JPH0224942A - Ion implanter - Google Patents

Abstract

PURPOSE:To prevent a nozzle from chocking by forming a part in contact with ion gas from a member easy to separate its attachment. CONSTITUTION:That part of a nozzle 63 of the solid ion seed cartridge body 60 which is in contact with gas, from carbon which has good thermal conductivity and poor wettability with Sb, etc. Accordingly the heat from a rod-shaped heater 18 conducts till the tip of the nozzle in good performance, and the gasified ion seed gas is hindered from recrystallization, and the nozzle is prevented from chocking. In the case of eventual attachment the crystals can be easily removed. This enhances the serviceability and maintenance easiness. The gas having flowed out of the nozzle 63 flows into an ion producing chamber and ionized.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an ion implantation device.

(Prior Art) Generally, an ion implantation device is widely used as a device for doping impurities into, for example, semiconductor wafers, and uses gas or solid ion species as an ion source.

Among these ion implanters, those that use solid ion species heat the solid ion species,
A gas generation mechanism for gasification by sublimation or evaporation is arranged.

In a conventional ion implanter, the gas generation mechanism is configured as follows, for example. That is, as shown in FIG. 8, the gas generating mechanism 3 inserted and fixed from the outside so as to close the opening 2 of the vacuum chamber 1 includes a base body 4 formed into a rod shape from heat-resistant stainless steel, etc., and this base body. 4
A fixing plate 5 is provided at the end of the vacuum chamber 1 and fixed to the wall of the vacuum chamber 1 so as to close the opening 2, and a heater 6 is wound around the base 4. ,
An ionic species accommodation hole 7 is bored to accommodate solid ionic species.

Further, a nozzle 8 made of stainless steel or the like is provided at the tip of the ionic species accommodation hole 7 so that it can be attached and detached by, for example, a screw.
It is configured such that it can be filled with solid ionic species such as phosphorus, arsenic, and antimony having a particle size of, for example, several millimeters.

Then, by energizing the heater 6, the solid ion species are heated to generate gas, and this gas is introduced into an ion generation chamber (not shown) through a nozzle 8, and ions are generated by, for example, applying a DC voltage. .

Note that, as mentioned above, since the heater 6 of the gas generation mechanism 3 is provided within the vacuum chamber 1, heat conduction through the air does not occur, so that the heat generated by the heater 6 is efficiently transmitted to the base 4. As such, the cover 6 is welded to the base body 4 by, for example, brazing.

(Problems to be Solved by the Invention) However, in the conventional ion implantation apparatus described above,
There are the following problems.

That is, for example, when the heater starts to be energized, the heat generated by the heater is transmitted through the base, and the solid ion species in the ion species accommodation holes are heated. Then, when the temperature of the solid ion species reaches a predetermined 1H degree, gas begins to be generated from the solid ion species. This gas is introduced into the ion generation chamber by a nozzle, but since this nozzle is located far from the heater, the temperature inside this nozzle does not rise to the vaporization temperature of solid ion species, especially immediately after the start of electricity supply. . Therefore, the gas that has entered the nozzle begins to recrystallize, and the crystals adhere to the inside of the nozzle, thereby clogging the nozzle.

Such problems are particularly severe when antimony is used as the solid ionic species. Furthermore, when antimony is used, the crystallized antimony firmly adheres to the stainless steel and cannot be easily removed. For this reason, problems arise, such as crystals adhering to the threaded portion of the nozzle, making it impossible to attach or detach the nozzle.

The present invention has been made in response to such conventional circumstances, and can prevent nozzle clogging due to adhesion of crystals, and can easily remove adhering crystals, resulting in a higher operating rate than in the past. An object of the present invention is to provide an ion implantation device that can improve the performance and maintainability.

[Configuration of the Invention (Means for Solving the Problems) In other words, the present invention provides an ion implantation apparatus that generates an ion beam by ionizing a gas generated from solid ion species, in which a portion that comes into contact with the gas is It is characterized in that it is constructed of a member that can be easily attached and separated by gas.

(Function) In the ion implantation apparatus of the present invention having the above-mentioned configuration, the part that comes into contact with the gas generated from the solid ion species is a member that easily releases deposits caused by the gas, such as the inside of the nozzle, which has a high thermal conductivity and is made of antimony. It is made of a member made of carbon, which has poor wettability with respect to the like.

By efficiently transmitting heat to the nozzle tip, it is possible to prevent recrystallization of vaporized gas, prevent nozzle clogging due to adhesion of crystals, and easily remove adhering crystals. It is possible to improve the operating rate and maintainability compared to the conventional method.

(Example) Hereinafter, an example of the ion implantation apparatus of the present invention will be described with reference to the drawings.

An opening 12 is formed in the vacuum chamber 11, and a gas generating mechanism 13 is inserted and fixed from the outside so as to close the opening 12.

That is, at the end of the gas generation mechanism 13, as shown in FIG.
4, and this fixing plate 14 is provided with an O-ring 1 that is in contact with the vacuum chamber 11 to ensure airtightness.
5 is placed.

