JP4229145B2 - Ion beam irradiation equipment - Google Patents

Description

  The present invention irradiates a target with an ion beam extracted from an ion source, and performs ion implantation, ion doping (registered trademark), ion beam alignment treatment, ion milling, ion beam etching, and the like on the target. More specifically, the present invention relates to an ion beam irradiation apparatus in which an ion source has a split structure electrode.

  A conventional example of this type of ion beam irradiation apparatus is shown in FIG. The ion beam irradiation apparatus includes an ion source 2 that generates (extracts) an ion beam 12. The ion source 2 includes a plasma generation unit 4 that generates plasma 6 using, for example, arc discharge or high-frequency discharge, and one or more electrodes that extract an ion beam 12 from the plasma 6 by the action of an electric field. Yes. More specifically, in this example, the electrode has two electrodes, that is, the first electrode 8 disposed on the most upstream side in the ion beam extraction direction and the second electrode 10 disposed on the downstream side thereof. ing.

  Assuming that the three axes orthogonal to each other at one point are the x-axis, y-axis, and z-axis, the electrodes 8 and 10 are arranged along the xy plane and arranged with a predetermined gap from each other in the direction along the z-axis. The ion beam 12 can be extracted in the direction along the z axis. Each of the electrodes 8 and 10 has a plurality (more specifically, many) of ion extraction holes 9 and 11 for extracting the ion beam 12 at corresponding positions. In this specification, a typical example of the “direction along” is a substantially parallel (including parallel) direction.

  In this example, both the electrodes 8 and 10 have a rectangular planar shape in which the dimension in the direction along the x axis is larger than the dimension in the direction along the y axis. Therefore, the ion beam 12 drawn out from the ion source 2 has a shape close to a rectangular cross section in which the dimension in the direction along the x axis is larger than the dimension in the direction along the y axis.

  A positive DC voltage is applied to the first electrode 8 for extracting and accelerating the ion beam 12 from a DC power source (not shown). The first electrode 8 may be called a plasma electrode or an acceleration electrode. For example, a negative DC voltage is applied to the second electrode 10 for suppressing backflow electrons from a DC power source (not shown). The second electrode 10 is sometimes called a suppression electrode or a deceleration electrode.

  In this ion beam irradiation apparatus, the target 14 together with the holder 16 that holds the target 14 in the irradiation region of the ion beam 12 extracted from the ion source 2 is seen in a plan view as indicated by an arrow Y, for example. A target driving device 18 that moves linearly in the direction along the y-axis is provided. This movement may be in one direction or in a reciprocating direction. “Looking in a plane” means that the ion source 2 or the target driving device 18 (usually the ion source 2) is rotated by a predetermined angle about an axis substantially parallel to the x axis and the z axis is set as the target. In some cases, the ion beam 12 is incident on the surface of the target 14 at an incident angle smaller than 90 degrees by tilting obliquely rather than perpendicularly to the surface of the target 14, and even in that case, the target 14 moves in the direction along the y axis. It is meant to include this case.

  The target 14 is, for example, a semiconductor substrate, a glass substrate, a substrate with an alignment film, or another substrate. The substrate with an alignment film is obtained by forming an alignment film for aligning liquid crystal molecules in a certain direction on the surface of a substrate such as a glass substrate.

  The dimension of the ion beam 12 in the direction along the x-axis is larger than the dimension of the target 14 in the same direction. By moving the target 14 in the direction along the y-axis as described above, the entire surface of the target 14 is obtained. By irradiating the ion beam 12, the target 14 can be subjected to processes such as ion implantation, ion doping (registered trademark), ion beam alignment treatment, ion milling, and ion beam etching.

  By the way, when the ion beam 12 having a large area is extracted from the ion source 2, both the electrodes 8 and 10 have a large area accordingly. In that case, one or both of the electrodes 8 and 10 are, for example, patented for reasons such as (a) difficult to manufacture with one electrode material, (b) reducing deformation due to thermal expansion (thermal deformation), etc. As described in Documents 1 and 2, there are cases where the electrode is divided into a plurality of electrode pieces.

  For example, when extracting the ion beam 12 having a large dimension in the direction along the x-axis (for example, about 600 mm to 1200 mm), the electrodes 8 and 10 may be divided into a plurality of electrode pieces in the direction along the x-axis. . FIG. 16 shows an electrode having such a divided structure, taking the first electrode 8 as an example. The first electrode 8 is divided into a plurality of electrode pieces 81 in the direction along the x axis. Each of the divided portions 20 is formed substantially parallel to the y axis. Each electrode piece 81 is normally kept at the same potential.

