JP4784544B2 - Method of measuring beam width and divergence angle of ion beam and ion implantation apparatus - Google Patents

Description

  According to the present invention, a beam in the X direction of an ion beam in an ion implantation apparatus configured to irradiate a substrate (eg, a semiconductor substrate; the same applies below) with an ion beam that is substantially scanned in parallel in the X direction (eg, a horizontal direction; the same applies hereinafter) The present invention relates to a width measurement method, a divergence angle measurement method, a beam scanning distance setting method, and an ion implantation apparatus capable of implementing these methods.

  In Patent Document 1, parallelism in which the parallelism of an ion beam is measured using two multipoint beam monitors provided relatively upstream and downstream in the traveling direction of the ion beam scanned in parallel in the X direction. Degree measurement methods are described.

Japanese Patent No. 2969788 (column 8, FIGS. 1 and 4)

  The parallelism measuring method described in Patent Document 1 is a method of measuring the orbit of the center of gravity in the X direction (scanning direction) of the ion beam by measuring the center of gravity of the ion beam on the upstream side and the downstream side. Patent Document 1 does not describe a method for measuring the size (beam width) or divergence angle of an ion beam.

  In general, an ion beam generally refers to (a) an ion beam having a relatively small cross section from which scanning is performed, and (b) an entire ion beam having a relatively large cross section that is scanned and spread. However, in this specification, the beam width, the divergence angle, etc. are focused on the former (a) ion beam. In order to distinguish this ion beam from the ion beam of the latter (b), there is also a document called a spot-like ion beam.

  The ion beam has a property of diverging due to the space charge effect. This becomes larger as the ion beam becomes higher current and lower energy. The beam width and divergence angle of this ion beam are classified into those in the X direction and those in the Y direction (a direction substantially perpendicular to the X direction, for example, the vertical direction, the same applies hereinafter). Focus on things.

  It has recently been found that the beam width in the X direction and the divergence angle in the X direction of this ion beam affect the ion implantation characteristics of the substrate. In particular, as the substrate becomes larger and the device (for example, a semiconductor device; the same applies hereinafter) formed on the surface thereof becomes finer, the influence becomes larger.

  For example, when ion implantation is performed on the entire surface of the substrate using both the parallel scanning of the ion beam in the X direction and the mechanical scanning of the substrate along the Y direction, the ion beam having any beam width can be used. Depending on whether the beam is used, it affects the so-called filling method by the ion beam on the entire surface of the substrate. Therefore, the beam width affects the implantation uniformity. This effect increases as the substrate size increases.

  In addition, when the divergence angle of the ion beam is large, a shadow portion where the ion beam is not incident is generated on the device formed on the surface of the substrate, so that the device characteristics are deteriorated. As the device becomes finer, the problem of shadowing due to the divergence angle becomes more serious.

  In order to deal with the above problem, first, it is necessary to know the beam width and divergence angle of the ion beam in the X direction.

  One method is to determine the beam width and divergence angle of the ion beam by simulation. However, in reality, there is no practical calculation model that can accurately evaluate the space charge effect of the ion beam. A correct simulation is difficult for a low-energy, high-current ion beam, and it is difficult to obtain accurate simulation results.

  Accordingly, the present invention provides a beam width measuring method and ion implantation apparatus that can easily and accurately measure the beam width in the X direction of an ion beam that is scanned substantially parallel to the X direction. It is aimed.

  It is another object of the present invention to provide a beam scanning distance setting method and an ion implantation apparatus that can set an appropriate scanning distance in the X direction of the ion beam according to the beam width.

  Another object of the present invention is to provide a divergence angle measurement method and an ion implantation apparatus that can easily and accurately measure the divergence angle in the X direction of the ion beam.

A first beam scanning distance setting method according to the present invention is an ion beam scanning distance setting method in an ion implantation apparatus configured to irradiate a substrate with an ion beam that is substantially parallel scanned in the X direction.
(A) Using a first and a second beam measuring instrument which receives an ion beam and measures the beam current, and is spaced apart from each other in the X direction,
(B) By scanning the ion beam across both beam measuring instruments and monitoring temporal changes in the beam current flowing into each beam measuring instrument, the start time and inflow of the beam current in each beam measuring instrument Find the end point respectively
(C) Based on at least three of these time points, the width of the beam entrance hole of each beam measuring device in the X direction, and the distance between the centers of the beam entrance holes of both beam measuring devices in the X direction, According to a beam width measuring method for obtaining a preliminary beam width in the X direction of the ion beam,
(D) The ion beam is reciprocally scanned across the first and second beam measuring instruments, and the preliminary beam width in the X direction of the ion beam is determined in both the forward and backward beam scanning. And an arithmetic average of both of the obtained beam widths as a preliminary beam width in the X direction of the ion beam,
(E) Using a third and a fourth beam measuring instrument which receives an ion beam and measures its beam current and is spaced apart from each other in the X direction ,
( F) The preliminary beam width in the X direction of the ion beam, the width in the X direction of each beam entrance hole of the third and fourth beam measuring instruments, and the center in the X direction of both beam measuring instruments Based on the distance between the ion beam at the position where the beam current starts to flow into the third beam measuring instrument and the ion beam at the position where the beam current stops flowing in the fourth beam measuring instrument. Obtaining a first scanning distance which is a distance in the direction;
(G) A scanning distance in the X direction of the ion beam is set to a second scanning distance larger than the first scanning distance.

  According to the first beam scanning distance setting method, the ion beam is set to a second scanning distance larger than the first scanning distance obtained using the preliminary beam width in the X direction of the ion beam. Since the scanning distance in the X direction is set, the scanning distance in the X direction of the ion beam can be easily set to the optimum scanning distance.

  The third beam measuring device may be the same as the first beam measuring device, and the fourth beam measuring device may be the same as the second beam measuring device (this case may be the second beam measuring device). This is called a scanning distance setting method.

The first beam width measuring method according to the present invention includes: (a) receiving an ion beam located within the second scanning distance set according to the first or second beam scanning distance setting method; An ion beam is scanned at a predetermined scanning period and the second scanning distance so as to cross the fifth beam measuring instrument for measuring the beam current, and (b) from the scanning period and the second scanning distance. Based on the determined ion beam scanning speed, the time difference between the inflow start time and the inflow end time of the beam current in the fifth beam measuring instrument, and the X-direction width of the beam entrance hole of the fifth beam measuring instrument. Thus, the X-direction beam width of the ion beam at the position of the fifth beam measuring device is obtained.

According to the first beam width measuring method, by using the ion beam scanning speed determined from the ion beam scanning period and the second scanning distance, the first position of the desired position within the second scanning distance of the ion beam is used. The beam width in the X direction of the ion beam at the position of the beam measuring instrument 5 can be measured easily and accurately.

A plurality of the fifth beam measuring devices may be arranged in the X direction, and the beam width in the X direction of the ion beam may be measured at a plurality of positions in the X direction according to the first beam width measuring method.

  The first divergence angle measuring method according to the present invention is as follows: (a) The fifth beam measuring instrument is arranged so as to be separated from each other at two positions in the front and rear of the ion beam traveling direction and receives the ion beam. Using the former stage beam measuring instrument and the latter stage beam measuring instrument for measuring the beam current, (b) the ion beam at the two front and rear positions at substantially the same position in the X direction according to the third beam width measuring method. X-direction beam widths are respectively obtained, and (c) and the divergence angle of the ion beam in the X-direction is measured based on the difference between both beam widths and the separation distance.

