KR20040101756A - A source head arc chamber of ion implantation machine - Google Patents

Abstract

PURPOSE: A source head arc chamber of an ion-implantation apparatus is provided to prevent an inner surface of an arc generating chamber from being damaged due to the impact between thermoelectrons and dopant molecules by using a protection layer and to improve ionization-efficiency by using a nozzle-like gas inlet hole. CONSTITUTION: A source head arc chamber includes a body, a cover, a cathode and a repeller, a filament and an inlet port. The body includes an arc generating chamber. The cover with an arc slit is installed on the body. The cathode and repeller are installed on an inner wall of the arc generating chamber. The filament for supplying current to the cathode is installed on an outer wall of the body. The inlet port(21) includes a gas inlet hole connected through the arc generating chamber. A protection layer(41) is formed on the inner wall of the arc generating chamber. The gas inlet hole is formed like a nozzle.

Description

Source head arc chamber of ion implanter {A SOURCE HEAD ARC CHAMBER OF ION IMPLANTATION MACHINE}

The present invention relates to a source head arc chamber of an ion implantation apparatus.

In general, an ion implantation apparatus used for ion implantation on a semiconductor wafer includes a source head for generating an ion beam. The space where the ion beam is made in such a source head is called an arc chamber.

An arc chamber is a facility that removes electrons from a neutral atom to form positively charged particles. The arc chamber shoots an electron beam from a heated filament at a neutral atom to remove electrons bound to the atom. The cations thus generated are extracted from the ion supply to make an ion beam to be used for ion implantation.

1 is a perspective view illustrating the arc chamber 100 in a state in which the cover 140 is separated to explain the configuration of the source chamber 200 of the conventional ion implantation apparatus 100.

Referring to FIG. 1, the arc chamber 100 protrudes a square fence 120 on one surface of the base plate 110 to provide an arc generating chamber 130 inside the square fence 120, and the square fence 120. It is configured by installing a cover 140 having an arc slit 150 on the open upper surface of the 120. The inlet 190 having a gas inlet hole 191 is formed in the base plate 110 located in the arc production chamber 130 as described above.

In addition, one side wall and the other side wall of the arc generation chamber 130, the cathode 170 (CATHOD) for applying a current to the filament 160 (FILAMENT) to release the hot electrons, and the hot electrons by the supplied gas and cathode (170) A repeller 180 (REPELLER) in which ionized gas is deposited due to the collision of the electrons is installed.

Accordingly, in the arc generation chamber 130, hot electrons emitted from the filament 160 collide with the cathode 170 due to the potential difference with the cathode 170 to heat the cathode 170. Secondary hot electrons are emitted from the surface of the heated cathode 170 and the secondary hot electrons collide with gas dopant molecules introduced into the arc generation chamber 130 to generate ionized gas.

However, the conventional arc chamber 100 corrodes or closes the gas transfer hole 191 in the arc generating chamber 130 and sidewalls to which the repeller 180 and the cathode 170 are attached in the process of forming the ionized gas. Etching can cause damage. Such damage is a factor that shortens the life of the arc chamber 100 has a problem that the maintenance cost is consumed a lot.

In addition, since the gas transfer hole 191 of the existing inlet 190 is formed as a simple straight through hole as shown in FIG. 2, the flow of the gas dopant molecules introduced through the gas transfer hole 191 is slow, the cathode ( 170) There is a problem that the ionization efficiency is lowered because the collision with hot electrons emitted from the surface is not activated.

Accordingly, the present invention was devised to solve the general problems of the source head arc chamber of the conventional ion implantation apparatus described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a source head arc chamber of an ion implantation apparatus capable of preventing a damage caused by collision of hot electrons and dopant molecules to extend the service life thereof.

In another aspect, the present invention provides a source head arc chamber of an ion implantation apparatus that can improve ionization efficiency by activating collision between secondary heat electrons and dopant molecules emitted from the surface of the cathode by improving the structure of the gas transfer hole.

1 is a perspective view illustrating an arc chamber in which a cover is removed to explain a configuration of a source head arc chamber of a conventional ion implantation apparatus.

2 is a side cross-sectional view of a conventional arc chamber.

Figure 3a is a side cross-sectional view for explaining the source head arc chamber of the ion implantation apparatus according to the present invention.

3B is a plan view illustrating a source head arc chamber of the ion implantation apparatus according to the present invention.

4 is an enlarged view of portion A of FIG. 3A.

<Explanation of symbols for major parts of drawing>

1: Source head arc chamber of ion implantation device 2: Base plate

3: Square fence 4: Ich generating room

21: inlet 211: gas transfer hole

41: protective film

As a specific means of the present invention for achieving the above object;

A main body included in the source head and provided with an arc generating chamber in an inner space of the rectangular fence protruding from one surface of the base plate;

A cover installed on an upper surface of the arc generating chamber and provided with an arc slit;

A cathode and a repeller installed on one side wall and the other side wall of the arc production room;

A filament installed at one outer wall of the square fence to supply current to the cathode;

And an inlet formed in a predetermined portion of the base plate located inside the arc generation chamber and having a gas inlet hole penetrating through the arc generation chamber.

