JP5103968B2 - Ion beam traveling angle correction method and ion implantation apparatus - Google Patents

Description

  The present invention is a ribbon-like shape in which the dimension in the x-direction is larger than the dimension in the y-direction substantially perpendicular to the x-direction, without passing through the scanning in the x-direction or without going through the scanning in the x-direction. In an ion implantation apparatus configured to irradiate a target with an ion beam (which may also be referred to as a band shape), a traveling angle correction method for correcting a traveling angle in the y direction of the ion beam near the target and the correction method are performed. The present invention relates to an ion implantation apparatus capable of

  For example, with higher performance and higher miniaturization of semiconductor devices, ion implantation technology has more precise implantation so that more specific examples can realize ion implantation with steep implantation boundaries. There is a tendency to enable angle control. For example, when ion implantation is performed on a target using the ribbon-shaped ion beam as described above, an ion beam implantation angle in the y direction (in other words, an ion beam to the target), which has not been a problem in the past. It is becoming important to control the angle of incidence of the light with high accuracy.

  The implantation angle in the y direction and the traveling angle in the y direction of the ion beam are greatly related. This is because the injection angle is obtained by adding the above-mentioned advance angle to the inclination of the target in the y direction. Therefore, in order to perform highly precise implantation angle control, the traveling angle of the ion beam in the y direction is also important.

  The advance angle in the y direction is provided on the upstream side and the downstream side of the target, respectively, and a front-stage multipoint Faraday in which a plurality of detectors for measuring the beam current of the ion beam are arranged in parallel in the x direction, and Patent Documents 1 and 2 describe a measurement method and an ion implantation apparatus for measuring the advancing angle in the y direction of a ribbon-like ion beam using a subsequent multipoint Faraday. This advancing angle is called an angular deviation in the y direction in both patent documents, but both are substantially the same.

Japanese Unexamined Patent Publication No. 2007-5779 (paragraphs 0031-0033, 0042, FIG. 7) Japanese Patent Laying-Open No. 2005-195417 (paragraphs 0028-0030, FIG. 7)

  The techniques described in Patent Documents 1 and 2 are to measure the traveling angle of the ion beam in the y direction. However, in an actual ion implantation apparatus, it is important to proceed further from the measurement and to correct the advance angle to a predetermined one. For specific means for the correction, see Patent Documents 1 and 2 above. Is not listed.

  Accordingly, the main object of the present invention is to provide a method of correcting a traveling angle and an ion implantation apparatus capable of correcting the traveling angle of the ion beam in the y direction.

One of the methods of correcting the traveling angle of an ion beam according to the present invention is such that the traveling direction in the design of the ion beam is the z direction, and two directions substantially orthogonal to each other in a plane substantially orthogonal to the z direction are x. Direction and y direction, which is an ion beam extracted from an ion source having an extraction electrode system, the x-direction dimension is greater than the y-direction dimension through the x-direction scan or without the x-direction scan. The apparatus is configured to irradiate a target with a large ribbon-shaped ion beam, and the ion beam when irradiated to the target is a substantially parallel beam in the x-direction and in the ion beam traveling direction in the vicinity of the target. A plurality of detectors that are provided relatively upstream and downstream and measure the beam current of the ion beam are arranged in parallel in the x direction. In an ion implantation apparatus having a multistage Faraday stage and a multipoint Faraday stage, a plurality of detectors of the front stage multipoint Faraday are electrically connected in parallel to each other, and a plurality of detectors of the backstage multipoint Faraday are connected to each other. In an electrically connected state, the ion beam is gradually incident on each multipoint Faraday in the y direction, and the center position of the ion beam in the y direction is set at two locations on the upstream side and the downstream side in the ion beam traveling direction. And a traveling angle measurement step of measuring the traveling angle in the y direction of the ion beam near the target using the distance in the y direction between the center positions and the distance in the z direction between the two locations, and the traveling The inclination angle in the y direction of the extraction electrode system of the ion source is changed in the direction of decreasing the advancing angle measured in the angle measurement step, and the The movement angle correcting step of changing the angle in the y direction of the ion beam to draw from on source, have rows least once to the traveling angle measured by the movement angle measuring step falls within a first tolerance range, and, The characteristic indicating the relationship between the inclination angle of the extraction electrode system and the advance angle of the ion beam in the ion implantation apparatus that has been examined in advance is used in the advance angle correction step .

  According to this advancing angle measurement method, the advancing angle in the y direction of the ion beam can be corrected until the advancing angle measured in the advancing angle measuring step falls within the first allowable range.

  After the advance angle measured in the advance angle measurement step falls within the first allowable range, an ion beam is gradually incident on each multipoint Faraday in the y direction using the preceding multipoint Faraday and the subsequent multipoint Faraday. Thus, the center position in the y direction of the ion beam is obtained at two positions upstream and downstream in the ion beam traveling direction, and the distance in the y direction between the center positions and the distance in the z direction between the two positions are determined. Is used to measure the advancing angle in the y direction of the ion beam near the target, and the advancing angle distribution measuring step in which such measurement is performed at a plurality of positions in the x direction, and the advancing angle distribution measuring step A travel angle distribution determining step for determining whether or not there is a travel angle whose magnitude is out of the second allowable range among the travel angles of the position. There.

One of the ion implantation apparatuses according to the present invention includes an electrode driving device having a function of changing an inclination angle of at least the y-direction of the extraction electrode system of the ion source, and (a) the front-stage multipoint Faraday. In the state where the plurality of detectors are electrically connected in parallel with each other and the plurality of post-stage multipoint Faraday detectors are electrically connected in parallel with each other, an ion beam gradually enters each multipoint Faraday in the y direction. Thus, the center position in the y direction of the ion beam is obtained at two locations upstream and downstream in the ion beam traveling direction, and the distance in the y direction between the center positions and the distance in the z direction between the two locations are determined. Advancing angle measurement control for measuring the advancing angle in the y direction of the ion beam near the target, and (b) the advancing angle measured by the advancing angle measurement control. The angle of the ion beam extracted from the ion source in the y direction by changing the tilt angle in the y direction of the extraction electrode system of the ion source in a direction to reduce the traveling angle by controlling the electrode driving device based on A control device having a function of performing the advance angle correction control for changing the advance angle once or more until the advance angle measured by the advance angle measurement control falls within the first allowable range , and The control device uses, in the advance angle correction control, a characteristic representing the relationship between the inclination angle of the extraction electrode system and the advance angle of the ion beam in the ion implanter previously examined.