  According to the first divergence angle measurement method, the beam width in the X direction of the ion beam is obtained at two positions in the traveling direction of the ion beam and at substantially the same position with respect to the X direction, and the divergence angle is obtained using them. Therefore, the divergence angle in the X direction of the ion beam at a predetermined position within the second scanning distance can be measured easily and accurately.

  A plurality of the former stage beam measuring instruments and the latter stage beam measuring instruments are respectively arranged in the X direction, and according to the first divergence angle measuring method, the divergence angles in the X direction of the ion beam are set at a plurality of positions in the X direction. It may be measured.

  An ion implantation apparatus according to the present invention includes a beam scanning unit that scans an ion beam in the X direction, and a beam collimating unit that cooperates with the beam scanning unit to scan the ion beam substantially in the X direction. And an ion implantation apparatus configured to irradiate the substrate with an ion beam that is substantially scanned in parallel in the X direction, the beam measuring instrument corresponding to that used in each of the above methods, and the contents of each of the above methods And a control device having a function of performing arithmetic control corresponding to the above.

According to the invention described in claim 1, 7, by using a scanning ion beam and the first and second beam measuring instrument, the preliminary beam width in the X direction of the ion beam, easily and accurately It can be measured well.

In addition , the preliminary beam width is obtained in both the forward and backward scans, and the obtained beam widths are arithmetically averaged to obtain the preliminary beam width in the X direction of the ion beam. Measurement accuracy can be further increased.

Furthermore , since the scanning distance in the X direction of the ion beam is set to a second scanning distance larger than that based on the first scanning distance obtained using the preliminary beam width in the X direction of the ion beam, It becomes easy to set the scanning distance of the ion beam in the X direction to an optimum scanning distance. That is, even if the beam width in the X direction of the ion beam changes from the preliminary beam width obtained by the above measurement for some reason, the beam width in the X direction of the ion beam should be correctly measured using each beam measuring instrument. This makes it possible to solve the problem that it becomes impossible to perform overscanning of the ion beam with respect to the substrate.

According to invention of Claim 2 , 8, there exists the following further effect. That is, since the first scanning distance can be obtained using the same beam measuring instrument as that for obtaining the preliminary beam width in the X direction of the ion beam, measurement was performed at the same position as that for obtaining the first scanning distance. A preliminary beam width can be used. Therefore, the first scanning distance can be obtained more accurately, and as a result, the second scanning distance can be set more accurately. In addition, the number of beam measuring instruments required for measurement can be reduced.

According to invention of Claim 3 , 9, there exists the following further effect. That is, by using the ion beam scanning speed determined from the ion beam scanning period and the second scanning distance, the ion beam at the position of the fifth beam measuring device at the desired position within the second scanning distance of the ion beam. It is possible to easily and accurately measure the beam width in the X direction.

According to invention of Claim 4 , 10, there exists the following further effect. That is, the beam width in the X direction of the ion beam can be measured at a plurality of positions in the X direction. Therefore, for example, the distribution of the beam width in the X direction can be measured.

According to invention of Claim 5 , 11, there exists the following further effect. That is, the beam width in the X direction of the ion beam is obtained at two locations in the traveling direction of the ion beam and at substantially the same position in the X direction, and the divergence angle is obtained using them. The divergence angle in the X direction of the ion beam at a predetermined position can be measured easily and accurately.

According to invention of Claim 6 , 12, there exists the following further effect. That is, the divergence angle in the X direction of the ion beam can be measured at a plurality of positions in the X direction. Therefore, for example, the distribution of the divergence angle in the X direction can be measured.

(1) Configuration of Entire Ion Implantation Apparatus FIG. 1 is a schematic plan view showing an embodiment of an ion implantation apparatus according to the present invention. In this specification and drawings, the design traveling direction of the ion beam 4 is always the Z direction, and two directions substantially orthogonal to each other in a plane substantially orthogonal to the Z direction are the X direction and the Y direction. Direction. 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.

  The ion implantation apparatus includes an ion source 2 that emits (extracts) an ion beam 4, and a mass separator that receives the ion beam from the ion source 2 and separates and extracts the ion beam 4 having a desired mass from the ion beam 4. 6, an ion beam 4 from the mass separator 6 is incident and an accelerator / decelerator 8 that accelerates or decelerates the ion beam 4, and an ion beam 4 from the accelerator / decelerator 8 is incident and desired from the ion beam 4. An energy separator 10 that separates and extracts an ion beam 4 of energy, a beam scanner 12 that receives the ion beam 4 from the energy separator 10 and scans the ion beam 4 in the X direction, and the beam scanner 12 The ion beam 4 from the beam is incident, the ion beam 4 is bent, and the ion beam 4 is moved in the X direction in cooperation with the beam scanner 12. A beam collimator 14 that performs row scanning, and a substrate driving device 20 that mechanically reciprocates (reciprocates) the substrate 16 in a direction along the Y direction within an irradiation region of the ion beam 4 from the beam collimator 14; It has.

  The mass separator 6 is, for example, a mass separation electromagnet that performs mass separation of the ion beam 4 using a magnetic field. The accelerator / decelerator 8 is, for example, an acceleration / deceleration tube that includes a plurality of electrodes and accelerates / decelerates the ion beam 4 by an electrostatic field. The energy separator 10 is, for example, an energy separation electromagnet that performs energy separation of the ion beam 4 using a magnetic field. The beam scanner 12 is, for example, a scanning electromagnet that scans the ion beam 4 with a magnetic field. The beam collimator 14 is, for example, a beam collimating electromagnet that collimates the ion beam 4 with a magnetic field. The substrate driving device 20 has a holder 18 that holds the substrate 16.

  A beam scanner 12 and a scanning power supply 13 for supplying beam scanning power to the beam scanner 12 constitute the beam scanning means, and a beam collimator 14 constitutes the beam collimating means.

  With the above configuration, the substrate 16 is irradiated with the ion beam 4 having a desired mass and desired energy while being scanned in parallel in the X direction, and the substrate 16 is mechanically reciprocated in the direction along the Y direction with respect to the ion beam 4. The ion implantation can be performed by scanning and irradiating the entire surface of the substrate 16 with the ion beam 4. As described above, a method in which the electrical or magnetic scanning of the ion beam 4 and the mechanical scanning of the substrate 16 are used together is called a hybrid scanning method.

  The cross-sectional shape of the ion beam 4 is illustrated as a circular shape as an example in FIGS. 4 and 5, but is not limited thereto. For example, an oval, an ellipse, a quadrangle, etc. may be sufficient. Although the ion beam 4 is shown by a thick line in FIGS. 2 and 3 for simplification of illustration, the ion beam 4 actually has the cross-sectional shape as described above.

  As shown in FIGS. 2 and 3, in the vicinity of the substrate 16, the upstream side and the downstream side in the traveling direction Z of the ion beam 4, more specifically, in this example, the upstream side of the position of the substrate 16. A front-stage Faraday device 30 and a rear-stage beam monitor 50 are provided on the side and the downstream side with a distance (separation distance) L therebetween. However, the front stage Faraday device 30 and the rear stage beam monitor 50 do not necessarily have to sandwich the substrate 16 as in this example.

