Vacuum Deposition of Dielectric and Semiconductor Films by a CO(2) Laser.

The paper describes a technique for producing thin films by high vacuum evaporation with a CO(2) laser of continuous emission at lambda = 10.6 micro. It is shown that at this wavelength many dielectrics are highly absorbing and that several semiconductors become sufficiently absorbing at elevated temperatures to allow their evaporation by intense irradiation. The arrangement used for focusing the laser beam on the evaporant is described. The optical properties of films of SiO, SiO(2), MgF(2), Al(2)MgO(4), and Te produced by the CO(2) laser evaporation technique are discussed. It is demonstrated that SiO(2) films prepared by this technique are undecomposed and nonabsorbing in the uv. The future capabilities and the unique advantages of this technique for producing extremely clean films under ultrahigh vacuum conditions are outlined.