Post CMP cleaning is necessary for contaminant removal after CMP process. The zeta potential of slurry particle and substrate has been considered to be a critical factor in terms of particle adhesion and removal. The fundamental research such as the calculation and measurement of adhesion forces between slurry particle and wafer surfaces can enhance the understanding of cleaning mechanism and development of cleaning process. The presence of more than two different materials during CMP introduces new defects at the materials interface, corrosion and severe scratches. Device specific chemistry and cleaning process should be introduced and developed for future and current CMP. The highest particle removal efficiency is observed when using cleaning solutions that yields the lowest adhesion force. The effect of frictional and adhesion forces attributed to slurry particles on the quality of Cu surfaces was experimentally investigated during metal CMP process. The magnitude of the adsorption of the organic acid on the slurry particle surfaces can have a significant effect on the frictional behavior as well as the adhesion force. Higher particle adhesion forces resulted in higher friction and might induce defects such as particle contamination and scratches on the polished surface after polishing. The magnitude of particle adhesion force on wafer surfaces in slurries can be directly related to the frictional forces and polished surface quality during CMP process. As low k and poly or bare silicon polishing introduced in fabrication process, the hydrophobicity of these surfaces could affect the defects after polishing. The control of wettability during and after polishing becomes more important in reducing the defects. The organic particles are major defects during metal and poly silicon CMP which may be caused by the surface reaction of organic sources with surfaces.

Silver nanoparticles dispersed in a silica matrix were made by the consolidation of a Ag-attached silica colloid, which was synthesized via the electrolysis of a pure Ag electrode, the reduction of Ag+ ions by H2, and the nucleation and growth of Ag particles on the silica nanoparticles in water. This simple process produced Ag/silica nanocomposites with a high concentration and narrow size distribution of nanoparticles, which was confirmed by transmission electron microscopy and x-ray diffraction. As estimated by Raman and photoluminescence measurements, the quantity of broken oxygen bonds was increased with increasing Ag concentration due to the intervention of Ag ions as structural modifiers in the silica network structure. Ag ions in the matrix are probably a residue of the Ag+ ions that could not be reduced by H2 during the electrolysis/reduction reaction. The optical-absorption spectra and the HCl-soaking test suggested that a chemical-interface damping effect, which was caused by electron transfer from the metal particles to the oxide matrix, dominates the optical-absorption properties in this system.

The crystallinity dependence of the microwave dielectric losses in (Ba,Sr)TiO3 thin films was investigated. The sputter-deposition temperatures were altered to vary the level of thin-film crystallinity on a Pt/Si substrate. The dielectric losses (tan δ) were measured up to 6 GHz without parasitic (stray) effects by using a circular-patch capacitor geometry and an equivalent-circuit model. The microwave dielectric losses increased from 0.0024 ± 0.0018 to 0.0102 ± 0.0017 with increasing crystallinity. These deteriorated dielectric losses showed a good correlation with the symmetry-breaking defects, as confirmed by Raman spectra at approximately 760 cm−1, inducing microscopic polar regions above the Curie temperature of the bulk (Ba0.43Sr0.57)TiO3.

In this study, Adhesion force and Nanotribological Characteristics of fluorocarbon (FC) films on Al deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) were evaluated. The contact angle of FC thin films on Al was measured to be around 110°. The surface energy was calculated to be 15 dynes/cm from the measurements of contact angles of polar and nonpolar solutions on surfaces. The contact angle hysteresis, which is an indicator for the surface heterogeneity, was lower than 30°. The friction force of FC films coated surfaces was three times lower than bare Al. The adhesion force of bare Al was measured to be around 9.6nN. The presence of FC films on Al reduced it to below 4nN. Fourier transform infra-red (FTIR) spectra showed the presence of fluorocarbon groups such as –CFn- and =CF=CF2.

We investigated the photoluminescence spectra as well as the crystal structure and optical energy gaps of the Zn1-xCdxAl2Se4 single crystals grown by the chemical transport reaction method. It was shown from the analysis of the observed x-ray diffraction patterns that these crystals have a defect chalcopyrite structure for a whole composition. The lattice constant a increases from 5.5561 A for x = 0.0 (ZnAl2Se4) to 5.6361 A for x = 1.0 (CdAl2Se4) with increasing x, whereas the lattice constant c decreases from 10.8890 A for x = 0.0 to 10.7194 A for x = 1.0. The optical energy gaps at 13 K were found to range from 3.082 eV (x = 1.0) to 3.525 eV (x = 0.0). The temperature dependence of the optical energy gaps was well fitted with the Varshni equation. We observed two emission bands consisting of a strong blue emission band and a weak broad emission band due to donor–acceptor pair recombination in the Zn1-xCdxAl2Se4 for 0.0 ⩽ x ⩽ 1.0. These emission bands showed a red shift with increasing x. The energy band scheme for the radiative mechanism of the Zn1-xCdxAl2Se4 was proposed on the basis of the photoluminescence thermal quenching analysis along with the measurements of photo-induced current transient spectroscopy. The proposed energy band model permits us to assign the observed emission bands.

We have studied the depositions of amorphous silicon, silicon carbon alloy, doped microcrystalline silicon in order to apply these films as the component materials for the p-i-n and double stacked solar cells. We have obtained low band gap a-Si:H by decreasing the deposition rate under the proper preparation conditions and highly conductive, thin microcrystalline Si and SiC layers. We have developed a stable a-Si/a-Si double stacked solar cell with a conversion efficiency of ∼ % using narrow band gap a-Si:H as a i-layer of bottom cell.The performance of this cell does not degrade until 100 hrs illumination under 350 mW/cm2.

We have studied the effect of RF power on the properties of Si thin films prepared by a conventional plasma and remote plasma(RP)- CVD. The structure of the Si film changes from amorphous to crystalline with increasing RF power in RP-CVD. However, the structure of Si film deposited by P-CVD remains amorphous with increasing RF power. The relaxation of Si atoms by means of chemical annealing of He metastable atoms gives rise to the formation of macrocrystalline structure at the high RF powers.

We studied the layer by layer deposition technique of a-Si:H film, where the hydrogen radicals are exposed between the deposition of each layer. The effects of each layer thickness and hydrogen radical exposure time on the electrical and optical properties were studied. With the decrease of the each layer thickness, more hydrogen is involved in the network if the structure is still amorphous, but the hydrogen content is very small for microcrystal Si formed by long exposure to hydrogen radicals in between the depositions of thin layers.

We have studied the improvement of the quality of undoped a-Si:H deposited by remote-plasma chemical vapour deposition. The effects of reactant gas concentration, rf power, substrate bias voltage on the electrical and optical properties have been investigated. Some hydrogen dilution of si lane improves the photoeletric property and a high rf power gives rise to the defect creation due to the ion bombardment on the growing surface. The positive substrate bias improves the quality of undoped a-Si:H.