  In this example, the front-stage Faraday device 30 has an opening 33 that allows the ion beam 4 to pass when the ion beam 4 is incident on the substrate 16 and an opening that allows the ion beam 4 to pass when the ion beam 4 enters the rear-stage beam monitor 50. 34, and a first beam measuring instrument 36 and a second beam measuring instrument 38, which receive the ion beam 4 and measure the beam current thereof, and are spaced apart from each other in the X direction. And a pre-stage beam monitor 40 having a plurality of m beam measuring devices 42 which are arranged in parallel in the X direction at predetermined intervals and receive the ion beam 4 and respectively measure the beam current.

  In this embodiment, the beam measuring instruments 36 and 38 are provided near both outer sides in the X direction of the opening 33. The aperture 33 and the beam measuring instruments 36 and 38, the aperture 34, and the front beam monitor 40 are arranged in three stages in the Y direction.

The beam measuring instruments 36 and 38 are disposed at substantially the same position with respect to the Z direction. _Let that position (for example, the position of the entrance) be Z _f . The beam measuring devices 42 constituting the front beam monitor 40 are also arranged at the same position in the Z direction. The position (for example, the position of the entrance) is the same position Z _f as the beam measuring instruments 36 and 38 in this example.

The post-stage beam monitor 50 includes a plurality of n beam measuring devices 52 that are arranged in parallel in the X direction at predetermined intervals and receive the ion beam 4 and measure the beam current thereof. Each beam measuring instrument 52 is arranged at the same position in the Z direction. Its position (e.g., the inlet position) and Z _b. Distance in the Z direction between the position Z _b and the position Z _f is the a spacing distance L.

  Each of the above m and n is an integer of 2 or more. For example, it is about 10-20.

  Each of the beam measuring instruments 36, 38, 42, and 52 actually has a depth in the ion beam traveling direction Z (see, for example, FIG. 7), but in FIG. 2 and FIG. 3, the depth is omitted for simplification of illustration. is doing. Each beam measuring instrument 36, 38, 42, 52 has beam incident holes 37, 39, 43, 53 for receiving the ion beam 4, respectively (see also FIGS. 4 and 5). Each beam measuring instrument 36, 38, 42, 52 is, for example, a Faraday cup.

  The front-stage Faraday device 30 is moved up and down in at least three stages in the Y direction as indicated by an arrow A by the front-stage Faraday drive device 26 via the shaft 28. For example, when the measurement is performed with the ion beam 4 incident on the front beam monitor 40, the front Faraday device 30 is positioned at the upper position as shown in FIG. When the measurement is performed by making the ion beam 4 incident on the post-stage beam monitor 50, as shown in FIG. 3, the pre-stage Faraday device 30 is positioned at an intermediate position. When the ion beam 4 is incident on the rear stage beam monitor 50, the substrate 16 is retracted out of the path of the ion beam 4 by the substrate driving device 20. When the ion beam 4 is incident on the substrate 16 and ion implantation is performed, and when the ion beam 4 is incident on the beam measuring devices 36 and 38 and the measurement is performed, the front Faraday device 30 is further lower than that in FIG. Located in the lower position.

  The ion implantation apparatus further includes a control device 60. The control device 60 includes beam current information measured by the beam measuring instruments 36 and 38, m beam current information respectively measured by the beam measuring instruments 42 constituting the former stage beam monitor 40, and a latter stage beam monitor 50. The n pieces of beam current information and the like measured by each beam measuring instrument 52 are captured. The control device 60 (a) functions to control the substrate driving device 20 to mechanically drive the substrate 16 as described above, and (b) controls the front stage Faraday driving device 26 to control the front stage Faraday. It has a function of performing control to raise and lower the apparatus 30 in three stages as described above, and (c) further has a function of performing various calculations and controls described later.

(2) Measurement of Preliminary Beam Width D of Ion Beam Next, a beam width measuring method and an ion implantation apparatus for obtaining the preliminary beam width D in the X direction of the ion beam 4 will be described. “Preliminary” means that the beam width D obtained in advance is obtained by setting or setting scanning distances L _b1 and L _b2 and beam width W _b of an ion beam 4 to be described later. This is because it can be used.

For this measurement, for example, the first and second beam measuring instruments 36 and 38 are used. Referring to FIG. 4, the widths in the X direction of the beam incident holes 37 and 39 of the beam measuring instruments 36 and 38 are W _d1 and W _d2 , respectively, and the center-to-center distance in the X direction is L _d .

  The ion beam 4 is scanned across both beam measuring instruments 36 and 38. In this case, the ion beam 4 is scanned so as to surely pass through the beam incident holes 37 and 39 of both beam measuring instruments 36 and 38.

In this embodiment, the ion beam 4 at the time of measurement is handled as follows. This is close to that in an actual ion implantation apparatus and is reasonable. That is, (a) the scanning speed of the ion beam 4 is substantially constant regardless of the location. “Substantially constant” means that even if it is not completely constant, slight (for example, several percent) speed variation is allowed. However, it is not necessary to know the specific value of the scanning speed at this stage. (B) Even if the beam width in the X direction of the ion beam 4 may change depending on the position in the X direction, it is considered that it does not change abruptly. That is, the beam width at the adjacent position can be regarded as constant. Therefore, here, the beam width near the beam incident hole 37 is D ₁ , and the beam width near the beam incident hole 39 is D ₂ .

  The substantially constant scanning speed of the ion beam 4 is, for example, (a) a scanning current or scanning voltage of a triangular wave (referred to as a basic triangular wave) having a constant period and amplitude from the scanning power supply 13 to the beam scanner 12. This can be realized by supplying In addition, (b) according to the method described in Patent Document 1, the scanning current or the scanning voltage having a waveform after the waveform of the basic triangular wave is supplied from the scanning power supply 13 to the beam scanner 12. . The latter (b) can realize a more constant scanning speed. When the basic triangular wave (a) is used, the measurement error may be slightly larger (for example, about several percent) than the case where the scanning waveform (b) is used. Therefore, in order to perform more accurate measurement, the scanning waveform (b) may be used.

  Then, as described above, the ion beam 4 is scanned at a substantially constant scanning speed so as to cross both the beam measuring instruments 36 and 38, and the temporal change in the beam current flowing into each of the beam measuring instruments 36 and 38 is measured. By monitoring, the inflow start time and the inflow end time of the beam current in each of the beam measuring instruments 36 and 38 are obtained, respectively, and at least three of these time points and the beam entrance holes of the respective beam measuring instruments 36 and 38 are obtained. The preliminary beam width in the X direction of the ion beam 4 is obtained based on the width in the X direction of 37 and 39 and the distance between the centers of the beam incident holes 37 and 39 in both beam measuring instruments.

More specifically, the ion beam 4 is scanned so as to cross both the beam measuring instruments 36 and 38, and the beam which is first traversed by the ion beam 4 in one way of the beam scanning, for example, in the forward path shown in FIG. 4B. The inflow start time T _a at which the beam current starts to flow into the measuring instrument 36, the inflow end time T _b at which the inflow ends, and the inflow start time T _c at which the beam current starts to flow into the beam measuring instrument 38 that the ion beam 4 crosses next. Then, the inflow end point T _d is measured.

The inflow start time points T _a and T _c may be, for example, the time point when the inflowing beam current exceeds 0, but may be the time point when the predetermined threshold value is exceeded in order to avoid the influence of noise. For example, a threshold of several percent of the peak value of the incoming beam current is used. Or you may make it switch a some threshold value according to a case.

