1. Ion-Matter Intraction:
IBM is a major technique for synthesis of different phases and alloys under different processing condition. The synthesis of metal silicides are important as contact and interconnect materials in semiconductor device technology. We have studied Fe-Si, Co-Si, Au-Si, Fe-Cr and Cu-Ge system for silicide and alloy formation respectively.
2. Synthesis, Structural and Optical studies of Si, and SiO2:
In this area we mainly concentrated on synthesis and understanding the associated mechanism of epitaxial growth and regrowth of Si and SiO2. We used the energetic ions both for modification of the materials and characterization of the modified layer. The heavy ions in the energy range of 200 keV to 100 MeV has been handled at different stage of the study. Doping of Ge ions into single crystalline alpha-quartz without destroying the crystalline structure have been studied. Along with ion-matter interaction study we also used Micro-Raman, photo and cathodoluminecsence to observe the structural and light emitting properties of Si and SiO2 respectively. The surface modification has also been studies by AFM and the route of the light emission has been investigated by using Transmission Electron Microscopy (TEM). TEM has been employed for studying nanosilicon embedded in the amorphous and crystalline matrix. The mechanism of the Ion beam induced epitaxial crystallization (IBIEC) and dynamic annealing (DA) has been modeled and compares with thermal annealing behavior.
3. Synthesis of 1-D, 2-D and 3-D Nano-materials:
In this area we mainly concentrated on synthesis and understanding the associated mechanism for different applications with interesting properties, like electron-phonon-transport, photoluminescence, aborption and non-linear properties. We have developed ZnO and AuSi compound nano particle and nanowires using special techniqus.
4. Nano-Photonic (Sub-wavelength optics):
Extreme ultraviolet interference lithography (EUV-IL) is a newly developed technique for the production of periodic nano-structures with resolution below 50 nm. The technique is based on coherent radiation that is obtained through undulators at synchrotron radiation laboratories. The high resolution is afforded by small wavelength and practical absence of the proximity effect at this energy. The throughput of this parallel exposing method is much higher than that of the serial electron-beam lithography. Interference schemes based on both reflection (mirrors) and diffraction (gratings) optics have been realized. Both one-dimensional and two-dimensional patterns such as arrays of dots have been achieved. Periodic Au nano-dots are patterned using X-Ray interference lithography and studied the surface plasmon sub-wavelength optics.
The FDTD simulation of the nano-patterns for understanding its plasmonic and sensor application is also an important aspect of our group.