US 6,207,964 B1 · Continuously variable aperture for high-energy ion implanter

Abstract

A variable aperture assembly (30) is provided for controlling the amount of ion beam current passing therethrough in an ion implantation system (10). The aperture assembly (30) comprises an aperture (44) defined by opposing first and second aperture plates (44A, 44B) through which an ion beam passes; control arms (46A, 46B) connected, respectively, to the first and second aperture plates (44A, 44B); and an aperture drive mechanism (36) for simultaneously imparting movement to the control arms in opposite directions, to adjust a gap (50) between the aperture plates (44A, 44B) to thereby control the amount of current passing through the aperture (44). Each of the opposite directions in which the control arms move is generally perpendicular to an axis along which the ion beam passes. A control system (120) is also provided for automatically adjusting the aperture gap (50) based on inputs representing actual ion beam current passing through the implanter, desired ion beam current, and aperture position. The control system (120) includes control logic (122, 124) for receiving the inputs and outputting control signals (126, 128) to the aperture drive mechanism to adjust the aperture gap.

Claims20

Dependent claims

A variable aperture (30) for controlling the amount of ion beam current passing therethrough in an ion implantation system (10), comprising:

(i) an aperture (44) defined by opposing first and second aperture plates (44A, 44B) through which an ion beam passes;
(ii) control arms (46A, 46B) connected, respectively, to said first and second aperture plates (44A, 44B);
(iii) an aperture drive mechanism (36) for simultaneously imparting movement to said control arms in opposite directions, each of said opposite directions being generally perpendicular to an axis along which the ion beam passes, to adjust a gap (50) between said aperture plates (44A, 44B) to thereby control the amount of current passing through said aperture (44);
and
(iv) a closed loop control system (120) for adjusting said gap (50) by controlling said aperture drive mechanism (36), comprising (a) a first input for receiving a first input signal from an ion beam current detection device (35) representing actual ion beam current passing through the implanter;
(b) a second input for receiving a second input representing a desired ion beam current;
(c) a third input for receiving a third input signal from an aperture position feedback mechanism (116, 118) representing aperture position;
(d) an output for outputting control signals (126, 128) to the aperture drive mechanism to control the ion beam current passing therethrough;
and (e) control logic (122, 124) for determining said output control signals based on said first, second, and third inputs.

6 more elements

An implanter beamline assembly (14, 16, 18, 30) for a high energy ion implanter (10), comprising:

(i) an ion source (14) for generating an ion beam;
(ii) a mass analysis magnet (16) for mass analyzing the ion beam generated by the ion source;
(iii) a linear accelerator (18) for accelerating the ion beam analyzed by the mass analysis magnet;
(iv) a variable aperture assembly (30) disposed between said mass analysis magnet (16) and said linear accelerator (18), said variable aperture comprising an aperture (44) through which the ion beam passes, said aperture (44) having a gap (50) which is varied by an aperture drive mechanism (36) to control the amount of ion beam current passing therethrough;
and
(v) a closed loop control system (120) for adjusting said gap (50) by controlling said aperture drive mechanism (36), comprising (a) a first input for receiving a first input signal from an ion beam current detection device (35) representing actual ion beam current passing through the implanter;
(b) a second input for receiving a second input representing a desired ion beam current;
(c) a third input for receiving a third input signal from an aperture position feedback mechanism (116, 118) representing aperture position;
(d) an output for outputting control signals (126, 128) to the aperture drive mechanism to control the ion beam current passing therethrough;
and (e) control logic (122, 124) for dete nining said output control signals based on said first, second, and third inputs.

7 more elements

Dependencies are inferred from the claim text.

Continuously variable aperture for high-energy ion implanter

Life of this patent

Continuously variable aperture for high-energy ion implanter

Life of this patent

Abstract

Claims20