JP2667206B2 - Ion source test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an ion source test apparatus.

(Prior Art) In an ion implantation apparatus, a filament of an ion source set in a chamber is energized, and thermions emitted by heating the filament ionize a carrier gas in the chamber, and the ionized gas is converted into a gas. The ion implantation for the wafer is performed based on the above.

Here, the ion source set in the above-mentioned ion implantation apparatus is periodically replaced after the filament is replaced or the ion source is disassembled due to the wear of the filament used as the hot cathode, the insulator for filament insulation, the contamination of the arc chamber, and the like. It is necessary to frequently perform cleaning and the like.

Usually, a plurality of ion sources of this kind are provided, and after the end of their life, they are replaced with ion sources whose maintenance has been completed, and during that time, cleaning of the contaminated ion sources, replacement of filaments, and the like are performed.

(Problems to be Solved by the Invention) The ion source used in the ion implantation apparatus is detached from the ion implantation apparatus for regular maintenance as described above, and this is again replaced by the ion implantation apparatus. When set to, defects may occur due to disassembly and assembly,
Conventionally, the above-mentioned deficiencies were found when the ion implantation apparatus was operated with an ion source attached. Accordingly, in such a case, the operation of the ion implantation apparatus is stopped, and a method of resetting a different ion source or repairing the defect of the ion source and using the same is adopted.

As described above, conventionally, after the ion source was set in the ion implanter, it was discovered that the ion source was defective in its operation. Therefore, it was time-consuming to attach and detach the ion source, and the operating rate of the ion implanter was poor.

Therefore, an object of the present invention has been made in view of the above points, and in order to guarantee the normal operation of the ion source set in the ion implanter by replacement, a function test of the ion source is performed. An object of the present invention is to provide an ion source test apparatus that can be executed.

[Structure of the Invention] (Means for Solving the Problems) An ion source test apparatus according to the invention of claim 1 is an ion source capable of ionizing a carrier gas in an arc chamber that insulates and supports a thermoelectron emission unit. And a chamber whose interior can be evacuated so that the thermoelectron emission portion of the ion source, which is the test object, is set in a vacuum atmosphere. Energizing means for energizing the thermoelectron emitting portion of the ion source, and a current value for energizing the thermoelectron emitting portion being variable; current detecting means for detecting a current flowing from the thermoelectron emitting portion into the arc chamber; A comparing unit that compares a current detected by the current detecting unit with a predetermined reference value; and a display unit that displays an abnormal state based on a comparison result of the comparing unit. Wherein the energizing means, the current detecting means, and the comparing means are also used for a current leak test and a thermoelectron emission amount determination test, and a current value applied to the thermoelectron emitting section by the energizing means is When the comparing means determines that the current detected by the current detecting means when the current is high is lower than a reference value, the display means displays an abnormality in the amount of thermionic emission, and the thermoelectric emission from the energizing means is performed. The current leak abnormality is displayed on the display means when the current detected by the current detection means when the current value supplied to the unit is low is determined by the comparison means higher than a reference value. And

The invention according to a second aspect is characterized in that the ion source, which is the test object, has a filament as the thermoelectron emitting section, and the energizing means energizes the filament.

(Operation) The lifetime of the thermionic emission portion of the ion source, for example, the filament lifetime is short, and the lifetime of the ion source coincides with the lifetime of this filament. In such a case, filament replacement is an indispensable maintenance operation. For this reason, as a defect when the ion source after maintenance work is attached to the ion implanter, even if the newly set filament is energized, thermoelectrons are not emitted to the reference value and the carrier gas is properly discharged. There are many situations where ionization is not possible.

According to the present invention, it is possible to test the operation of emitting thermionic electrons from a thermionic emission unit, for example, a filament, before setting the ion source whose maintenance work has been completed in the ion implantation apparatus.

