JPH0740480B2 - Ion implantation system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion implantation system, and more particularly, to an ion having an automatic start-up function capable of improving the start-up accuracy and shortening the start-up time. Regarding infusion system.

[Prior Art] As an ion implanting device for accelerating impurity ions generated in an ion source in a high electric field to implant them in a semiconductor substrate,
For example, there is an ion implanter having a hot cathode type ion source represented by the Freeman type. This is widely used as an ion implantation apparatus for a semiconductor manufacturing apparatus because ions are generated in a stable state and maintenance is easy.

FIG. 5 (a) shows an example of such a conventional Freeman type ion implanter, and FIG. 5 (b) shows
It is explanatory drawing of the ion source.

Reference numeral 1 denotes an ion source, and positive ions are extracted from the ion source 1 with a constant energy by an extraction electrode 2 serving as a pre-accelerating portion for ion extraction, and subjected to mass analysis by a mass analyzer 3 serving as a mass analysis portion. Then, the desired ions completely separated by the slit 4 are accelerated to the final energy by the accelerating tube 5.

Next, the ion beam is quadrupole lens 6 as a lens system.
Are converged by the substrate surface 12 so as to have a converging point, and the scanning electrode as the beam deflector and the scanning electrode of the deflection electrodes
The implantation amount is controlled so as to be uniformly distributed on the substrate by 7, 8 and is bent by the deflection electrode 9 to reach the substrate 12 through the mask 10 as the target portion and the Faraday cup 11.

Here, the Faraday cup 11 is provided to detect whether the ion beam is being controlled as intended, and includes a corner Faraday cup, a fixed Faraday cup, a variable Faraday cup, and the like. When the primary ions collide with the end plate and the wall of the cup 11 in the cup 11, secondary electrons and secondary positive ions are generated. By measuring these, the beam current is measured.
In order to improve the accuracy, a mask 10 is provided on the front surface of the Faraday cup 11 to limit the incident angle of primary ions to a fixed value. These act as detectors, and the ion beam currents detected by these detectors are displayed on an oscilloscope and used as reference data when the operator makes adjustments.

The beam current waveform displayed on the oscilloscope usually has a trough in the central portion when it is scanned in the X or Y direction from the structure of the Faraday cup (the structure of FIG. 5 is simplified). It has a double mountain shape that generates a characteristic current value.

By the way, the dose amount for controlling the doping concentration is defined as follows.

Here, I is the beam current [μA], t is the time [s], and A is the scanning area [cm ² ].

On the other hand, as shown in FIG. 5 (b), the ions are ionized in the ion source chamber 22 which has been evacuated to a vacuum degree of about 1 × 10 ⁻⁷ torr, and the rod-shaped filaments arranged there. It is extracted as an ion beam in the direction perpendicular to 21.

In addition, 20 is an ion source housing, 23 and 23 are electromagnets, 24 is a ground electrode, 25 is a slit, 26 is a gas inlet,
27 is an ion beam.

Now, in order to start up such an ion implanter on a daily basis and change the set value, the operator observes the waveform of the oscilloscope and adjusts it so that it becomes an appropriate value.
This is done by first stopping the scanning in the X and Y directions to find the minimum value of the beam current, storing this value, and approximating it to that data during actual operation.

[Problems to be Solved] Generally, the minimum value of the beam current is obtained by moving the beam little by little to obtain a quadratic curve and then obtaining the value of the minimum point. However, in such a method, there is no guarantee that the beam scanning will be equivalent in actual operation and sufficient accuracy cannot be ensured.

Further, such an approximate operation for obtaining the minimum value of the beam electrode requires the operation of a skilled operator, and since this operation is so-called open-loop control, if there is any condition change in the device, Can not be determined, there is no guarantee that it is set to the optimum value,
It's a problem.

In addition, the operator must observe the oscilloscope waveform every time the ion implanter is started up and changes the setting value, and make adjustments so that the value is appropriate. In reality, it is difficult to control variations and accuracy.

[Object of the Invention] The present invention solves the above-mentioned problems of the prior art, and automatically starts an ion implantation apparatus that has been conventionally adjusted manually, thereby reducing the number of adjustment steps and variation in startup. An object of the present invention is to provide an ion implantation system capable of improving its accuracy.

