AVS 50th International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoA

Paper PS-MoA2
Next Generation RF Ion Beam Source for Three-Dimensional and other Critical Etching Applications

Monday, November 3, 2003, 2:20 pm, Room 314

Session: Plasma Sources
Presenter: A.V. Hayes, Veeco Instruments, Inc.
Authors: A.V. Hayes, Veeco Instruments, Inc.
V. Kanarov, Veeco Instruments, Inc.
R. Yevtukhov, Veeco Instruments, Inc.
C. Borges, Veeco Instruments, Inc.
K. Williams, Veeco Instruments, Inc.
M. Campo, Veeco Instruments, Inc.
B. Druz, Veeco Instruments, Inc.
Correspondent: Click to Email
Rf plasma broad ion beam etch technology is used in manufacturing of magnetic, optical, and other types of thin film devices due to its unique capabilities to etch difficult materials and control ion energy and incidence angles. Requirements for increased critical dimension (CD) control and directional "static etch" processes have started to exceed the ion current density and directionality uniformity capabilities of conventional ion sources. "Static etch" processes in which the substrate is tilted at ion incidence angles of up to 70°-80° with no or only partial substrate rotation, are particularly challenging, requiring the ion beam to be very uniform and collimated across a three dimensional space within the beam occupied by the wafer. Development of a novel rf ICP broad ion beam source with dynamic plasma magnetic field configuration designed to achieve these requirements will be described. In addition, the role of the beam divergence angle and other beam dispersion parameters on the CD and static etch uniformity will be discussed. Results will be measured in terms of etch uniformity on silicon oxide coated wafers and etch divergence using a shadow mask type measurement fixture. In an optimum configuration the source is capable of achieving a uniformity of less than 1% sigma/mean on a static wafer (about a 4-5X improvement compared with current technology sources) and less than 0.5% on a rotated wafer (a 2-3X improvement) with excellent repeatability. The full etch divergence angle is less than 3°, and uniform across the substrate within 0.5°. Other applications of this source could include uniform etching of features mounted on 3-dimensional substrates.