The inflow end time points T _b and T _d may be, for example, the time point when the inflowing beam current becomes 0, but may be the time point when it falls below a predetermined threshold in order to avoid the influence of noise. For example, a threshold of several percent of the peak value of the incoming beam current is used. Or you may make it switch a some threshold value according to a case.

The measurement at time points T _e and T _f (see FIG. 5) described later is the same as described above.

  As described above, the scanning speed of the ion beam 4 is substantially constant.

[Equation 1]
_{v = (L d + W d1} / 2 + W d2 / 2 + D 1/2 + D 2/2) / (T d -T a) = (L d -W d1 / 2-W d2 / 2-D 1/2-D 2 / 2) / (T _c −T _b )

Here, in order to simplify the formula, the following formula is used. This D is the average of D ₁ and D ₂ the beam width of the (arithmetic mean. Similarly), W _d is the average width of W _d1 and W _d2, represents respectively. The fact, the width W _d2 width W _d1 and the beam entrance aperture 39 of beam incidence hole 37 may be equal to the width W _d to each other. The same applies to other measurement methods described below.

[Equation 2]
D = (D ₁ + D ₂ ) / 2
W _d = (W _d1 + W _d2 ) / 2

  Substituting this into Equation 1, the following equation is obtained.

[Equation 3]
v = (L _d + W _d + D) / (T _d −T _a ) = (L _d −W _d −D) / (T _c −T _b )

  When this is arranged with respect to the beam width D, the following expression is obtained. Therefore, based on the following expression (or an expression that is mathematically equivalent thereto, the same applies to other expressions), a preliminary beam width D in the X direction of the ion beam 4 is obtained. Ask for.

[Equation 4]
D = L _d {(T _d −T _c + T _b −T _a ) / (T _d + T _c −T _b −T _a )} − W _d

Determination of the beam width D by the number 1 to number 4, four time T _a, in view of the T _b, T _c, T _d, the scanning speed between the time T _d and T _a, and the time point T _c Although the scanning speed between T _b is an example of a case in which equal to each other, may be calculated beam width D by other methods.

For example, three time T _a, T _c, by paying attention to T _d, the scanning speed between the time T _c and T _a, and the scanning speed between the time T _d and T _a being equal to each other, the beam width D You may ask. In this case, in order to simplify the equation, using the average width W _d of the beam incident holes 37 and 39 and the average beam width D of the ion beam 4 as shown in the above equation 2, the following equation is obtained. The beam width D can be obtained. Based on the same idea, the beam width D may be obtained by paying attention to the other three time points.

[Equation 5]
D = L _d (T _d −T _a ) / (T _c −T _a ) −L _d −W _d

  According to this beam width measuring method, by using the scanning of the ion beam 4 and the first and second beam measuring devices 36 and 38, the preliminary beam width D in the X direction of the ion beam 4 can be easily obtained. And it can measure with high accuracy.

  In this embodiment, the control device 60 (see FIG. 2) has a function of performing arithmetic control corresponding to the contents of the beam width measurement method. That is, the control device 60 controls the scanning power source 13 (see FIG. 1) constituting the beam scanning means to scan the ion beam 4 at a substantially constant scanning speed so as to cross the beam measuring instruments 36 and 38. Thus, by monitoring the temporal change of the beam current flowing into each beam measuring instrument 36, 38, the inflow start time and inflow end time of the beam current in each beam measuring instrument 36, 38 are obtained, respectively. Of the beam incident holes 37 and 39 of each beam measuring instrument in the X direction and the distance between the center of the beam incident holes 37 and 39 of both beam measuring instruments in the X direction. The ion beam 4 has a function for obtaining a preliminary beam width D in the X direction.

In this case, necessary information other than the beam current, for example, the widths W _d1 and W _d2 and the center-to-center distance L _d are given to the control device 60 (for example, set, and so on) and stored in the control device 60. What is necessary is just to do (the same applies to other embodiments described later).

  Therefore, according to the ion implantation apparatus of this embodiment provided with such a control device 60, it is possible to achieve the same effect as the above-described beam width measurement method and to save the measurement.

  In the return path of beam scanning, the preliminary beam width D in the X direction of the ion beam 4 can be obtained based on the above formulas 4 and 5 as in the forward path.

Accordingly, the ion beam 4 may be reciprocally scanned so as to cross the beam measuring instruments 36 and 38 in a reciprocating manner, and the beam width D may be obtained in both the forward and backward paths of the beam scanning. When the time points T _{a to} T _d in the forward path are T _{1 to} T ₄ , the beam width is D _a , the time points T _{a to} T _d in the return path are T _{5 to} T ₈ , and the beam width is D _b , for example, 4, both beam widths D _a and D _b can be expressed by the following equations, and are thus obtained.

[Equation 6]
D _a = L _d {(T ₄ −T ₃ + T ₂ −T ₁ ) / (T ₄ + T ₃ −T ₂ −T ₁ )} − W _d

[Equation 7]
D _b = L _d {(T ₈ −T ₇ + T ₆ −T ₅ ) / (T ₈ + T ₇ −T ₆ −T ₅ )} − W _d

Then, both beam widths D _a and D _b may be averaged as in the following equation to obtain a preliminary beam width D of the ion beam 4.

[Equation 8]
D = (D _a + D _b ) / 2

  In this beam width measurement method, the preliminary beam width is obtained in both the forward and backward scans, and the obtained beam width is averaged to obtain the preliminary beam width D in the X direction of the ion beam 4. The measurement accuracy of the beam width D can be further increased.

  In this embodiment, the control device 60 further has a function of performing calculation control corresponding to the content of the beam width measurement method. That is, the control device 60 controls the scanning power source 13 to reciprocately scan the ion beam 4 so as to cross the beam measuring instruments 36 and 38 in a reciprocating manner, thereby setting a preliminary beam width in the X direction of the ion beam 4. It further has a function of obtaining a preliminary beam width D in the X direction of the ion beam 4 obtained in both the forward and backward passes of the beam scanning and averaging the obtained beam widths.

  Therefore, according to the ion implantation apparatus of this embodiment provided with such a control device 60, it is possible to achieve the same effect as the above-described beam width measurement method and to save the measurement.

  Note that the first and second beam measuring instruments 36 and 38 include a mask plate 46 having the beam incident holes 37 and 39 and a rear side thereof (the traveling direction Z of the ion beam 4), as in the example shown in FIG. It may be configured with a common beam measuring instrument 48 provided in the vicinity. In this case, one beam incident hole 37 and the beam measuring instrument 48 at the rear part thereof constitute a first beam measuring instrument 36, and the other beam incident hole 39 and the beam measuring instrument 48 at the rear part thereof are arranged. It can be seen that the second beam measuring instrument 38 is configured. The beam measuring instrument 48 is, for example, a Faraday cup. The mask plate 46 may be the same as the mask plate 32. Even with such a configuration, a beam current waveform similar to that shown in FIG. 4 can be measured.

  The third and fourth beam measuring instruments to be described later, a plurality of beam measuring instruments 42 constituting the former stage beam monitor 40, and a plurality of beam measuring instruments 52 constituting the latter stage beam monitor 50 also adopt the above-described configuration. Also good.

  Further, as the first and second beam measuring instruments 36 and 38, for example, two of the plurality of beam measuring instruments 42 constituting the preceding stage beam monitor 40 may be used.

