Process and apparatus for converged fine line electron beam treatment objects

Claim 2

A process for heat treatment of a solid object of solid material having a major surface by means of electron beam energy, that comprises: generating and propagating electrons within a vacuum along a predetermined direction and in a linear beam that extends transverse to said direction; converging the beam into a fine line of intense charge; impacting the converged fine line beam upon said major surface of the object being treated; relatively moving said beam and object so that said beam relatively scans said major surface in a direction at right angles to said fine line; and regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the velocity with which the latter relatively scans said major surface such that a layer of said object at said major surface with a maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material underlying said layer is substantially precluded by limiting the time that any given location on said major surface is impacted by said beam.

Claim 3

A process as claimed in claim 1 and in which the said object is disposed in said vacuum.

Claim 4

A process as claimed in claim 1 and in which the converged beam is exited outside the vacuum and there impacted upon said object.

Claim 5

A process as claimed in claim 1 and in which said linear beam extends along substantially a straight line.

Claim 6

A process as claimed in claim 1 and in which said linear beam extends along lines of changing direction including curvalinear lines.

Claim 7

A process as claimed in claim 1 and in which the beam is adjusted to be of transverse length of from about 2 to 15 cm. or longer and converged to a width of the order of between substantially 10 -3 and 1 cm., or wider and the beam profile is adjusted to produce beam current densities of the order of up to about 1000 A/cm 2 under beam voltages with limits from about 1 to 30 Kv.

Claim 8

A process as claimed in claim 1 and in which the kinetic energy and flux of said beam and the energy density (fluence) absorbed by said object from said impacting beam are adjusted to effect at least one of annealing, welding, etching, curing, cutting, polishing and surface alteration.

Claim 9

A process as claimed in claim 1 and in which the beam is modulated in intensity during the scan.

Claim 10

A process as claimed in claim 8 and in which the beam is pulsed.

Claim 11

A process as claimed in claim 1 and in which the further step is performed of masking predetermined portions of the object from the beam during the scan.

Claim 12

A process as claimed in claim 1 and in which the effective rate of scan is varied during transverse of the object.

Claim 13

A process as claimed in claim 1 and in which the progress of the electron beam treatment of the object is monitored at the object and the treatment of the same is controlled in accordance with said monitoring.

Claim 14

A process as claimed in claim 1 and in which the length of the strip is adjusted substantially to correspond to a dimension of the object under treatment.

Claim 15

A process as claimed in claim 6 and in which the treatment time of the fine line beam upon any point of the object is of the order of microseconds.

Claim 16

A process as claimed in claim 1 and in which the beam is stationary and the object is moved past the fine line beam at velocities up to the order of about 1000 cm./sec.

Claim 17

A process as claimed in claim 1 and in which said converging is effected by at least one of electrostatic and ion focusing.

Claim 18

A process as claimed in claim 1 and in which the electron beam has a kinetic energy of the order of a few keV and less at power densities ranging from a few 10's of KW/cm 2 to several 10's of MW/cm 2 .

Claim 19

A process as claimed in claim 1 and in which the power density of the beam and the velocity with which the later relatively scans said major surface are regulated to deposit energy in said object at energy densities (fluence) of the order of from a few Joules/cm 2 to several hundred Joules/cm 2 .

Claim 20

A process as claimed in claim 1 and in which the object is of semiconductor material and the said treatment by the fine line electron beam effects one of annealing, formation of metal-silicide interconnectors, formation of doped SiO 2 layers, formation of homogeneous substrates, surface diffusion, zone refining, impurity gettering, and solid-or-liquid-phase regrowth of large single crystals by one of epitaxial, heteroepitaxial, and graphrepitaxial recrystallization.

Claim 21

Apparatus for generating a fine line strip electron beam for the heat treatment of a solid object of solid material having a major surface for physical, chemical, mechanical and other modifications at said major surface, comprising, in combination: electron gun means for propagating electrons along a predetermined direction and disposed within an evacuated housing and including a cathode for generating the electrns extending linearly transversely to said direction, control grid and acceleration and focusing means, and means for adjusting the latter to converge the linear beam into a fine line electron beam strip; means for supporting the object-to-be treated with said major surface thereof in the path of the converged fine line beam strip; the cathode being of a length corresponding substantially to a dimension of said major surface so that the same is treated by the fine line beam simultaneously across such dimension; means for relatively moving said beam and object so that said fine line beam strip relatively scans said major surface at a predetermined velocity and in a direction at right angles to said dimension; and means for regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the velocity with which the latter relatively scans said major surface such that a layer of said object at said major surface with a maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material of said object underlying said layer is substantially precluded by limiting the time that any given location on said major surface is impacted by said beam.

Claim 22

Apparatus for generating a fine line strip electron beam for the heat treatment of a solid object of solid material having a major surface for physical, chemical, mechanical and other modifications at said major surface, comprising, in combination: electron gun means for propagating electrons along a predetermined direction and disposed within an evacuated housing and including a cathode for generating the electrns extending linearly transversely to said direction, control grid and acceleration and focusing means, and means for adjusting the latter to converge the linear beam into a fine line electron beam strip; means for supporting the object-to-be treated with said major surface thereof in the path of the converged fine line beam strip; the cathode being of a length corresponding substantially to a dimension of said major surface so that the same is treated by the fine line beam simultaneously across such dimension; means for relatively moving said beam and object so that said fine line beam strip relatively scans said major surface at a predetermined velocity and in a direction at right angles to said dimension; and means for regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the velocity with which the latter relatively scans said major surface such that a layer of said object at said major surface with a maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material of said object underlying said layer is substantially precluded by limiting the time that any given location on said major surface is impacted by said beam.

