Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/02—Details
  • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement, ion-optical arrangement
  • H01J37/08—Ion sources; Ion guns
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J27/00—Ion beam tubes
  • H01J27/02—Ion sources; Ion guns
  • H01J27/16—Ion sources; Ion guns using high-frequency excitation, e.g. microwave excitation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/06—Sources
  • H01J2237/08—Ion sources
  • H01J2237/0815—Methods of ionisation
  • H01J2237/0817—Microwaves
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/06—Sources
  • H01J2237/083—Beam forming

Definitions

• Device for creating an adjustable energy ion beam in particular for processing on parade and under vacuum of large surfaces.
• the present invention relates to a device for creating an adjustable ion beam of energy, in particular for processing on parade and under vacuum of large surfaces.
• the processing on parade of a sheet consists of moving the latter in the field of a stationary ion beam, so that the ion beam scans the entire surface of the sheet. Depending on the density of the ion beam, the sheet is moved at an appropriate speed to obtain the desired bombardment.
• the present invention aims to provide a device capable of providing a dense ion beam of large width and of good homogeneity, which is therefore particularly suitable for the treatment of large surfaces on parade.
• the subject of the present invention is a device for creating an ion beam, in particular for treating parade of large surfaces, comprising an ionization chamber into which a gas can be introduced to undergo the action of a field.
• excitation means capable of establishing the high frequency alternating electric field at l interior of the ionization chamber, being connected by a waveguide to a microwave generator, characterized in that said excitation means comprise a conductive box attached to a wall of the ionization chamber , the interior of this box being divided into a first part, opposite the ionization chamber, in which opens the waveguide, and a second part, adjacent to the ionization chamber, in which are substantially distributed substantially identical cylindrical conducting cavities, open at their two ends, and whose longitudinal axes are mutually parallel and perpendicular to said wall of the ionization chamber, each cavity comprising an adjustment member capable of adjusting the amount of microwave energy passing through said cavity.
• cylindrical cavity means a cavity whose cross section is constant. This section can be of any shape, and preferably rectangular.
• the excitation means according to the invention constitute a power divider which has the function of distributing the energy supplied by the microwave generator between the different cavities, which each constitute an independent waveguide which radiates , at its opening adjacent to the ionization chamber, in said ionization chamber.
• the cavities being substantially identical, they emit the same amount of energy in the ionization chamber.
• the electric field generated in the ionization chamber has good homogeneity.
• the cavities are aligned in two rows parallel to the large dimension of the face of the ionization chamber which is located opposite the extraction optics, and are staggered between these two rows.
• the displacement of the parts to be treated in a direction perpendicular to the two rows of cavities makes it possible to further improve the homogeneity of the ionic treatment of each part, because the less dense areas of the first row are compensated by the densest areas of the second row, and vice versa.
• the ionization chamber is separated from the conductive box by a dielectric window which is impermeable to the gas to be ionized and is permeable to electromagnetic waves.
• the dielectric window tends to metallize and thereby lose its dielectric properties. This may result in a degradation of the effectiveness of the device.
• the device according to the invention comprises a large dielectric window which constitutes an expensive part and difficult to replace.
• the axis of the extraction optic is inclined relative to the longitudinal axis of the device, so as to prevent possible metallic particles emitted by the surface. of the part being treated to reach said dielectric window.
• the outer wall of the ionization chamber includes permanent magnets which have the effect of creating a static magnetic field in the ionization chamber.
• the efficiency of ionization is increased by the known phenomenon of cyclotron electronic resonance.
• FIG. 2 is a sectional view along II-II of FIG. 1,
• FIG. 3 is a view similar to FIG. 1 of a device according to a second embodiment of the invention.
• FIG. 4 is a sectional view on a larger scale according to IV-IV of FIG. 3.