(3) Setting of the Second Scanning Distance L _b2 of the Ion Beam When the beam width D of the ion beam 4 is known, the first X-direction X direction of the ion beam 4 depending on the beam width D is determined based thereon. The scanning distance (see the scanning distance L _{b1 in} FIG. 4) can be obtained, and further, based on the first scanning distance, the second scanning distance in the X direction of the ion beam 4 (in FIGS. 5 and 10). Scanning distance _Lb2 ) can be set. A beam scanning distance setting method and an ion implantation apparatus that perform this will be described below.

In this case, by using the third and fourth beam instrument disposed apart from each other in a in X-direction as to measure the beam current by receiving (a) the ion beam 4, (b) the The preliminary beam width D of the ion beam obtained according to the beam width measurement method, the X-direction width of each beam entrance hole of the third and fourth beam measuring instruments, and the X-direction center of both beam measuring instruments. Based on the distance between the ion beam at the position where the beam current starts to flow into the third beam measuring instrument and the ion beam at the position where the beam current stops flowing in the fourth beam measuring instrument. A first scanning distance that is a distance in the direction is obtained, and (c) a scanning distance in the X direction of the ion beam 4 is set to a second scanning distance that is larger than the first scanning distance.

  The third beam measuring instrument may be different from the first beam measuring instrument 36, and the fourth beam measuring instrument may be different from the second beam measuring instrument 38, or they may be the same. There may be. A more specific example of the beam scanning distance setting method will be described below with an example of the case where they are the same.

Referring to FIG. 4, first, the case of the beam width measurement method as well as by scanning the ion beam 4 at a substantially constant scanning speed, the a beam width D, the beam of the beam measuring instruments 36, 38 Based on the widths W _d1 and W _d2 of the incident holes 37 and 39 and the distance L _d between the centers of both beam measuring instruments 36 and 38 (more specifically, the beam incident holes 37 and 39) in the X direction. Between the ion beam 4 at the position where the beam current starts to flow into the measuring instrument 36 (ie, the inflow start time T _a ) and the position where the beam current stops flowing in the beam measuring instrument 38 (ie, the inflow end time T _d ). A first scanning distance L _b1 that is a distance in the X direction is obtained based on the following equation.

[Equation 9]
L _b1 = L _d + W _d1 / 2 + W _d2 / 2 + D

In this case as well, the following equation is obtained if W _d = (W _d1 + W _d2 ) / 2 based on the same idea as in Equation 2.

[Equation 10]
L _b1 = L _d + W _d + D

The first scanning distance L _b1 is the minimum scanning distance at which the ion beam 4 can cross both the beam measuring instruments 36 and 38. Rather than using the scanning distance L _b1 as it is in the following, in order to perform the following various measurements and uniform ion implantation to the substrate 16, the second distance is based on the scanning distance L _b1 as follows. It is preferable to set the scanning distance L _b2 .

  Considering the positional relationship between the two beam measuring instruments 36 and 38 and the substrate 16 in the X direction, the two beam measuring instruments 36 and 38 are provided on both outer sides of the substrate 16 in the X direction, for example, as shown in FIG. Closely arranged.

In this case, when the ion beam 4 is scanned with the scanning distance L _b1 obtained by the above equation 10, the beam width D of the ion beam 4 for some reason is obtained by the above measurement, for example, as shown in FIG. When it changes from D (refer FIG. 8), in both beam measuring devices 36 and 38, one of the inflow start time of the beam current and the inflow end time cannot be measured correctly. Therefore, in this case, the beam width in the X direction of the ion beam 4 cannot be measured correctly using the beam measuring instruments 36 and 38.

  Further, in order to perform uniform ion implantation in the surface of the substrate 16, the ion beam 4 is usually scanned larger than the substrate 16 so as to allow uniform implantation to the substrate 16 with a margin. In this case, if the beam width D is changed for some reason, there is a possibility that the overscan cannot be reliably performed.

Therefore, for example, as shown in FIG. 10, based on the first scanning distance L _b1 , the scanning distance of the ion beam 4 is set to a second scanning distance L _b2 larger than that. This makes it possible to solve the above problem. The relationship between the scanning distances L _b1 and L _b2 can be expressed by the following equation, for example. k ₁ is a constant.

[Equation 11]
L _b2 = k ₁ L _b1

The constant k ₁ is a value larger than 1 when the beam measuring instruments 36 and 38 at the positions are used. If the constant k ₁ is too small, the above problem cannot be solved. If it is too large, useless scanning of the ion beam 4 increases. This constant k ₁ is a value peculiar to each ion implantation apparatus, and it has been found by experience that, when using the beam measuring instruments 36 and 38 at the above positions, for example, a range of 1.1 to 1.3 is preferable. Yes. Therefore, the value of the constant k ₁ is set within the range. Specifically, the X-direction of the scanning distance of the ion beam 4 by the beam scanner 12 k ₁ may be multiplied by. For this purpose, for example, the size of the scan is supplied from the scanning power source 13 to the beam scanner 12 current or scanning voltage k ₁ may be multiplied by.

Instead of Equation 11, the second scanning distance L _b2 may be set according to the following equation. k ₂ is a constant. The constant k ₂ is a value larger than 0 when the beam measuring instruments 36 and 38 at the above positions are used. A preferable range of the constant k ₂ can also be determined by experience or the like.

[Equation 12]
L _b2 = L _b1 + k ₂ D

However, the positions of the beam measuring instruments 36 and 38 may be positions other than the positions described with reference to FIG. 8, and in this case, the values of the constants k ₁ and k ₂ are determined according to the positions. Change it.

According to this beam scanning distance setting method, based on the first scanning distance L _b1 obtained using the preliminary beam width D of the ion beam 4 in the X direction, the second scanning distance L _b2 that is larger than that is used. Since the scanning distance in the X direction of the ion beam 4 is set in the X direction, the scanning distance in the X direction of the ion beam 4 can be set to a predetermined distance that reliably includes the first and second beam measuring instruments 36 and 38. It becomes easy.

In addition, since the first scanning distance L _b1 can be obtained using the same beam measuring instruments 36 and 38 as those for obtaining the preliminary beam width D in the X direction of the ion beam 4, the first scanning distance L _{b1 is obtained.} It is possible to use a preliminary beam width D measured at the same position as when obtaining. Therefore, the first scanning distance L _b1 can be obtained more accurately, and as a result, the second scanning distance L _b2 can be set more accurately. In addition, the number of beam measuring instruments required for measurement can be reduced.

In this embodiment, the control device 60 further has a function of performing calculation control corresponding to the content of the beam scanning distance setting method. That is, the control device 60 (a) controls the scanning power source 13 constituting the beam scanning means to scan the ion beam 4 substantially constant across the first and second beam measuring instruments 36 and 38. Scanning at a speed, the preliminary beam width D of the ion beam 4, the X-direction width of each beam entrance hole of the beam measuring instruments 36, 38, and the X-direction center of both beam measuring instruments 36, 38 A function for _obtaining the first scanning distance L _b1 based on the distance; and (b) controlling the scanning power source 13 to ionize the second scanning distance L _b2 larger than the first scanning distance L _b1. It further has a function of setting the scanning distance of the beam 4 in the X direction.

In this case, of the necessary information other than the beam current, the necessary information other than the information described above, for example, the constant k ₁ or k ₂ is given to the control device 60 and stored in the control device 60. Just keep it.