[Means for Solving Problems] The feature of the ion implantation system of the present invention for achieving such an object is that the Faraday cup reduces the beam current by X.
It has a structure in which a current value having a characteristic of having a valley in the central portion is generated when the beam current is scanned in the Y direction or the Y direction. The first integral value of the first rising portion of the measured waveform corresponding to the scanning direction of the current value obtained from the measuring means, the second integral value of the falling portion of the central portion and the rising portion thereof, and finally The integrated value calculating means for calculating the third integrated value of the trailing edge of the, and various control values stored in the storage device are set so that the first, second and third integrated values become the minimum values. The various control values obtained when the ion implantation apparatus is controlled so that the first, second and third integral values of the minimum values are stored corresponding to these various control values. When starting up the device Arithmetic processing unit,
The control values stored in the memory device are used as target values, and various control values are given to the ion implanter for control to determine whether the current various device values of the ion implanter are within the allowable range with respect to the target value. Then, the current various control values given to the ion implantation apparatus are set within an allowable range, and the arithmetic processing device stores the first, second, and third values stored in association with the various control values stored in the storage device. The current values are given to the ion implantation apparatus so that the respective first, second and third integral values calculated by the integral value calculating means by using the third respective integral values as the target judgment values are minimum values. The control unit sets the optimum control values by controlling the various control values of, and the arithmetic processing unit has the obtained optimum present control values and the present first, second and third integral values. With various control values already stored in the storage device 1, is to update instead of the second and third integrated value.

[Operation] Normally, if various control values are automatically set to target values, the optimum value is set to a general manufacturing apparatus.
In the ion implantation apparatus with the focusing of the beam current, it changes depending on the operating environment of the apparatus, and therefore it cannot be set with a fixed target value.

Moreover, the form of the beam current changes even if any of the variably set control values is changed, and influences each other, so that it takes a very long time to manually adjust it to the optimum value.

Therefore, as described above, if the past optimum set value is used and set as a target value in the vicinity of the target value, there is an allowable range, so it is possible to narrow down to a range that changes according to the operating environment. it can.

After this narrowing down, in the measured waveform of the beam current, the optimum adjustment mainly based on the focusing of the beam current is made with the integrated values of the first rising part, the central falling part and the rising part and the last falling part as parameters. to go into.

By thus dividing the control into two stages to obtain the optimum value, it becomes easy to finely adjust to the optimum value, and it is possible to operate at the optimum value in a short time. The judgment function is greatly improved. Furthermore, the non-uniformity of the dose amount can be eliminated, and the yield can be improved.

As a result, working efficiency can be improved.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an ion implantation system to which the present invention is applied, and FIG. 2 is a flow chart of its startup processing,
FIG. 3 is an explanatory diagram of a search table necessary for the processing, and FIG. 4 is an explanatory diagram of observed waveforms.

As shown in FIG. 1, this ion implantation system 100
An ion implanter 30 and an automatic start-up controller 31, a control data measuring circuit 32, and an input / output control circuit 33 are provided. The ion implanter 30 is a device corresponding to FIG. In the figure, the internal structure is shown as a block.

Here, the ion implanter 30 has an ion source (ion source) 41, an ion extraction pre-stage acceleration unit 42, and an ion source control unit 43 that controls the ion source 41 and the ion extraction pre-stage acceleration unit 42. , Selection of specified gas,
A gas flow rate control, a filament current, a source magnet current, an arc current, etc. are selected or controlled by the ion source control unit 43, and a desired ion beam is sent to the mass analysis unit 44. Then, this ion beam is controlled under the control of the analyzer magnet controller 45, and only the necessary ions are deflected by 90 ° and extracted.

Next, the ions selected from the ion beam are sent to the post-stage acceleration unit 46, and under the control of the beam energy control unit 47, acceleration control is performed at, for example, about 10 kV to 200 kV, and the lens control unit in the lens system 48. The focus is controlled by the control of 49 and enters the beam deflecting unit 50. In the beam deflection unit 50, the XY scan offset control unit 51 scans the beam in the X and Y directions, and a DC offset voltage is applied to remove the neutralized beam.

