Browse Prior Art Database

Generation of Particles From Thin Films and High Energy Source

IP.com Disclosure Number: IPCOM000122534D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 83K

Publishing Venue

IBM

Related People

Baseman, R: AUTHOR [+3]

Abstract

Disclosed is a method of generating particles of essentially arbitrary size and composition using the impingement of radiation on thin films. Energy sources useful for particle generation include lasers, ion beams, electron beams, neutral particle beams, incoherent photon sources, and other subatomic particle beams. The specific preferred source depends upon the nature of the thin film and the type of particles desired. Thin films useful for particle generation can be single or multilayer, and chemically homogeneous or heterogeneous, depending on the particles desired. Alternatively, bulk samples can be used in the place of thin films. Without loss of generality, the following describes the use of a frequency doubled Nd:YAG laser as the energy source, and the use of single layer, chemically homogeneous thin films.

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Generation of Particles From Thin Films and High Energy Source

      Disclosed is a method of generating particles of
essentially arbitrary size and composition using the impingement of
radiation on thin films.  Energy sources useful for particle
generation include lasers, ion beams, electron beams, neutral
particle beams, incoherent photon sources, and other subatomic
particle beams.  The specific preferred source depends upon the
nature of the thin film and the type of particles desired.  Thin
films useful for particle generation can be single or multilayer, and
chemically homogeneous or heterogeneous, depending on the particles
desired.  Alternatively, bulk samples can be used in the place of
thin films. Without loss of generality, the following describes the
use of a frequency doubled Nd:YAG laser as the energy source, and the
use of single layer, chemically homogeneous thin films.

      The invention is comprised of an apparatus consisting of a
laser, an optical system, a thin film sample, and an operating
procedure whereby particles of controllable composition and size
distribution can be deposited in gases, liquids and on surfaces. In
the operating procedure, the medium of choice is placed just opposing
the thin film area to be irradiated.  The thin film is deposited on a
substrate which is transparent to the laser radiation of choice,
i.e., quartz works for 532 nm.  Such a film can be deposited using a
variety of well known techniques including evaporation or sputtering.
A laser pulse is delivered through the optical system to the surface
of the thin film of material with the desired composition.  The
penultimate optical element of the system is a mask which selects a
portion of the beam and determines the total mass of material to be
ejected into the medium.  The portion of the thin film which absorbs
the radiation is ejected as particulate matter into the medium. The
ejection of particulate into gases is st...