The current-neutralization fraction of a rotating and propagating light ion beam (LIB) injected into a low density plasma is investigated numerically. The beam space charge is essentially neutralized by a redistribution of the background plasma electrons in a time duration equal to the inverse of electron plasma frequency. When the density of the background plasma is comparable with that of the beam, incomplete current neutralization occurs because the strong magnetic field induced by the intense ion beam restricts the return plasma current.

In the simulation, the ion beam and the background plasma are treated as the fluids coupled with Maxwell's equations and Ohm's law, including the effect of the magnetic field on electrical conductivity. The calculations assume that the ion beam is injected in an unsteady fashion into the uniform plasma. It is found that the return current strongly depends on the density of the background plasma. The beam deceleration and the acceleration of the beam head and tail are also considered.

Focusing processes of rotating and propagating proton beams in a neutral hydrogen gas are studied numerically by using a two-dimensional hybrid code. Processes including beam impact ionization, plasma avalanche and field emission are taken into consideration. The plasma formation time depends on the initial gas density and the beam intensity. When 2-Torr neutral gas is filled initially, enough plasma density is created by the rising part of the beam pulse, so that the main pulse is focused and forms a rotating and propagatingbeam configuration.

Rotating motion of a propagating LIB is analyzed in order to suppress the mixed mode of the Kelvin-Helmholtz instability, the tearing instability and the sausage instability by the action of a self-induced magnetic field in the axial direction. The beams are assumed to be charge-neutralized but not current-neutralized. The steady-state solutions of a propagating LIB with rotation are first obtained numerically. Through the dispersion relation with respect to the ikonal type of perturbations, which are added to the steady-state solutions, the growth rates of instabilities appearing in an LIB are obtained. It is concluded that if the mean rotating velocity of an LIB is comparable to the propagation velocity, in other words, if the induced magnetic field intensity in the axial direction is comparable to the magnetic field intensity in the azimuthal direction, the instability disappears in the propagating ion beam.

Focusing processes of a rotating and propagating light ion beam in the drift region are studied numerically by using a 2-dimensional hybrid (particle–fluid) code. An intense ion beam with the current density of 8 kA/cm2 and the total current of 2·5 MA, which is extracted from the diode with the applied voltage of 5·6 MV, is injected into the drift region filled with a low-density plasma. When a radial magnetic field is applied to the neighborhood of entrance, the beam ions start to rotate in the azimuthal direction owing to the Lorentz force. When the pressure of the background plasma is chosen such as the density of the beam becomes comparable with that of the background plasma in the vicinity of the focal spot, the current-neutralization fraction decreases and large self-magnetic fields are induced. The beam is confined by the fields within a small radius, even after passing the focal spot. Because the angular momentum of the beam is conserved, the beam rotation velocity increases up to the same order of the propagation one at a few mm radius. This rotation motion induces the azimuthal magnetic field and stabilizes the beam propagation. In the case where the plasma pressure was 3·0 Torr and the 0·2-Tesla radial magnetic field was applied over the distance of 2·0 cm near the entrance, the maximum beam intensity of 108TW/cm2 in the axial direction was obtained and the half width at half maximum (HWHM) of the focused profile was 3·5 mm.

We have investigated MSA, namely, Laser Spike Annealing (LSA) and Flash Lamp Annealing (FLA), dopant activation technology of source/drain extension for 45 nm node, which can be substituted for spike RTA. Since it is possible to achieve a similar relation between a sheet resistance and a junction depth by using either FLA or LSA, both annealing methods are capable of providing the junction characteristics required by the ITRS target. However, we have noticed that there are three crucial issues from the viewpoints of device integration and CMOSFET performance: junction leakage current, gate leakage current and pattern dependence. In this report, we discuss these issues and indicate how to cope with them.