Rui Xia Yang

The Parameter Estimate Method to Determine the Optimal Thickness for DSSC Electrode

For physical structure of TiO2 films is the core of photoelectric conversion on the photovoltaic performance of DSSC, the method by parameter estimate to determine the optimal thickness of DSSC working electrode is deduced, which is consistent with the analysis of real physical meaning about the TiO2 layer thickness and the photocurrent, while gives the specific optimal value as an addition. As a mathematical proof of the optimal conclusion extracting from the complex working mechanism of DSSCs and accidental factors, the equivalent circuit parameters of each curve are estimated corresponds to the equivalent circuit method first. According to the inflection point, which obtained through the synthesis of scattered experment points to the trend curve, the optimal thickness of DSSC working electrode are optimal identified.

Study on CMP Test Technology of 65 nm and below Node Wafers with Copper Interconnects

It is of significance to research high-removal efficiency and low-cost CMP process for the 65 nm and below node. Chemical mechanical polishing (CMP) can realize the planarization of the wafer with free defects, free contamination and below nanometer level roughness. Test project of CMP slurry is main contain of these detections such as pH value, chelating agent content, SiO2 gel particle size, ζ-potential detection and the observation by Transmission electron microscopy (TEM). End point detection method of pattern wafer CMP usually includes the non destructive optical measurement, motor current feedback measurement and polishing pad temperature test. The main problems of the measurement for pattern wafer CMP are critical dimension (CD), section, film thickness, defects and particles measurement. Some of the new type of testing technology, such as atomic force profiler (AFP), can be used to compare CMP effect, such as dishing, erosion, tungsten plugs, the height of steps and flatness of the wafer, which is significant for wafer CMP research.

A Method to Determine the Optimal Solids Content of TiO2 in DSSC Working Electrode

The way to determine the optimal solids content of TiO2 in DSSC working electrode was discussed. As a mathematical proof of the optimal conclusion extracting from the complex working mechanism of DSSCs and accidental factors, the equivalent circuit parameters of each curve are estimated corresponds to the equivalent circuit method first. And then, the trends in each parameter are analyzed. According to these trends, the optimal solids content of TiO2 are optimal identified

Fabrication of Microfluidic Chip and Test of a Hydro-Focusing Based on Sheath Flow

Silicon etching is an essential process step for the fabrication of micro-electro-mechanical systems (MEMS). However, the rough edge of the silicon etching technology has some resistance to microspheres. This study presents fabrication process of the SU-8 photoresists mold which provides sharp edges and smooth sidewalls of the channel and details the RIE bonding of PDMS and glass substrate to realize the fabrication of microfluidic chips. This paper also investigates the hydrodynamic focusing and microsphere single-pass based on sheath flow with the aid of the plunger piston, which is important to the further combination of the microfluidic chip and the flow cytometry.

Prepared for GaAs PHEMT Material

In this paper, GaAs PHEMT samples are prepared by the method of molecular beam epitaxy (MBE), The optimal parameters are determined by studying the impact of the barrier layer thickness, spacer layer thickness, Al composition of the barrier layer and the spacer layer , the channel thickness and channel In composition on Ns and μn.

Surface Measurement of GLSI Wafer with Copper Interconnects after CMP

Chemical mechanical polishing (CMP) is the best global planarization technology of GLSI process. After CMP process, there may appear large roughness, micro scratch, dishing pit, erosion pit, with-in-wafer-non-uniformity (WIWNU), organic contamination, particles and metal ions pollution on wafer with copper interconnects. Surface measurement of CMP process on the wafer mainly involves the test of roughness, defects and the contaminations. Atomic force profiler (AFP) combined with the resolution of the AFM and long-range-scan ability of the steps instrument (100 mm), is suitable for CMP process which needs to measure both the planarization of long-range scanning and tungsten plug and copper interconnects with high resolution imaging. Optical detection technology combined with the advantages of dark and bright view detection is suitable for detection of particles, crystal originated pits (COP), defects, etc. The time-of-flight static secondary ion mass spectrometry (TOF-SIMS) and total reflection X-ray fluorescence (TXRF) are applicable to detect metal ions. The selection and use of advanced data analysis theory and method can help to improve the speed of analysis and to find the main factors of influence surface quality. Pareto diagram analysis is very beneficial for study polishing effects and the main reason of the surface state for Cu-CMP wafer. Nine sampling method and five sampling method fit to analysis the uniform surface distribution, on the contrast isometric sampling can reflect the distribution of the surface state along the radius difference.

Characterization of Wafer Surface Topography after CMP

Characterization of the surface morphology after CMP vital refers to the roughness of surface outline at present. The two dimensional parameters characterization based on scanning the outline of surface as the test foundation already cannot satisfy the requirements of engineering; hence three dimensional detection and quantitative calculation of surface morphology can complete characterization. Characterization of surface morphology has made great development from low to high precision accuracy, from a single variety of touch probe to optical, atomic force, and other varieties, from the contact to non-contact, from two dimensions to three dimensions, from a single roughness measurement to simultaneously measurement of waviness, shape error outline information. Scanning probe microscopy can give surface topography of the whole measured area. Because discrimination all can reach the nanometer level surface roughness in x, y and z three directions, Scanning probe microscopy is suitable for measured structure with vertical structure units in nm magnitude and horizontal area in μm scale.

Low-Cost Heat Insulating Film Design for BIPV Modules Based on Multi-Layer Inorganic Materials

By analyzing the transmitionce and heat rate of insulating antireflection films conposed by refractive-index adjustable SiO2 layer and TiO2 layers, the optimum combination of antireflection films of BIPV is obtained. The absorption rate at the ultraviolet part that wavelenght excessive inadequate 400nm of the optimized fils is 99.9%, which are directly designed on the surface of the low iron tempered glass panel of BIPV, and in the wavelength range 400nm-800nm, the visible light transmitionce rate is up to 99.5%, and the heat that wavelenght excessive 800nm is reflected of 20%. For the multilayer heat insulation films are composed with the same kind of material while with different refractive indexes, there is no projecting stress between these films and no constraints during the production process of different films for the possible low cost heat insulating of BIPV.

Estimating the Threading Dislocation Density of Thick GaN Films

The threading dislocation density (TDD) of thick GaN films grown by hydride vapor phase epitaxy (HVPE) was estimated through counting etch pit density (EPD) and calculating full width at half maximum(FWHM)of double crystal X-Ray diffraction (DCXRD). TDD was about 108 through counting EPD, while it was about 109 through calculating the FWHMs of (0002) and (10î2). The experiment results show that the two methods are both suited to estimating the TDD of the thick HVPE-GaN films with 350um thickness. But they have some difference: EPD method is fitter in evaluating the dislocation density of the surface of thick GaN film, but FWHM method can gain the total dislocation density of thick GaN film. The method calculating the FWHMs possesses more general statistical significance.

TiCl4 Treatment to the Substrate of Dye-Sensitized Solar Cell for the Applications on BIPV

The process of TiCl4 treatment on the FTO substrate of DSSC were analyzed and the microstructures of substrates before and after treatment were observed. Further more, the influence of TiCl4 treatment on the substrate of Dye-sensitized solar cell to photo-current voltage performance was numerical analyzed.