Axcelis Technologies, Inc.

Advanced Ion Beam Technology, Inc.

Varian Associates, Inc.

Applied Materials, Inc.

Novellus Systems Incorporated

Varian Semiconductor Equipment Associates, Inc.

Tel America, Inc.

Sensitech, Inc.

Proteros, LLC

Donald Wayne Berrian

John W Vanderpot

John D Pollock

Zhimin Wan

Xiao Bai

Robert E Kaim

Hans Meiling

Han Westendorp

Billy W Ward

Jiong Chen

Causon Ko-Chuan Jen

Cheng-Hui Shen

William A Tout

Ernest M Santin

Peter M Nunes

John Pollack

The time-averaged ion beam profile of an ion beam for implanting ions on a work piece may be smoothed to reduce noise, spikes, peaks, and the like and to improve dosage uniformity. Auxiliary magnetic field devices, such as electromagnets, may be located along an ion beam path and may be driven by periodic signals to generate a fluctuating magnetic field to smooth the ion beam profile (i.e., beam current density profile). The auxiliary magnetic field devices may be positioned outside the width and height of the ion beam, and may generate a non-uniform fluctuating magnetic field that may be strongest near the center of the ion beam where the highest concentration of ions may be positioned. The fluctuating magnetic field may cause the beam profile shape to change continuously, thereby averaging out noise over time.

Magnetic field fluctuation for beam smoothing

A variable aperture within an aperture device is used to shape the ion beam before the substrate is implanted by shaped ion beam, especially to finally shape the ion beam in a position right in front of the substrate. Hence, different portions of a substrate, or different substrates, can be implanted respectively by different shaped ion beams without going through using multiple fixed apertures or retuning the ion beam each time. In other words, different implantations may be achieved respectively by customized ion beams without high cost (use multiple fixed aperture devices) and complex operation (retuning the ion beam each time). Moreover, the beam tune process for acquiring a specific ion beam to be implanted may be accelerated, to be faster than using multiple fixed aperture(s) and/or retuning the ion beam each time, because the adjustment of the variable aperture may be achieved simply by mechanical operation.

Implant method and implanter by using a variable aperture

To select a scan distance to be used in scanning a wafer with an implant beam, a dose distribution along a first direction is calculated based on size or intensity of the implant beam and a scan distance. The scan distance is the distance measured in the first direction between a first path and a final path of the implant beam scanning the wafer along a second direction in multiple paths. A relative velocity profile along the second direction is determined based on the dose distribution. Dose uniformity on the wafer is calculated based on the wafer being scanned using the relative velocity profile and the determined dose distribution. The scan distance is adjusted and the preceding steps are repeated until the calculated dose uniformity meets one or more uniformity criteria.

Implant beam utilization in an ion implanter

A system and method for mitigating contamination in an ion implantation system is provided. The system comprises an ion source, a power supply operable to supply power to a filament and mirror electrode of the ion source, a workpiece handling system, and a controller, wherein the ion source is selectively tunable via the controller to provide rapid control of a formation of an ion beam. The controller is operable to selectively rapidly control power to the ion source, therein modulating a power of the ion beam between an implantation power and a minimal power in less than approximately 20 microseconds based, at least in part, to a signal associated with a workpiece position. Control of the ion source therefore mitigates particle contamination in the ion implantation system by minimizing an amount of time at which the ion beam is at the implantation current.

Particulate prevention in ion implantation

A system, method, and apparatus for determining a profile of an ion beam are provided. The apparatus comprises a measuring device positioned along a path of the ion beam, a drive mechanism, and a first plate rotatably coupled to the drive mechanism. The drive mechanism is operable to rotate the first plate about a first axis through a path of the ion beam, therein selectively blocking the ion beam from reaching the measuring device. The apparatus may comprise a second plate further rotatably coupled to the drive mechanism, wherein the drive mechanism is operable to rotate the second plate about the first axis through the path of the ion beam independently from the rotation of the first plate, therein further selectively blocking the ion beam from reaching the measuring device. The drive mechanism may further linearly translate first plate and/or second plate through the ion beam.

Ion beam profiler

A reciprocating drive system, method, and apparatus for scanning a workpiece are provided, wherein a motor comprising a rotor and stator operable to individually rotate about a first axis is operable to reciprocally translate the workpiece with respect to a stationary reference. A shaft rotatably driven by the rotor extends along the first axis, and a scan arm is operably coupled to the shaft, wherein the scan arm is operable to support the workpiece thereon. Cyclical counter rotations of the shaft by the motor are operable to rotate the scan arm, therein scanning the workpiece through the ion beam along a first scan path, wherein the stator acts as a reaction mass to the rotation of the rotor. A controller is further operable to control an electromagnetic force between the rotor and the stator, therein generally determining a rotational position of the rotor and the stator.

