Highly reliable oxide‐semiconductor TFT for AMOLED displays

Abstract— The stability and reliability of oxide‐semiconductor TFTs were investigated. The contact material to the oxide semiconductor affected the thermal stability of the TFT, and a molybdenum‐contact source/drain showed good stability. And the passivating film and TFT structure affected the stability against bias stress and humidity stress, and dc‐sputtered Al²O³ passivation and fully covered channel structure with an etching stopper or source/drain showed good reliability. Moreover, high photo‐stability was confirmed by the bias‐enhanced photo‐irradiation stress test. An 11.7‐in.‐diagonal qHD AMOLED display was demonstrated to provide an applicable solution for a large‐sized OLED and an ultra‐high‐definition LCD‐TV mass production.     

Transport properties of undoped Cd0.9Zn0.1Te grown by high pressure bridgman technique

The electron drift mobility of undoped Cd_0.9Zn_0.1Te grown by high-pressure Bridgman method is measured by a time-of-flight technique. The sample shows a room temperature mobility and mobility lifetime product of 950 cm²/Vs and 1.6 × 10⁻⁴cm²/V, respectively. The mobility increases monotonically with decreasing temperature to 3000 cm²/Vs at 100 K. The dominant scattering mechanism for the electron transport is discussed by comparing with the theoretical mobility obtained by iterative solution of the Boltzmann equation.     

Dendrite growth processes of silicon and germanium from highly undercooled melts

The crystal growth behavior of a semiconductor from a very highly undercooled melt is expected to be different from that of a metal. In the present experiment, highly pure undoped Si and Ge were undercooled by an electromagnetic levitation method, and their crystal growth velocities (V) were measured as a function of undercooling (ΔT). The value of V increased with ΔT, and V=26 m/s was observed at ΔT=260 K for Si. This result corresponds well with the predicted value based on the dendrite growth theory. The growth behaviors of Si and Ge were found to be thermally controlled in the measured range of undercooling. The microstructures of samples solidified from undercooled liquid were investigated, and the amount of dendrites immediately after recalescence increased with undercooling. The dendrite growth was also observed by a high-speed camera.     

Detection of moving object by mobile stereo omnidirectional system (SOS)

Moving object detection with a mobile image sensor is an important task in robotics and computer vision, when considering the practical use of robotics in human environments. In this paper, we propose a robust method that detects moving objects in the environment using the omnidirectional depth information obtained by a mobile Stereo Omnidirectional System (SOS). In order to detect only the moving objects within the depth image that are obtained by a sensor in motion, we first estimate the ego‐motion of the sensor, and generate a predicted depth image for the current time from the depth obtained at the previous time by only considering the ego‐motion of the sensor. Then the predicted depth image is compared with the actual one obtained at the current time, and the inconsistent regions are detected as moving objects. When the sensor moves, occlusions will occur in the scene and they will cause false detections. However, these false detections can be suppressed by estimating the occlusion regions using the ego‐motion parameters of the sensor and the jump edges in the depth image. The effectiveness of the method is shown with experimental results for a real environment. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 29–38, 2005; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20155     

Tunable wavelength-selective demultiplexer using a liquid-crystalfilter

The authors describe a new tunable wavelength-selective demultiplexer with a liquid crystal Fabry-Perot interferometer. The demultiplexer has six output ports, and, at each output port, any wavelength can be tunably selected within a range of 50 nm at a bandwidth of 0.5-0.6 nm. A simulated result shows that the loss of this demultiplexer is smaller than that of a conventional demultiplexer     

Tunable light source using a liquid-crystal Fabry-Perot interferometer

A tunable light source with a liquid-crystal Fabry-Perot interferometer (LC-FPI) tuning element that emits a laser beam with a tuning range of 41 nm has been constructed. Incorporating a multiple quantum well (MQW) laser diode with a phase control (PC) section enables the selection of almost all external modes. Stable single-mode emission is obtained for the region, except where the slope of the lasing wavelength versus applied voltage to the liquid crystal is quite large.<>     

Probabilistic fault grading based on activation checking and observability analysis

A simplified probabilistic fault grading method is described. The concept of propagation probability is introduced in place of the sensitization probability of STAFAN, and the empirical parameters of STAFAN are eliminated. The division of input vectors into subsets is monitored by the activation or toggle rate. The accuracy of the method is examined for fault coverage estimation and for predicting the undetected faults.     

钝化多晶线路中电迁移损伤的预测

1　Introduction　　Thelatestprogressinpackagedsiliconinte gratedcircuits (ICs)isnoteworthy .Withthead vance ,however,someproblemsaboutthedeterio rationofthereliabilityhavebeenraised .Forin stance,thehighercurrentdensityduetoscalingdowncauseselectromigrationininterconnectmetalline.Electromigrationisthetransportationofthemetallicatomsbyelectronwind .Voidsareformedasaresultofdepletionofatoms,andhillocksareformedasaresultofaccumulationofatomsinthemetalline .Thegrowthofvoidsultimatelyleadstometal…     

A 2-V, 1-10 GHz BiCMOS transceiver chip for multimode wirelesscommunications networks

This paper concerns the design consideration, fabrication process, and performance results for an ultra-broadband, low-voltage, low-power, BiCMOS-based transceiver chip for cellular-satellite-LAN wireless communication networks. The transceiver chip incorporates an RF amplifier, a Gilbert down-mixer, and an IF amplifier in the receive path, and an IF amplifier, a Gilbert up-mixer, and an RF amplifier in the transmit path. For an RF frequency in the 1-10 GHz band and an IF frequency in the 100-1000 MHz band, the developed transceiver chip consumes less than 60 mW at 2 V, to yield a downconversion gain of 40 dB at 1 GHz and 10 dB at 10 GHz and an upconversion gain of 42 dB at 1 GHz and 11 dB at 10 GHz. To avoid possible start-up problems caused during “stand-by” to “enable” mode transition, a simple switching technique is employed for enabling either the receive or the transmit path, by changing the value of a reference voltage applied to both the down- and the up-mixers. While the developed transceiver chip exhibits the best performance for a dc supply voltage of 2 V, it shows a graceful degradation for a ±0.15 V voltage deviation. The transceiver's chip size is 1.04 mm×1.04 mm