By the way, since the XY scanning of the beam and the removal of the neutralized beam are affected by the ion species, the beam energy, the beam current value, etc., the set value should be selected as an appropriate value on the target. The wafer is centered. Also, to avoid excessive overscan, X,
Adjust the Y scan voltage.

The target part 52 is irradiated with the ion beam controlled in this way, but the target control part 53 controlling the target part 52 scans the current value measured in the main Faraday with an X or Y scan. Then, the display 36 displays the oscilloscope observation waveform as shown in FIG. 4 through the arithmetic processing unit 35 of the automatic start-up control unit 31.

The target control unit 53 is the main Faraday control unit.
53a and an end station control section 53b for controlling an end station for switching a sample wafer.

In addition, the dose processor 54 measures the ion beam current hitting the wafer, continues ion implantation until a preset dose amount is reached (usually, a value that ends in about 10 seconds), and integrates the ion beam current. When the value reaches a target dose amount, wafer switching is performed via the end station control unit 53b.

The control data measurement circuit 32 includes an ion source control unit 43, an analyzer magnet control unit 45, a beam energy control unit 4
7, lens control unit 49, XY scan offset control unit 5
1, the main Faraday control unit 53a, and the end station control unit 53b to detect or measure the current control value, respectively, each detected value or measured value is calculated by the automatic start-up control device 31 via the input-output control circuit 31 It is sent to the processing device 35.

Here, as the detected value or the measured value, as shown in the column 62 of the control data table 60 shown in FIG. 3, the filament current value, arc current value, source magnet current value, analyzer current value, lens adjustment value, XY scan It is the voltage value, offset value (OFFSET value), beam current value (maximum value), judgment A, B, C, etc. for the observed waveform.

The automatic start-up control device 31 has an input / output control circuit 33 connected to an arithmetic processing unit 35 via a bus 34. The arithmetic processing unit 35 includes an ion source control unit 43, an analyzer magnet control unit 45, and a beam energy. Control unit 47, lens control unit
49, the XY scan offset control unit 51, the main Faraday control unit 53a, and the end station control unit 53b obtain respective control values corresponding to the current operating state from the input / output control circuit 33 via the control data measuring circuit 32. . In addition, the arithmetic processing unit 35 outputs, via the input / output control circuit 33, a vacuum value of the ion implantation apparatus 30, an open / closed state signal of each opening / closing door or the like for confirming the sealed state, and other various state information regarding the ion implantation apparatus 30. From the ion implanter 30. Then, the optimum control value is sent to each of the control units of the ion implantation apparatus 30 via the input / output control circuit 33.

The input / output control circuit 33 includes a D / A conversion / relay switching control circuit and the like, and the A / D conversion circuit converts control analog data such as voltage value and current value obtained from each control unit into a digital value. And transfers it to the arithmetic processing unit 35. Similarly, the D / A conversion circuit converts the control value of the digital value sent from the arithmetic processing unit 35 side into an analog value and sends it to each control unit.

Further, the relay switching circuit is for sending to the ion source control unit 43 a control signal for selectively switching ion species based on a command from the arithmetic processing unit 35.

The arithmetic processing unit 35 of the automatic start-up control device 31 includes a microprocessor and a memory, is realized by each program stored in the memory, and is configured by the following means. That is, the arithmetic processing unit 35, the control value determination means 35a, the control value output means 35b, the control data search means 35c, the observation data generation means 35d, the operating state monitoring means 35e, the trial optimum control data storage means 35f. And a work condition calculation determination means 35g, an optimum waveform control means 35h, and a beam current integral value calculation means 35i.

Then, the observation data generation means 35d synthesizes the observation display data based on the detection data obtained from the target control unit 53,
The keyboard is controlled while sending it to the display 36 to graphically display the observed waveform n shown by the dotted line in FIG.
Control data search means 35 according to the work name input from 37
The disk (hard DK) 38 in which c is an external storage device is searched, and the recipe name (work name) in the column 61 of the control data table 60 (see FIG. 4) is searched to see the match. When there is the same work name, it is determined by the flag in the column 62 whether it has been tried before, and if it is the one tried before, the control data corresponding to the work name is changed from the work name. The table 60 is taken out and read into the memory of the arithmetic processing unit 35.

