JPS6261257A - Ion implantation method - Google Patents

Abstract

PURPOSE:To enhance the rate of operation of a device, by performing an operation preparing treatment on one ion source while another ion source is in operation. CONSTITUTION:A first and a second ion sources 31, 32 are provided in positions symmetric with each other as to a mass spectrograph 39. The ion sources 31, 32 are controlled so that one of them is selectively put in operation under a power supply circuit 40 and the other is selectively put in an operation preparing state. If the filament of one of the ion sources 31, 32 is cut off, ions are generated by the other to continue ion implantation work.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to an ion implantation method, and particularly to an apparatus for implanting ions one-on-one into a conductor substrate, to improve its operating efficiency and efficiency. This invention relates to an ion implantation method that allows for ion implantation.

[Prior Art] As an ion implantation device that accelerates impurity ions generated by an ion source using a high electric field and implants them into a semiconductor substrate, for example, a hot cathode type ion source such as a Freeman type ion source is used as an ion implantation device. There is a 71-person device, and this is because it emits ions in a stable state and is easy to maintain.

It is widely used as an ionizer device for conductor manufacturing equipment. In such an apparatus, it is necessary to periodically clean the ion source and replace parts such as the ion source chamber (ion source head).

FIG. 3(a) shows a small example of such a conventional Freeman-type ion 1-person device, and FIG. 3(b)
is an explanatory diagram of the ion source.

2 is an ion source, in which +E ions are extracted from the ion source 1 with constant energy by an extraction electrode 2, and subjected to quality h1 analysis by a quality analyzer 3; Then, the desired ions completely separated by the slit 4 are transferred to the accelerator tube 5.
is accelerated to its final energy.

Next, the ion beam is transmitted to the substrate surface 12 by a quadrupole lens 6.
The laser beams are converged so as to have a convergence point, controlled by scanning electrodes 7 and 8 to uniformly distribute the driving spears on the substrate, and bent by deflection electrode 9.

Mask 10. It reaches the substrate 12 via the Faraday cup 11.

Here, as shown in FIG. 3(b), the ions are ionized in the ion source chamber 22, which has been evacuated by 1" to a vacuum level of lXl0-'torr, and are placed there. The ion beam is extracted as an ion beam in a direction perpendicular to the rod-shaped filament 21.

In addition, 20 is an ion source housing, and 23.2
3 is an electromagnetic right side, 24 is a ground electrode, 25 is a slit, 26 is a gas introduction rj, and 27 is an ion beam.

By the way, as a matter of course, as such an ion source is used, the rod-shaped filament 2 becomes worn out and breaks. If the ion source filament breaks, the ion source chamber itself is heated considerably, so it must be kept in a vacuum and allowed to cool naturally.

In addition, the ion source housing 20. The ion source chamber 22 may become contaminated due to ion burnout. When such a state occurs, the ion implantation method should be stopped 1, and the ion source chamber 22 should be replaced.
It is necessary to clean the ion source housing 20 itself.

[Problem to be Solved] The natural cooling takes at least several hours, and if this time is short, the material 9, for example, molybdenum, may be oxidized by exposing the ion source Senyamba itself to popularity. There is a problem in that the chamber's own life is reduced by 1υ.

In addition, when replacing the ion source chamber, the ion source chamber itself is vacuumed and the gas is released by dry firing the ion source chamber itself. The work efficiency is extremely low.

In addition, if a high voltage discharge occurs due to the 7t of the ion source housing itself, the housing itself must be removed from the main body, disassembled, and cleaned. The ion source chamber is then attached to the ion implantation apparatus and then air-evacuated. However, this operation takes more time than the case of dry-firing the ion source chamber itself as described above.

If you have to interrupt the ion implantation work to replace or disassemble the ion implantation work,
For the user, this also corresponds to the device being down,
This also causes the MTBF (uniform mean time between failures) to not increase.

Therefore, the time during which the device is not operational from such filament replacement to ion 11 operation.

And the time when the equipment is not in operation, from cleaning work to ion implantation operation, is a huge loss of time in the current situation where the demand for I' conductor equipment is growing, and the work like the one described above is done by 1j. This causes serious problems such as low equipment availability.

