FIELD OF THE DISCLOSURE

The disclosure relates generally to techniques for manufacturing electronic devices, and more particularly, to techniques for improving the performance and extending the lifetime of components within a processing chamber.

BACKGROUND OF THE DISCLOSURE

Ion implantation is a process by which dopants or impurities are introduced into a substrate via bombardment. In semiconductor manufacturing, the dopants are introduced to alter electrical, optical, or mechanical property. For example, dopants may be introduced into an intrinsic semiconductor substrate to alter the type and level of conductivity of the substrate. In manufacturing an integrated circuit (IC), a precise doping profile is often important for proper IC performance. To achieve a desired doping profile, one or more dopants may be implanted in the form of ions in various doses and various energy levels.

A conventional ion implantation system may comprise an ion source and a series of beam-line components through which an ion beam passes. The ion source may comprise a chamber where desired ions are generated. The ion source may also comprise a power source and an extraction electrode assembly disposed near the chamber. The beam-line components, may include, for example, a mass analyzer, a first acceleration or deceleration stage, a collimator, and a second acceleration or deceleration stage. Much like a series of optical lenses that manipulate a light beam, the beam-line components can filter, focus, and manipulate ions or ion beam having desired species, shape, energy, and other qualities. The ion beam that passes through the beam-line components may be directed toward a substrate that is mounted on a platen or clamp. The substrate may be moved in one or more dimensions (e.g., translate, rotate, and tilt) by an apparatus, sometimes referred to as a roplat. It should be appreciated by those skilled in the art that the entire path traversed by the ion beam is typically evacuated during ion implantation.

The ion implanter system is required to generate a stable, well-defined ion beam for a variety of different ion species and extraction voltages. It is therefore desirable to operate the ion source for extended periods of time without the need for maintenance or repair. After several hours of normal operation using source gases (such as AsH3, PH3, BF3, and other species), beam constituents eventually create deposits on beam optics. Beam optics within a line-of-sight of the wafer also become coated with residues from the wafer, including Si and photoresist compounds. These residues build up on the beam-line components, causing spikes in the DC potentials during normal operation (e.g., in the case of electrically biased components) and eventually flake off, causing increased particulate contamination to be transferred to the wafer.

One way to prevent the effect of the material accumulation is to intermittently replace beam-line components of the ion implanter system. Alternatively, beam-line components may be manually cleaned. However, these measures require the ion source or the entire ion implanter system to be powered down and to release the vacuum within the system. Moreover, the ion implanter system, after replacing or cleaning the beam-line components, must be powered and evacuated to reach operational condition. Accordingly, these maintenance processes may be very time consuming. In addition, the beam-line component is not used during the maintenance processes. As such, frequent maintenance processes may decrease the time available for IC production, while increasing overall manufacturing cost.

SUMMARY

In view of the foregoing, it would be advantageous to provide a system and method for in-situ plasma cleaning of ion beam-line components (e.g., ion beam optics), wherein the in-situ plasma cleaning may be performed over a short time and without having to vent and/or manually clean the ion beam optics. Moreover, it would be advantageous to provide a system and method for in-situ plasma cleaning of ion beam optics wherein a plasma is locally generated in an area surrounding just those components that need to be cleaned, thereby reducing unwanted etching to other components of the beam-line.

An exemplary ion implanter in accordance with the present disclosure may include a beam-line component including a chamber for generation of a plasma, a power supply in communication with the chamber. The power supply may be configured to supply a first voltage and a first current to the beam-line component during a processing mode and a second voltage and a second current to the beam-line component during a cleaning mode, wherein the second voltage and the second current are applied to a plurality of conductive beam optics of the beam-line component, in parallel, to generate a plasma around the plurality of conductive beam optics.

An exemplary system in accordance with the present disclosure may include a beam-line component including a chamber for generation of a plasma, wherein the beam-line component includes a plurality of conductive beam optics disposed along an ion beam-line. The system may further include a power supply in communication with the chamber, the power supply configured to supply a first voltage and a first current to the beam-line component during a processing mode and a second voltage and a second current to the beam-line component during a cleaning mode. The second voltage and the second current may be applied to one or more of the plurality of conductive beam optics, in parallel, to generate a plasma around the one or more of the plurality of conductive beam optics. The system may further include a flow controller for adjusting an injection rate of an etchant gas supplied to the beam-line component, and a vacuum pump for adjusting a pressure of the beam-line component.

An exemplary method in accordance with the present disclosure may include providing a beam-line component including a chamber for generation of a plasma, and supplying a first voltage and a first current to the beam-line component during a processing mode. The method may further include supplying a second voltage and a second current to the beam-line component during a cleaning mode, wherein the second voltage and the second current are applied to a plurality of conductive beam optics of the beam-line component, in parallel, to selectively generate a plasma around the conductive beam optics.