That is, the test whether or not the thermoelectron emission operation is reliably performed in the state of the ion source alone is conducted by energizing the thermoelectron emission part of the ion source set in the chamber of the test apparatus, for example, the filament, Since electrons flow into the arc chamber, it becomes possible by checking the emission current value at this time. At this time, it is not always necessary to introduce a process gas to perform ionization, but it is sufficient to check whether a specified amount of thermoelectrons are emitted by checking an emission current.

With the above configuration, if a low current that does not release thermoelectrons from the filament is passed, it is possible to test for the presence or absence of a leak current between the arc chamber that holds the filament insulator, so insulation failure is possible. Can be used as a test of whether or not.

Further, a configuration in which a vacuum leak test is also performed may be employed. That is, the ion source is inserted through the opening of the chamber, and the opening is arranged so as to be sealed by the ion source (usually a flange portion of the ion source). It becomes possible by measuring the degree.

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

This test apparatus includes a first operation display unit 2 on the upper left side of the gantry 1, a second operation display unit 4 inside the gantry 1 and exposed by opening the door 3, and a right side in the gantry 1. And a test port 5 on which an ion source is set.

The test port 5 will be described with reference to FIGS. 2 to 4. First, the vacuum piping system of the chamber 10 in the gantry 1 is configured as shown in FIG.

The chamber 10 has an ion source inserted from above, and the inside of the chamber 10 can be evacuated. At least the flange 10a, which is the opening for inserting and removing the ion source of the chamber 10, and the ceiling 10b (see FIG. 7) attached to the flange 10a should have the same shape as that used in the chamber of the ion implantation apparatus. Is preferred. As means for making the interior of the chamber 10 evacuable, a vacuum pump 12, a fore valve 16, a rotary pump
18 is connected. Further, the vacuum pipe 12 is
A leak test port 22 is connected via a valve 20, and a helium leak detector (not shown) can be connected to the leak test port 22, for example.
The helium leak detector detects a leak location when a minute vacuum leak occurs when the ion source is set. Note that a quadrupole analyzer can be connected inside the chamber 10.

In addition, near the suction port of the rotary pump 18, a minute leak valve 24 is connected.
By the adjustment, the degree of vacuum at the suction port of the rotary pump 18 can be set to about 50 mTorr. If the micro leak valve 24 is closed too much, it causes oil up. Conversely, if the micro leak valve 24 is opened too much, the ultimate vacuum degree deteriorates, which causes abnormal operation.

Further, the chamber 10 has an HCIG 30 used for measuring a high vacuum of 1 × 10 ⁻³ Torr or more, and a pressure of 1 × 10 ⁻³ T from atmospheric pressure.
A convexron gauge 32 used for measuring the degree of vacuum up to orr, an atmospheric pressure sensor 34 for detecting that the pressure in the chamber 10 has become atmospheric pressure, and a leak valve 36 are connected to each other.

The chamber 10 is configured to purge with N2 after the test of the ion source at a high vacuum degree is completed and before the ion source is carried out. As a configuration for this, as shown in FIG. From 4 to 7 kg /
N2 pipe 38 leading to the fore valve 16 at a pressure of ² cm, 0.3 kg
There is provided a pressure reducing valve 40 that reduces the pressure to / cm ² and guides the N 2 gas to the leak valve 36 and the minute leak valve 24. This N2 purge is continued until the atmospheric pressure sensor 34 detects that the atmospheric pressure has been reached.
The ion source is departed from within 10.

Next, regarding the cooling water piping system of the test apparatus,
Explaining with reference to the figure, this piping system has an IN side valve 5
The 0, OUT side valve 52 and the flow switch 56 are provided, and water cooling is performed by circulating cooling water around the chamber 10, the rectifier 54, and an electrode 80 described later of the ion source. The flow switch 56 checks the flow rate of the cooling water by a sequencer (not shown), and circulates cooling water at a temperature of 25 ° C. or less at a rate of 1.5 to 2 / min or more.

Next, the ion source will be described with reference to FIG.