[Purpose of the Invention] The present invention has been made in view of the problems of the prior art, and is intended to solve these problems and improve the operation of an ion implanter. 1-1 to provide a method for 71 people who can
target

[How to solve the problem] By the way, there are two possible reasons why the current ion source chamber has a short lifespan.

■There is a problem with the lifespan of the filament itself. In other words, the filament becomes thin and breaks.

■Even if the filament does not IJI, the ion source housing itself will zfJ, resulting in a lot of high electric field discharge, making it virtually impossible to use 1 unit.

Regarding the cause of (2), it can be said that even if the life of the filament is extended in the future, this is a phenomenon that will inevitably occur over time.

Therefore, this invention takes into account these two causes and is an attempt to substantially extend the time of the 71-person method. In other words, by installing two ion sources and switching between them, when one is unavailable, the other can be activated to shorten the interruption time of ion implantation work. This time is used to naturally cool down the ion source chamber of other ion sources that become unusable at the same time, or to remove the ion source housing.

In this way, the operation preparation work for the unusable ion source is carried out simultaneously with the ion implantation work using the currently operating ion source, and during this time, the unusable ion source side is brought to the standby state, and the next operation is carried out. To enable immediate bank-up of ion implantation work when the middle one becomes unusable.

10- Therefore, the first step in the ion implantation method of the present invention to achieve the above object is to implant ions 71 in a single-person ion apparatus that uses the first and second ion sources.
The method includes operating one of the first and second ion sources that is in an operational state, and performing operation preparation processing for the other ion source while the one ion source is operating. It is called doing.

By configuring this way, even if the filament of the ion source breaks, ions can be generated from the ion source and the ion implantation operation can be continued at 11 degrees. Since the ion source chamber of the ion source can be kept empty for a period of time to slowly cool naturally, natural cooling of 1 minute can be achieved. Therefore, the life of the chamber itself can be extended, and there is no need to interrupt the ion service during this period.

Also, even if the unusable ion source goes into 11 emptying after replacing the filament, and the ion/source chamber and the ion source itself are being degassed, the ion source cannot be drained from the other ion source during this time. The efficiency of the AEON 21 person device can be improved since it can train people.

In case a high voltage discharge occurs due to a defect in the ion source housing itself, remove the housing from the main body, disassemble it, clean it, and then disassemble it. After returning, we will assemble the ion source housing, attach it to the ion equipment, and vacuum it. It is also possible to continue ion work by 11 people from an ion source.

Therefore, the time during which the device is not operational between such filament exchange and ion implantation operation.

The time during which the device is not in operation, from cleaning work to ion implantation by one person, is almost a small amount of time related to the transition of these tasks, and the operation of the ion implantation device is greatly improved.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings:
Explain in detail.

FIG. 1 is a schematic diagram mainly showing the ion source portion of an ion 21-man device to which the ion 21-man power method of the present invention is applied, and FIG. 2 is an explanatory diagram of its power supply circuit. Note that the same parts as those in FIGS. 3(a) and 3(b) are indicated by the same symbol.

In FIG. 1, 7,30 is a 41721 person device,
1st. The second ion sources 31 and 32 are ready, and these first ion sources 31 and 32 are ready. The second ion sources 31 and 32 are laid out at symmetrical positions with respect to the quality analyzer 39, respectively. Each of these ion sources 31 and 32 is controlled by a power supply circuit 40 shown in FIG. 2 to selectively put one of them into operation and the other one into operation preparation state.

In FIG. 1, there is an electric fA section in which 33 power supply circuits 40 are built-in, and consists of an ion source electric gap 41, a dry firing power supply 42, and a Q-glue changing circuit section 43. Further, 34 in FIG. 1 is a gas box, inside which a first ion source 31 and a second ion source 3 are installed.
Gas is supplied from the built-in cylinder to either one or both of the first ion source 31 and the second ion source 32.

Further, 35a is a first ion source diffusion pump provided corresponding to the first ion source 31;
5b is a second ion source diffusion pump provided corresponding to the second ion source 32.

The first ion source diffusion pump 35a communicates with the mass spectrometer 39 behind the openable and closable first blocking section 37a provided in the first ion beam introduction tube 3E3a.