Next, obtain the working conditions in column 63 and the various control values in column 64,
Ion source controller 43, analyzer magnet controller 4
5, beam energy control unit 47, lens control unit 49, X-
The control values for the Y scan offset control unit 51, the main Faraday control unit 53a, and the end station control unit 53b are read out in a predetermined order and sent to the control value determination means 35a.

Here, as the working conditions, as shown in FIG. 3, as shown in the corresponding column 63 of the recipe name in the control data table 60, the implantation energy [kV], the beam electrode [μA], the dose value [the number of ions] / cm ² ], ion species [B, P, As, etc.].

Further, as various control values as the control parameters for the ion implantation device 30, as shown in the column 62 of the control data table 60, the filament current value, arc current value, source magnet current value, analyzer current value, lens adjustment value, X
Y scan voltage value, offset value (OFFSET value), beam current value (maximum value), judgment values A, B, C for the observed waveform. Note that A is the integrated value of the beam current in the first rising portion of the observed waveform shown in FIG. 4, and B is the integrated value of the beam current in the central falling portion + the rising portion of the next waveform. Yes, C is the integrated value of the beam current at the trailing trailing edge of the next waveform. Here, each of these values is calculated by the beam current integral calculation means 35i based on the data from the observation data generation means 35d.

In the observed waveform of FIG. 4, the horizontal axis shows the scan voltage corresponding to the scanning in the X or Y direction, and the vertical axis shows the measured beam current value measured by the main Faraday 53. For example, when the beam current value is measured corresponding to the scanning (scanning time) in the X direction, the code a corresponds to the overscan area deviated from the mask 10, and the first code b is the beam current from the mask 10 to the main. This corresponds to the area until the Faraday 53 is scanned, and this corresponds to the rising area. The integrated current value in this region is the integrated value A. Code c
Corresponds to the area where the beam current scans the main Faraday 53. Reference numeral d corresponds to a region for scanning the hole portion at the center of the main Faraday. Therefore, this corresponds to a region that falls and rises again in response to scanning in the X direction. The integrated current value in this region is the integrated value B. The last code b corresponds to the area from the main Faraday 53 to the mask 10 where the beam current scans, and this corresponds to the falling area. The integrated current value in this region is the integrated value C
become.

On the other hand, the control value measuring means 35a sequentially obtains these control values (excluding the judgment values A, B, and C) corresponding to each control unit from the control data searching means 35c, sets these as target values, and inputs / outputs them. The measured control data from each control unit obtained from the control circuit 33 is compared with the target value, and the control data corresponding to the difference value is sequentially sent to the control value output means 35b as each control value.

The control value output means 35b sends the control data sent from the control value determination means 35a and the optimum waveform control means 35h described later to the input / output control circuit 33, and the ion source control unit 43, the analyzer magnet control unit 45, the beam sequentially. Energy control unit 4
7, lens control unit 49, XY scan offset control unit 5
1, the data is sent to the main Faraday control unit 53a and the end station control unit 53b, and control is performed so that the control value indicated by the work name is obtained.

Further, the work condition calculation determining means 35g is the ion implanter 30.
The data measured from the respective control units of the above are obtained from the input / output control circuit 33, and from these, the working energy which is the working condition [kV], the beam current [μA], the dose amount [the number of ions / c
m ² ] and these calculated values are obtained from the control data retrieving means 35c. The implantation energy [kV], the beam current [μA] in the column 63 of the control data table 60 of FIG.
Dose determine whether or not to match the predetermined control range or these for each value of [the number of ions / cm ^2], becomes optimal control when entering the allowable range with respect to these target values A signal is generated and sent to the trial optimum control data storage means 35f.

In the trial optimum control data storage means 35f, the AND condition of the optimum control signal and the optimum control signal from the optimum waveform control means 35h described later corresponds to the work condition (target control value) input with a specific work name. Then, each control value (filament current value,
The arc current value, source magnet current value, analyzer current value, lens adjustment value, XY scan voltage value, offset value (OFFSET value), beam current value (maximum value) are obtained from the input / output control circuit 33, and the beam current integrated value is also obtained. Obtain the judgment values (A, B, C, etc.) for the observed waveform from the computing means 35i,
It is stored in the column 64 of the control data table 60 corresponding to the work name.

