Mass flow in laser-plasma deposition of carbon under oblique angles of incidence

The angular distribution of the mass flow in carbon laser plasmas, generated from graphite targets at laser power densities around 10¹¹ W/cm² and 1064 nm, was studied. Under oblique angles of incidence the mass flow is not perpendicular to the target surface but rather symmetrical around the bisecting angle between the laser beam and the surface normal. For all angles, however, a cos⁴-pattern is observed. Compared to normal incidence the mass flow is weaker by about a factor of 2 to 3 for 30° and 50° angle of incidence. The dependence of film quality on deposition angle with regard to the symmetry axis of the plume is demonstrated.Presented at LASERION '91, June 12–14, 1991, München (Germany)