US4556794A — Secondary ion collection and transport system for…

Claim 1

Independent Claim 130 words

A secondary ion collection and transport system for an ion microprobe, the microprobe directing a primary ion beam onto a target to form secondary ions as a result of the beam's impact, comprising: means for collecting secondary ions from the target area and directing the ions into general alignment with a desired transport path; a plurality of spaced electric field members distributed along the desired ion path, the field members being adapted to produce electrostatic fields in response to applied electrostatic voltages; and means for applying electrostatic voltages to the respective field members such that the ions are alternately accelerated and focused by the electrostatic fields produced by successive members, and emerge from the desired path with a substantially smaller velocity than their maximum velocity during transit along the path.

Claim 2

Dependent Claim 130 words

A secondary ion collection and transport system for an ion microprobe, the microprobe directing a primary ion beam onto a target to form secondary ions as a result of the beam's impact, comprising: means for collecting secondary ions from the target area and directing the ions into general alignment with a desired transport path; a plurality of spaced electric field members distributed along the desired ion path, the field members being adapted to produce electrostatic fields in response to applied electrostatic voltages; and means for applying electrostatic voltages to the respective field members such that the ions are alternately accelerated and focused by the electrostatic fields produced by successive members, and emerge from the desired path with a substantially smaller velocity than their maximum velocity during transit along the path.

Claim 3

Dependent Claim 38 words

The secondary ion collection and transport system of claim 1, wherein the desired ion path has an axis, each of the field members being substantially coaxial with the ion path axis and mutually spaced in the axial direction.

Claim 4

Dependent Claim 28 words

The secondary ion collection and transport system of claim 2, wherein each of the field members comprises a hollow conductive cylinder disposed coaxially with the ion path axis.

Claim 5

Dependent Claim 21 words

The secondary ion collection and transport system of claim 2, wherein each of the field members comprises a multi-pole electrostatic device.

Claim 6

Dependent Claim 51 words

The secondary ion collection and transport system of claim 2, wherein the voltage applying means applies alternately greater and lesser voltages to the field members to alternately accelerate and focus the ions, with the first member in the direction of ion travel having a substantially greater voltage than the last member.

Claim 7

Dependent Claim 25 words

The secondary ion collection and transport system of claim 5, wherein the field members comprise first through sixth members in the direction of ion travel.

Claim 8

Dependent Claim 63 words

The secondary ion collection and transport system of claim 6, wherein the voltage applying means applies electrostatic voltages relative to the collected ion polarity of approximately -1,000 volts to the first member, +200 volts to the second member, -1,000 volts to the third member, -100 volts to the fourth member, -1,000 volts to the fifth member and -20 volts to the sixth member.

Claim 9

Dependent Claim 28 words

The secondary ion collection and transport system of claim 2, wherein each of the field members is approximately 5 mm long, with inner diameters of approximately 10 mm.

Claim 10

Dependent Claim 23 words

The secondary ion collection and transport system of claim 8, wherein adjacent field members are spaced from each other by approximately 1 mm.

Claim 11

Dependent Claim 90 words

The secondary ion collection and transport system of claim 1, wherein the ion collection means comprises first and second members having generally concentric, generally arcuate and conductive surfaces adapted to be placed adjacent a target, the conductive surfaces being mutually spaced to form an ion collection path between their arcuate surfaces, and means for applying a relatively greater electrostatic voltage to the member having the lesser radius and a relatively lesser electrostatic voltage to the member having the greater radius, the voltage polarities being opposite to the collected ion polarity.

Claim 12

Dependent Claim 47 words

The secondary ion collection and transport system of claim 10, wherein the curvature of the arcuate members and the voltages applied thereto are selected to transmit only ions within a predetermined energy band, and to capture other ions on one or the other of the arcuate members.

Claim 13

Dependent Claim 41 words

The secondary ion collection and transport system of claim 11, wherein the arcuate members have radii of approximately 5.3 mm and 7.8 mm, respectively, and the electrostatic voltage means applies a voltage differential of approximately 100 volts across the arcuate members.

Claim 14

Dependent Claim 18 words

The secondary ion collection and transport system of claim 10, wherein the arcuate members comprise generally cylindrical sections.

Claim 15

Dependent Claim 18 words

The secondary ion collection and transport system of claim 10, wherein the arcuate members comprise generally spherical sections.

Claim 16

Dependent Claim 46 words

The secondary ion collection and transport system of claim 10, wherein the greater radius arcuate member includes an opening of sufficient size to admit the primary ion beam, and is positioned to allow the primary beam to travel between the two arcuate members to the target.

Claim 17

Dependent Claim 28 words

The secondary ion collection and transport system of claim 15, wherein the greater radius arcuate member comprises a conductive mesh material having mesh openings of approximately 0.3 mm.

Claim 18

Dependent Claim 52 words

The secondary ion collection and transport system of claim 10, further comprising a plurality of electrodes positioned about the desired ion transport path between the arcuate members and the field members, and means for applying electrostatic voltages to the electrodes to steer ions emerging from the arcuate members onto the desired path.