The inner surface of the arc generation chamber is provided with a protective film, the gas inlet hole is achieved by having a source head arc chamber of the ion implantation device, characterized in that it is configured in the form of a nozzle, the diameter decreases from the inlet side to the outlet side.

At this time, the protective film is formed in a form corresponding to the inner surface of the arc generating chamber is inserted into the inner surface of the arc generating chamber.

The protective film is made of a molybdenum film.

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

Figure 3a is a side cross-sectional view for explaining the source head arc chamber of the ion implantation apparatus according to the present invention, Figure 3b is a plan view for explaining the source head arc chamber of the ion implantation device according to the invention, Figure 4a Part A enlarged view of.

As shown, the source head arc chamber 1 of the ion implantation apparatus of the present invention has a protective film 41 in the arc generating chamber 4 provided inside the rectangular fence 3 protruding from one surface of the base plate 2. And a gas transfer hole 211 of the inlet port 21 installed in the base plate 4 positioned in the arc generating chamber 4 is configured in the form of a nozzle.

Here, the arc chamber 1 of the present invention is a cathode and a repeller (not shown) in the arc generating chamber 4 provided inside the rectangular fence 3 protruding from the base plate 2 without being different from the conventional one. Not shown.) Is installed, the cover having an arc slit (not shown in the drawing) is installed on the square fence (3), the filament (not shown in the drawing) on the outer wall of the square fence (3). ) Is configured.

At this time, in the present invention, the protective film 41 is installed on the inner surface of the arc production chamber 4, that is, the inner wall of the square fence 3 and one surface of the base plate 2 located inside the square fence 3. do. Such a protective film 41 has a structure corresponding to that of the inner surface of the arc generating chamber 4 and is formed in a thin film form. Accordingly, the protective film 41 is inserted into the inner surface of the arc generation chamber 4, and has a structure that can be replaced when the protective film 41 itself wears.

Here, as the constituent material of the protective film 41, it is preferable to apply molybdenum having excellent abrasion resistance, and when such a molybdenum film is applied as the protective film 41, it is preferable to set the thickness to 1.5 mm in consideration of economical efficiency. .

On the other hand, the inlet 21 provided in the base plate 2 located in the arc production chamber 41 is provided with a gas transfer hole 211 for introducing gas into the interior of the arc generation chamber 4, such as The gas transfer hole 211 is configured in the form of a nozzle that is smaller in diameter as shown in FIG. 4.

Here, the gas transfer hole 211 of the inlet port 21 formed in the nozzle form as described above is a conventional venturi that the speed of the fluid passing through the outlet side is smaller than the speed of the fluid passing through the large inlet side diameter The principle of the tube applies.

Thus, looking at the operating state of the source head arc chamber 1 according to the present invention having the configuration as described above;

The arc chamber 1 of the present invention is a rectangular fence (3) after the cathode and the repeller (not shown in the figure) is installed in a state in which the protective film 41 is installed on the inner surface of the arc generating chamber (4) The assembly is completed by installing a cover (not shown in the figure) having an arc slit on the upper surface of which is opened.

At this time, the protective film 41 installed inside the arc generating chamber 4 is damaged by the collision of hot electrons and dopant molecules in the ionization process performed in the arc generating chamber 4. Will be prevented.

In addition, the gas transfer hole 211, which is a passage for supplying gas to the arc generation chamber 4, is configured in the form of a nozzle to inject the dopant molecules while the gas passing through the gas transfer hole 211 has a high transfer speed. Can be supplied to the arc generation chamber 4 to activate the collision with the secondary hot electrons.

As described above, the source head arc chamber of the ion implantation apparatus according to the present invention is provided with a protective film on the inner surface of the arc generating chamber to prevent the inner surface of the arc generating chamber from being damaged by the collision of hot electrons and dopant molecules. It has the effect of extending the service life.

In addition, since the gas transfer hole is configured in the form of a nozzle, the dopant molecules can be supplied to the arc generating chamber by the spray method, thereby improving the ionization efficiency by activating a collision with the secondary hot electrons emitted from the surface of the cathode. There is.

Claims (3)

A main body included in the source head and provided with an arc generating chamber in an inner space of the rectangular fence protruding from one surface of the base plate; A cover installed on an upper surface of the arc generating chamber and provided with an arc slit; A cathode and a repeller installed on one side wall and the other side wall of the arc production room; A filament installed at one outer wall of the square fence to supply current to the cathode; And an inlet formed in a predetermined portion of the base plate located inside the arc generation chamber and having a gas inlet hole penetrating through the arc generation chamber. The inner surface of the arc generation chamber is provided with a protective film, the gas inlet hole source head arc chamber of the ion implantation device, characterized in that the diameter of the nozzle is configured to decrease from the inlet side to the outlet side. The source head arc chamber of claim 1, wherein the passivation layer has a shape corresponding to an inner surface of the arc generating chamber and is inserted into an inner surface of the arc generating chamber. The source head arc chamber of claim 1, wherein the protective film is made of a molybdenum film.