  The case where the second electrode 10 is divided is the same as the first electrode 8 described above.

JP 2000-301353 A (paragraphs 0015-0017, FIGS. 1 and 4) Japanese Patent Laid-Open No. 5-114366 (paragraph 0009, FIGS. 1 and 2)

  If the electrodes 8 and 10 are divided as described above, the ion extraction holes 9 and 11 cannot be arranged in each divided portion 20 as in other places, so that the ion beam 12 is provided downstream of each divided portion 20. Unlike the others, the density distribution of the ion beam 12 becomes non-uniform.

  For example, when each division part 20 is a gap penetrating vertically as shown in FIG. 16, the density of the ion beam 12 is larger than the others downstream of each division part 20.

  Moreover, each division | segmentation part 20 is hold | suppressed with the holding metal fittings described in patent document 1, for example, or as described in patent document 2, for example, the electrode pieces 81 on both sides are overlapped with each other in the division part 20. If it arrange | positions, the density of the ion beam 12 will become smaller downstream than each division | segmentation part 20 from others.

  However, since the target 14 is moved in the direction along the y-axis as described above, a pattern having a large and small ion beam density downstream of each divided portion 20 is transferred as it is onto the surface of the target 14. As a result, it is impossible to perform processing with good uniformity on the target 14.

  Therefore, the main object of the present invention is to provide an ion beam irradiation apparatus capable of performing a uniform processing on a target even if the ion source has an electrode having a divided structure.

One of the ion beam irradiation apparatuses according to the present invention has a plurality of ion extraction holes each having two axes perpendicular to each other as an x axis and a y axis, and an electrode along the xy plane is 1 in the ion beam extraction direction. An ion beam irradiation apparatus comprising : an ion source having at least one sheet; and a target driving device that moves the target in a direction along the y axis in a planar view within an irradiation region of an ion beam extracted from the ion source. The extraction hole region of each electrode of the ion source, in which the plurality of ion extraction holes are distributed, has a rectangular shape in which the long side is substantially parallel to the x axis and the short side is substantially parallel to the y axis. And at least one of the electrodes of the ion source is divided into a plurality of electrode pieces in a direction substantially parallel to the x-axis, and each divided portion is inclined with respect to the y-axis. Placed in It is characterized in Rukoto.

  According to this ion beam irradiation apparatus, each divided portion of the divided electrode is arranged obliquely with respect to the y-axis, so that a large or small pattern is generated in the ion beam density downstream of each divided portion. However, the pattern is averaged on the target by movement of the target along the y-axis. As a result, processing with good uniformity can be performed on the target.

  The ion extraction holes of the divided electrode may be arranged so that the total area of the plurality of ion extraction holes in the direction along the y-axis is substantially constant in the direction along the x-axis. .

  Each of the divided portions of the divided electrode has a linear shape, and the two divided portions are substantially parallel to each other and are sandwiched at a substantially equal distance in the direction along the x-axis. The fixing means for fixing the electrode piece to the fixing portion may be respectively arranged at four positions on the straight line and outside the extraction hole region where the ion extraction holes are distributed.

  In each divided portion of the divided electrode, the electrode pieces on both sides thereof may be arranged with a gap between each other in the direction along the x axis and overlapping each other in the ion beam extraction direction. .

According to the first aspect of the present invention, since each divided portion of the electrode divided and formed as described above is disposed obliquely with respect to the y-axis, the ion beam density is reduced downstream of each divided portion. Even if a large or small pattern is generated, the pattern is averaged on the target by the movement of the target along the y-axis. As a result, processing with good uniformity can be performed on the target.

According to the second aspect of the present invention, since each divided portion of the electrode divided and formed as described above is disposed obliquely with respect to the y-axis, the ion beam density is reduced downstream of each divided portion. Even if a large or small pattern is generated, the pattern is averaged on the target by the movement of the target along the y-axis. As a result, processing with good uniformity can be performed on the target. Furthermore, the following effects are produced.
That is, the ion extraction holes of the divided electrodes are arranged so that the total area of the plurality of ion extraction holes in the direction along the y-axis is substantially constant in the direction along the x-axis. The density distribution of the ion beam applied to the target becomes more uniform in the direction along the x axis. As a result, a process with better uniformity can be performed on the target.