  After the advance angle measured by the advance angle measurement control falls within the first allowable range, the control device uses (a) the multi-stage Faraday and the multi-stage Faraday of the preceding stage to generate y for each multi-point Faraday. The center position in the y direction of the ion beam is obtained at two locations on the upstream side and the downstream side in the ion beam traveling direction so that the ion beam gradually enters in the direction, and the distance in the y direction between the center positions Advancing angle distribution measurement control in which the advancing angle in the y direction of the ion beam near the target is measured using the distance in the z direction between the two locations, and such a measurement is performed at a plurality of positions in the x direction; ) It is determined whether or not there is a traveling angle whose magnitude is out of the second allowable range among the traveling angles measured by the traveling angle distribution measurement control. It may further have a function of performing a movement angle distribution determination control for outputting a signal representative of.

According to the first aspect of the present invention, the traveling angle of the ion beam in the y direction can be corrected until the traveling angle measured in the traveling angle measurement step falls within the first allowable range. As a result, more accurate implantation angle control can be performed in ion implantation with respect to the target. As a result, it becomes possible to cope with high miniaturization of the semiconductor device formed in the surface layer portion of the target. Further, it is possible to improve the ion beam transport efficiency by reducing the possibility that the ion beam in the middle of transportation collides with the structure.
Further , since the characteristic indicating the relationship between the inclination angle of the extraction electrode system and the advance angle of the ion beam in the ion implantation apparatus previously examined is used in the advance angle correction step, the advance angle of the ion beam in the y direction can be corrected. It can be done more quickly.

According to invention of Claim 2, there exist the following further effects. That is, after the advancing angle enters the first allowable range, the advancing angle whose magnitude deviates from the second allowable range among the advancing angles at a plurality of positions measured in the advancing angle distribution measuring step. Therefore, it is possible to prevent ion implantation into the target by an ion beam having a poor traveling angle distribution.

According to the third aspect of the present invention, the traveling angle of the ion beam in the y direction can be corrected until the traveling angle measured by the traveling angle measurement control falls within the first allowable range. As a result, more accurate implantation angle control can be performed in ion implantation with respect to the target. As a result, it becomes possible to cope with high miniaturization of the semiconductor device formed in the surface layer portion of the target. Further, it is possible to improve the ion beam transport efficiency by reducing the possibility that the ion beam in the middle of transportation collides with the structure. Moreover, since the measurement and control can be performed using the control device and the electrode driving device, labor saving can be achieved.
Further , since the control device uses the characteristic representing the relationship between the inclination angle of the extraction electrode system and the traveling angle of the ion beam in the ion implantation device, which has been examined in advance, in the traveling angle correction control, The advance angle in the direction can be corrected more quickly.

According to invention of Claim 4, there exist the following further effects. That is, after the advancing angle enters the first allowable range, the advancing angle whose magnitude is out of the second allowable range among the advancing angles at a plurality of positions measured by the advancing angle distribution measurement control. Since a signal representing the result is output and a signal representing the result is output, ion implantation to the target by an ion beam having a poor traveling angle distribution can be prevented. In addition, since the measurement and control can be performed using a control device, labor saving can be achieved.

(1) Configuration of Ion Implantation Device FIG. 1 is a schematic plan view showing an example of an ion implantation device. In this specification and the drawings, the design traveling direction of the ion beam 4 is always the z direction, and two directions that are substantially orthogonal to each other in a plane substantially orthogonal to the z direction are the x direction and the y direction. Yes. For example, the x direction and the z direction are horizontal directions, and the y direction is a vertical direction. In other words, the “designed traveling direction” refers to a predetermined traveling direction, that is, a traveling direction that should originally proceed.

  This ion implantation apparatus emits (extracts) an ion beam 4 having a small cross-sectional shape, which is a source of a ribbon-like ion beam, and an ion beam from the ion source 2 is incident and a desired mass is obtained from the ion beam 4. A mass separator 6 that separates and extracts the ion beam 4, an accelerator / decelerator 8 that is irradiated with the ion beam 4 from the mass separator 6 and accelerates or decelerates the ion beam 4, and from the accelerator / decelerator 8. An energy separator 10 that receives an ion beam 4 and separates and extracts the ion beam 4 having a desired energy from the ion beam 4, and an ion beam 4 from the energy separator 10 that is incident and scans the ion beam 4 in the x direction. And the ion beam 4 from the beam scanner 12 is incident and the ion beam 4 is bent to A beam collimator 14 that collimates the ion beam 4 in cooperation with the scanner 12, and a target (for example, a semiconductor substrate) 16 within the irradiation region of the ion beam 4 from the beam collimator 14 4, a target drive device 20 that mechanically reciprocates (reciprocates) in the y direction, for example, in the direction intersecting the main surface 4b (see FIG. 3) (see arrow 22 in FIG. 6).

  This ion implantation apparatus further includes measurement devices and control devices such as the front multipoint Faraday 24, the rear multipoint Faraday 28, and the control device 50 shown in FIG. Although FIG. 6 will be described in detail later, the target 16 is held by the holder 18 of the target driving device 20 as shown in FIG.

As in the example shown in FIG. 2, the ion source 2 includes a plasma generation unit 70 that generates plasma 72, an extraction electrode system 74 that extracts the ion beam 4 from the plasma 72 in the plasma generation unit 70 by the action of an electric field, The lead electrode system 74 is tilted left and right from the y direction as indicated by an arrow B, and the tilt angle of the lead electrode system 74 at least in the y direction (more strictly speaking, the tilt angle from the y direction in the yz plane). ) An electrode driving device 76 having a function of changing β _y is provided.

  In the example shown in FIG. 2, the extraction electrode system 74 is shown as a single electrode for simplification of illustration. However, the extraction electrode system 74 is not limited to this, and the number of electrodes constituting the extraction electrode system 74 is one. Any number of sheets is optional.

The tilt angle β _y is also called a tilt angle. The inclination angle β _y can be set to be positive or negative. Here, as in the example indicated by the two-dot chain line in FIG. 2, the case where the extraction electrode system 74 is inclined downward in the y direction is negative ( Minus).

In the above example, the ion beam 4 derived from the beam collimator 14 shown in FIG. 1 and applied to the target 16 is scanned in the x direction at a high speed (for example, about several tens of kHz) (more specifically, parallel scanning). ), The dimension W _x in the x direction is larger than the dimension W _{y in the} y direction (more specifically, sufficiently large), as in the example shown in FIG. Such an ion beam 4 is also called a ribbon-like ion beam in this specification. The cross-sectional shape of the ion beam 4 before scanning is, for example, a small rectangle as indicated by reference numeral 4a in FIG.