Further, the optimum waveform control means 35h sends a control signal to the control value output means 35b to finely control the filament current value, the arc current value, the source magnet current value, and the analyzer current value, and the input / output control circuit 33. The peak value is detected from the beam current measurement value obtained from the control data measurement circuit 32 via the control data measurement circuit 35i and the current judgment values A, B, C are obtained from the beam current integral value calculation means 35i, and this and the control data retrieval are performed. The judgment values A, B, C of the control data table 60 obtained from the means 35c are compared and it is judged whether they match (or fall within a predetermined allowable range). Then, as a result of this determination, a control signal corresponding to the difference between these determination values is sent to the control value output means 35b for fine adjustment control. If the result of this determination is that they match (or within the allowable range), the optimum control signal is sent to the trial optimum control data storage means 35f.

Further, the optimum waveform control means 35h has a waveform m corresponding to the beam current value and the target judgment values A, B, C (see FIG. 4).
To the display 36 and display it in the form of a graphic.
Is displayed on the control data table 6 and the peak value or the maximum value is sent to the work condition calculation determination means 35g.
It is determined whether or not it matches the value stored in 0 (or whether or not it falls within a predetermined control range).

By the way, in this embodiment, the accuracy is improved and the start-up time is shortened by the two-step control. In the first step, only one of X and Y is alternately changed by the optimum waveform control means 35h. By scanning, the optimum value is obtained and controlled in the sharp portion of the waveform (integral areas A, B, C in FIG. 4). Then, in the second stage, the trial optimum control data storage means 35
By f, the adjusted value after execution is stored for each recipe name and used as the next rising data.

Next, the overall processing of such automatic startup control will be described with reference to FIG.

Ion implanter 30 and automatic startup controller in steps
The control data table 60 shown in FIG. 3 of the recipe name corresponding to the recipe name is input from the disk 38 in accordance with the entered recipe name by inputting the recipe name (work name) from the keyboard 37 in step 31 by turning on the power supply of 31. To memory.

In the next step, the current control value of each control unit of the ion implantation apparatus 30 is obtained via the control data measuring circuit 32, and a status signal such as a vacuum value and a door open / close state is input / output control circuit 33.
Then, confirm the operation mode and set a fixed value for starting up the device.

In this case, the fixed values are predetermined values such as selection of control ion species, setting of gas flow rate, beam energy for raising the beam, control value for lens control unit, control value for offset control unit, and the like. .

Then, in the next step, the beam is activated, and in the step, it is determined whether or not there is past trial control data. This judgment is made in the column of the presence / absence of trial data in the control data table 60.
It judges by referring to the flag of 62. As a result of this determination, if the flag indicating that trial data exists is set, in step, according to the data shown in the control data table 60 corresponding to the working conditions, the control ion species is selected as the target control value, and the gas flow rate is set. Again, the beam energy for starting the ion beam, the corresponding control values in the lens control unit 49 and the offset control unit 51 are sequentially set again, and the filament current value is set in accordance with the control data shown in the control data table 60. And the arc current value, the source magnet current value, and the analyzer current value are slowly increased while monitoring the control current values, and the respective control values are matched with the data shown in the column 64 of the control data table 60, or The target value is set as a target value, and control is performed so as to be within a predetermined control range.
Then, the peak value of the beam current is detected. In addition, this detection is a value previously obtained by the ion species,
Initially, it is controlled so that it is set to a smaller value, and each control value is adjusted so that the beam takes the maximum value while rising.

Next, in step, fine adjustment and check are performed.

The contents of the fine adjustment are: I offset fine adjustment Generally, only the X direction is adjusted, and the offset LOW adjust and the OFF HIGH adjust are adjusted to a value of l ₁ ≈l ₂ in the observed waveform of FIG.

II Lens fine adjustment Alternately scans only one of X and Y to obtain the optimum value in the sharp part of the waveform (integral areas A, B and C in Fig. 4) and control it. Lens TRIM (lens trimmer), lens balance, lens for both Y scans
Adjust the LOW adjust and lens HIGH adjust to the 4th
Set the values that minimize the integrated beam current values in the A, B, and C parts of the waveform in the figure.

III Overscan fine adjustment Adjust the X and Y scans for both X and Y scans, and adjust the value to be 15% for the entire waveform scan range in Fig. 4.