Claim 19

Dependent Claim 97 words

A secondary ion collection and transport system in an ion microprobe, the microprobe directing a primary ion beam onto a target to form secondary ions as a result of the beam's impact, comprising: means for collecting secondary ions from the target area and directing the ions into general alignment with a desired transport path; and means distributed along the transport path for applying alternate accelerating and focusing electrostatic fields to the collected ions, the accelerating fields propelling the ions with sufficient velocity to traverse the path, and the focusing fields forming the ions substantially into a beam.

Claim 20

Dependent Claim 97 words

A secondary ion collection and transport system in an ion microprobe, the microprobe directing a primary ion beam onto a target to form secondary ions as a result of the beam's impact, comprising: means for collecting secondary ions from the target area and directing the ions into general alignment with a desired transport path; and means distributed along the transport path for applying alternate accelerating and focusing electrostatic fields to the collected ions, the accelerating fields propelling the ions with sufficient velocity to traverse the path, and the focusing fields forming the ions substantially into a beam.

Claim 21

Dependent Claim 46 words

The secondary ion collection and transport system of claim 18, wherein the initial field in the ion path imparts a predetermined energy level to the ions, and the last field in the path imparts to the ions a substantially lower energy level than the predetermined level.

Claim 22

Dependent Claim 100 words

The secondary ion collection and transport system of claim 19, wherein the transport path has an axis, the distributed field means comprises six conductive members which are substantially symmetrically disposed about the axis and mutually spaced in the direction of ion travel and including means for applying electrostatic voltages relative to the collective ion polarity of approximately: -1,000 volts to the first member in the direction of ion travel, +200 volts to the second member, -1,000 volts to the third member, -100 volts to the fourth member, -1,000 volts to the fifth member and -20 volts to the sixth member.

Claim 23

Independent Claim 161 words

A system for collecting, transporting and focusing secondary ions emitted from a target surface in a small working space, comprising: first and second conductive members adapted to be positioned near the target surface, the first and second members having mutually opposed arcuate surfaces defining therebetween an ion collection path; means for applying respective electrostatic voltages to the two members of opposite polarity to the ions and of sufficient magnitude to impel ions from the target area within a predetermined energy band along the collection path; means for steering the collected ions into alignment with a desired transport path defined by an axis; a series of generally annular conductive members spaced along the axis and coaxial therewith; and means for applying electrostatic voltages to the successive annular members to establish electrostatic fields along the axis of alternately greater and lesser strengths, the greater fields imparting sufficient energy to the ions to traverse the transport path, and the lesser fields focusing the ions.

Claim 24

Independent Claim 161 words

A system for collecting, transporting and focusing secondary ions emitted from a target surface in a small working space, comprising: first and second conductive members adapted to be positioned near the target surface, the first and second members having mutually opposed arcuate surfaces defining therebetween an ion collection path; means for applying respective electrostatic voltages to the two members of opposite polarity to the ions and of sufficient magnitude to impel ions from the target area within a predetermined energy band along the collection path; means for steering the collected ions into alignment with a desired transport path defined by an axis; a series of generally annular conductive members spaced along the axis and coaxial therewith; and means for applying electrostatic voltages to the successive annular members to establish electrostatic fields along the axis of alternately greater and lesser strengths, the greater fields imparting sufficient energy to the ions to traverse the transport path, and the lesser fields focusing the ions.

Claim 25

Dependent Claim 12 words

The system of claim 21, wherein the annular members comprise hollow cylinders.

Claim 26

Dependent Claim 13 words

The system of claim 21, wherein the annular members comprise multi-pole electrostatic devices.

Claim 27

Dependent Claim 23 words

The system of claim 21, wherein the annular members are approximately 5 mm long axially and having inner diameters of approximately 10 mm.

Claim 28

Dependent Claim 63 words

The system of claim 21, including six annular members having voltages applied thereto relative to the ion polarity of approximately: -1,000 volts for the first member in the direction of ion travel, +200 volts for the second member, -1,000 volts for the third member, -100 volts for the fourth member, -1,000 volts for the fifth member and -20 volts for the sixth member.

Claim 29

Dependent Claim 38 words

The system of claim 21, wherein the two arcuate members are generally concentric with respective radii of approximately 5.3 mm and 7.8 mm, said electrostatic voltage means applying a voltage differential of approximately 100 volts across the members.

Claim 30

Dependent Claim 75 words

The system of claim 21, the two arcuate members being generally concentric, the member having the greater radius comprising a conductive mesh having an opening of sufficient size to admit a primary ion beam and positioned to allow the primary beam to travel between the two arcuate members to the target, and mesh openings of sufficient size to enable the escape through the mesh of ions having an opposite polarity relative to the collected beams.

Claim 31

Dependent Claim 44 words

The system of claim 21, said steering means comprising a pair of electrodes disposed on opposite sides of the ions emerging from between the arcuate members, and means for applying a voltage differential across the electrodes to steer the ions along the desired path.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-12-02	1989-06-03	1989-12-03	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-12-02	1993-06-03	1993-12-03	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-12-02	1997-06-03	1997-12-03	$7700.00	Window Closed / Lapsed

Secondary ion collection and transport system for ion microprobe

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