  Therefore, according to the ion implantation apparatus of this embodiment provided with such a control device 60, it is possible to achieve the same effect as the above-described beam scanning distance setting method and to save labor in measurement.

As described above, the first scanning distance L _b1 is measured using the third and fourth beam measuring instruments different from the first and second beam measuring instruments 36 and 38, and the first scanning distance L _b1 is measured. A scanning distance L _b2 of ₂ may be set. For example, two of the plurality of beam measuring instruments 42 constituting the preceding beam monitor 40 may be used as the third and fourth beam measuring instruments.

The scanning period T _sc of the ion beam 4 is divergent when the beam width D is measured, when the scanning distance L _b1 is measured and when the scanning distance L _b2 is set, and when a beam width W _b described later is measured. Although it is not necessarily the same at the time of measuring the angle α, the measurement is simpler and more practical if they are the same, and in this embodiment, they are the same.

(4) Measurement of beam width W _b of the ion beam will be described beamwidth measuring method and ion implantation apparatus for determining the beam width W _b of the ion beam 4 at a desired position of the second in scanning distance L _b2. This beam width W _b is important in performing uniform ion implantation on the substrate 16 as described above.

In this case, as shown in the example shown in FIG. 5, the fifth beam measuring device 56 that is located within the second scanning distance L _b2 and that receives the ion beam 4 and measures its beam current is crossed. The ion beam 4 is scanned at a substantially constant scanning speed, a predetermined scanning period T _sc , and the scanning distance L _b2 .

The fifth beam measuring instrument 56 may be, for example, a desired beam measuring instrument 42 among the plurality of beam measuring instruments 42 constituting the former stage beam monitor 40, or a plurality of beam measuring instruments constituting the latter stage beam monitor 50. Of these, a desired beam measuring instrument 52 may be used. A desired beam measuring device out of the first to fourth beam measuring devices may be used. The width in the X direction of the beam incident hole 57 of this beam measuring instrument 56 is set to W _f .

Then, the time difference between the scanning speed of the ion beam 4 determined from the scanning cycle T _sc and the second scanning distance L _b2 and the inflow start time _Te and the inflow end time _Tf of the beam current in the beam measuring device 56. If, based on the width W _f of the X direction of the beam incident holes 43 of the beam measuring instrument 56 calculates the beam width W _b of the X direction of the ion beam 4 at the position of the beam measuring instrument 56.

And more specific examples, by measuring the time T _e and the time T _f, obtaining the beam width W _b based on the number 14. That is, since the scanning speed of the ion beam 4 is expressed by L _b2 / (T _sc / 2), _Equation 13 is established, and when it is transformed, Equation 14 is obtained, and the beam width W _b is obtained based on this. .

[Equation 13]
L _b2 / (T _sc / 2) = (W _b + W _f ) / (T _f −T _e )

[Formula 14]
W _b = L _b2 {2 (T _f −T _e ) / T _sc } −W _f

According to this beam width measurement method, by using the ion beam scanning speed determined from the ion beam scanning period T _sc and the second scanning distance L _b2 , a known number other than two time points _Te and _Tf is obtained. Therefore, the beam width W _b in the X direction of the ion beam at the position of the beam measuring instrument 56 at a desired position within the second scanning distance L _b2 can be measured easily and accurately.

Further, since the scanning speed of the ion beam 4 is treated as a constant value, the relative value comparison of the beam width W _b at various positions of the beam measuring instrument 56 is simplified, and the state of change of the beam width W _b in the X direction is known. It becomes easy.

A plurality of the beam measuring devices 56 may be arranged in the X direction, and the beam width W _b of the ion beam 4 may be measured at a plurality of positions in the X direction according to the beam width measuring method. Thereby, the distribution of the beam width _{Wb in} the X direction can be measured. For example, by using a plurality of beam measuring instruments 42 constituting the former stage beam monitor 40 as the fifth beam measuring instrument 56, the distribution in the X direction of the beam width W _b at the position of the former stage Faraday device 30 is measured. be able to. Further, by using a plurality of beam measuring instruments 52 constituting the latter stage beam monitor 50 as the fifth beam measuring instrument 56, the distribution in the X direction of the beam width W _b at the position of the latter stage beam monitor 50 is measured. can do.

Since the ion beam 4 is scanned in parallel as described above, the scanning distance L _b2 at the position of the front stage Faraday device 30 may be used as the scanning distance L _b2 at the position of the rear stage beam monitor 50. There is no. For example, 0.5 degrees when viewed in large the parallelism of the ion beam 4, 736 mm the distance L of the spacing, if a scanning distance L _b2 and 400 mm, the scanning distance L _b2 and the rear at the position of the front Faraday device 30 The difference from the scanning distance L _b2 at the position of the beam monitor 50 is about 12 mm, and the error is about 3%. This is practically acceptable.

Therefore, when the desired beam measuring instrument 52 of the plurality of beam measuring instruments 52 constituting the latter stage beam monitor 50 is used as the fifth beam measuring instrument 56 and the width in the X direction is W _f , Based on Equation 14, the beam width W _b at the position of the beam measuring instrument 52 can be measured.

The width W _f of the X direction of the beam measuring instrument 42 of the front beam monitor 40, the X direction width W _f of the beam measuring instrument 52 which constitutes the subsequent beam monitor 50 need not necessarily be the same as one another. Therefore, when distinguishing both, let the former width be _Wff and the latter width be _Wfb . However, it is preferable to set both widths W _ff and W _fb to the same width W _f because the accuracy and reliability of measurement are increased.

In this embodiment, the control device 60 further has a function of performing arithmetic control corresponding to the contents of the beam width measurement method. That is, the control device 60 controls the scanning power source 13 constituting the beam scanning means, and causes the ion beam 4 to traverse the fifth beam measuring device 56 with the scanning period T _sc and the second scanning. distance scanned with L _b2, and the scanning speed of the ion beam 4 which is determined by the relevant scan period T _sc scanning distance L _b2 Prefecture, and time difference between the inflow beginning and the inflow end of the beam current in the beam measuring instruments 56 Further, based on the X-direction width W _f of the beam entrance hole 57 of the beam measuring device 56, it further has a function of obtaining the X-direction beam width W _b of the ion beam 4 at the position of the beam measuring device 56. Further, it has a function of measuring the beam width W _b of the ion beam 4 at a plurality of positions in the X direction by using a plurality of fifth beam measuring devices 56.

In this case, necessary information other than the beam current may be stored in the control device 60 by giving the scanning cycle T _sc and the width W _f to the control device 60, for example. The second scanning distance L _b2 may be stored in the control device 60 as determined by the previous calculation.

  Therefore, according to the ion implantation apparatus of this embodiment provided with such a control device 60, it is possible to achieve the same effect as the above-described beam width measurement method and to save the measurement.

(5) Measurement of Divergence Angle α of Ion Beam Next, a divergence angle measuring method and an ion implantation apparatus for measuring the divergence angle α in the X direction of the ion beam 4 will be described.

In this case, as the fifth beam measuring instrument 56, a front-stage beam measuring instrument and a rear-stage beam measuring instrument that are spaced apart from each other at two positions in the front-rear direction Z of the ion beam 4 are used. Then, in substantially the same position in the X directions, determined according to the beam width measuring method described in the above item (4), in the X direction of the ion beam in the two front and rear positions the beam width W _b, respectively, and the beams Based on the difference in width and the distance L, the divergence angle α in the X direction of the ion beam 4 is measured.