According to the third aspect of the present invention, since each divided portion of the electrode divided and configured as described above is disposed obliquely with respect to the y-axis, the ion beam density is reduced downstream of each divided portion. Even if a large or small pattern is generated, the pattern is averaged on the target by the movement of the target along the y-axis. As a result, processing with good uniformity can be performed on the target. Furthermore, the following effects are produced.
That is, the total sum of displacements in the direction along the x-axis due to thermal expansion of the plurality of ion extraction holes arranged in the direction along the y-axis is substantially zero in a predetermined region near each divided part of the divided electrode. Can be. Since the target is moved in the direction along the y-axis, this is equivalent to obtaining the sum of the displacements on the target. As a result, even if each ion extraction hole is displaced in the direction along the x-axis due to thermal expansion, it becomes equivalent to the cancellation of the displacement on the target corresponding to the region, and accordingly, Processing with better uniformity can be performed.

  According to the fourth aspect of the present invention, since the structure of the third aspect and the structure of the fourth aspect are provided, the effects of the third aspect and the fourth aspect can be achieved. As a result, a process with better uniformity can be performed on the target.

  According to invention of Claim 5, there exists the following further effect. That is, in each divided portion, the electrode pieces on both sides thereof are arranged with a gap between each other in the direction along the x axis, so that the thermal expansion in the direction along the x axis of each electrode piece is released in this gap. Can do. As a result, since the thermal deformation of each electrode piece can be reduced, an ion beam with better uniformity can be irradiated to the target to perform treatment with better uniformity. Moreover, since the electrode pieces on both sides of each divided portion are arranged so as to overlap each other, leakage of the ion beam from each divided portion can be prevented. As a result, also from this viewpoint, it is possible to irradiate the target with an ion beam with better uniformity and perform processing with better uniformity.

  FIG. 1 is a schematic view showing an embodiment of an ion beam irradiation apparatus according to the present invention. FIG. 2 is a plan view showing an example of the first electrode in FIG. 1 together with the lower target. Portions that are the same as or equivalent to those in the conventional example shown in FIGS. 15 and 16 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below.

  This ion beam irradiation apparatus includes the same ion source 2 and target driving device 18 as described above. However, the structure around the electrodes 8 and 10 of the ion source 2 is different from the conventional example as described below.

(1) Divided structure of electrode In this ion beam irradiation apparatus, the first electrode 8 of the ion source 2 is divided into a plurality of electrode pieces 82 in the direction along the x axis, and each divided portion (in other words, In other words, the joints 22 are arranged obliquely with respect to the y-axis. That is, each divided portion 22 is linear, and 0 ° <α <90 °, where α is the angle with respect to the y-axis. Each division part 22 is substantially parallel to each other (the same applies to the other examples and the division part 24). The number of the electrode pieces 82, that is, the number of divisions of the first electrode 8 is four in the example shown in FIG. 2, but is not limited thereto. What is necessary is just to determine according to the dimension of the direction in alignment with the x-axis of the 1st electrode 8, etc. The same applies to the second electrode 10. Each electrode piece 82 is normally kept at the same potential.

  A support frame 26 is provided at the lower end of the plasma generation unit 4 of the ion source 2, and each electrode piece 82 is fixed at a portion outside the extraction hole region 32 where the ion extraction holes 9 are distributed. The bolt 34 is fixed to the support frame 26. The support frame 26 is an example of a fixing portion for the electrode piece 82, and the fixing bolt 34 is an example of a fixing means.

  Further, in this embodiment, the second electrode 10 of the ion source 2 is also divided into a plurality of electrode pieces 102 in the direction along the x axis, and the divided portions 24 are formed in the y direction, similarly to the first electrode 8. It is arranged obliquely with respect to the axis. Each electrode piece 102 is normally kept at the same potential.

  A support frame 28 is provided on the downstream side of the support frame 26 with an insulator 30 interposed therebetween, and each electrode piece 102 of the second electrode 10 has an extraction hole region in which the ion extraction holes 11 are distributed. The outer portion is fixed to the support frame 28 by fixing bolts (not shown). The support frame 28 is an example of a fixing portion for the electrode piece 102, and a fixing bolt is an example of a fixing means.

  The second electrode 10 has substantially the same structure as the first electrode 8 in this embodiment. Therefore, in the following, the first electrode 8 will be mainly described. The following description also applies to the second electrode 10 unless otherwise specified.

  Each divided portion 22 of the first electrode 8 is represented by a single straight line for simplification of illustration in FIG. 2 and FIG. 6 described later, but may be a gap penetrating vertically. Alternatively, as in the example shown in FIGS. 3 to 5, for example, the electrode pieces 82 on both sides of each divided portion 22 are spaced from each other in the direction along the x axis and the ion beam extraction direction (ie, In the direction along the z-axis (the same applies hereinafter), they may be placed one on top of the other.

