Other

Kaufman & Robinson, Inc.

Raymond S Robinson

Harold R Kaufman

James R Kahn

Viacheslav V Zhurin

William E Hughes

In accordance with one specific embodiment of the present invention, a Hall-current ion source of the end-Hall type has an anode that is contoured with one or more recesses in the electron-collecting surface which have areas that are protected from the deposition of externally generated contamination thereon, as well as one or more protrusions that have higher temperatures than the bulk of the anode, thereby increasing the removal or passivation of coatings during operation by the thermal degradation of the coating and the effects of thermomechanical stresses. In another specific embodiment, which can be combined with the above embodiment, electrically isolated baffle or baffles are located to protect a substantial fraction of the electron-collecting surface of the anode from the deposition of externally generated contamination thereon.

Hall-current ion source

In one embodiment of the present invention, the ion optics for use with an ion source have first and second electrically conductive grids having mutually aligned respective pluralities of apertures through which ions may be accelerated and wherein each has an integral peripheral portion. There is also a support member. There are first and second series of seats around the respective peripheral portions of the first and second grids. A plurality of first spherical insulators are distributed between seats of the first and second series, thereby establishing a predetermined distance between the grids while still enabling radial movement between their peripheral portions. There are third and fourth series of seats around the support member and the peripheral portion of the second grid, respectively, with seats of the fourth series displaced from those of the second series in the same grid. A plurality of second spherical insulators are distributed between seats of the third and fourth series, thereby establishing a predetermined distance between the support member and the second grid while still enabling motion in at least the radial direction between the support member and the peripheral portion of the second grid. A clamping force between the support member and the peripheral portion of the first grid maintains contact between the insulators and their seats.

Ion optics

Ion-beam probes of the planar, screened, and multilayer types are shown and described. These probes can detect the arrival of energetic ions and, in the latter type, also detect the arrival of energetic neutral molecules. A specific improvement is the use of a multilayer collection surface behind an aperture to measure the angular distribution of the etching contributions of energetic ions and/or energetic neutral molecules. After use, this multilayer collection surface provides a permanent record of the measurement. The improvement is also suitable for the adverse thermal and ion-etching environment of an energetic ion beam. In one embodiment, the aperture size and distance from the collection surface are such that a theoretical analysis of etch depth behind a straight-edge mask can be used to analyze the experimental results. The etch contour can be accurately reproduced from the measurement of half-maximum half angle, as long as the assumed distribution is incorporated in the measurement process.

Angular distribution probe

A pair of dissimilarly-sized electrodes are driven by a radiofrequency source to create a plasma. A magnetic field is oriented to be parallel to a surface area on the smaller electrode. The field strength increases to either side of that smaller electrode. As shown, ions are electrostatically accelerated out of the plasma, but they instead may be accelerated magnetically, electrons may in the alternative be extracted or there may be no accelerating mechanism.

Capacitively coupled radiofrequency plasma source

A coaxial cable has a plurality of insulated beads threaded onto an inner conductor and individually having an exterior shape such that a gap exits between each adjacent pair of beads with the gap increasing in width radially. A conductive flexible braid ensleeves the beads with that braid having interstices ventive of air but preclusive of the passage of plasma. An insulative covering ensleeves the braid and also is ventive of air but preclusive of passage of the plasma. A connector includes a termination having a barrel-shaped body fitting over the outer cable conductor. An outer connector element projects outward from the outer end of the body with that element having longitudinal slots that define a circumferentially-spaced series of flexible fingers. Those slots are ventive of air but have a size sufficiently small to preclude passage of a plasma. An inner electrical connector element projects outwardly from the inner cable conductor beyond the body. Finally, a mating connector fitting defines interchangeable connective elements. An overhang shadow-shields otherwise exposed slots.

Coaxial vacuum cable

A cathode has a pair of cavities in which are disposed respective electrically isolated electrodes. An inert gas is introduced individually into the cavities. Individually outletting from those cavities are a pair of respective apertures. Radio frequency energy is applied to the electrodes to establish a plasma.

Radio frequency hollow cathode

An ion source has the typical chamber wherein ions are produced and caused to be propelled outwardly through at least a pair of grids which have a mutually-aligned respective plurality of apertures. Thus, there are the usual cathode, anode, magnet assembly, ionizable gas inlet and supporting power supplies as well as neutralizing means. First and second grids each have an integrally-formed peripheral marginal portion. A support element has a shape which matches and overlies the marginal portion of one grid, while a clamp has a shape which matches that of and overlies the other marginal portion. The support element and clamp are secured together. First and second mutually-aligned seats are successively spaced around the respective marginal portions. A plurality of insulators, each having of circular cross-section, are individually seated between the two different marginal portions in a manner to cause general alignment while enabling radial movement due to thermal expansion of the marginal portions relative to the support element and the clamp and each other.

Ion source with particular grid assembly

A gas, ionizable to produce a plasma, is introduced into a region defined within an ion source. An anode is disposed near one end of that region, and a cathode is located near the other. A potential is impressed between the anode and the cathode to produce electrons which flow generally in a direction from the cathode toward the anode and bombard the gas to create a plasma. A magnetic field is established within the region in a manner such that the field strength decreases in the direction from the anode to the cathode. The direction of the field is generally between the anode and the cathode. The electrons are produced independently of any ion bombardment of the cathode, the magnet is located outside the region on the other side of the anode and the gas is introduced uniformly across the region.

End-Hall ion source

A broad-beam electron source has a chamber into which is introduced an ionizing gas. Electrons are emitted between a cathode and an anode assembly to ionize that gas. The electrons within the plasma are drawn outwardly from the chamber through an apertured wall, which constitutes a screen, and thereafter are accelerated toward a target in a well-directed beam. A comparatively copious supply of electrons is developed, while yet requiring only low voltages in connection with its generation and resulting in correspondingly low electron energies. Ions produced external to the electron source itself are utilized to assist in neutralizing the charge density of the electron beam in order to help maintain its definition. For insulative targets, secondarily emitted electrons permit conservation of surface charge.

Broad-beam electron source

An electron-bombardment ion source includes means defining a chamber for containing an ionizable gas together with means for introducing such gas into that chamber. Disposed therein is an anode and an electron-emissive cathode. The potential impressed between the anode and the cathode to effect electron emission at a sufficient velocity to ionize the gas. Also included are means for accelerating ions out of the chamber together with means for establishing a magnetic field within the chamber that increases the efficiency of ionization of the gas by the electrons. Mounted within the chamber is an anode of non-magnetic material that defines an essentially continuous and smooth surface which encloses substantially all of the volume within which the ionization occurs except the exit for the accelerated ions out of the chamber. The entire design is such as to ensure ready removability of the different components for quick and easy cleaning.

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Fort Collins, CO, United States of America

Raymond S Robinson