On the other hand, the second ion source diffusion pump 35b communicates with the analyzer 39 behind the openable and closable second blocking section 37b provided in the second ion beam introduction tube 3etb. Here, the blocking parts 37a + 37b are provided to separate the ion source in operation from the ion source in operation and the ion source on the other side of the operating barrier so that they cannot influence each other. It is something that exists.

Now, the first ion source 31 has an ion beam 38a.
The second ion source 32 emits a second ion beam 381), which passes through the same quality τ-analyzer 39 and is focused in four directions. It reaches the acceleration tube 5.

Here, the mass analyzer 39 is a double-headed type whose curved structure is developed symmetrically so that it receives ion beams from both blade directions, and when the first ion source 31 is used and when the second ion beam is used. When the source 32 is used, its current polarity can be switched. As a result, by using one mass spectrometer 39, the entire device can be miniaturized.

The ion beam output 11 of the mass spectrometer 39 is provided with a magnetic pole ball (or ii) as an adjustment unit that can adjust the angle of the magnetophoric force in order to converge the output ion source. It is being

This magnetic pole ball is the first. By setting the ion beam from the first ion source 31 to the second position, the ion beam from the first ion source 31 and the ion source from the second ion source 32 are set to the open [1 position]. It can be converged.

The magnetic pole ball is driven by a stepping motor or the like so that the angle can be adjusted within a specific range between the first set position and the second set position.
+J Noh.

By providing the mass analyzer 39 with such a structure,
One quality axillary analyzer allows adjustment of the convergence of the ion beam to the variable slit 4 side in the cylinder.

However, this invention thus provides one quality axillary analyzer 39
Of course, the present invention is not limited to this, and two 5% quality analyzers may be provided at corresponding positions and adjusted individually.

Now, the switching circuit 43 in FIG. 2 includes two uJ switching switches 43a that operate in conjunction with each other.

43b, and the changeover switch 43a switches the ion source power supply 41 to the first. This is a switch for switching connection to one of the second ion sources 31 and 32. In addition, the changeover switch 43b
The dry baking mold I%I42 was used as the first. This is a switch that connects the second ion source 31, 32 to the other ion source to which the ion source power source 41 is not connected, and operates in conjunction with the changeover switch 43a.

Note that 44 is a power supply switch for the ion source mold 1141, and 45 is a power supply switch for a power supply 42 for dry firing. It is something that can be done.

Next, to explain the ion implantation method using the ion implantation apparatus having the following configuration, firstly, when the filament of one ion source, for example, the first ion source 31, is broken, the ion source chamber must be cooled. It's going to be 1j. At this time, the first shutoff section 37a is operated to close the first ion bee 11 introduction pipe 36a and to open the second shutoff ffl<37b.

Next, the switching circuit 43 of the power supply section 33 shown in FIG. The ion source 32 side is operated to continue the ion implantation operation 1. Note that this switching may be performed with the ion source power supply switch 44 turned on, or may be performed after it is once turned off.

Incidentally, in this case, even if the ion beam 38b for ion implantation from the second ion source 32 enters the first ion source 31, the first blocking section 37a is closed, so the first ion Source 31 is not affected.

The first ion source 31 can then independently enter a state of natural cooling.

The ion source chamber of the first ion source 31 is t-
When the ion source chamber 22 has cooled down for a few minutes, the ion source chamber 22 is replaced. By doing this, oxidation of the ion source chamber 22 and the ion source housing 20 can be prevented.
Then, these 11 lives can be turned into 1- direction.

Here, the first. For example, the second blocking parts 37a and 37b are
The chamber is constructed with an air valve and a gas valve to block the ion beam, and serves as an independent chamber in terms of pressure, serving as the ion source side and the quality analyzer 39 side in the ion beam introduction tube. By doing so, the ion source chamber can be replaced without interrupting the ion implantation operation. Also, if the configuration is made up of only a shutter that blocks the mourning ion beam, the -c1 ion implantation work will be stopped at this point, but the cooling work and the ion implantation work can proceed at the same time. .

The shutters of the blocking parts 37a and 37b are provided with a protective film on the side of the h1 analyzer 39, where ions collide with each other.
For example, it can be provided by coating with graphite or the like.