To give a more specific example, for example, the beam measuring instrument 42 constituting the former stage beam monitor 40 can be used as the former stage beam measuring instrument, and the beam measuring instrument 52 constituting the latter stage beam monitor 50 can be used as the latter stage beam measuring instrument. . This case will be described below as an example. The width in the X direction of the beam incident hole 43 (see FIG. 2) of each beam measuring instrument 42 constituting the former stage beam monitor 40 is W _ff , and the beam incident hole 53 (see FIG. 2) is _defined as W _fb .

In accordance with the beam width measuring method described in the above section (4), the beam measuring devices 42 and 52 are used at substantially the same position in the X direction, in other words, at the corresponding positions in the X direction. As shown, the beam width W _bf of the ion beam 4 at the position Z _f of the beam measuring device 42 and the beam width W _bb of the ion beam 4 at the position Z _b of the beam measuring device 52 are respectively obtained. This can be obtained by substituting the widths W _ff and W _fb for W _f in the _equation (14), respectively.

The substantially the same position with respect to the X direction typically refers to the center position _{Xf in} the X direction of the beam measuring instrument 42 used to determine the beam width W _bf and the beam width with reference to FIG. The combination of the beam measuring instruments 42 and 52 is such that the center position X _{b in} the X direction of the beam measuring instrument 52 used to determine W _bb is substantially the same position in the X direction.

Based on the following equation, the divergence angle α in the X direction of the ion beam 4 is obtained. L, as described above, the distance apart between the two positions Z _f, Z _b.

[Equation 15]
α = tan ⁻¹ {(W _bb −W _bf ) / 2L}

According to this divergence angle measurement method, the beam widths W _bf and W _bb are obtained at two positions upstream and downstream in the traveling direction Z of the ion beam 4 and at substantially the same position in the X direction, and these are used. Therefore, the divergence angle α in the X direction of the ion beam 4 at a predetermined position within the second scanning distance L _b2 can be measured easily and accurately.

  Further, by using a plurality of beam measuring devices 42 constituting the front stage beam monitor 40 and a plurality of beam measuring devices 52 constituting the rear stage beam monitor 50, the divergence angle α of the ion beam 4 is set to a plurality of X directions. It can also be measured in position. Accordingly, the distribution of the divergence angle α in the X direction can be measured.

Note that, as in the example shown in FIG. 7, the position of the beam measuring instrument 42 constituting the former stage beam monitor 40 and the position of the beam measuring instrument 52 constituting the latter stage beam monitor 50 are shifted from each other in the X direction. For example, the divergence angle α may be measured as follows. In the example of FIG. 7, two beam measuring instruments 42 (for example, the eighth and ninth beam measuring instruments 42) of the beam measuring instruments 42 constituting the former stage beam monitor 40. One beam measuring instrument 52 (for example, the sixth beam measuring instrument 52, for example, the beam incident hole 53) of the beam measuring instrument 52 constituting the latter stage beam monitor 50 in the middle of the center position _Xf8 , _Xf9 ). The center position in the X direction is _Xb6 ).

In this case, the two beam measuring devices 42 are used to measure the beam width W _bf at both positions by the beam width measuring method, and the average value is the beam at the position Z _f at the preceding stage (upstream side). The width is W _bf . As the beam width W _bb at the downstream (downstream) position Z _b , the value measured by the beam width measuring method using the beam measuring device 52 is used as it is. When the average value of the beam width W _bf is obtained as described above in the preceding stage, the average value is an intermediate position between the center positions X _f8 and X _f9 , that is, a position substantially the same as the center position X _b6 with respect to the X direction. It can be assumed that the beam width. Therefore, it can be said that the average beam width W _{bf at} the front stage and the beam width W _{bb at the} rear stage are beam widths at substantially the same position in the X direction. The divergence angle α can be measured by the divergence angle measurement method.

Contrary to the above example, the average beam width W _bb measured using the two beam measuring instruments 52 in the latter stage beam monitor 50 and the preceding stage at a position corresponding to the intermediate position of the two beam measuring instruments 52. The divergence angle α may be measured using the beam width W _bf measured using the beam measuring instrument 42.

  If more strictness is to be pursued, an approximate value by the least square method or the like may be used instead of using the average value as described above.

In this embodiment, the control device 60 further has a function of performing arithmetic control corresponding to the content of the divergence angle measurement method. That is, the control unit 60, preceding-stage using a beam instruments and subsequent beam instrument obtains respectively the beam width W _b of the X direction of the ion beam 4 in the above two front and rear positions, and that the difference between the above two beam width Based on the separation distance L, it further has a function of measuring the divergence angle α in the X direction of the ion beam. Further, it has a function of measuring the divergence angles α of the ion beam 4 at a plurality of positions in the X direction by using a plurality of front-stage beam measuring instruments and rear-stage beam measuring instruments arranged in the X direction.

  In this case, among the necessary information other than the beam current, information that is further necessary in addition to the information described above may be stored in the control device 60 by giving the distance L to the control device 60, for example. .

  Therefore, according to the ion implantation apparatus of this embodiment provided with such a control device 60, it is possible to achieve the same effect as the above divergence angle measurement method and to save labor in measurement.

1 is a schematic plan view showing an embodiment of an ion implantation apparatus according to the present invention. It is a figure which shows one state around a front stage Faraday device and a back stage beam monitor, and a control apparatus. It is a figure which shows the other state around a front stage Faraday apparatus and a back stage beam monitor. The relationship between the first and second beam measuring instruments and the ion beam crossing the first and second beam measuring instruments (A), the beam current waveform (B) measured in the forward path of beam scanning, and the beam current waveform ( It is the schematic which shows the example of C). It is the schematic which shows the example of the beam current waveform (B) measured by the relationship (A) of the 5th beam measuring device and the ion beam which crosses it, and the outgoing path of beam scanning. It is a figure explaining the divergence angle in the X direction of an ion beam. It is the schematic which shows the example which the beam measuring device which comprises a front | former stage beam monitor, and the beam measuring device which comprises a back | latter stage beam monitor have shifted | deviated in the X direction. It is a front view which shows an example of the relationship between the 1st and 2nd beam measuring device, a board | substrate, and the ion beam which crosses them. It is a front view which shows the other example of the relationship of a 1st and 2nd beam measuring device, a board | substrate, and the ion beam which crosses them. It is a front view which shows an example of the relationship between the 1st scanning distance and the 2nd scanning distance. It is sectional drawing which shows the example in the case of comprising a some beam measuring device using a mask plate and a common beam measuring device.

