KR200166109Y1 - Cathode structure for generating arc - Google Patents

Abstract

A cathode structure for uniform ionization in an arc chamber is disclosed. An annular tab is formed on the outer circumferential surface of the cathode cap to form an optimal gap between the filament and the cathode cap. In the assembly of the cathode cap, the insertion degree is limited by the tab without a separate check device, so that an optimum gap with the filament can be formed. By forming an optimum gap, upon application of voltage to the filament, a stable load is applied to the cap, resulting in uniform ionization in the arc chamber.

Description

Cathode Structure for Arc Generation {CATHODE STRUCTURE FOR GENERATING ARC}

The present invention relates to a cathode of an arc chamber, and more particularly to a cathode having a structure capable of achieving optimal ionization.

Recently, cathode ray tubes have been fabricated to have larger sizes and higher brightness than before. For this purpose, for cathode ray tubes with high current density There is an active research on cathodes.

1 discloses the cathode described in US Pat. No. 5,402,035. Referring to FIG. 1, the cathode body includes a cathode cap 16 having an electron emitting material 17 and a hollow sleeve 11 made of a metal material having high heat resistance such as molybdenum (Mo). Equipped. The heater 15 is mounted in the sleeve 11. The cathode for the high current density cathode ray tube requires a cathode current density of approximately 10 A / cm ² .

A plurality of spaced metal ribbons 13 are provided to connect the outer circumferential surface of the bottom of the sleeve 11 and the top of the cathode holder 12 to each other.

When a rated voltage is applied to the heater 15, the temperature of the heat generating site of the heater 15 increases above a predetermined temperature, and thus the heat is transferred to the electron emitting material 17 in the cathode cap 16, Thermal ions of a predetermined density are released from the surface of the electron emitting material 17.

2 shows the arc chamber 100 when the principle of such a cathode ray tube is applied to ionization in a semiconductor manufacturing apparatus. The ionization begins by applying low energy to the filament 110. When the filament 110 is heated to generate hot electrons, the hot electrons impact the cathode cap 120. At this time, the cathode cap 120 plays a role of the filament 110 in the source head and reacts with the toxic gas supplied in the arc chamber 100 to ionize. That is, when a low voltage, for example, 10V is applied to the filament 110, 600V is applied to the cathode cap 120 Degree of voltage is induced. In this case, the distance between the filament 110 and the cathode cap 120 should maintain a predetermined distance, that is, a distance at which optimal ionization can occur. If the distance is set incorrectly, the hot electrons generated in the filament 110 is not smoothly transferred to the cathode cap 120, thereby losing the ionization function.

3 shows a cathode cap 120 according to the prior art. After fixing the filament 110 first, the cathode cap 120 is coupled. Conventionally, the cathode cap 120 is assembled until the filament 110 is in contact with the filament 110 by using a check device. ) Is rotated 180 degrees to set the distance to the filament (110).

Therefore, the assembly of the filament and the cathode cap according to the prior art should use a check device for each assembly, and furthermore, the cathode cap is rotated 180 degrees to be spaced apart from the filament by a predetermined distance, but is manually rotated by 180 degrees. There is a problem that setting at intervals is not easy.

Therefore, an object of the present invention is to provide a cathode structure for arc generation that can increase the arc generation efficiency for plasma generation.

1 is a cross-sectional view of a cathode structure for a cathode ray tube according to the prior art;

2 is a schematic diagram of a cathode structure of an arc chamber according to the prior art;

3 is a cross-sectional view of the cathode cap shown in FIG.

4 is a cross-sectional view of a cathode in an arc chamber according to one embodiment of the present invention.

5 is a cross-sectional view of a cathode cap according to one embodiment.