  By using such a ribbon-like ion beam 4 and mechanically scanning the target 16 as described above, the ion beam 4 is irradiated on the entire surface of the target 16 to perform ion implantation with good uniformity. it can.

However, instead of the ribbon-like ion beam 4 that has been scanned in the x direction as described above, the scanning is not performed in the x direction (for example, the ion beam 4 extracted from the ion source 2 as shown in FIG. 4). The target 16 is irradiated with the ion beam 4 having a ribbon shape in which the dimension W _{x in the} x direction is larger than the dimension W _{y in the} y direction (more specifically, sufficiently large). Also good. In the measurement and control of the advance angle θ _y described below, it is not necessary to distinguish between the ion beam 4 in FIG. 3 and the ion beam 4 in FIG. 4 unless otherwise noted. This is because techniques such as measurement and control can be applied to either ion beam 4.

In summary, the traveling angle θ _y of the ion beam 4 in the y direction is an angle of the actual ion beam 4 in the y direction with respect to the designed traveling direction z of the ion beam 4 as in the example shown in FIG. (Strictly speaking, it is the angle of the central trajectory of the ion beam 4 from the z direction in the yz plane). Therefore, in the ideal case where the ion beam 4 follows a trajectory completely parallel to the z direction, θ _y = 0 °. Although how to take the positive and negative of the movement angle theta _y are arbitrary, here, as in the example shown in FIG. 5, the case where the ion beam 4 is tilted upward in the y direction as positive (plus). More detailed definition of this progression angle θ _y will be described later.

Referring to FIG. 6, the ion implantation apparatus includes a front multipoint Faraday 24 and a rear multipoint Faraday 28 on the upstream side and the downstream side in the traveling direction z of the ion beam 4 near the target 16. Yes. More specifically, in this embodiment, with respect to the position in the traveling direction z of the ion beam 4, the front stage multipoint Faraday 24 is provided at the position z _ff on the upstream side of the target 16, and the position on the downstream side of the target 16. z _fb has a multi-point Faraday 28 in the subsequent stage. A position in the z direction of the target 16 is set to z _t . When the target 16 is tilted as in the example shown in FIG. 6, the position of the center of the target 16 in the z direction is set to z _t .

  Both of the multipoint Faradays 24 and 28 each measure the beam current of the ion beam 4 and have a plurality of detectors (not shown) arranged in parallel in the x direction. The number of the plurality of detectors constituting both the multipoint Faraday 24 and 28 is m and n (m and n are integers of 2 or more, respectively). m and n are 10-20, for example. In front of each detector, slit-shaped inlets 26 and 30 are provided, respectively. Each detector is, for example, a Faraday cup.

Note that both the multipoint Faraday 24 and 28 are provided on the upstream side and the downstream side of the target 16 as in this embodiment, so that the advance angle θ _{y in} the vicinity of the target 16 can be measured with higher accuracy. However, the present invention is not limited to this, and both multi-point Faraday 24 and 28 may be provided on the upstream side or the downstream side in the vicinity of the target 16.

(2) Measurement of ion beam advance angle θ _y Using the preceding multi-point Faraday 24 and the subsequent multi-point Faraday 28, the ion beam 4 is gradually incident on each multi-point Faraday 24, 28 in the y direction. Thus, the center position of the ion beam 4 in the y direction is obtained at two locations upstream and downstream of the ion beam traveling direction z, and the distance between the center positions in the y direction and the distance between the two locations in the z direction are determined. The traveling angle θ _y in the y direction of the ion beam 4 near the target 16 is measured. This measuring method will be described in detail below.

Referring to FIG. 6, a front beam limiting shutter 32 that can block the ion beam 4 that is wide in the x direction is provided at a position z _f in the vicinity of the upstream side of the front multipoint Faraday 24. The front beam limiting shutter 32 has a side 34 substantially parallel to the x direction. This side 34 is preferably kept parallel to the x direction as precisely as possible. The front beam limiting shutter 32 has a rectangular shape that is long in the x direction in this example, but is not limited thereto. Further, in this example, the one side 34 is the lower side of the preceding beam limiting shutter 32, but it may be the upper side.

A pre-stage shutter driving device 36 is provided that holds the pre-stage beam limiting shutter 32 and drives it back and forth in the y direction as indicated by an arrow 38. In this example, the front shutter driving device 36 is a control circuit that precisely controls the position of the front beam limiting shutter 32 in the y direction, and a position sensor that precisely measures and outputs the position y ₁ of the one side 34 in the y direction. (Both not shown).

Further, the width in the x direction is at a position z _b near the upstream side of the rear multi-point Faraday 28, more specifically, at a position z _b downstream of the target 16 and near the upstream side of the rear multi-point Faraday 28. A rear-stage beam limiting shutter 42 that can block the wide ion beam 4 is provided. The rear beam limiting shutter 42 has a side 44 substantially parallel to the x direction. This side 44 is preferably kept in parallel with the x direction as precisely as possible. The post-stage beam limiting shutter 42 has a rectangular shape that is long in the x direction in this example, but is not limited thereto. The one side 44 is the lower side of the rear beam limiting shutter 42 in this example, but may be the upper side.

A rear-stage shutter driving device 46 that holds the rear-stage beam limiting shutter 42 and drives it back and forth in the y direction as indicated by an arrow 48 is provided. In this example, the rear-stage shutter driving device 46 includes a control circuit that precisely controls the position of the rear-stage beam limiting shutter 42 in the y direction, and a position sensor that precisely measures and outputs the position y ₁ of the one side 44 in the y direction. (Both not shown).

Referring also to FIG. 8, the distance between the front beam limiting shutter 32 and the rear beam limiting shutter 42 in the z direction, that is, the distance between the position z _f and the position z _b is L.

The ion implantation apparatus further includes a control device 50 that performs various processes and controls described later. The control device 50 controls the front-stage shutter driving device 36 and the rear-stage shutter driving device 46 to drive the front-stage beam limiting shutter 32 and the rear-stage beam limiting shutter 42 as described above. The information of the position y ₁ is fetched from the shutter driving device 46, respectively. Further, information on beam currents S _{f, i} (y) and S _{b, i} (y), which will be described later _, is fetched from the front multipoint Faraday 24 and the rear multipoint Faraday 28, respectively. Further, the control device 50 is given (for example, set) information on the distance L.