This ion source 60 is composed of a large-diameter upper flange 62 formed with handle portions 62a and 62b and a small-diameter lower flange 64 formed of four columns.
66, the arc chamber 68 is fixed to the lower flange 64. The arc chamber 68 is provided with an opening 68a forming an ion passage hole, and a filament 72 supported by the arc chamber 68 with both ends insulated by an insulator 70 is provided therein.

In order to energize the filament 72, both ends of the filament 72 are screwed and fixed to electrode rods 74, 74, respectively, and the upper ends of the electrode rods 74, 74 are insulated and supported by the upper flange 62. . Further, the portions of the electrode rods 74, 74 projecting above the upper flange 62 can fix the electrode 80 as shown in FIG. 6 by bolts 76, 76.

The electrode 80 has a hole for inserting the bolt 76 at the center thereof.
82 and two holes 84, 84 for fixing the cable on two slopes of the hexagonal side surface. Note that these two holes 8
4, 84 are formed so that the shape of the two electrode portions 80, 80 is common, and the power lead cable is inserted into one of the holes 84.
Used by connecting 86. Further, in order to cool the electrode 80 itself, cooling water pipes 88 and 89 on the IN side and the OUT side are connected.

Since the ion source 60 needs to introduce a carrier gas into the arc chamber 68 when it is set in the ion implantation apparatus, a gas introduction tube 78 is provided.

The ion source 60 can be set in the ion source test apparatus by being inserted into the chamber 10 so that the flange 10a of the chamber 10 and the upper flange 62 are in close contact as shown in FIG. There is. A sealing member 10b for hermetically sealing the upper opening of the chamber 10 by being in close contact with the upper flange 62 is provided on the flange 10a of the chamber 10, and the flange 10a
A sensor (not shown) for detecting that the upper flange 62 has been set is disposed in the sensor.

Further, in the present embodiment, the ion source 60 is simply attached to the flange 10a by its own weight, and bolt fixing is not required. After the ion source 60 is set in this way, the electrodes 80, 80 are fixed to the ion source 60 by bolts 76, 76.

Next, an electric system for energizing the filament 72 of the ion source 60 will be described with reference to FIG.

The filament 72 is used as a hot cathode, so that a negative voltage, for example, -80 V is applied,
On the other hand, the arc chamber 68 is installed, and an electric field can be formed during the installation.

As an electric system for energizing this filament 72,
A sequencer 90, a control circuit 92, a filament power supply 94, and an emission power supply 96 are provided.

Then, AC100V can be supplied to each block, the power supply to the control circuit 92 and the emission power supply 96 is controlled by the relay control of the sequencer 90, and the filament power supply 94 is controlled by the relay control of the control circuit 92. It is possible to control the power supply of.

The filament power supply 94 is for supplying a filament current to the filament 72, and can vary a current value within a range of 0 to 200A.

On the other hand, the emission power supply 96 energizes the filament 72 when insulating the filament 72 and checking the emission current, as described later. A current detection circuit is provided in the emission power supply 96 as the insulation check and the emission current value check.

Next, the first and second operation display sections 2 and 4 will be described.

On the first operation display section 2, an HCIG controller 100 and an operator panel 102 are vertically arranged. The HCI
The G controller 100 is used for measuring a high vacuum of 1 × 10 ⁻³ Torr or more in the chamber 10.

The operator panel 102 performs an operation when the apparatus is operated fully automatically, and displays the degree of vacuum and the filament current, and has the configuration shown in FIG.

Convectron gauge: As mentioned above, 1 from atmospheric pressure
Displays the degree of vacuum up to × 10 ^-3 Torr.

Filament current: The filament current flowing through the ion source 60 is displayed between 0 and 200 A.

Abnormal display / vacuum leak: Lights when there is a vacuum leak in the ion source 60.

Abnormal display / insulation failure ... Lights up when a leak current flows in the ion source 60.

Abnormality display / device abnormality ... Lights in the following states.

1. When the fore valve 16 is not completely open.

2. When the rotation is abnormal due to the failure of the turbo pump 14.

3. When the degree of vacuum is poor and the rotation of the turbo pump 14 does not reach a constant speed.

4. When the cooling water is not flowing.

5. When filament current is not flowing.

Mode / degas switch: Checks the following.