≪ Description of code for main part of drawing>

200: cathode structure 210: arc chamber

220: filament 230: cathode cap

235: annular tab

In order to achieve the above object of the present invention, the present invention is provided on one side of an arc chamber for forming an ionized field therein, and when a voltage is applied, the temperature rises to emit the first hot electrons. Filament, and the filament Closes and collides with the hot electrons emitted from the filament and is discharged under high voltage into the arc chamber to release the second hot electrons, which are amplified by the ratio of the first hot electrons, on the outer periphery of which the front end and the gap with the filament are optimally spaced. It provides a cathode structure for arc generation, characterized in that it comprises a cathode cap (tab) is formed to the tab (tab) to fit.

At this time, an optimum gap between the cathode cap and the filament is formed upon contact of the annular tab with the arc chamber wall. In this way, by forming the optimum gap, when a voltage is applied to the filament, a stable load is applied to the cap, thereby achieving uniform ionization in the arc chamber.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail.

4 shows a cathode structure 200 for arc generation in accordance with one embodiment of the present invention. The cathode structure for arc generation refers to a cathode provided as an arc source in a process such as plasma or ion etching. Referring to FIG. 4, the cathode structure 200 is provided on one side of the arc chamber 210 for forming an ionized field therein. The cathode structure 200 according to an embodiment includes a filament 220 that emits first hot electrons when a voltage is applied, and a cathode cap 230 that encloses the filament 220. A filament insulator is installed at the bottom of the filament to suppress the formation of electromagnetic fields due to the filament's release of hot electrons.

5 shows the cathode cap 230 shown in FIG. 4. 5, The cathode cap 230 is placed under high voltage by colliding with the first hot electrons emitted from the filament 220, and has a function of emitting a second ratio of amplified ratios of the second hot electrons to the first hot electrons into the arc chamber 210. An outer circumference of the cathode cap 230 is formed with an annular tab 235 for matching the front end and the gap with the filament 220 to the optimum gap. Preferably, the cross section of the annular tab 235 is rectangular, and upon assembly of the cathode cap 230, it abuts with the inner wall of the arc chamber 210 so that the cathode cap 230 is no longer forward assembled. . That is, an optimum gap between the cathode cap 230 and the filament 220 is formed when the annular tab 235 contacts the wall of the arc chamber 210.

On the other hand, the tab 235 may be composed of at least three projections spaced apart from the annular.

A method of assembling the cathode structure 200 described above will be described with reference to FIG. 4.

First, the filament 220 is installed at a predetermined position on the inner wall of the arc chamber 210, and then the cathode cap 230 is inserted into the inner wall of the arc chamber 210 to enclose the filament 220. Upon insertion of the cathode cap 230, as soon as the tab 235 formed on the outer circumferential surface of the cathode cap 230 and the inner wall of the arc chamber 210 abut, assembly of the cathode cap 230 is completed. Then, the gap between the tip of the cathode cap 230 and the tip of the filament 220 is set to be optimal.

In the optimum gap state, the efficiency of the filament 220 is optimized, and a stable load is applied to the cathode cap 230. Therefore, in the arc chamber 210, the bacteria Work and stable ionization are achieved.

As described above, since the optimum gap with the filament can be matched without using a check device or the like when assembling the cathode cap, a stable load is applied to the cathode cap, thereby achieving uniform ionization in the arc chamber. Can be.

As described above with reference to the preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated.

Claims (3)

A filament provided at one side of an arc chamber for forming an ionized field therein, the temperature of which is increased when a voltage is applied to emit first hot electrons; And Enclosing the filament and colliding with the first hot electrons emitted from the filament to release the second hot electrons which are under high voltage into the arc chamber and amplified to the first hot electrons by a predetermined ratio with respect to the first hot electrons, the front and the filaments of the outer periphery thereof. A cathode structure for arc generation, characterized in that it comprises a cathode cap (tab) is formed to fit the gap with the optimum gap. The cathode structure as claimed in claim 1, wherein an optimum gap between the cathode cap and the filament is formed upon contact of the tab with the arc chamber wall. The cathode structure of claim 1, wherein the tab is annular.