IV check Judgment of lens adjustment value (A, B, C) min based on the judgment value data A, B, C in the data that was tried last time and l ₁ ≒
l _2, a unit performs a determination of whether or not to enter within 20% of the total.

Then, in the next step, the trial data is stored in the storage device.

This storage is performed by the trial optimum control data storage means 35f, and the data of the result finely adjusted in the above step is stored as the input recipe name table in the form of the control table 60 shown in FIG. When there is already stored control data, it is updated and the latest control data is stored.

The control data stored here is as follows.

a) Filament current value, b) Arc current value, c) Source magnet current value, d) Analyzer magnet current value, e) Lens adjustment value (lens TRIM, lens balance, lens LOW adjust, lens HIGH adjust), f) offset Adjustment value (offset LOW adjust, OFF HIGH adjust),
g) XY scan voltage value, h) beam current value, i) judgment value (A, B, C). Note that A, B, and C are the minimum values (min), respectively.

In this way, the adjusted values after execution are stored for each recipe name and used as the next rising data. When such control data is stored, the dose processor 54 is activated in the next step to start ion implantation into the wafer.

On the other hand, if there is no trial data in the determination in the previous step, the acceleration voltage is controlled in step a so that the beam energy becomes the specified [keV] value. The monitoring data at this time only determines whether or not the acceleration voltage has reached the set value. In this way, the beam energy is set.

Next, in step a, a value corresponding to the ion species and the acceleration voltage is obtained in advance, and the offset LOW adjust value and the OFF HIGH adjust value are set. And X, Y
Both stop scanning and offset to a value that minimizes the current flowing through the main Faraday LOW Adjust, OFF HIGH
Adjust the offset to adjust the offset.

In the next step a, the values corresponding to the ion species and the acceleration voltage are obtained in advance, and the lens TRIM, lens balance,
Set each value of lens LOW adjust and lens HIGH adjust. Then, scanning is stopped for both X and Y, and the lens system is adjusted by adjusting the lens balance to a value that minimizes the current flowing through the main Faraday.

In the next step a, the target current value when the X and Y scans are stopped and the overscan is performed is calculated.

Target value = beam value × (1−R) ² However, the beam value is a measured value without scanning, and R is an overscan ratio. Then, the X and Y scans are adjusted so that the target beam value is obtained, and overscanner adjustment is performed.

In the next step a, the dose level is set to set the dose amount in the dose processor 54, and in step a, the arc current is controlled so that the beam current becomes a specified value and the beam current is set. Enter the process of obtaining the value. In addition, step a, step a
Is a processing routine for changing the work name, and enters a step.

By the way, conventionally, when observing the beam current waveform of an oscilloscope manually, it was not possible to determine the rounding of the observed waveform n (shown by a dotted line) as shown in FIG. Therefore, in the circular edge portion 66 of the wafer 65, there was a portion where the dose amount was non-uniform. In addition, 67 is a wafer outer peripheral part, 68 is a wafer installation stand (susceptor).

However, as in the present invention, by calculating the integrated value of A, B, and C and starting it up to the target value (target waveform m: solid line display), even if it becomes the observed waveform n, the judgment value A-
As can be seen from A ', B-B, and C-C', minute changes in the beam current appear as amplified in the integrated value, so the judgment function is considerably improved compared to the case where a person discriminates the waveform.

Therefore, by performing the fine adjustment as described above, the accuracy can be improved, and since each control value can be set to an appropriate value in advance, it is possible to shorten the time until the appropriate startup.

Furthermore, the non-uniformity of the dose amount can be eliminated, and the yield can be improved.

As described above, in the embodiment, the filament current value, the arc current value, the source magnet current value, and the variable current value are set as variable setting values according to the data shown in the control data table.
Analyzer current value, lens adjustment value, XY scan voltage value,
Although the lens adjustment value and the like are mentioned as the offset value, the control value does not have to be applied to all of them, and the implantation energy, the beam current value, the dose amount, which are the working conditions,
Then, some of the ion species and the like may be included in the control value.