Then, by fixing the fixing plate 14 to the vacuum chamber 11 with, for example, screws, the opening 12 is hermetically closed, and the gas and screw mechanism 13 is provided so as to protrude into the vacuum chamber 11.

Further, a rod-shaped base body 16 made of a material such as heat-resistant stainless steel is fixed at one end to the fixing plate 14, and as shown in FIG. Four heater insertion holes 1 along the longitudinal direction from the side
7 are bored, and rod-shaped heaters 18 are inserted into these heater insertion holes 17, respectively. Note that the front half of these heaters 18 is the heat generating part 18 from the tip.
The rear half of a1 is a support part (non-heat generating part) 18b,
These heaters 18 are configured to be replaceable from outside the vacuum chamber 11. Furthermore, one temperature detector insertion hole and three cooling gas introduction holes 20 are bored between these heater insertion holes 17. As shown in FIGS. 3 and 4, a thermocouple 21, for example, is inserted as a temperature detector into one temperature sensor insertion hole, and a cooling gas, such as air, is inserted into the cooling gas introduction hole 20. A pipe 22 for delivery is inserted. Note that the thermocouple 21 is used to detect the temperature inside the base 16 and adjust the amount of electricity supplied to the heater 16 to control the temperature, and the piping 22 is used for rapid cooling during maintenance, for example. belongs to.

On the other hand, a cartridge accommodating hole 24 for accommodating a solid ion species cartridge 23 is bored on the tip side of the base body 16 . Moreover, two L-shaped notches 25, for example, are provided at the tip of the base body 16 as a mechanism for locking the solid ion species cartridge 23.

As shown in FIG. 5, the solid ion species cartridge 23 is constructed as follows.

That is, the cartridge body 60 has a hollow cylindrical shape so as to accommodate solid ionic species therein, and the outer wall 6
It has a two-layer structure in which 1 is made of a material such as heat-resistant stainless steel, and the inner wall 62 is made of carbon. Further, a nozzle 63 is detachably provided on the distal end side of the cartridge body 60 with a fixing screw 64, and the outer wall 64 of this nozzle 63 is made of a material such as heat-resistant stainless steel, and the inner wall 63 is made of a material such as heat-resistant stainless steel.
5 is a two-layer structure made of carbon material.

The gas flow path 66, which is provided at the end of the cartridge body 60 on the nozzle 63 side and communicates the inside of the cartridge body 60 with the nozzle 63, is bent eccentrically with respect to the nozzle 63. The solid ionic species filled inside the nozzle 63 is configured so that it exits from the nozzle 63.

A heat transfer rod 67 made of carbon is provided in the rear end opening 66 of the cartridge body 60 so as to close the opening 66. The heat transfer rod 67 is detachable, for example, by a screw, and is configured such that solid ionic species can be filled into the cartridge body 60 by removing the heat transfer rod 67.

That is, all the parts in contact with the solid ion species in the solid ion species cartridge 23 and the gas generated from the solid ion species are made of a member that easily removes the deposits caused by the gas, such as a member made of carbon.

Further, a stepped portion 68 is provided on the outer side of the cartridge body 60 so that the opening side has a larger diameter.
is provided with an L-shaped claw 69.

Therefore, the cartridge housing hole 24 provided in the base body 16 has a small diameter and extends to the area between the heaters 18, where the heat transfer rod 6 of the solid ion species cartridge 23 is inserted.
7 is inserted, and the heater 18 is configured to efficiently heat the solid ion species.

Then, the solid ion species cartridge 23 is inserted into the cartridge accommodation hole 24 of the base 16, and the claw 69 of the ion species cartridge 23 is inserted into the L-shaped notch 25 of the base 16.
For example, four disc springs 27 are arranged at the tip of this ion species cartridge 23, and as shown in FIG. The two L-shaped notches and the base 16
The protrusion 30 provided on the holder is engaged with the protrusion 30 to be fixed.

That is, the solid ion species cartridge 23
7 and is fixed in a pressed state to the base body 16, so that heat from the base body 16 is efficiently transmitted to the solid ion species cartridge 23.

Further, the heat reflecting cover 28 is used to reflect heat radiated from the base body 16 and return it to the base body 16, thereby increasing thermal efficiency.

In the ion implantation apparatus of this embodiment having the above configuration, the cartridge body 60 is filled with solid ion species such as antimony with a particle size of several millimeters, for example, about several tens of grams, the gas generation mechanism 13 is assembled as described above, and the vacuum chamber is Place it at 11. Then, by applying electricity to the heater 18, the solid ion species are heated and gas is generated. This gas passes through the nozzle 63 from inside the cartridge body 60, flows into an ion generation chamber (not shown) in which ions are generated by applying a DC voltage, for example, and is ionized. These ions are electrically extracted from the ion generation chamber, converted into a desired electron beam by a mass spectrometer magnet, accelerator tube, electrostatic lens, etc., and scanned by a deflection electrode, etc., and then scanned and irradiated onto, for example, a semiconductor wafer.