Here, the definition of the central trajectory of the ion beam 4 in the y direction and the traveling angle θ _y in the y direction in this specification will be described.

FIG. 7 shows an example of the distribution j (y) of the beam current density j in the y direction of the ion beam 4. Although the beam current density distribution j (y) has a shape close to a Gaussian distribution in many cases, the beam current density distribution j (y) does not necessarily have such a shape. Take up the shape that is. At this time, the center position (in other words, the position of the center of gravity) of the integration of the beam current density distribution j (y) is set as the center position y _c . That is, the center position y _c is the position where the hatched upper half area S _a and the lower half area S _b are equal to each other. However, when the beam current density distribution j (y) has a shape close to a Gaussian distribution as described above, the peak position may be set as the center position y _C. Such a trajectory of the center position y _c of the ion beam 4 is a central trajectory of the ion beam 4 in the y direction.

When the center position y _c is different between two points separated by a predetermined distance in the z direction, specifically, the position z _{f of} the front stage beam limiting shutter 32 and the rear stage beam limiting shutter 42 which are separated by a distance L. If the position differs from the position z _b (see FIG. 8), the central trajectory of the ion beam 4 has a traveling angle θ _y in the y direction. In this case, assuming that the center position y _c of the ion beam 4 at the position z _f of the front beam limiting shutter 32 and the position z _b of the rear beam limiting shutter 42 is y _cf and y _cb , the advance angle θ _y is expressed by the following equation. Is done.

[Equation 1]
θ _y = tan ⁻¹ {(y _cb −y _cf ) / L}

Next, a method for measuring the advancing angle θ _y expressed as described above will be described.

In the measurement, as shown in FIG. 9, the front stage multi-point Faraday 24 is positioned on the path of the ion beam 4 by a driving device (for example, the front stage Faraday driving device 56 shown in FIG. 11), and the front stage shutter driving device. The beam current of the ion beam 4 incident on the front multi-point Faraday 24 is measured by the front multi-point Faraday 24 while driving the front-stage beam limiting shutter 32 in the y direction. The front beam limiting shutter 32 may be driven from a state in which the front beam limiting shutter 32 does not block the ion beam 4 at all, but here, the front beam limiting shutter 32 completely blocks the ion beam 4. An example of driving from the blocked state to the unblocked state will be described. The driving direction of the upstream beam limiting shutter 32 is indicated by an arrow 39. In this case, initially, the ion beam 4 is completely blocked by the front stage beam limiting shutter 32, so that the ion beam 4 does not enter the front stage multipoint Faraday 24 at all. At this time, the y coordinate position of the one side 34 of the front beam limiting shutter 32 is set to y ₀ .

When the front beam limiting shutter 32 is driven in the y direction as indicated by the arrow 39, as the driving proceeds, a part of the ion beam 4 blocked by the front beam limiting shutter 32 is outside the one side 34. And gradually enters the preceding multipoint Faraday 24. Here, the y coordinate position of the one side 34 of the front beam limiting shutter 32 when at least a part of the ion beam 4 is incident on the front multipoint Faraday 24 is y ₁ .

Now, paying attention to the i-th detector in the x direction of the preceding multipoint Faraday 24, the x coordinate position of the center is assumed to be x _i . At this time, a function representing the beam current density distribution j _f (y) in the y direction at the coordinate x _i in the x direction at the position z _f of the upstream beam limiting shutter 32 is defined as j _{f, i} (y). At this time, the beam current S _{f, i} (y ₁ ) measured by the i-th detector is expressed by the following equation. This is illustrated in FIG. Here, the beam current density j _{f, i} is assumed to be zero below y ₀ .

Accordingly, the beam current S _{f, i} (y) is measured by the front multi-point Faraday 24 while the front beam limiting shutter 32 is driven in the y direction by the front shutter driving device 36, and the rate of change expressed by the following equation: That is, the beam current density distribution j _{f, i} (y) in the y direction of the ion beam 4 at the positions z _f and x _i is obtained by differentiating the beam current S _{f, i} (y) by the distance y. Do it so you can. This is called a pre-stage beam current density distribution measurement step.

[Equation 3]
dS _{f, i} (y) / dy = j _{f, i} (y)

In the same manner as described above, the beam current density distribution j _{b in} the y direction of the ion beam 4 at the positions z _b and x _i using the latter multi-point Faraday 28, the latter beam limiting shutter 42, and the latter shutter driving device 46 _{. i} (y) can be determined, so do it. This is called a post-stage beam current density distribution measurement step. During the subsequent measurement, the front beam limiting shutter 32, the front multipoint Faraday 24, and the target 16 are removed from the path of the ion beam 4 so as not to hinder the measurement. This control may be performed by the control device 50. In this case, the pre-stage multipoint Faraday 24 may be removed from the path of the ion beam 4 using a drive device (for example, the pre-stage Faraday drive device 56 shown in FIG. 11).

Further, from the beam current density distributions j _{f, i} (y) and j _{b, i} (y) obtained as described above, the respective positions z _f and z _{b of the} front beam limiting shutter 32 and the rear beam limiting shutter 42 are obtained. The center positions y _cf and y _cb in the y direction of the ion beam 4 in FIG. These are referred to as a front stage center position calculation step and a back stage center position calculation step, respectively.

Further, using the center positions y _cf , y _cb and the distance L obtained as described above, the traveling angle θ _y in the y direction of the ion beam 4 based on the equation 1 or an equation mathematically equivalent thereto. Ask for. This is called the advance angle calculation step.

  On the front stage side, instead of providing the front stage beam limiting shutter 32 and the front stage shutter drive device 36 for driving it in the y direction as in the above-described embodiment (the embodiment shown in FIG. As in the embodiment shown in FIG. 11, a mask 52 having an opening 54 through which the ion beam 4 passes is provided in the vicinity of the upstream side of the front multipoint Faraday 24, and the front multipoint Faraday 24 is You may make it drive in a direction. An embodiment in this case will be described below.

  The front multi-point Faraday 24 is driven by the front Faraday drive device 56 through the shaft 57 in the ascending direction indicated by the arrow 58 or vice versa, so that it is taken in and out of the path of the ion beam 4 as described above. It is configured. The front multipoint Faraday 24 and the shaft 57 are electrically insulated by an insulator (not shown) so as not to hinder the beam current measurement by the front multipoint Faraday 24.

