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US 5,216,253 AGranted
Ion implantation apparatus with variable width slits providing an ion beam of high purity
AssigneeHitachi, Ltd.
InventorHidemi Koike
Life of this patent
Estimating the term…
Abstract
In an ion implantation apparatus, a first slit for limiting an ion beam width is provided between an ion source and a mass separation electromagnet. An accelerator is provided behind the mass separation electromagnet. A second slit for separating the ion beam is provided between a deflector provided behind the accelerator and a wafer. The slit widths of the first and second slits are controlled by a controller which monitors an ion source acceleration voltage, a magnetic field intensity of the mass separation electromagnet, an accelerator voltage, and a magnetic field intensity of the deflector, and control the slit widths of the first and second slits based on the monitored information.
Claims17
An ion implantation apparatus comprising:
- an ion source for producing an ion beam;
- a first slit having an adjustable width for limiting a width of the ion beam from the ion source in a predetermined plane;
- a mass separation electromagnet for deflecting the width-limited ion beam from the first slit in the predetermined plane to perform mass separation of the width-limited ion beam;
- an ion accelerator for accelerating the mass-separated ion beam from the mass separation electromagnet;
- a detector for deflecting the accelerated ion beam in a predetermined plane to separate the accelerated ion beam into a desired ion beam and an undesired ion beam;
- a second slit having an adjustable width for passing the desired ion beam from the deflector and blocking the undesired ion beam from the deflector;
- and
- means for holding a wafer in a path of the desired ion beam passed by the second slit such that the desired ion beam passed by the second slit is implanted into the wafer.
5 more elements
An ion implantation apparatus comprising:
- an ion source for producing an ion beam;
- a first slit having an adjustable width for limiting a width of the ion beam from the ion source in a predetermined plane;
- a mass separation electromagnet for deflecting the width-limited ion beam from the first slit in the predetermined plane to perform mass separation of the width-limited ion beam;
- an ion accelerator for accelerating the mass-separated ion beam from the mass separation electromagnet;
- a deflection magnet producing a uniform magnetic field for deflecting the accelerated ion beam in the predetermined plane to separate the accelerated ion beam into a desired ion beam and an undesired ion beam;
- a second slit having an adjustable width for passing the desired ion beam from the deflection magnet and blocking the undesired ion beam from the deflection magnet;
- slit width adjusting means for adjusting the widths of the first slit and the second slit;
- control means for detecting an accelerating voltage of the ion source, a magnetic field intensity of the mass separation electromagnet, an accelerating voltage of the ion accelerator, and a magnetic field intensity of the deflection magnet, determining optimum widths of the first slit and the second slit for obtaining a desired degree of purity of the desired ion beam passed by the second slit based on the detected accelerating voltages and magnetic field intensities, and controlling the slit width adjusting means to adjust the widths of the first slit and the second slit to the optimum widths;
- a rotary disc holding a plurality of wafers disposed such that the wafers pass through a path of the desired ion beam passed by the second slit when the rotary disc is rotated such that the desired ion beam passed by the second slit is implanted into the wafers;
- and
- means for rotating the rotary disc such that the wafers are mechanically moved relative to the desired ion beam passed by the second slit, thereby providing a mechanical scan type ion implantation apparatus.
8 more elements
An ion implantation apparatus comprising:
- an ion source for producing an ion beam;
- a first slit having an adjustable width for limiting a width of the ion beam form the ion source in a predetermined plane;
- a mass separation electromagnet for deflecting the width-limiting ion beam from the first slit in the predetermined plane to perform mass separation of the width-limited ion beam;
- an ion accelerator for accelerating the mass-separated ion beam from the mass separation electromagnet;
- an electrostatic deflector for deflecting the accelerated ion beam in the predetermined plane to separate the accelerated ion beam into a desired ion beam and an undesired ion beam;
- a second slit having an adjustable width for passing the desired ion beam from the electrostatic deflector and blocking the undesired ion beam from the electrostatic deflector;
- slit width adjusting means for adjusting the widths of the first slit and the second slit;
- control means for detecting an accelerating voltage of the ion source, a magnetic field intensity of the mass separation electromagnet, an accelerating voltage of the ion accelerator, and an electric field intensity of the deflection magnet, determining optimum widths of the first slit and the second slit for obtaining a desired degree of purity of the desired ion beam passed by the second slit based on the detected accelerating voltages, magnetic field intensity, and electric field intensity, and controlling the slit width adjusting means to adjust the widths of the first slit and the second slit to the optimum widths;
- means for holding a wafer in a path of the desired ion beam passed by the second slit such that the desired ion beam passed by the second slit is implanted into the wafer;
- and
- means for scanning the desired ion beam passed by the second slit across a surface of the water, thereby providing a beam scan type ion implantation apparatus.
8 more elements
Dependencies are inferred from the claim text.