Claim 23

Apparatus as claimed in claim 20 and in which the material supporting means is disposed within said housing.

Claim 24

Apparatus as claimed in claim 20 and in which the beam voltage is of the order of a few 10's of kV at power densities ranging from a few 10's of KW/cm 2 to several 10's of MW/cm 2 .

Claim 25

Apparatus as claimed in claim 20 and in which the fine line beam strip is adjusted to be of transverse length of from about 2 to 15 cm. or longer and is converged to a width of the order of between substantially 10 -3 cm. and a few centimeters.

Claim 26

Apparatus as claimed in claim 23 and in which the current densities of said beam strip are adjusted to be of the order of up to about 1000 A/cm 2 under beam voltages within limits from about 1 to 30 Kv.

Claim 27

Apparatus as claimed in claim 20 and in which the accelerating means and means for relatively moving are adjusted to provide energy densities (fluence) in the object of the order of from a few Joules/cm 2 to several hundred Joules/cm 2 .

Claim 28

Apparatus as claimed in claim 20 and in which the material is a semiconductor and the the said treatment by the fine line electron beam effects one of annealing, formation of metal-silicide interconnectors, formation of doped SiO 2 layers, formation of homogeneous substrates, surface diffusion, zone refining, impurity gettering, and solid-or-liquid-phase regrowth of large single crystals by one of expitaxial, heteroepitaxial, and graphrepitaxial recrystallization.

Claim 29

Apparatus as claimed in claim 20 and in which there is provided, interposed between the focusing and material supporting means, electron beam deflection means for enabling deflection of the fine line strip, as for stepped and other position-changing scanning.

Claim 30

Apparatus as claimed in claim 20 and in which means is provided for moving the material past the fine line strip.

Claim 31

Apparatus as claimed in claim 28 and in which deflecting means is provided for supplementing the scanning effected by material moving, by electron scanning of the strip.

Claim 32

Apparatus as claimed in claim 29 and in which means is provided for intensity-modulating the fine line strip beam, including pulsing the same.

Claim 33

A process for heat treatment of a solid object of solid material having a major surface by means of electron beam energy, that comprises: generating and propagating electrons within a vacuum along a predetermined direction and in a linear beam that extends transverse to said direction; converging the beam into a fine line of intense charge; impacting the converged fine line beam upon a region of said major surface of the object being treated; and regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the time for which the latter impacts said region of said major surface such that a layer of said object in said region with maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material underlying said layer is substantially precluded.

Claim 34

A process for heat treatment of a solid object of solid material having a major surface by means of electron beam energy, that comprises: generating and propagating electrons within a vacuum along a predetermined direction and in a linear beam that extends transverse to said direction; converging the beam into a fine line of intense charge; impacting the converged fine line beam upon a region of said major surface of the object being treated; and regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the time for which the latter impacts said region of said major surface such that a layer of said object in said region with maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material underlying said layer is substantially precluded.

Claim 35

A process as claimed in claim 31; in which said solid material is a semi-conductor having a small grain size, and said heat treatment causes melting of said layer for epitaxial recrystallization thereof to form a semi-conductor having a large grain size.

Claim 36

Apparatus for generating as fine line strip electron beam for the heat treatment of a solid object of solid material having a major surface for physical, chemical, mechanical and other modifications at said major surface, comprising, in combination: electron gun means for propagating electrons along a predetermined direction and disposed within an evacuated housing and including a cathode for generating the electrons extending linearly transversely to said direction, control grid and acceleration and focusing means, and means for adjusting the latter to converge the linear beam into a fine line electron beam strip; means for supporting the object-to-be treated with said major surface thereof in the path of the converged fine line beam strip; the cathode being of a length corresponding substantially to a dimension of a region of said major surface so that the same is impacted and treated by the fine line beam simultaneously across such dimension; and means for regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the time for which the latter impacts said region of said major surface such that a layer of said object in said region with a maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material of said object underlying said layer is substantially precluded.

Claim 37

Apparatus for generating as fine line strip electron beam for the heat treatment of a solid object of solid material having a major surface for physical, chemical, mechanical and other modifications at said major surface, comprising, in combination: electron gun means for propagating electrons along a predetermined direction and disposed within an evacuated housing and including a cathode for generating the electrons extending linearly transversely to said direction, control grid and acceleration and focusing means, and means for adjusting the latter to converge the linear beam into a fine line electron beam strip; means for supporting the object-to-be treated with said major surface thereof in the path of the converged fine line beam strip; the cathode being of a length corresponding substantially to a dimension of a region of said major surface so that the same is impacted and treated by the fine line beam simultaneously across such dimension; and means for regulating the kinetic energy of said beam to limit the depth of penetration of said object by said electrons and the power density (flux) of said beam and the time for which the latter impacts said region of said major surface such that a layer of said object in said region with a maximum depth of the order of several microns has its temperature raised sufficiently to effect said heat treatment of said layer while thermal diffusion to the solid material of said object underlying said layer is substantially precluded.

Claim 38

Apparatus as claimed in claim 33; in which said solid material is a semi-conductor having a small grain size, and said heat treatment causes melting of said layer for epitaxial recrystallization thereof to form a semi-conductor having a large grain size.