Ion source, ion injection device and ion source operation method

Abstract

The present invention provides a technique for suppressing an abnormal electric discharge inside an ion generation container from an ion source, which is caused by an insulation film originating fromby-products when an ionization gas and an ion source material are reacted to generate ions. This ion source comprises: a vacuum chamber (10A) having a cooling mechanism; an ion generation container (11) provided inside the vacuum chamber (10A), wherein the ionization gas and the ion source material are reacted to generate the ions; an extraction electrode (15) provided inside the vacuum chamber (10A), for extracting the ions generated inside the ion generation container (11) to generate an ion beam; and a shielding member (30) provided on the inner side and in the vicinity of an inner wall (10d) of the vacuum chamber (10A), having a main body section (31) comprising an electric conductive metal for the purpose of blocking the adhesion of an insulating material onto the inner wall (10d) ofthe vacuum chamber (10A). Provided in the main body section (31) of the shielding member (30) are a plurality of protrusion-shaped support parts (32), which establish contact with the inner wall (10d)of the vacuum chamber (10A) to support the main body section (31) in such a manner that the mounting thereof onto the inner wall (10d) of the vacuum chamber (10A) establishes a gap therebetween.

Description

technical field [0001] The present invention relates to ion sources, in particular to the maintenance technology of ion sources used in ion implantation devices. Background technique [0002] In recent years, methods for manufacturing silicon carbide (SiC) substrates that are superior in heat resistance and voltage resistance compared with conventional silicon (Si) substrates have been established, and they can be obtained relatively cheaply. [0003] Among the processes using the SiC substrate, there is a process of implanting aluminum ions as a dopant, and an ion implantation apparatus having an ion source for generating an aluminum ion beam is used. [0004] Figure 10 It is a sectional view showing the inside of a conventional ion source. [0005] Such as Figure 10 As shown, the ion source 50 has a vacuum tank 51 formed of a metal such as stainless steel in a cylindrical shape and connected to a vacuum exhaust device (not shown). The ion generating container 52 that r...

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Problems solved by technology

[0009] However, in such a way of making aluminum nitride etc. with PF 3 In the reaction method, insulating aluminum fluoride (AlF x ), there is a problem that the generated aluminum fluoride causes abnormal discharge in the vacuum chamber 51 via the insulating film (especially the insulating film 160 among the insulating films 160 and 161 ) attached to the inner wall of the vacuum chamber 51

[0010] If such an abnormal discharge occurs, in addition to fluctuations in the ion beam current and a decrease in the yield of the ion implantation target object, electromagnetic noise may cause failure of the power supply of the ion implantation device and the vacuum pump.

[0011] Therefore, conventionally, when abnormal discharges frequently occur, the vacuum chamber 51 of the ion source 50 is opened to the atmosphere to remove the insulating film 160. However, in the prior art, such maintenance must be performed frequently, which may degrade production efficiency. topic

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