  The measurement of the ion beam 4 using the front multipoint Faraday 24 may be performed when the front multipoint Faraday 24 is raised or may be performed when the front multipoint Faraday 24 is lowered. As shown in Fig. 2, an example of performing at the time of rising will be described.

  As described above (see, for example, FIG. 6), the front multipoint Faraday 24 has an inlet 26 in front of a plurality of detectors. In this embodiment, the line connecting the upper ends 60 of the plurality of inlets 26 is made substantially parallel to the x direction. This is because the measurement balance in the x direction is improved.

The front-stage Faraday drive device 56 has a position sensor (not shown) that accurately measures and outputs the position y ₁ of the upper end 60 in the y direction.

In this embodiment, the control device 50 drives the front-stage Faraday drive device 56 as described above, instead of driving the front-stage shutter drive device 36 and taking in the information of the position y ₁ from the front-stage shutter drive device 36 as in the previous embodiment. And the information of the position y ₁ from it is taken in.

Further, in this embodiment, the position of the inlet 26 of the preceding stage multipoint Faraday 24 and z _f, the distance between the inlet 26 and the rear stage beam limiting shutter 42 in the z-direction, i.e. between the position z _f and the position z _b Let L be the distance.

In this example, the front shape of the opening 54 of the mask 52 is a rectangle that is long in the x direction. The dimension W _{m in} the y direction of the opening 54 is preferably set to be equal to or _smaller than the dimension W _{f in} the y direction of the inlet 26 of the front multi-point Faraday 24. In this embodiment, W _m <W _f is set, and an example in that case will be mainly described.

Initially, it is assumed that the upper end 60 of the front multi-point Faraday 24 is below the opening 54 of the mask 52. In this case, the ion beam 4 is blocked by the mask 52 and does not enter the preceding multipoint Faraday 24 at all. At this time, the y-coordinate position of the upper end 60 of the preceding multipoint Faraday 24 is set to y ₀ .

When the front multi-point Faraday 24 is driven in the y direction as indicated by the arrow 58, as the driving proceeds, a part of the ion beam 4 blocked by the mask 52 passes through the opening 54 gradually. To the front multi-point Faraday 24. Here, the y coordinate position of the upper end 60 of the entrance 26 of the front multipoint Faraday 24 when at least a part of the ion beam 4 is incident on the front multipoint Faraday 24 is y ₁ .

As in the case of the above-described embodiment, paying attention to the i-th detector in the x direction of the preceding multipoint Faraday 24, the x coordinate position of the center is assumed to be _xi . At this time, a function representing the beam current density distribution j _f (y) in the y direction at the x coordinate x _i at the position z _f of the entrance 26 of the preceding multipoint Faraday 24 is assumed to be j _{f, i} (y). At this time, the beam current S _{f, i} (y ₁ ) measured by the i-th detector is expressed by the formula 2. This is the same as FIG.

Therefore, the front stage multi-point Faraday 24 is driven in the y direction by the front stage Faraday drive device 56, and the beam current S _{f, i} (y) is measured by the front stage multi-point Faraday 24, and is expressed by the above equation (3). By differentiating the beam current S _{f, i} (y) by the distance y from the rate of change, the beam current density distribution j _{f, i} (y) in the y direction of the ion beam 4 at the positions z _f and x _i is obtained. Can be sought.

Contrary to the above example, the beam current density distribution j _{f, i} (y) of the ion beam 4 may be obtained by lowering the front multipoint Faraday 24 from above. In that case, instead of the upper end 60, attention should be paid to the lower end 62 of the inlet 26 of the preceding multipoint Faraday 24. The line connecting the lower ends 62 of the plurality of inlets 26 may be substantially parallel to the x direction.

When the dimension W _m of the opening 54 of the mask 52 is larger than the dimension W _f of the inlet 26 of the preceding multi-point Faraday 24, the beam current increases and decreases cancel each other during the driving of the preceding multi-point Faraday 24. It is possible, but it is possible to avoid this effect. For example, the measurement may be divided into measurement performed by raising the front multi-point Faraday 24 from below to the center in the y direction of the ion beam 4 and measurement performed by lowering the front multi-point Faraday 24 from above.

When the dimension W _{y in} the y direction of the ion beam 4 is smaller than the dimension W _{m of the} opening 54 at the position of the mask 52, this dimension W _y and the dimension W _f of the preceding multipoint Faraday 24 are used instead of the dimension W _m. This relationship may be considered in the same manner as described above.

Further, as can be understood by summarizing the contents described in the above two paragraphs, the dimension W _m of the opening 54 of the mask 52 is the dimension W _f of the inlet 26 of the preceding multi-point Faraday 24 and the dimension of the ion beam 4 in the y direction. It may be larger than W _y , in other words, the mask 52 is not necessarily provided.

Using the beam current density distribution j _{f, i} (y) obtained as described above, the center position y _cf in the y direction of the ion beam 4 is obtained in the same manner as in the above embodiment, and further the ion beam 4 The advancing angle θ _y in the y direction can be obtained.

Since the front multipoint Faraday 24 and the rear multipoint Faraday 28 have m detectors and n detectors in the x direction, respectively, i is 1 to m and 1 to n, respectively. Can take any value. Therefore, the traveling angle θ _y of the ion beam 4 can be measured at any position in the x direction using any i-th detector of 1 to m and 1 to n. In that case, the detector before and after the multipoint Faraday 24, 28, that the position in the x direction using substantially the same or close to the detector to each other, from the viewpoint of measuring the movement angle theta _y more accurately.

Further, by changing the i-th position of interest (used for measurement) within the above range, the advance angle θ _y is measured at a plurality of positions in the x direction, and the distribution of the advance angle θ _{y in} the x direction is measured. be able to. This is the advance angle distribution measuring step. This advance angle distribution measuring step is a combination of the preceding beam current density distribution measuring step, the latter beam current density distribution measuring step, the former center position calculating step, the latter center position calculating step, and the advance angle calculating step.

If the distribution of the advance angle θ _{y in} the x direction is not uniform in an actual ion implantation apparatus, it is often inclined obliquely, for example, as in the advance angle distribution P ₁ shown in FIG. I know from experience. This inclination may be opposite to the advance angle distribution P ₁ .