  That is, in the example of FIG. 3, the electrode pieces 82 on both sides of the divided portion 22 have stepped portions 36 and 38 that overlap each other, and have gaps 40 and 42 between each other in the direction along the x axis. ing.

  In the example of FIG. 4, the electrode pieces 82 on both sides of the dividing portion 22 have slope portions 44 and 46 that overlap each other with an inclined gap 48.

  In the example of FIG. 5, the electrode pieces 82 on both sides of the dividing portion 22 have a ridge portion 50 and a ridge portion 52 into which the ridge portion 50 is fitted, and a gap 54 between each other in the direction along the x-axis. , 56.

  In this ion beam irradiation apparatus, the divided parts 22 and 24 of the divided electrodes 8 and 10 are arranged obliquely with respect to the y-axis, so that the ion beam is provided downstream of the divided parts 22 and 24. Even if a pattern having a large or small density is generated, the pattern is averaged on the target 14 by the movement of the target 14 in the direction along the y-axis.

  This will be described in detail mainly with reference to FIG. 2. For example, each of the dividing portions 22 and 24 has a structure as shown in the example of FIGS. In the case where the ion beam density is not extracted, a pattern having a smaller ion beam density than the others is generated downstream of each of the dividing portions 22 and 24. However, when the target 14 is moved in the direction along the y-axis, the divided portions 22 and 24 are arranged obliquely with respect to the y-axis, so that the target 14 has an ion beam density downstream of the divided portions 22 and 24. And the other part (the part where the density is not low) pass through together. As a result, the pattern is not directly transferred onto the target 14 as in the conventional example, but is averaged over the target 14. In other words, the pattern is relaxed or thinned on the target 14 (the same applies hereinafter).

  In the case of a gap in which each of the divided portions 22 and 24 penetrates vertically, if the upper and lower divided portions 22 and 24 overlap each other in the ion beam extraction direction, the ion beam 12 is extracted through the divided portions 22 and 24. Thus, there may be a pattern in which the ion beam density is larger than the others downstream of each of the division parts 22 and 24. However, also in this case, when the target 14 is moved in the direction along the y-axis, the respective divided portions 22 and 24 are arranged obliquely with respect to the y-axis, so that the target 14 is located downstream of the respective divided portions 22 and 24. A portion having a high ion beam density and other portions (portions having a low density) pass through together. As a result, the pattern is not directly transferred onto the target 14 as in the conventional example, but is averaged on the target 14.

  Therefore, in any of the above cases, the target 14 can be processed with good uniformity (specifically, uniformity in the direction along the x-axis. The same applies to other cases).

  Also, as in the example shown in FIGS. 3 to 5, when the electrode pieces 82 and 102 on both sides of each divided portion 22 and 24 are arranged with a gap between each other in the direction along the x axis. In this gap, the thermal expansion of each electrode piece 82, 102 in the direction along the x-axis can be released, so that the thermal deformation of each electrode piece 82, 102 can be reduced. As a result, it is possible to irradiate the target 14 with the ion beam 12 with better uniformity and perform processing with better uniformity.

  Further, as in the example shown in FIGS. 3 to 5, if the electrode pieces 82, 102 on both sides of each divided portion 22, 24 are arranged so as to overlap each other in each divided portion 22, 24, the ion beam 12 from each divided portion 22, 24. From this point of view, the target 14 can be irradiated with the ion beam 12 having better uniformity in the direction along the x-axis to perform processing with better uniformity. .

(2) Structure in which the total area of the ion extraction holes is constant The electrode divided as described above, for example, the ion extraction hole 9 of the first electrode 8 is, for example, as shown in FIG. It is preferable that the total area of the plurality of ion extraction holes 9 in the direction along the y-axis is arranged so as to be substantially constant in the direction along the x-axis.

  More specifically, in the example shown in FIG. 2, each ion extraction hole 9 is a circular hole having the same area as each other, and there is an oblique divided portion 22 where the ion extraction hole 9 cannot be formed. The number of ion extraction holes 9 in the direction along the y-axis is the same number (eight in the illustrated example) in any row in the direction along the x-axis. Accordingly, the total area of the ion extraction holes 9 in the direction along the y-axis is constant in any row in the direction along the x-axis.

