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Correlation between gas phase composition of rf plasma of argon diluted tetraethylgermanium and chemical structure of therewith deposited Ge/C films J.

Abstract— Low‐temperature poly‐Si TFT data drivers for an SVGA a‐Si TFT‐LCD panel have been developed. The data drivers include shift registers, sample‐and‐hold circuits, and operational amplifiers, and drive LCD panels using a line‐at‐a‐time addressing method. To reduce the power consumption of the shift register, a dot‐clock control circuit has been developed. Using this circuit, the power consumption of the shift register has been reduced to 36% of that of conventional circuits. To cancel the offset voltage generated by the operational amplifier, an offset cancellation circuit for low‐temperature poly‐Si TFTs has been developed. This circuit is also able to avoid any unstable operation of the operational amplifier. Using this circuit, the offset voltage has been reduced to one‐third of the value without using the offset cancellation circuit. These data drivers have been connected to an LCD panel and have realized an SVGA display on a 12.1‐in. a‐Si TFT‐LCD panel.

Recent studies of a direct-contact type fingerprint sensor are published [1,2]. Compact, thin-package sensors are needed for remote terminal use. However, as these fingerprint sensors are produced by the standard CMOS process, the chip cost is high. Production costs using low-temperature poly-Si that could produce ICs directly on soda glass substrate would be lower than those using CMOS. A capacitive fingerprint sensor with low-temperature poly-Si TFTs is reported [3]. There charge saved between the finger surface and sensor plate is transferred to external CMOS amplifiers with two TFTs in the sensor pixel. They realize a 200x200 fingerprint sensor with 100mm pitch. However this method has problems. First, the S/N is worse due to the parasitic capacitance of the scanning line. Second, many high-precision amplifiers are needed to amplify the weak output signal from each pixel, so silicon ICs are used. Third, it is not easy to increase the resolution to 500dpi demanded by users, because two TFTs are used in a pixel. The capacitive fingerprint sensor reported here employs a sensor plate and only one TFT for amplifying charge.Figure16.4.1 shows the structure of the sensor cell. The cell is composed of the sensor plate and a pixel transistor for amplification. The sensor plate is connected to the gate of a pixel transistor. The perception capacitance C f and the parasitic capacitance CGS of a pixel transistor are connected to a gate electrode of transistor Tra in series. Perception capacitance Cf acts between the finger surface and the sensor plate. The detection principle is given below. It is assumed that the surface potential of a finger is 0V, and that VOUT, VSROa and VSROb are 0V as initial conditions. When VSROa becomes Va, the gate electric potential VGa rises by capacitance combination and becomes selfconsistently V Ga =C GS ×V a /(C GS +C f ). Because the gate electrical potential V Ga depends on the perception capacitance C f , the finger surface information is converted into gate electrical potential V Ga . Furthermore V Ga is converted into a drain current I Pa determined by the characteristic of Tra. The parasitic capacitance of an output line, C OUT, is charged by IPa, so the output voltage VOUT rises. When the sampling time of TS has passed, the output voltage can be sampled by turning on Trc, that is, VOUT . =.IPa×TS/COUT. The fingerprint information is then obtained by analyzing the voltage waveform of VOUT.Since the pixel transistors are not isolated, there is a fear of IPa leakage to other pixels (for example, to VSROb through transistor Trb). In an actual sensor array, many of those other pixels flow the leak current, so that the total leak current is large and the S/N of the output signal degrades. To solve this problem, advantage is taken of the high threshold voltage characteristics of the low temperature poly-Si TFTs, which is considered a disadvantage in circuit design. In Figure 16.4.1, assume that the gate electrical potential V Gb is 0V. If the electric potential V HRn reaches a value equal...

We show a series of two-dimensional (2D) space distributions of submicron insulating particles in Ar rf-capacitively coupled plasma (CCP) as a function of time after injection by using a fluid model under the external conditions of 102 sccm < flow rate < 105 sccm and 10-8 m < particle radius < 10-5 m at 13.56 MHz in Ar. The final density profile is strongly dependent on the flow rate. For low flow rates, the profile of density is disk shaped at low pressure and dome shaped at high pressure. As the flow rate increases, the profile becomes ring shaped, and finally all particles are exhausted. There is a linear relation between the flow rate and the minimum radius of a particle which can be exhausted. It was found that high pressure, low voltage and strong gas flow are the most effective for the purpose of exhausting particles from the reactor.