Influence of Hf and H2O2 on Morphology of Silicon Formed by Ag Assisted Chemical Etching

The Ag-assisted electroless etching of p-type silicon substrate in HF/H2O2solution at room temperature was investigated. In this work, the effects of HF, H2O2and their volume ratio on morphology and growth of p-type silicon substrate surface by using metal assisted etching were investigated in order to produce a highly efficient antireflecting structure. The Ag metal particles were deposited onto Si wafer by electroless deposition from a metal salt solution including HF. The experimental results show that the growth rate and morphology of the pores formed on the Ag metalized Si surfaces are strongly dependent on the volume ratio of HF and H2O2.

EFFECT OF ANNEALING ON THE PROPERTIES OF VANADIUM PENTOXIDE FILMS PREPARED BY SOL–GEL METHOD

The vanadium pentoxide ( V 2 O 5) films were obtained by using sol–gel procedure and then were annealed at different temperature in air. The effect of different annealing temperatures on the composition, the microstructure, the surface morphology and the optical properties of the films were characterized by methods such as by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and spectral transmittance. The results revealed that the film annealed at 150°C has amorphous structure and dense with a smooth surface and the films annealed at 300°C and 450°C have a polycrystalline V 2 O 5 structure with preferred growth orientation along (001) planes, the c-axis and perpendicular to the silicon substrate surface. From the spectral transmittance we determined the absorption edge using the Tauc plot. The results indicated that optical bandgap of V 2 O 5 thin films decreased with annealing temperature.

Effect of FA/O Chelating Agent on Copper Ion Removing on Silicon Surface

Along with the feature size reducing and the increase of integration level rapidly in ULSI，the request for metal impurities contamination on silicon substrate surface appears specially rigorous. In this paper the chelating agent was added in cleaning solution in order to removing copper ion. FA/O, a new kind of chelating agent was studied in RCA cleaning solutions, which has 13 chelating rings and is free of sodium, stable and easily soluble. The XPS and GFAAS measured results indicate that FA/O is more efficient than NH4OH as a ligand. Cu contaminations on silicon wafer can be removed remarkably when adding a little FA/O to the cleaning solution or polishing slurry. When the chelating agent concentration of cleaning solution is 0.1% the removal rate of Cu atom reaches 83 percent. The FA/O chelating agent substituting NH4OH in SC-1 may simplify cleaning steps, and one cleaning step can remove Cu pollution on silicon wafer surface and meet the requirements of microelectronics technology.