1. Vacuum leak of ion source 60.

2. Insulation of ion source 60.

3. Emission source of ion source 60.

Mode / leak check: A vacuum leak test of the ion source 60 is performed.

RESET: Lights up when an error occurs or when END occurs. Since the buzzer sounds at the same time, it is released by this button.

START: Used when starting an automatic sequence and when restarting after HOLD.

HOLD: Used to pause the sequence midway.

STOP / END: Used to completely stop the sequence midway. When the sequence is in the stop mode, the sequence blinks. When the sequence is completely stopped, the sequence is turned on.

Next, the second operation display unit 4 will be described.
The second operation display unit 4 is provided with a turbo pump controller
104, manual operation panel 106, rotary pump breaker 10
8 and a main breaker 110.

The turbo pump controller 104 controls the number of revolutions of the turbo pump 14. If an abnormality occurs in the turbo pump 14 or the degree of vacuum in the chamber 10 is poor, the turbo pump 14
If the load is too high, the FAILURE lamp will light up and stop.

The manual operation panel 106 is used when performing manual operation of the present apparatus and when operating each unit alone for maintenance. Each switch and LED perform the following operations.

AUTO / MAN: Selects AUTO (automatic) and MAN (manual) operation.

BUZZER ON / OFF… If an error occurs automatically during operation,
Also, the buzzer sounds when the progress of the sequence is completed, and it is turned off when the buzzer sounding function is stopped.

FV OPEN / CLOSE: Open / close the fore pulp 16 between the vacuum pump rotary pump 18 and the turbo pump 14.

N2V OPEN / CLOSE: Opens and closes the N2 leak valve 36 when the vacuum chamber 10 is set to the atmospheric pressure.

Emission power ON / OFF: DC power supply and control circuit for insulation of ion source 60 and emission confirmation
Turn ON / OFF 92.

Filament power ON / OFF Turns on / off the filament power supply of the ion source 60.

Filament current UP / DOWN: UP / DOWN the filament current of the ion source 60.

Sequencer / CPU: Lights when the sequencer 90 is not operating due to an error.

Sequencer / BATT: Lights when the battery for the sequencer 90 memory is low.

The rotary pump breaker 108 supplies electric power to the rotary pump 18, and the main breaker 110 turns on / off the electric power supplied to the device.

Next, the operation of the above embodiment will be described with reference to the flowchart of FIG.

After purging N2 gas into the chamber 10, the ion source
After setting 60 in the chamber 10 of the test apparatus and connecting the electrode 80 to the filament 72 of the ion source 60, first check the mounting switch of the ion source (step 1), and then open the fore valve 16 Yes (step 2). After 2 seconds (step 3), the fore valve
It is determined whether or not 16 is in the open state (step 4), and if NO, a device abnormality is displayed and the stop mode is set (step 5).

If the determination in step 4 is YES, it is determined whether or not the degree of vacuum of the chamber 10 is 0.15 Torr or less after a predetermined time has elapsed (step 6). Display and enter stop mode (step 7,
8).

If the determination in step 6 is YES, the turbo pump 14
Is turned on (step 9), and it is determined whether or not the turbo pump 14 is in the RUN state (step 10). NO after 15 minutes
If so, a device abnormality is displayed and the stop mode is set (steps 11 and 12).

If the determination in step 10 is YES, HCIG is turned ON (step 13), and it is determined whether HCIG emission is ON (step 14). If NO, turn on HCIG every 5 minutes
The operation is repeated (steps 15 and 16), and if NO even after repeating three or more times, a vacuum leak is displayed and the stop mode is set (step 17).

If the determination in step 14 is YES, after 2 minutes have passed (step 18), the degree of vacuum in the chamber 10 is reduced to 2E-4 Torr.
It is determined whether or not it is below (step 19). If NO after 10 minutes, a vacuum leak is displayed and the stop mode is set (steps 20 and 21).

