Effect of Implantation Dose and Annealing Time on the Formation of Si Nanocrystals Embedded in Thermal Oxide
- PDF / 68,371 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 80 Downloads / 182 Views
1020-GG07-19
Effect of Implantation Dose and Annealing Time on the Formation of Si Nanocrystals Embedded in Thermal Oxide Cong Qian1, Zheng-xuan Zhang2, Feng Zhang2, and Cheng-lu Lin2 1 National Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and and Information Technology, Chinese Academy of Sciences, Rm 514, No.6 Building, No.865 Changning Rd, Changning District, Shanghai City, P.R. China, Shanghai, 200050, China, People's Republic of 2 Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China, People's Republic of ABSTRACT Photoluminescence (PL) and X-ray Photoelectron Spectroscopy (XPS) are employed to study the Si nanocrystals formed in the thermal oxide by Si+ implantation. PL results estimate the size of nanocrystals and the concentration of Pb centers in the Si-SiO2 nanocrystal-matrix interfaces. It is shown that the size of Si nanocrystals increase with implantation dose. Increasing the dose from 1×1016 to 1×1017 Si+/cm2 shifts the size of nanocrystals from ~2 nm to ~3.5nm, while prolonging the annealing time from 1h to 2h has no effect on the position of PL peak. P and Ar implantations into the SiO2 films are also investigated to suggested that the PL peak is due to implant induced chemical changes rather than implant induced damage. XPS analysis shows that the concentration of Si nanocrystals increases with Si implantation dose. Research on the annealing dependence of the forming of Si nanocrystals suggests that 1000 annealing produces larger amount of Si nanocrystals than 1100 annealing.
℃
℃
INTRODUCTION Si nanocrystals(or nanoclusters) embedded in SiO2 films have attracted much attention recently[1], which exhibit new quantum phenomena and have potential applications in optoelectronic devices, single electron memory devices and other single electron devices. A promising techniques for producing Si nanocrystals is Si ion implantation into SiO2 films grown by thermal oxidation of a Si wafer [1]. The PL spectrum arising from the Si nanocrystals has been an important method to investigate these structures. The wavelength of the peak PL emission has been shown to be correlated with the diameter of the nanocrystals, redshifting from ~700 to ~870 nm as the average nanocrystals diameter increases from 3 to 7 nm [2]. The redshifting can be explained as resulting from quantum confinement effects [3]. It was reported [2] that the PL intensity inversely correlates with the amount of Pb paramagnetic centers at the Si-SiO2 nanocrystalmatrix interfaces, which can be measured by electron spin resonance(ESR).
EXPERIMENT Sample preparation The samples studied were 380-nm-thick thermal oxides grown on 10-25 ohm·cm p-type Si (100) substrates at 1000 . The energies of implanted Si are 50, 75, 100, 125 and 150keV. According to the TRIM simulation, the Si peak concentration are about 90, 135, 180, 225 and 270 nm below the surface of the thermal oxide, corresponding to the five implant energies respectively. The implantatio
Data Loading...
