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In the three-dimensional flash memory manufacturing technology, the etching process of high aspect ratio multi-level contact holes structure was studied. Using capacitive coupled plasma (CCP) etching equipment, the effects of C 4 F 6/ /C 4 F 8 /O 2 /Ar mixed gas atmosphere on the deep holes’ total profile were investigated to optimize bowing profile of the hole. Furthermore, multi-level stop layer loss was optimized by adjusting over etching time and lithography exposure critical dimension (CD), which proved good compatibility with existing process. Results show that adding proper amount of C 4 F 8 into C 4 F 6 gas atmosphere can achieve better verticality and less stop layer loss. Enlarging middle layer exposure CD can reduce specific stop layer loss independently while reducing over etching time can reduce all stop layer loss together. Under the optimized process parameters, the multi-level contact holes with aspect ratio range from 2.5/1 to 30/1 on staircase can be achieved at one etching time, and each stop layer loss is less than 50%.

This paper presents a high-gain, low-power amplifier based on cascade structure and clock-control technique for MEMS acceleration sensor readout circuit. By controlling the clock signal, the amplifier has a superior performance. With ±5 V power supply, using the 0.5 um CMOS process technology, the Cadence simulation shows that, the total gain is about 167 dB with the unity gain bandwidth of 2.63 MHz. The power consumption of the amplifier is only 127.5 uW, which significantly reduces the whole power of the circuit.

A low noise voltage reference is designed in this paper. The voltage reference structure is realized by using a low noise bandgap reference and a low pass filter. A +/− 3.7V voltage reference chip with low noise has been fabricated in a standard CMOS 0.5µm technology. By selecting suitable feedback resistance of the amplifier, the two measured results show that the noise of voltage reference VRP is reduced from 82.16µV to 8.58µV and the noise of voltage reference VRN is reduced from 146.12µV to 9.1µV.

Phytoremediation is an relatively low cost, energy efficient, pleasing method of remediating heavy metals contaminated soil compared to other traditional remedial methods. It has been the reseach focus of the environmental scientists. This article views about the phytoremediation effect of strengthening measures through adding the EDTA, Citric acid, tartaric acid into the soils etc. and some other additional measures, such as fertilization, irrigation, plant cultivation and so on. The results of the measures' mechanisms and application discussed here provided a technical reference for the reseach and application of improving the phytoremediation efficiency.

In sewage treatment, the application of the denitrifying phosphorus removal technology which has played a positive role in the modern wastewater treatment has the advantages of reducing the amount of aeration, saving energy, reducing the amount of sludge and saving cost etc; Especially it can solve the problems of water C/N, C/P which are on the low side in south China. The paper is mainly about the theory of DPB, mechanism, analysis of the technology's effects to carbon source, nitrate, nitrite, temperature, pH and ORP, sludge age and hydraulic detention time etc. It also analyzes the research progress of denitrifying phosphorus removal technology.

The paper describes typical structures of conductive adhesives and anisotropic conductive adhesive film. A tailored conductive particle with optimum loading is important to a good-performance adhesive. The paper also discuss typical applications in electronic devices for solving electrical connection issue, ESD grounding issue, EMI shielding issue and particular for anisotropic conductive adhesive's special application for flex bonding, chip bonding to PCB or glass surface. The diversity of conductive adhesives provides many effective solutions to solve design or assembly issues.

This paper presents the methods and results of a simulation study of voltage stability of a power system. Important load and reactive power components are included. A nine-machine electric power system is chosen as the working example so that the dynamic interactions among machines in a system are adequately represented. Since it is a very high-order system with many nonlinearities and variable constraints and including both fast transients and slow dynamics, a variable step size is chosen for the integration and a new method is developed to solve the Jacobian matrix equations in each integration step without taking the inverse of a very large matrix directly. Case study results show that all voltage-dependent load and reactive power components are important and must be adequately modeled in voltage stability studies. >