Now, when the replacement of the ion source chamber of the first ion source 31 is completed, the dry firing operation of the replaced ion source chamber is started. This is done by turning on the dry firing start switch 45 shown in FIG.

Even during this dry firing, the ion implantation operation of the second ion source 32 is continued. Then, when the dry firing is completed, the first ion source 32 enters a standby state, either as it is, or after being evacuated, and finishes its operation preparation process.
do.

Note that the time required to replace the ion source chamber is only a few minutes, so it is negligible with respect to the overall operating time. In addition, when the blocking section is configured with only a shutter that blocks the ion beam with It, the ion implantation operation will be carried out during the 11-day period. The injection work will be done after: ・After vacuuming.

In this way, when the ion implantation operation is continued by the second ion source 32 and the filament of the second ion source 32 is IJJ, this time, the ion source chamber of the second ion source 32 is Cooling will be performed.

At this time, the second blocking section 371) is moved f1 to close the second ion beam introduction tube 361) and to open the first blocking section 37a. Next, the switching circuit 43 of the power supply unit 33 shown in FIG. 2 is switched to the first ion source 31 selection connection side, and the ion source power supply 41
Then, power is supplied to the first ion source 32 to operate the first ion source 31 side, thereby continuing the ion implantation operation.

Then, in the same manner as described above, the first ion source 31 is placed in an operating state, and the second ion source 32 is subjected to operation preparation processing.

By the way, when the ion source housing itself breaks down, the ion source itself must be taken out from the main body, the ion source housing removed, and disassembled for cleaning. In this case as well, the same steps as in the case of replacing the ion source chamber described above will be performed. Second blocking section 37
If air valves are installed in a and 37b to separate the ion source side and the mass spectrometer 39 side, making them independent rooms in terms of pressure, this disassembly work can be done while the other side is in operation. What is ion implantation essay using ion source?
There are advantages that can be achieved with γ.

Furthermore, if the blocking parts 37a and 37b are constructed of shutters, the ion implantation operation from the other operating ion source is interrupted only when the ion source itself is removed. After assembly after disassembly and cleaning, the ion implantation work is interrupted and reinstalled in the same manner as in step 1. This makes it possible to improve the operating rate of ion implantation work compared to the conventional method.

In this way, one of the first and second ion sources that is ready for operation is operated, and while this ion source is in operation, operation preparation processing is performed for the other ion sources. I do. In other words, it is possible to continue ion implantation using the other ion source during maintenance work on one ion source, and in particular, when replacing the ion source chamber, etc. A1 It is something that increases.

By the way, the power supply for dry firing is economical because a power supply that is not highly accurate can be used, and while the other ion source is operating, one ion source can be used immediately. I can do the following. Therefore, it is possible to ensure an operating rate substantially close to 1.0%.

As described above, two ion source systems are provided in the embodiment so that the ion source chamber can be fired even during ion implantation work, but if there are multiple ion sources, However, the number is not limited to two, and the arrangement thereof does not have to be symmetrical in opposing positions, as in the embodiments.

In addition, in the example, two ion source systems are provided, and a vacuum υ1 gas system is provided for each of them, and a dedicated power supply for dry firing of 1γ is provided, and the power supply system and gas box are commonly used. However, there are various other items that can be shared, including the vaporizer system and the ion source electromagnet power system. However, it goes without saying that various power supply systems such as gas boxes may be provided independently.

Further, in the embodiment, a blocking portion is provided on the ion beam introduction tube side to block the ion beam from the ion source, but the location does not matter as long as it can block the ion beam. Particularly, when the structure is such that a plurality of ion sources are not arranged in opposing positions, such a blocking part is not necessarily 7 hazes.

[Effects of the Invention] As can be understood from the explanation below, the ion implantation method of the present invention is a 21-person ion device having a first and a second ion source, Operation of these first and second ion sources
Since the ion source - which is in a functional state is operated, and the preparation process for the other ion source is performed while one ion source is in operation, the filament of the ion source may break. Even if the other ion source emits ions, the ion 21 device can be
1, it is possible to secure time for the ion source chamber of one of the ion sources to cool down slowly and naturally while maintaining the ion source chamber itself in a vacuum.

As a result, the chamber itself can be naturally cooled for 1 minute, extending its life span, and the ion beam does not need to be interrupted during this period.