• the device shown in the drawing comprises "r.e ionization chamber 1 into which a gas can be introduced through an orifice 2.
• Chamber 1 which is parallelepipedic, is elongated in a direction X.
• An extraction optic 3 preferably comprising three grids is placed in front of one of the faces 1a of the ionization chamber.
• the axis of the grids is parallel to the longitudinal axis of the device.
• the ionization chamber On its face 1b opposite to the face 1a, the ionization chamber comprises a wall made of a dielectric material, permeable to microwaves, for example quartz, which constitutes a dielectric window tight against vacuum, and therefore gas, sense of invention.
• a dielectric material permeable to microwaves, for example quartz, which constitutes a dielectric window tight against vacuum, and therefore gas, sense of invention.
• Permanent magnets 5 are arranged on the two large side faces lç_ of the ionization chamber.
• a power divider 6 is applied against the face 1b of the ionization chamber 1.
• This power divider 6 comprises an electrically conductive box 7, shown diagrammatically in broken lines, with the same cross section as the ionization chamber 1. According to the invention, the interior of the box 7 is divided into a first part 8 opposite to the ionization chamber 1 and a second part 9, contiguous to the first and adjacent to the ionization chamber 1.
• a waveguide 10 opens out inside the box 7 in its first part 8.
• This waveguide 10 is connected to an impedance adapter 11, which advantageously comprises three tuning pistons 11a, and is itself even powered by a microwave generator not shown.
• the second part 9 of the box 7 comprises cylindrical conductive cavities of rectangular section of the same dimensions which are constituted by a single wall 12, parallel to the direction X, and extending over the entire length of the box 7, and by partitions 13 , perpendicular to the wall 12, arranged on either side of the latter.
• the wall 12 and the partitions 13 are electrically conductive.
• the cavities 14 thus defined in the second part 9 of the box 7 have the same dimensions.
• the cavities 14 are thus aligned on two parallel rows 15a and 15b and are furthermore staggered between these two rows.
• the box 7 also comprises, on its large side walls, adjusting screws 16 which each open into a cavity 14.
• the part of each adjusting screw 16 which opens into the corresponding cavity 14 constitutes an obstacle to the passage of microwaves, so that by more or less screwing this screw 16, the amount of energy which passes through said cavity 14 is regulated.
• the cavities furthest from the mouth of the waveguide 10 can radiate in the ionization chamber 1 substantially the same amount of energy as the cavities located near the mouth of the waveguide 10.
• the unused spaces 17 are occupied by conductive shims made of brass or aluminum 18, in the form of a parallelepiped, truncated along a diagonal plane.
• the wedges 18 are arranged in each space 17 with their base applied against the wall 4 of the ionization chamber.
• each shim 18 increases from the interface between the parts 8 and 9 of the box 7 in the direction of the ionization chamber 1. In this way, any reflections of waves in the first part are avoided. 8 of the box, which could disturb the distribution of energy between the cavities 14.
• FIGS. 3 and 4 show a second embodiment of the invention in which the extraction optic 3 ′, which also consists of three grids, is positioned with its axis ⁇ inclined relative to the axis longitudinal of the device.
• the ionization chamber l has the shape of a half-parallelepiped whose cross section is a rectangle and whose front face is inclined, as seen in Figures 3 and 4, by compared to its rear side the b.
• this arrangement of the extraction optics 3 prevents possible metallic particles emitted by the surface of a part 20 subjected to an ion beam delimited by two lines mixed 21 to reach the gas-tight window 4.
• the trajectories 19 of the metallic particles which pass through the extraction optics 3 in the opposite direction of the ion beam end up on one of the side walls ç. the ionization chamber.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Analytical Chemistry (AREA)
• Electron Sources, Ion Sources (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9465003

Family Applications (1)

Country Status (5)

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Family Cites Families (8)

• 1994
  • 1994-07-05 FR FR9408279A patent/FR2722213B1/fr not_active Expired - Fee Related
• 1995
  • 1995-07-05 EP EP95925012A patent/EP0769201A1/de not_active Withdrawn
  • 1995-07-05 US US08/765,348 patent/US5754008A/en not_active Expired - Fee Related
  • 1995-07-05 JP JP8503710A patent/JPH10506220A/ja active Pending
  • 1995-07-05 WO PCT/FR1995/000900 patent/WO1996001490A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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