Explanation of symbols

4 Ion beam 12 Beam scanner 13 Scanning power supply 14 Beam collimator 16 Substrate 30 Pre-Faraday device 36 Beam measuring instrument 38 Beam measuring instrument 40 Pre-stage beam monitor 42 Beam measuring instrument 50 Subsequent beam monitor 52 Beam measuring instrument 56 Beam measuring instrument 60 Controllers D, D ₁ , D ₂ Preliminary beam widths L _b1 , L _b2 Scanning distances W _b , W _bf , W _bb Beam width α Divergence angle

Claims (12)

A method for setting a scanning distance of an ion beam in an ion implantation apparatus configured to irradiate a substrate with an ion beam that is scanned substantially parallel to an X direction,
(A) Using a first and a second beam measuring instrument which receives an ion beam and measures the beam current, and is spaced apart from each other in the X direction,
(B) By scanning the ion beam across both beam measuring instruments and monitoring temporal changes in the beam current flowing into each beam measuring instrument, the start time and inflow of the beam current in each beam measuring instrument Find the end point respectively
(C) Based on at least three of these time points, the width of the beam entrance hole of each beam measuring device in the X direction, and the distance between the centers of the beam entrance holes of both beam measuring devices in the X direction, According to a beam width measuring method for obtaining a preliminary beam width in the X direction of the ion beam,
(D) The ion beam is reciprocally scanned across the first and second beam measuring instruments, and the preliminary beam width in the X direction of the ion beam is determined in both the forward and backward beam scanning. And an arithmetic average of both of the obtained beam widths as a preliminary beam width in the X direction of the ion beam,
(E) Using a third and a fourth beam measuring instrument which receives an ion beam and measures its beam current and is spaced apart from each other in the X direction ,
( F) The preliminary beam width in the X direction of the ion beam, the width in the X direction of each beam entrance hole of the third and fourth beam measuring instruments, and the center in the X direction of both beam measuring instruments Based on the distance between the ion beam at the position where the beam current starts to flow into the third beam measuring instrument and the ion beam at the position where the beam current stops flowing in the fourth beam measuring instrument. Obtaining a first scanning distance which is a distance in the direction;
(G) A beam scanning distance setting method, wherein a scanning distance in the X direction of the ion beam is set to a second scanning distance larger than the first scanning distance. 2. The beam scanning distance setting according to claim 1, wherein the third beam measuring instrument is the same as the first beam measuring instrument, and the fourth beam measuring instrument is the same as the second beam measuring instrument. Method. (A) crossing a fifth beam measuring device for measuring the beam current be located in claim 1 or claim 2 in the scan distance set in accordance with the beam scanning distance setting method 2 described subjected to ion beam And scanning the ion beam at a predetermined scanning period and at the second scanning distance,
(B) The ion beam scanning speed determined from the scanning cycle and the second scanning distance, the time difference between the inflow start time and the inflow end time of the beam current in the fifth beam measuring instrument, and the fifth beam A beam width measuring method, wherein the X-direction beam width of the ion beam at the position of the fifth beam measuring device is obtained based on the X-direction width of the beam entrance hole of the measuring device. A plurality of the fifth beam measuring devices are arranged in the X direction, and the beam width in the X direction of the ion beam is measured at a plurality of positions in the X direction according to the beam width measuring method according to claim 3. Beam width measurement method. (A) As the fifth beam measuring instrument, a first-stage beam measuring instrument and a second-stage beam measuring instrument which are arranged at two positions before and after the ion beam in the traveling direction and receive the ion beam and measure the beam current. Using a vessel
(B) At substantially the same position with respect to the X direction, according to the beam width measurement method of claim 3 , the beam widths in the X direction of the ion beams at the two front and rear positions are respectively determined;
(C) A divergence angle measurement method characterized in that the divergence angle in the X direction of the ion beam is measured based on a difference between both beam widths and the distance of the separation. 6. A plurality of said front beam measuring instruments and a plurality of subsequent beam measuring instruments are respectively arranged in the X direction, and according to the divergence angle measuring method according to claim 5 , the divergence angles in the X direction of the ion beam are set at a plurality of positions in the X direction. A divergence angle measuring method, characterized by: Beam scanning means for scanning the ion beam in the X direction, and beam collimation means for cooperating with the beam scanning means for substantially parallel scanning of the ion beam in the X direction, An ion implantation apparatus configured to irradiate a substrate with an ion beam that is scanned in parallel,
(A) a first and a second beam measuring instrument that receive an ion beam and measure the beam current thereof and are spaced apart from each other in the X direction;
(B) controlling the beam scanning means, scanning the ion beam across both beam measuring instruments, and monitoring the temporal change of the beam current flowing into each beam measuring instrument, whereby each beam measuring instrument; The beam current inflow start time and the inflow end time are respectively obtained in the above, and at least three of these time points, the width in the X direction of the beam entrance hole of each beam measuring device, and the beam entrance holes of both beam measuring devices Based on the distance between the centers in the X direction, and having a function of obtaining a preliminary beam width in the X direction of the ion beam, and controlling the beam scanning means, The ion beam is reciprocated and scanned across the beam measuring instrument, and the preliminary beam width in the X direction of the ion beam is determined in both the forward and backward paths of the beam scan, and Features and it has a control device which has to be preliminary beam width in the X direction of the ion beam which both the beam width and the arithmetic mean was determined,
(C) a beam current is measured by receiving an ion beam, and includes third and fourth beam measuring instruments disposed apart from each other in the X direction;
(D) and the control device comprises:
(D1) and the preliminary beam width in the X direction before Symbol ion beam, each of the width in the X direction of the beam incident hole of the third and fourth beam instrument, in the X direction of the beams Instrument Based on the center-to-center distance, the ion beam at the position where the beam current starts to flow into the third beam measuring instrument and the ion beam at the position where the beam current stops flowing in the fourth beam measuring instrument. A function of obtaining a first scanning distance which is a distance in the X direction;
(D2) It further has a function of controlling the beam scanning means to set a scanning distance in the X direction of the ion beam to a second scanning distance larger than the first scanning distance. Ion implantation equipment. 8. The ion implantation apparatus according to claim 7, wherein the third beam measuring instrument is the same as the first beam measuring instrument, and the fourth beam measuring instrument is the same as the second beam measuring instrument. (A) further comprising a fifth beam measuring instrument positioned within the second scanning distance and receiving an ion beam and measuring the beam current;
(B) The control device controls the beam scanning unit to scan the ion beam at a predetermined scanning period and the second scanning distance so as to cross the fifth beam measuring instrument, The ion beam scanning speed determined from the scanning period and the second scanning distance, the time difference between the inflow start time and the inflow end time of the beam current in the fifth beam measuring instrument, and the beam of the fifth beam measuring instrument based on the width of the X direction of the entrance aperture, a fifth beam instrument the ion beam at the position of the ion implanter of further have claim 7 or 8, wherein a X-direction function of obtaining the beam width. (A) a plurality of the fifth beam measuring devices arranged in the X direction;
(B) the control device, using a fifth beam instrument of the plurality, the ion beam in the X direction of the beam width of claim 9, characterized in that have a function for measuring at a plurality of positions in the X direction Ion implanter. (A) As the fifth beam measuring instrument, the ion beam is arranged at two positions before and after the ion beam in the traveling direction, receives the ion beam, and measures the beam current. It has a front beam measuring instrument and a rear beam measuring instrument installed at substantially the same position,
(B) The controller determines the beam width in the X direction of the ion beam at the two front and rear positions using the front beam measuring device and the rear beam measuring device, and determines the difference between the two beam widths and the separation distance. The ion implantation apparatus according to claim 9 , further comprising a function of measuring a divergence angle in the X direction of the ion beam based on the distance. (A) comprising a plurality of the former stage beam measuring instruments and the latter stage beam measuring instruments arranged in the X direction;
(B) said control device, these front beam instruments and using the subsequent beam instrument, the ion beam in the X-direction divergence angle claims are have a function for measuring at a plurality of positions in the X direction 11 The ion implantation apparatus as described.

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