Therefore, in order to use for the advance angle correction described below, the average advance angle θ _{ya of} the advance angle θ _y having the advance angle distribution P ₁ as described above, or the advance angle θ _yc near the center in the x direction. Measure. This is the advance angle measurement step. Since both the advance angles θ _ya and θ _yc are one value, they are convenient for use in the subsequent advance angle correction process and advance angle correction control. Both traveling angles θ _ya and θ _yc are usually close to each other due to the above-mentioned tendency in an actual ion implantation apparatus. Therefore, either may be used. This advance angle measurement process is also a synthesis of the preceding stage beam current density distribution measurement process, the latter stage beam current density distribution measurement process, the former stage center position calculation process, the latter stage center position calculation process, and the advance angle calculation process.

In order to measure the average traveling angle θ _ya , a plurality of detectors of the front multipoint Faraday 24 are electrically connected in parallel to each other, and a plurality of detectors of the rear multipoint Faraday 28 are electrically connected in parallel to each other. In the connected state, as described in detail above, the ion beam 4 is gradually incident on each multipoint Faraday 24, 28 in the y direction, and the center position of the ion beam 4 in the y direction is set as the ion beam traveling direction. The ion beam 4 travels in the y direction in the vicinity of the target 16 using the distance in the y direction between the center positions and the distance in the z direction between the two positions, which are obtained at two positions upstream and downstream of z. Measure the angle θ _ya . In order to electrically connect a plurality of detectors in parallel with each other, for example, a plurality of signal lines from a plurality of detectors drawn into the control device 50 may be connected in parallel in the control device 50 with switches. .

In order to measure the advancing angle θ _yc near the center, the detectors near the center in the x direction of the front multipoint Faraday 24 and the rear multipoint Faraday 28 are used as described in detail above. The ion beam 4 is gradually incident on the Faraday 24 and 28 in the y direction, and the center position of the ion beam 4 in the y direction is obtained at two locations upstream and downstream of the ion beam traveling direction z. The advancing angle θ _yc in the y direction of the ion beam near the target 16 is measured using the distance in the y direction between the positions and the distance in the z direction between the two locations. In order to use the detector near the center, for example, among the signal lines from the plurality of detectors drawn into the control device 50, the signal line from the detector near the center in the x direction is switched by a switch. Just choose.

  The control device 50 performs a pre-stage beam current density distribution measurement process having substantially the same contents as the pre-stage beam current density distribution measurement process, and a post-stage beam current density distribution measurement process having substantially the same contents as the post-stage beam current density distribution measurement process. , A front-stage center position calculation process having substantially the same content as the preceding-stage center position calculation process, a back-stage center position calculation process having substantially the same contents as the back-stage center position calculation process, and a content substantially same as the advance angle calculation process. Can be performed. That is, it is possible to perform the advance angle measurement control with substantially the same content as the advance angle measurement step and the advance angle distribution measurement control with substantially the same content as the advance angle distribution measurement step.

(3) To perform movement angle theta _y modification of the ion beam for correction of movement angle theta _y of the ion beam, in addition to the movement angle measuring step, movement angle was measured in the movement angle measuring step theta _ya or theta _{Using yc} , the inclination angle β _y of the extraction electrode system 74 of the ion source 2 is set so as to decrease the advance angle θ _ya or θ _yc (that is, in the direction of approaching the advance angle θ _ya or θ _yc to 0 degrees). By changing (see FIG. 2), the angle in the y direction of the ion beam 4 extracted from the ion source 2 is changed. This is the advance angle correction process. More specifically, the inclination angle β _y of the extraction electrode system 74 in the y direction is changed in the direction opposite to the direction of the advance angle θ _ya or θ _{yc in} the y direction.

For example, when the advance angle distribution is on the plus side in the y direction as in the advance angle distribution P ₁ shown in FIG. 12, the advance angle θ _ya or θ _yc is on the plus side (in simple terms, upward) ( This is the same as the state shown in FIG. 5). In this case, the extraction electrode system 74 is inclined so as to face downward. For example, the inclination angle β _y is set to the minus side. When the inclination angle β _y is originally on the plus side, the inclination angle β _y of the extraction electrode system 74 is changed so that the inclination angle β _y approaches 0 degrees or on the minus side. As a result, the direction of the ion beam 4 extracted from the ion source 2 becomes more downward, so that the advancing angle θ _ya or θ _yc can be reduced to approach 0 degrees. When the advance angle θ _ya or θ _yc is on the minus side (or simply downward), the inclination angle β _y of the extraction electrode system 74 is changed in the opposite direction.

In the advance angle correction method of this embodiment, the advance angle θ _ya or θ _yc measured in the advance angle measurement step in the advance angle measurement step and the advance angle correction step is the first allowable range R ₁ (see FIG. 12). Do it once or more until inside. The allowable range R ₁ is set to a range close to 0 degrees, for example, about ± 0.1 degrees.

As a result, for example, the advance angle distribution P ₁ shown in FIG. 12 decreases as a whole while maintaining its original shape, and is centered around 0 degrees, like the advance angle distribution P ₂ indicated by a two-dot chain line. It will be the one. Contrary to the above-mentioned advance angle distribution P ₁ , when the advance angle distribution is large on the minus side, the whole rises and is centered around 0 degree.

Therefore, according to this traveling angle correction method, the traveling angle θ _y in the y direction of the ion beam 4 is corrected until the traveling angle θ _ya or θ _yc measured in the traveling angle measurement step falls within the first allowable range R ₁ . can do.

  As a result, more accurate implantation angle control can be performed in ion implantation for the target 16. As a result, for example, when ion implantation is used in the process of manufacturing a semiconductor device in the surface layer portion of a semiconductor substrate, which is an example of the target 16, it is possible to reduce variation in device characteristics within one semiconductor substrate, improve device manufacturing yield, etc. Can be planned. It is also effective in reducing variations in device characteristics between different lots.

  Furthermore, the possibility that the ion beam 4 in the middle of transportation collides with the structure can be reduced, and the transport efficiency of the ion beam 4 can be improved. As a result, for example, it is effective to increase the processing capability (throughput) of the target 16.

FIG. 13 shows an example of characteristics representing the relationship between the inclination angle β _y of the extraction electrode system 74 and the traveling angle θ _y of the ion beam 4. This represents how much the advance angle θ _y near the target 16 changes when the tilt angle β _y is changed, and is specific to each ion implantation apparatus. From this characteristic, it is possible to know the magnitude and direction (positive / negative) of the inclination angle β _y that is optimal for correction to make the advance angle θ _y close to 0 degrees. For correction, the sign of the tilt angle β _y is viewed opposite to the characteristic shown in the figure. For example, when the advance angle θ _y is θ _y1 , the tilt angle β _y may be set to −β _y1 .