That is, in the ion implantation apparatus of this embodiment, as described above, the solid ion species in the cartridge body 60 and the nozzle 63 and the parts that come into contact with the gas generated from the solid ion species all have high thermal conductivity, and are made of antimony, etc. It is made of a member made of carbon, which has poor wettability. Therefore, for example, even immediately after heating by the heater 18 is started, the difference between the temperature inside the cartridge body 60 and the temperature of the nozzle 63 is small, and the gas generated from the solid ion species is cooled within the nozzle 63 and recrystallized. This can prevent the nozzle 63 from becoming clogged. Further, even when antimony is used as the solid ionic species, since carbon has poor wettability with antimony, antimony does not stick firmly and can be easily removed. Furthermore, since the heat transfer rod 67 provided on the side of the heater 18, which has a relatively high temperature, is removable with a screw and is used as an opening/closing mechanism for filling the solid ion species into the cartridge body 60, this screw portion, etc. There is no possibility that antimony will stick firmly to the opening and closing of the opening will become impossible.

Next, referring to FIG. 7, an ion implantation apparatus according to another embodiment will be described.

The base body 80 provided in the vacuum chamber is made of, for example, heat-resistant stainless steel and has a cylindrical shape, and a heater 81 is wound around the outside of the base body 80 .

Further, a cartridge accommodating hole 82 that opens toward the tip side is formed in the base body 80, and a solid ion species cartridge 83 for accommodating solid ion species is provided in this cartridge accommodating hole 82. Note that the heater 8
1 is welded to the base body 80 by, for example, brazing.

This solid ion species cartridge 83 is constructed as follows, and as in the previous embodiment, the solid ion species and the gas generated from the solid ion species come into contact with each other in the following manner:
All members are made of carbon.

That is, at the tip of the cartridge main body 90, which is made of carbon and has a hollow cylindrical shape, there is a nozzle 93 having a two-layer structure, in which an outer wall 91 is made of heat-resistant stainless steel, and an inner wall 92 is made of carbon, for example. It is removably provided by a fixing screw 94 consisting of. Further, an opening 95 is formed at the rear end of the cartridge main body 90, and the opening 95 is closed.
A heat transfer rod 96 made of carbon is provided.

This heat transfer rod 96 is made to be freely removable by, for example, a screw, and when this heat transfer rod 96 is removed, the cartridge main body 90
It is configured such that solid ionic species can be filled inside.

The solid ion species cartridge 83 is fixed in the cartridge accommodation hole 82 by screwing the screw provided on the outer periphery of the distal end side of the cartridge body 90 with the screw provided on the inner wall of the cartridge accommodation hole 82 of the base body 80. Ru.

In the ion implantation apparatus of this embodiment having the above configuration, the cartridge body 90 is filled with solid ion species, such as antimony with a particle size of several millimeters, for example, on the order of several tens of grams.
By applying electricity to the solid ionic species, the solid ionic species is heated and gas is generated. This gas passes through the nozzle 93 from within the cartridge body 90, flows into an ion generation chamber (not shown) in which ions are generated by applying a DC voltage, and is ionized. These ions are electrically extracted from the ion generation chamber, converted into a desired electron beam by a mass spectrometer magnet, accelerator tube, electrostatic lens, etc., and scanned by a deflection electrode, etc., to be scanned and irradiated onto, for example, a semiconductor device. .

In this embodiment with the above-mentioned structure, the solid ion species and the parts that come in contact with the gas generated from the solid ion species are all made of carbon members, as in the previous embodiment. A similar effect can be obtained.

[Effects of the Invention] As described above, according to the ion implantation device of the present invention, it is possible to prevent the nozzle from being blocked due to adhesion of crystals, and in the event that the crystals do adhere, it can be easily removed.
It is possible to improve the operating rate and maintainability compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main structure of an ion implantation apparatus according to an embodiment of the present invention, FIG. 2 is a view taken along arrow A in FIG. 1, and FIG. Figure 4 is a sectional view taken along line C-C in Figure 2.
FIG. 5 is an exploded view of the solid ion species cartridge shown in FIG. 1, FIG. 6 is a side view of FIG. 1, and FIG. FIG. 8 is a sectional view showing the configuration of main parts of a conventional ion implantation device. 11... Vacuum chamber 13... Gas generation mechanism, 18... Heater, 23...
Solid ion species cartridge, 60... Cartridge body, 61... Outer wall of cartridge body (made of stainless steel), 62... Inner wall of cartridge body (made of carbon), 63... ...Nozzle, 64...
...Nozzle outer wall (stainless steel), 65...
Nozzle inner wall (made of carbon), 67... Heat transfer rod (
Made of carbon).

Claims (1)

[Claims] (1) An ion implantation device that generates an ion beam by ionizing a gas generated from a solid ion species, characterized in that a portion that comes into contact with the gas is constituted by a member that is easily attached and separated by the gas. Injection device.