Also, the unusable ion source is Filamen]
・Even if the ion source chamber and the ion source itself are vacuumed up after replacement and degassed by dry firing of the ion source chamber and the ion source itself, ions can be implanted from the other ion source during this time, improving the efficiency of the 21-person ion system. Direction 1
- can be done.

Furthermore, in the event that a crystalline Fi discharge occurs due to a defect in the ion source housing itself, the chamber itself must be removed from the main body, disassembled, cleaned, and disassembled. After iJt cleaning, ion source 1 unong σ month 11 set ＼γ te 1
-1, I will attach it to the ion 71 person device and do 11 L'L empty pulls, but one side will eliminate the minute! It is also possible to continue ion work by 11 people from the other ion source even when the ion source is in the middle of the process.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram centered on the ion source part of a 21-person ion device to which the ion implantation method υ of the present invention is applied;
FIG. 2 is an explanatory diagram of the power supply circuit, FIG. 3(a) is an explanatory diagram showing an example of a conventional Freeman type ion source, and FIG. 3(b) is an explanatory diagram of the ion source. It is an explanatory diagram. DESCRIPTION OF SYMBOLS 30... Ion 21 person apparatus, 31... First ion source, 32... Second ion source, 33... Power supply part, 34... Gas box, 35a... First ion source Ion source diffusion pump, 351)...Second ion source diffusion pump, 36a...First ion beam introduction tube, 36b...Second ion beam introduction tube, 37a.
...first cutoff section, 37a...first cutoff section, 39.
... quality analyzer, 40 ... power supply circuit, 41 ... power supply for ion source, 42 ... power supply for dry firing, 43 ... switching circuit section. Patentil! Applicant: Tokyo Electron Co., Ltd. Representative Patent Attorney: Kaji Yama Kore Patent Attorney-1 Yamaki Tomi 1-O Figure 1 31 False Figure 2

Claims (4)

[Claims] (1) An ion implantation method in an ion implantation apparatus having first and second ion sources, in which one of the first and second ion sources in an operable state is operated, and one of the first and second ion sources is operated. An ion implantation method characterized by performing operation preparation processing on another ion source while one ion source is in operation. (2) The ion implantation device includes first and second extraction electrodes provided corresponding to the first and second ion sources;
Corresponding to the first and second ion beam introduction tubes that introduce ions extracted from the first and second ion sources into the mass spectrometer, and the channels of the first and second ion beam introduction tubes, respectively. The ion source is provided with first and second cutoff parts that separate the ion source in operation and the ion source in operation preparation processing so that they do not affect each other, and an ion source power supply, and the first and second cutoff parts are provided. ion source and the first
Then, the inside of the second ion beam introduction tube is evacuated, and then either the first blocking section or the second blocking section is opened, the other is blocked, and the side corresponding to the open state is opened. The ion source is operated by generating an ion beam by connecting the ion source power source to the ion source, and
Claim 1, characterized in that an operation preparation process is performed for the ion source on the side corresponding to the cut-off state.
Ion implantation method described in section. (3) The ion implantation device includes first and second extraction electrodes provided corresponding to the first and second ion sources;
Corresponding to the first and second ion beam introduction tubes that introduce ions extracted from the first and second ion sources into the mass spectrometer, and the channels of the first and second ion beam introduction tubes, respectively. The ion source is provided with first and second cutoff parts that separate the ion source in operation and the ion source in operation preparation processing so that they do not affect each other, and an ion source power supply, and the first and second cutoff parts are provided. The blocking part is connected to the first and second
an air valve, and first and second shutters that are provided correspondingly to the first and second air valves and interlock with these to shut off the ion beam, and a valve and a first shutter and a second
Either one of the air valve and the second shutter is opened, the other is closed, and the ion source and ion beam introduction tube on the side corresponding to the open state are evacuated, and then, The ion source is operated by generating an ion beam by connecting the ion source power supply, and the ion source on the side corresponding to the other side in the closed state is subjected to operation preparation processing. An ion implantation method according to claim 1. (4) The ion implantation method according to claim 2 or 3, wherein the dry firing process is performed by connecting a power source different from the ion source power source to the ion source in the operation preparation process.