-gates technology). With these technologies HDTV FT-CCD an image sensor with a high vertical frame-shift frequency of 25 MHz, a low on-chip power dissipation of 560 mW, and a high sensitivity in general (especially in blue), has been fabricated succesfully.<<ETX>>

Twin-layer PCCD performance for different doping levels of the surface layer

The performance and technology of the twin-layer PCCD has been investigated for different doping levels of the surface layer. With respect to charge transfer efficiency and charge handling capacity, optimum conditions for the doping level of the surface layer can be established.

Sensitivity improvement in progressive-scan FT-CCDs for digital still camera applications

Sensitivity improvements in a 3.2 M-pixel CCD image sensor developed for digital still camera applications are presented. The introduction of gap-less microlenses increases the sensitivity with 25-30% while the high angular response is maintained. With the binning possibility at the image-storage transition, the sensitivity in monitor mode can be increased. Finally the sensor output amplifier now combines low noise and excellent linearity with a much higher conversion factor. This improvement is obtained by reduced parasitic capacitances around the Floating Diffusion area.

The tacking CCD: a new CCD concept

The tacking CCD is a new type of charge transport mechanism that is suitable for junction- and MOS-type CCDs. A specific form, the trenched tacking CCD (TTCCD), promises high pixel density and high charge handling capability per unit of surface area. The charge handling capability is improved by using a trench to increase the charge storage area. With the new design concept it becomes possible to put the gates entirely into trenches, while simultaneously using the trenches as channel stops. The TTCCD structure is suitable for making new types of solid-state image sensors with increased light sensitivity, and it may be possible to incorporate a vertical overflow drain. First samples of the TTCCD have been realized, and its functionality has been confirmed. >

A 2/3" 1188(H) * 484(V) frame-transfer CCD for ESP and movie mode

A high-resolution frame-transfer CCD (charge coupled device) imager for NTSC standards was developed for use in both conventional movie mode and electronic still picture mode. The requirements for these modes of operation are illustrated. The CCD structure consists of an image section, an intermediate output register, a storage section and a second output register. Operation of the sensor in both modes is described. Special attention is paid to the 3-D potential calculations required to obtain a design guaranteeing a high-quality picture. Experimental results are presented.<<ETX>>