Therefore, such characteristics in the ion implantation apparatus may be examined in advance and used in the advance angle correction step. By doing so, the advance angle θ _y can be corrected more quickly.

The advancing angle distribution measuring step of measuring the distribution of the advancing angle θ _{y in} the x direction after the advancing angle θ _ya or θ _yc measured in the advancing angle measuring step falls within the first allowable range R ₁ ; It is determined whether or not there is a traveling angle θ _y whose magnitude is out of the second allowable range R ₂ (see FIG. 14) among the traveling angles θ _y measured at the traveling angle distribution measurement step. You may further perform the advancing angle distribution determination process to determine. The second allowable range R ₂ is set wider than the first allowable range R ₁ . For example, it is set to about ± 0.3 degrees.

In the advance angle distribution measurement step, unlike the advance angle measurement step in which one advance angle θ _ya or θ _yc is measured, a plurality of multi-point Faraday 24 and 28 detectors are connected in parallel or in the center in the x direction. Instead of using nearby detectors, the plurality of detectors are used to measure the traveling angles θ _y at a plurality of positions in the x direction. An example of the measured advance angle distribution P ₂ is shown in FIG. This advance angle distribution P ₂ is the same as the advance angle distribution P ₂ in FIG. In the case of the travel angle distribution P _{2 in} FIG. 14, there is no travel angle θ _y that is out of the allowable range R ₂ .

  By performing the determination as described above, ion implantation into the target 16 by the ion beam 4 having a poor traveling angle distribution can be prevented. As a result, for example, a large number of semiconductor devices with poor characteristics are formed in a semiconductor substrate which is an example of the target 16 to prevent the yield from being deteriorated or the loss of the semiconductor substrate or the loss of time due to defective implantation. be able to.

In this embodiment, the control device 50 performs (a) measurement with substantially the same content as the above-described advance angle measurement step, and measures the average advance angle θ _ya or the advance angle θ _yc near the center. And (b) controlling the electrode driving device 76 based on the advancing angle θ _ya or θ _yc measured by the advancing angle measuring control, and performing control substantially the same as the advancing angle correcting step. The advance angle correction control is performed once or more until the advance angle θ _ya or θ _yc measured by the advance angle measurement control falls within the first allowable range R ₁ . Therefore, since the measurement and control with substantially the same contents as the advance angle measurement step and the advance angle correction step can be performed using the control device 50 and the electrode driving device 76, labor saving can be achieved.

  When the characteristics as shown in FIG. 13 are used in the control device 50, for example, the characteristics may be stored in the control device 50.

In this embodiment, the control device 50 further includes (a) the advance angle distribution measuring step after the advance angle θ _ya or θ _yc measured by the advance angle measurement control is within the first allowable range R ₁ . substantially advanced angle distribution measurement control of the same content, within the movement angle theta _y of a plurality of positions measured in (b) the movement angle distribution measurement control, its size is disengaged from the second allowable range R within ₂ has a function of performing a movement angle distribution determination control for outputting a signal S _a representative of the result whether there is a movement angle theta _y and are determined to. For example, the signal _Sa is “1” if there is at least one advance angle θ _y outside the allowable range R _2, and it is “0” if there is none. Of course, this logical value may be reversed.

Therefore, since the control device 50 can perform measurement and determination with substantially the same contents as the above-described advance angle distribution measurement step and advance angle distribution determination step, labor saving can be achieved. Further, the signal S _a which is output from the control unit 50, alarm output or may be used to interlock the like to stop the ion implantation.

(4) for movement angle theta _x in the x direction of the ion beam in addition to the movement angle theta _y in the y-direction, for the movement angle theta _x in the x direction of the ion beam 4 in the vicinity target 16 (see FIG. 15), Measurement may be performed using the front multipoint Faraday 24 and the rear multipoint Faraday 28, and the correction may be made.

For example, as in the ion implantation apparatus shown in FIG. 1, when the ion beam 4 in the vicinity of the target 16 has a ribbon shape after scanning in the x direction (see FIG. 3), it is described in, for example, Japanese Patent No. 2969788. In the same manner as in the technique, the scanning positions in the x direction of the ion beam 4 at the time corresponding to each other are measured at two positions on the upstream side and the downstream side using the multipoint Faraday 24 and 28, and the measured scanning is performed. Based on the distance in the x direction between the positions and the distance in the z direction between the two positions, the traveling angle θ _x in the x direction of the ion beam near the target 16 is measured.

When the traveling angle θ _x is, for example, as shown in FIG. 15 (θ _x in this direction is negative for convenience), the current or voltage supplied to the beam collimator 14 is increased, and the beam collimator 14 The bending of the ion beam 4 is strengthened. When the advance angle θ _x is a positive value opposite to the above, the current or voltage is decreased to weaken the bending of the ion beam 4 in the beam collimator 14. Thereby, the advance angle θ _x can be brought close to 0 degree.

When the ion beam 4 in the vicinity of the target 16 is in the form of a ribbon without being scanned in the x direction as in the example shown in FIG. 4, a plurality of detectors of both multipoint Faraday 24 and 28 are used. The beam current distribution in the x direction of the ion beam 4 and its center position (center of gravity or peak position) are measured at two locations on the upstream and downstream sides, and the distance in the x direction between the measured center positions and the two locations are measured. Based on the distance in the z direction, the traveling angle θ _x of the ion beam 4 in the x direction is measured.

Then, for example, by using a beam deflector corresponding to the beam collimator 14, the current or voltage supplied to the beam deflector is increased or decreased in the same manner as described above, so that the advance angle θ _x approaches 0 degrees.

As described above, in addition to the movement angle theta _y in the y-direction, by performing the movement angle theta _x fixes closer to 0 degrees in the x-direction, x, the two-dimensional y directions, more accurate injection angle Control can be performed.

