Browse Prior Art Database

Method of Depositing Laser Ablated Films

IP.com Disclosure Number: IPCOM000120194D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 49K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+3]

Abstract

Synthesizing high quality superconducting thin films requires techniques that will satisfy stringent needs with respect to film stoichiometry, crystal phase, smooth surfaces, high Tc, small transition widths, and high critical current densities. Numerous deposition techniques have been tried and the one that appears to be the most promising is Pulsed Laser Deposition (PLD). The major problem that exists with PLD, however, is the presence of particulates in the film, whose typical size is on the order of one micron. Attempts to reduce or eliminate this rough surface morphology thus far have not proved satisfactory.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

Method of Depositing Laser Ablated Films

      Synthesizing high quality superconducting thin films requires
techniques that will satisfy stringent needs with respect to film
stoichiometry, crystal phase, smooth surfaces, high Tc, small
transition widths, and high critical current densities.  Numerous
deposition techniques have been tried and the one that appears to be
the most promising is Pulsed Laser Deposition (PLD).  The major
problem that exists with PLD, however, is the presence of
particulates in the film, whose typical size is on the order of one
micron.  Attempts to reduce or eliminate this rough surface
morphology thus far have not proved satisfactory.

      The particulate problem is a result of laser ablated fragments
that are ejected along with the dense high pressure plasma or plume
of target material.  The fragments typically travel at velocities on
the order of 105 cm. per sec.

      Disclosed is a method that introduces target material that is
travelling at a velocity comparable to that of the fragments, and is
synchronized to the firing of the pulsed laser, providing a small
amount of superconducting material that is ablated, creating the
plume, but providing the fragments with sufficient velocity to
continue to travel perpendicular to the plasma.  A Plasma Arc sprays
material into a stream, travelling at 105 cm.  per sec.  The material
is ejected in bursts of one microsecond.  The particle size is on the
order of 25 to 50 microns in...