Radio-frequency inductive coupling linear ion source

Abstract

The invention belongs to the technical field of ion beam control, and particularly relates to a radio-frequency inductive coupling linear ion source. The radio-frequency inductive coupling linear ionsource comprises an ion source shielding shell, a radio frequency coupling antenna, a dielectric coupling window used for transmitting radio-frequency power and isolating a discharge chamber from an antenna chamber, a plasma discharge chamber side wall used for accommodating discharge plasmas, a multi-grid ion beam extraction system used for extracting ion beams from the plasma discharge chamber,and a radio-frequency neutralizer used for providing initial electrons into the discharge chamber and providing neutralized electrons into the ion beams and a base material. The radio-frequency inductive coupling linear ion source can generate high-uniformity large-area narrow and long linear ion beams in a large size range, and is suitable for processes of ion beam cleaning, etching, thin film deposition and the like of large-area base materials.

Description

technical field [0001] The invention belongs to the technical field of ion beam control, and in particular relates to a radio frequency induction coupled linear ion source. Background technique [0002] The radio frequency inductively coupled ion source uses radio frequency inductive coupling to generate plasma, has no built-in electrodes, and has the characteristics of no pollution and high plasma density. It is the most widely used ion source in the field of microfabrication. According to the structural form of the radio frequency antenna, there are mainly two types - spiral tube type and coil incense type. The toroidal RF inductively coupled ion source adopts a spring-shaped helical antenna, and the antenna is helically coiled outside the dielectric discharge chamber. Due to the skin effect of RF power transmission, the electrons in the discharge chamber are accelerated by the inductively coupled electric field along the direction parallel to the inner wall of the discha...

AI Technical Summary

Problems solved by technology

On the one hand, because the beam spot increases, the area of ​​the RF antenna and the dielectric coupling window must also increase. The larger the antenna length, the larger the inductance, the larger the distributed capacitance and the RF voltage at both ends of the antenna, and the high voltage at both ends of the antenna will cause The capacitive coupling between the RF antenna and the plasma load and the discharge of the RF antenna cause problems such as uneven distribution of plasma density, unstable impedance matching between the RF power supply and the plasma load, and low RF coupling efficiency. The antenna also makes the plasma density more non-uniform due to the standing wave effect

At the same time, due to the strength requirements of the coupling window isolation vacuum structure, the larger the dielectric coupling window, the thickness of the coupling window needs to be increased, further reducing the coupling efficiency and the uniformity of the plasma density distribution. Dual requirements for transmitting RF power

On the other hand, as the beam spot increases, the design and processing of the large-area ion source extraction grid becomes more and more difficult, and the larger the extraction grid, the more difficult it is to control the deformation

The grid design of the traditional large-area ion source has basically reached the engineering limit of the ion source structure and the performance limit of the material. The problems of deformation control and thermal stability have become an insurmountable technical bottleneck in the grid design of the large-area ion source, and it is difficult to further improve it. , restricting the further increase of the ion beam spot

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