In this manner, the case where the opening of the chamber 10 is sealed by the ion source 60 and then the inside of the chamber 10 is evacuated, and if there is a vacuum leak in this sealed portion, in steps 8, 17, and 21, Since a display to that effect is made,
The presence or absence of the vacuum leak of the ion source 60 can be reliably inspected. And especially the flange 10 of the chamber 10.
If the shape of a and the function of the sealing 10b are configured in the same manner as the chamber configuration of the ion implantation apparatus, the same ion source 60 is set in the ion implantation apparatus if no vacuum leak occurs in this test apparatus. Also, it can be ensured that no vacuum leak occurs.

If the determination in step 19 above is YES, it is next determined whether or not a leak check has been selected (step 22). If YES, the stop mode is set (step 23). Is determined to be ON (step 24), and if NO is determined, a device abnormality is displayed and the stop mode is set (step 25).

If the determination in step 24 is YES, the filament power supply 94 and the emission power supply 96 are turned on (step 26). Then, in order to determine whether the insulation between the filament 72 and the arc chamber 68 is proper, the current detection circuit in the emission power supply 96 determines whether the leak current is 0.1 A or less (step 27). ). As a result, if NO, an insulation failure is displayed and the stop mode is set (step 28).

If the insulation is not defective, the counter of the filament control circuit 92 is reset (step 29), and the filament current is increased to a predetermined current value, for example, 80 A (step 30). Then, after 1 minute has elapsed (step 31), the emission current due to the thermoelectrons ejected by the heating of the filament 72 flowing into the arc chamber 68 is measured by the current detection circuit, and this is measured by a predetermined reference value, for example, 0.1 A. It is determined whether or not it is below (step 32).

If the determination in step 32 is NO, the operation is a normal operation in which an appropriate amount of thermionic electrons are emitted, so the process proceeds to step 42 described later. .

In step 33, the degree of vacuum in the chamber 10 is 3E-3Tor
It is determined whether or not it is equal to or less than r. If NO, the filament current is lowered by 20 A, and the process is repeated for 3 minutes (step 3).
Four). If YES, the filament current is increased to 20 A and the apparatus stands by for one minute (steps 35 and 36).

Next, it is determined whether or not the SLIDAC is HIGH LIMIT (step 37). If YES, the apparatus abnormality is displayed and the stop mode is set (step 38).

If the determination in step 37 is NO, it is determined again whether the emission current is 0.1 A or less (step 3).
9) If NO, the emission of thermoelectrons is normal, so the flow proceeds to step 42 described later.

If the determination in step 39 is YES, it is determined again whether or not the degree of vacuum in the chamber 10 is equal to or less than 3E-3TORR (step 40). If NO, the filament current is lowered by 20 A and waits for 3 minutes. Repeat (step 41). If YES, the process returns to step 35 to repeat the above flow.

The emission current is 0 in step 32 or step 39.
1A or more (Thermionic emission operation of ion source 60 is normal)
To reduce the filament current to zero (step 4
2) Even in this case, it is determined whether the emission current is 0.1 A or less (step 43). If NO, an insulation failure is displayed and the stop mode is set (step 4).
Four).

If the determination in step 43 is YES, the process waits for 30 minutes (step 45) and turns on HCIG (step 46). After this,
Wait for 2 minutes (step 47). The degree of vacuum in the chamber 10 is 2E
It is determined whether it is equal to or lower than -4TORR (step 48).
If NO, a vacuum leak is displayed (step 4
9).

If the judgment in step 48 is YES or step 5
When the STOP command is input at 0, the STOP display flashes and the following flow is executed. That is, the HCIG power, the filament power, and the emission power are turned off (step 51), and the turbo pump 14 is turned off to wait for 7 minutes (steps 52, 53).

Further, close the fore valve 16 (step
54), the vent valve is opened (step 55), and when the atmospheric pressure sensor 34 is turned on and the inside of the chamber 10 reaches atmospheric pressure, an END display is performed, and a series of operations is completed (steps 56 and 57).