[Effects of the Invention] As can be understood from the above description, the present invention is provided with the memory device, the measuring means for measuring the beam current of the target portion, the arithmetic processing device, and the ion implantation device. The arithmetic processing unit determines, based on the beam current value obtained from the measuring means, the first integral value of the first rising portion of the beam current waveform corresponding to the wafer, the falling portion of the central portion, and the rising portion of the next waveform. It has an integral value means for calculating the second integral value and the third integral value of the trailing trailing edge portion, and the first, second and third portions in the optimum control state when the ion implantation apparatus is operated. The integrated value of is stored in the storage device in correspondence with the working condition at that time, and when the ion implantation apparatus is started up, the work condition at the time of starting up the ion implanter 1, second and The present first, second and third integrated values calculated by the integrated value calculating means by reading the third integrated value from the storage device become the first, second and third integrated values in the optimum control state. Since the target control is performed so that the beam current approaches or becomes close to that, the beam current waveform is started up so as to be optimum, so it becomes easy to finely adjust to the optimum value, and operate at the optimum value in a short time. Is possible. The judgment function is greatly improved. Furthermore, it is possible to eliminate non-uniformity of the dose amount,
The yield can be improved.

As a result, working efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an ion implantation system to which the present invention is applied, and FIG. 2 is a flow chart of its startup processing,
FIG. 3 is an explanatory diagram of a search table necessary for the processing, FIG. 4 is an explanatory diagram of observed waveforms, FIG. 5 (a) is a block diagram of a conventional ion implantation apparatus, and FIG. 5 (b). FIG. 4 is an explanatory diagram of the ion source. 30 …… Ion implanter, 31 …… Automatic start-up controller, 32
...... Control data measurement circuit, 33 ...... Input / output control circuit, 34 ......
Bus, 35 ... Arithmetic processing unit, 35a ... Control value determination means, 3
5b: control value output means, 35c: operating data search means, 3
5d ... Observation data generating means, 35e ... Operating state monitoring means, 35f ... Trial optimal control data storage means, 35g ... Working condition calculation determining means, 35h ... Optimal waveform control means, 35i ...
Beam current integral value calculation means, 36 ... Display, 37 ...
... keyboard, 38 ... disk, 41 ... ion source,
42 …… Ion extraction front-stage acceleration section, 43 …… Ion source control section, 44 …… Mass analysis section, 45 …… Analyzer magnet control section, 46 …… Post-stage acceleration section, 47 …… Beam energy control section, 48 …… Lens system, 49 ... Lens control unit, 50 ... Beam deflection unit, 100 ... Ion implantation system.

Claims (1)

[Claims] 1. A storage device for storing various control values corresponding to variable set values in an ion implantation device relating to control of an ion beam in correspondence with working conditions, and a beam via the various control values and a Faraday cup of a target unit. The Faraday cup includes a measuring unit for measuring a current, an arithmetic processing unit, and an ion implantation unit, and the Faraday cup has a characteristic current value having a valley in a central portion when the ion beam is scanned in the X direction or the Y direction. Is a structure for generating, the arithmetic processing device, by the control of the arithmetic processing device,
The first integral value of the first rising part of the current value from the measuring means obtained by scanning the beam current in the X direction or the Y direction with respect to the measurement waveform corresponding to the scanning direction, and the rising of the central part. It has an integral value calculating means for calculating the second integral value of the falling portion and the rising portion and the third integral value of the last falling portion, and the various control values stored in the storage device are: Various control values obtained when the ion implantation apparatus is controlled so that the first, second, and third integrated values become minimum values, and the minimum control values corresponding to the various control values. 1st and 2nd
And a third integrated value are stored, and the arithmetic processing unit performs various controls on the ion implantation apparatus with the various control values stored in the storage device as target values when the ion implantation apparatus is started up. The current various control values given to the ion implanter by determining whether or not the various current control values of the ion implanter are within an allowable range with respect to the target value Is set within the permissible range, and the first, second, and third integral values stored corresponding to the various control values stored in the storage device are set as target determination values, and the integral value calculating means is set. For each of the present first, second and third integrated values calculated by the above, the present various control values given to the ion implantation apparatus are controlled so as to be minimum values, and the optimum control values are obtained. Set and get The various control values already stored in the storage device and the first, second, and third optimum control values and the current first, second, and third integral values that have been optimized. An ion implantation system characterized by rewriting and updating the integral value of 3.