It is a schematic plan view which shows an example of an ion implantation apparatus. It is the schematic which shows an example of an ion source. FIG. 4 is a schematic perspective view partially showing an example of a ribbon-like ion beam having a size in the x direction larger than a size in the y direction after scanning in the x direction. It is a schematic perspective view which partially shows an example of the ribbon-shaped ion beam whose dimension in the x direction is larger than the dimension in the y direction without passing through the scanning in the x direction. It is a figure which shows an example of the advance angle (theta) _y in the y direction of an ion beam. It is a figure which shows an example of the measuring apparatus and control apparatus of an ion beam in the vicinity of a target. It is a figure which shows an example of the beam current density distribution j (y) of the y direction of an ion beam. It is a figure for _{demonstrating} the more detailed definition of the advance angle (theta) _y in the y direction of an ion beam. It is a figure which shows an example of the method of measuring the beam current density distribution of the y direction in the position of a front | former stage beam limiting shutter. It is a figure which shows an example of the beam current density distribution of the y direction in the position of a front | former stage beam limiting shutter. It is a figure which shows the other example surrounding a front | former stage multipoint Faraday. It is a figure which shows an example of distribution in the x direction of the advance angle (theta) _y of an ion beam. It is a figure which shows an example of the characteristic showing the relationship between inclination-angle (beta) _{y of} an extraction electrode system, and the advance angle (theta) _y of an ion beam. It is a figure which shows the other example of distribution in the x direction of the advance angle (theta) _y of an ion beam. It is a figure which shows the example of the advance angle (theta) _x in the x direction of an ion beam.

Explanation of symbols

2 Ion source 4 Ion beam 16 Target 24 Previous stage multi-point Faraday 28 Rear stage multi-point Faraday 50 Controller 74 Extraction electrode system 76 Electrode driver θ _x , θ _y , θ _ya , θ _yc advance angle

Claims (4)

When the traveling direction in the design of the ion beam is the z direction and the two directions substantially orthogonal to each other in a plane substantially orthogonal to the z direction are the x direction and the y direction, the ion beam is extracted from the ion source having the extraction electrode system. An apparatus configured to irradiate a target with a ribbon-like ion beam having a dimension in the x direction larger than that in the y direction without passing through the x direction scan or the x direction scan. The ion beam at the time of irradiation to the target is a substantially parallel beam in the x direction, and is provided relatively upstream and downstream in the ion beam traveling direction in the vicinity of the target. A plurality of detectors for measuring the beam current of the front stage and the rear stage multipoint Faraday, each of which is arranged in parallel in the x direction. In the ion implantation apparatus,
A plurality of front-stage multipoint Faraday detectors are electrically connected in parallel with each other, and a plurality of rear-stage multipoint Faraday detectors are electrically connected in parallel with each other, and each multipoint Faraday is ion beam in the y direction. So that the center position in the y direction of the ion beam is obtained at two locations upstream and downstream in the ion beam traveling direction, and the distance in the y direction between the center positions and the distance between the two locations is determined. a traveling angle measurement step of measuring a traveling angle in the y direction of the ion beam near the target using the distance in the z direction;
Progression of changing the angle of the ion beam extracted from the ion source in the y direction by changing the tilt angle in the y direction of the extraction electrode system of the ion source in the direction of decreasing the advance angle measured in the advance angle measurement step. Corner correction process,
Do one or more times until the advance angle measured in the advance angle measurement step falls within the first allowable range,
And the progress of the ion beam, characterized in that the characteristic representing the relationship between the movement angle of the tilt angle between the ion beam of the extraction electrode system in the ion implantation apparatus which has been examined beforehand, is used in the travel angle correction step Corner correction method. After the advance angle measured in the advance angle measurement step falls within the first allowable range,
Using the preceding multi-point Faraday and subsequent multi-point Faraday, the ion beam is gradually incident on each multi-point Faraday in the y direction, and the center position of the ion beam in the y direction is set upstream of the ion beam traveling direction and Using the distance in the y direction between the center positions and the distance in the z direction between the two positions measured at two downstream locations, the advancing angle in the y direction of the ion beam near the target is measured, and this Advancing angle distribution measuring step for performing such measurement at a plurality of positions in the x direction;
A progress angle distribution determining step for determining whether or not there is a progress angle whose magnitude is out of the second allowable range among the advance angles measured at the progress angle distribution measuring step. movement angle correction method of the ion beam according to claim 1, wherein performing. When the traveling direction in the design of the ion beam is the z direction and the two directions substantially orthogonal to each other in a plane substantially orthogonal to the z direction are the x direction and the y direction, the ion beam is extracted from the ion source having the extraction electrode system. An apparatus configured to irradiate a target with a ribbon-like ion beam having a dimension in the x direction larger than that in the y direction without passing through the x direction scan or the x direction scan. The ion beam at the time of irradiation to the target is a substantially parallel beam in the x direction, and is provided relatively upstream and downstream in the ion beam traveling direction in the vicinity of the target. A plurality of detectors for measuring the beam current of the front stage and the rear stage multipoint Faraday, each of which is arranged in parallel in the x direction. In the ion implantation apparatus,
An electrode driving device having a function of changing an inclination angle in at least the y direction of the extraction electrode system of the ion source;
Further, (a) a plurality of front-stage multipoint Faraday detectors are electrically connected in parallel with each other, and a plurality of rear-stage multipoint Faraday detectors are electrically connected in parallel with each other, As the ion beam gradually enters in the y direction, the center position of the ion beam in the y direction is obtained at two locations upstream and downstream in the ion beam traveling direction, and the distance between the center positions in the y direction and Based on the advancing angle measurement control that measures the advancing angle in the y direction of the ion beam near the target using the distance in the z direction between the two locations, and (b) based on the advancing angle measured by the advancing angle measurement control. By controlling the electrode driving device, the inclination angle in the y direction of the extraction electrode system of the ion source is changed in the direction of decreasing the advance angle, A function of performing the advance angle correction control for changing the angle in the y direction of the ion beam to be emitted at least once until the advance angle measured by the advance angle measurement control falls within the first allowable range. Equipped with a control device,
And wherein the control device, that the characteristics representing the relationship between the movement angle of the tilt angle between the ion beam of the extraction electrode system in the ion implantation apparatus which has been examined beforehand, is to use in the traveling angle correction control A featured ion implanter. After the advance angle measured by the advance angle measurement control falls within the first allowable range, the control device uses (a) the multi-stage Faraday and the multi-stage Faraday of the preceding stage to generate y for each multi-point Faraday. The center position in the y direction of the ion beam is obtained at two locations on the upstream side and the downstream side in the ion beam traveling direction so that the ion beam gradually enters in the direction, and the distance in the y direction between the center positions Advancing angle distribution measurement control in which the advancing angle in the y direction of the ion beam near the target is measured using the distance in the z direction between the two locations, and such a measurement is performed at a plurality of positions in the x direction; ) It is determined whether or not there is a traveling angle whose magnitude is out of the second allowable range among the traveling angles measured by the traveling angle distribution measurement control. And it outputs a signal representative of the movement angle distribution determining control and further comprising in that claim 3 ion implantation apparatus according a function of performing.

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