As described above, according to the apparatus of the present embodiment, before the ion source 60 whose maintenance is completed is set in the ion implantation apparatus,
By heating the filament 72 in the state of 60 alone, it is possible to inspect by the test device whether or not the thermionic emission can be normally executed. In particular, since the replacement of the ion source 60 is often performed based on the life of the filament,
There is a high possibility that the mounting failure of the filament 72 or the failure of the filament 72 itself may occur, and the significance of performing this type of inspection before setting it in the ion implantation apparatus is increasing.

When the ion source 60 is set in the chamber 10, the presence or absence of a vacuum leak can be tested by evacuating the chamber 10 and measuring the degree of vacuum.

And if the operation of emitting thermoelectrons is not normal,
Or, if a vacuum leak occurs, it is possible to recognize this in the test stage before setting it in the ion implanter, so set only the ion source 60 that is guaranteed to operate normally in the ion implanter. Therefore, the operating rate of the ion implantation apparatus is improved, and it is possible to save the trouble of attaching and detaching the defective ion source 60 twice.

Further, in the present test apparatus, by degassing the filament 72, the insulator 70, the arc chamber 68, and the like by setting the inside of the chamber 10 to a high vacuum state and energizing the filament 72, the ion implantation apparatus can perform the degassing. There is also an advantage that the degassing step can be omitted or shortened.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

[Effects of the Invention] As described above, according to the present invention, before setting the ion source to be exchanged in the ion implantation apparatus, it is possible to confirm the thermionic emission operation in the state of the ion source alone, and It is possible to improve the operation rate of the ion implanter by saving the labor of attachment and detachment when the ion source is set in the ion implanter and ensuring that a normal ion source is always set in the ion implanter. it can.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an ion source test apparatus according to one embodiment of the present invention, FIG. 2 is a schematic explanatory view showing a vacuum piping system of the same apparatus, and FIG. 3 is an N2 piping system of the same apparatus. FIG. 4 is a schematic explanatory view showing a cooling water piping system of the above apparatus, and FIGS. 5 (A), (B) and (C) are front views for explaining an ion source, FIG. 6 is a schematic perspective view of an electrode attached to the ion source, FIG. 7 is a schematic cross-sectional view for explaining an attached state of the ion source to the chamber, FIG. FIG. 8 is a block circuit diagram showing a configuration of an electric system for energizing a filament of the ion source. FIG. 9 is a front view of the first and second operation display units. FIG. It is a flow chart for explaining operation. 10 ... chamber, 30 ... vacuum leak detection means (HCIG), 60 ... ion source, 68 ... arc chamber, 70 ... insulator, 72 ... filament.

Claims (2)

(57) [Claims] 1. A function test for an ion source capable of ionizing a carrier gas in an arc chamber that supports and insulates a thermoelectron emitting portion, the thermoelectron emission of the ion source being a test object. A chamber whose interior can be evacuated so that the section is set to a vacuum atmosphere; and a current value for energizing the thermoelectron emitting section of the ion source set in the chamber and energizing the thermoelectron emitting section. Is variable, current detecting means for detecting a current flowing from the thermoelectron emitting section into the arc chamber, and a comparison for comparing the current detected by the current detecting means with a predetermined reference value. Means, and a display means for displaying an abnormal state based on the comparison result by the comparison means, wherein the energization means, the current detection means and the comparison means,
Used as a current leak test and a thermoelectron emission amount determination test, when the current detected by the current detection unit when the current value supplied to the thermoelectron emission unit by the conduction unit is high is lower than a reference value. When judged by the comparison means,
The display means displays an abnormality in the amount of emitted thermoelectrons, and when the value of the current detected by the current detecting means when the value of the current supplied to the thermoelectron emitting section is lower than that of the conducting means, the comparison is made when the detected current is higher than a reference value. An ion source test apparatus, wherein the current leakage abnormality is displayed on the display means when judged by the means. 2. The ion source test apparatus according to claim 1, wherein the ion source as a test object has a filament as the thermoelectron emitting section, and the energizing means energizes the filament. .