Phase change memory (PCM) cells based on Ge2Sb2Te5 were synthesized and investigated. Currentvoltage measurements demonstrated different final resistances. Transmission electron microscopy (TEM),high resolution electron microscopy (HREM) and the energy dispersive X-ray spectroscopy (EDS) analyses were used to characterize the microstructures of the PCM cells. The architectures,structures and defects in the cells including the deposited elemental distributions and the interfacial structures between electrodes and barrier layers were studied in detail.
WANG KeHAN XiaoDongZHANG ZeWU LiangCaiLIU BoSONG ZhiTangFENG SongLin
We report on the investigation of the origin of high oxide to nitride polishing selectivity of ceria-based slurry in the presence of picolinic acid.The oxide to nitride removal selectivity of the ceria slurry with picolinic acid is as high as 76.6 in the chemical mechanical polishing.By using zeta potential analyzer,particle size analyzer,horizon profilometer,thermogravimetric analysis and Fourier transform infrared spectroscopy,the pre-and the post-polished wafer surfaces as well as the pre-and the post-used ceria-based slurries are compared.Possible mechanism of high oxide to nitride selectivity with using ceria-based slurry with picolinic acid is discussed.
We report on new experimental results for below-diffraction-limited hybrid recording.In our experiments,by means of focused laser assisted magnetic recording,the magnetic domains within TbFeCo thin films are obtained under an external perpendicular direct magnetic field.For a single magnetic medium,the domain size is mainly determined by the focused spot,which is about 620 nm for the laser wavelength λ=406 nm,and a numerical aperture of the lens of 0.80.However,when a silicon thin film structure is inserted between the substrate and the magnetic medium,the recording domains can be reduced obviously.By optimizing the experimental condition,even the size can be reduced to about 100 nm,which is below the diffraction limit,i.e.about 1/6 of the spot size.This is very useful for improving the hybrid recording density in practical applications.