Reciprocating drive for scanning a workpiece

An apparatus and a method are disclosed for rapidly controlling the rate of ion generation in an ion source. The ion source includes an ion chamber, filament-cathode, a mirror electrode, and a grid. The ion source is operable to generate an ion beam from the ionization of ion precursor gas present in the ion chamber by electrons emitted from the filament. The rate of ion generation is controlled by modifying the potential of the grid relative to the filament to control the number of electrons available for ionization between the grid and the mirror electrode. An alternative embodiment for rapidly controlling the rate of ion generation in an ion source is also disclosed. In the alternative embodiment, the ion source comprises an ion chamber having mutually opposed sides and configured to receive ion precursor gas; a filament-cathode located on one side of said ion chamber and operable to emit electrons for the ionization of the precursor gas for the generation of the ion beam; and a mirror electrode having a potential associated therewith and located on the other side of said ion chamber. The mirror electrode is connected to a circuit to vary its potential relative to said filament so as to vary the number of the electrons available in the ion chamber for ionization.

System and method for rapidly controlling the output of an ion source for ion implantation

A method for reciprocally transporting a workpiece on a scan arm through an ion beam is provided, wherein the scan arm is operably coupled to a motor comprising a rotor and stator that are individually rotatable about a first axis. An electromagnetic force applied between the rotor and stator rotates the rotor about the first axis and translates the workpiece through the ion beam along a first scan path. A position of the workpiece is sensed and the electromagnetic force between the rotor and stator is controlled in order to reverse the direction of motion of the workpiece along the first scan path, and wherein the control is based, at least in part, on the sensed position of the workpiece. The stator further rotates about the first axis in reaction to the rotation of the rotor, particularly in the reversal of direction of motion of the workpiece, thus acting as a reaction mass to the rotation of one or more of the rotor, scan arm, and workpiece.

Method for reciprocating a workpiece through an ion beam

A reciprocating drive system and apparatus for scanning a workpiece through an ion beam are provided, wherein a motor comprising a rotor and stator operable to individually rotate about a first axis is operable to reciprocally translate the workpiece with respect to the ion beam. A shaft rotatably driven by the rotor extends along the first axis, and a scan arm is operably coupled to the shaft, wherein the scan arm is operable to support the workpiece thereon. Cyclical counter rotations of the shaft by the motor are operable to rotate the scan arm, therein scanning the workpiece through the ion beam along a first scan path, wherein the stator acts as a reaction mass to the rotation of the rotor. A controller is further operable to control an electromagnetic force between the rotor and the stator, therein generally determining a rotational position of the rotor and the stator.

Reciprocating drive for scanning a workpiece through an ion beam

A substrate positioning system is provided to facilitate the performing of certain processing on the substrate, such as ion implantation. The system comprises a linkage rotatably mounted to a base and an end effector member rotatably mounted to the linkage and configured for receiving a substrate. Through the synchronized rotation of the linkage about the base and the end effector member about the linkage, the system acts as a robotic unit to move the substrate to the desired location for performing processing thereon. In another aspect, the base is movable along an axis such that the system maintains a constant distance of travel for an ion beam incident on the substrate as the linkage and end effector member travel in a curved path.

Substrate positioning system

A method is provided for uniformly implanting a wafer with an ion beam. The wafer is generally of the type with a surface area in the form of a disk with a diameter and center. The ion beam is first formed as an elongated shape incident on the wafer, the shape having a length along a first axis smaller than the diameter, and a width shorter than the length along a second axis. Next, the wafer is translated at a variable translational velocity in a direction substantially parallel with the second axis. The wafer is also rotated substantially about the center at a rotational velocity. These movements are made such that the ion beam implants the wafer with substantially uniform dose across the surface area of the wafer. The wafer is preferably translated such that the ion beam implants the wafer from one side of the wafer, across the surface area of the wafer, and through another side of the wafer, in a selected velocity versus position profile. The wafer is also tilted while rotating such that the ion beam implants the surface area at a substantially constant angle relative to a crystal axis of the wafer. The wafer can also be translated in a direction substantially parallel to the ion beam such that the ion beam implants the surface area with a substantially constant spot size. The methods of the invention also include determining beam current density of the ion beam, and adjusting the variable translational velocity, and rotational velocity, as a function of the current density.

System and method for implanting a wafer with an ion beam

An ion implantation system contains, in the ion implantation chamber, a workpiece holder that scans vertically while tilting a wafer at an angle of rotation that is rotated out of a perpendicular orientation with respect to the axis of projection in an ion beam. The implant angle into an implant surface on wafer that is retained by the workpiece holder is adjusted by selective rotation of the workpiece holder about its path of motion. A Faraday cup scans the ion beam along the intended location of the implant surface to form a setup measurement plane. The ion beam quality is adjusted to enhance beam uniformity along the setup plane according to these tilt-angle measurements. A charge neutralizing device, such as a flood gun, is moved in operational alignment with the workpiece.

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Topsfield, MA, United States of America

Donald Wayne Berrian