TRANSMISSION ELECTRON-MICROSCOPY AND SPECTROSCOPIC ELLIPSOMETRY STUDIES OF DAMAGE LAYER INDUCED BY LARGE TILT ANGLE ION-IMPLANTATION

Low energy ion implantation at large tilt angles is an attractive new technology for obtaining ultrashallow P-N Junctions for very large sca le integrated and vacuum microelectronic devices. Cross-sectional tran smission electron microscopy (XTEM), Rutherford backscattering spectro scopy and channeling, and spectroscopic ellipsometry were employed to study the damage behavior in silicon implanted with 10 keV arsenic ion s with the incident beam 7, 15, 30, 45, and 60 degrees off the [100] d irection, respectively. The thickness of the damaged layer is in good agreement with the stimulated results for R(p) + delta R, by TRIM-91, With increase of the implanting angle theta, the doped arsenic planar density decreases by a factor of cos theta. XTEM experiments and compu ter simulations indicate that a high critical energy (approximate to 6 to 8 eV) for damage is necessary for the transition from crystalline to amorphic states (C --> A).