In the example of FIG. 2, if the pitch in the direction along the x axis of the array of the plurality of ion extraction holes is P _x and the pitch in the direction along the y axis is P _y , the angle α of each divided portion 22 is The relationship of the following formula is satisfied. Then, the position of each divided portion 22 in the direction along the x-axis is determined so that the next divided portion 22 enters the inside of the drawing hole region 32 when one dividing portion 22 falls outside the drawing hole region 32. Yes.

[Equation 1]
α = tan ⁻¹ (P _x / P _y )

  As described above, the density distribution of the ion beam 12 irradiated to the target 14 becomes more uniform in the direction along the x-axis. As a result, a process with better uniformity can be performed on the target 14.

  As in the example shown in FIG. 6, the arrangement shown in (A) can be realized even if the angle α of each of the division portions 22 is made larger. In the case of this example as well, even if there is an oblique dividing portion 22 where the ion extraction holes 9 cannot be formed, the number of ion extraction holes 9 in the direction along the y axis is in any column along the x axis. Are the same number (8 in the illustrated example).

  As in the example shown in FIG. 7, even if the oblique nonexistent region 58 where the ion extraction hole 9 does not exist is provided as in the case of the dividing portion 22 although it is not the dividing portion 22, it is shown in the above (A). An array can be realized. The nonexistent region 58 is inclined at substantially the same angle as the dividing portion 22 with respect to the y axis. What is necessary is just to think that the division part 22 exists in this nonexistence area | region 58 virtually.

  In the case of this example as well, the number of the ion extraction holes 9 in the direction along the y-axis is as follows even if there are the divided portions 22 where the ion extraction holes 9 cannot be formed and the nonexistent regions 58 of the ion extraction holes 9. It is the same number (8 in the illustrated example) in any row in the direction along the x-axis. In this case, the number of divisions of the first electrode 8 can be reduced. A plurality of non-existing regions 58 may be provided between the end of the first electrode 8 in the direction along the x-axis and the first divided portion 22 or between adjacent divided portions 22.

  2, 6, and 7 are examples in which a plurality of ion extraction holes 9 having a circular shape with the same size are arranged in a square (square), similar ion extraction holes 9 are illustrated in FIG. A staggered arrangement may be used as shown in FIG. Also in this example, the number of ion extraction holes 9 in the direction along the y axis is the same in any row along the x axis, even if there are divided portions 22 where the ion extraction holes 9 cannot be formed. The same number (5 in the illustrated example). 8 and 9, the interval between adjacent ion extraction holes 9 is shown wider than in the case of FIG. 2 and the like. However, in a zigzag arrangement, generally, the ion extraction holes 9 are arranged more than the square arrangement. The density can be increased.

  The shape of each ion extraction hole 9 is not limited to a circular hole, but may be a slit shape as in the examples shown in FIGS. Each ion extraction hole 9 has the same width. Also in these examples, the arrangement shown in (A) above can be realized. In the slit shape, the total area of the ion extraction holes 9 with respect to the electrode area can be increased.

  That is, in the example shown in FIG. 10, the number of the ion extraction holes 9 in the direction along the y-axis is the direction along the x-axis, even if there are diagonal divisions 22 where the ion extraction holes 9 cannot be formed. The same number (eight in the illustrated example) at any of the positions.

In the example shown in FIG. 11, even if there is an oblique divided portion 22 where the ion extraction hole 9 cannot be formed, the total length L ₁ + L ₂ of the ion extraction hole 9 in the direction along the y axis is It is substantially constant in any row in the direction along the x-axis.

(3) Arrangement structure of fixing bolts in the vicinity of the divided portions The above-described fixing bolts 34 sandwiching each divided portion 22 in the direction along the x-axis are preferably provided at the following positions. That is, with reference to FIG. 12, consider two straight lines 60 and 62 that sandwich each linear segment 22 at an equal distance L ₃ in the direction along the x-axis and are substantially parallel to the segment 22. The fixing bolts 34 are preferably arranged at four positions on the straight lines 60 and 62 and outside the drawing hole region 32, respectively. As a result, in a predetermined region (region within the distance W shown in FIG. 14) in the vicinity of each divided portion 22, the plurality of ion extraction holes 9 arranged in the direction along the y-axis are in the direction along the x-axis due to thermal expansion. The total sum of displacement can be made substantially zero.

  More specifically, in the above case, the angles formed by the dividing portion 22, the straight lines 60 and 62, and the side along the x-axis of the extraction hole region 32 are substantially equal angles θ. And 0 ° <θ <90 °. This angle θ is θ = 90 ° −α in relation to the angle α. Further, referring to FIG. 14, a point B where the straight line 60 intersects with one side along the x axis of the extraction hole region 32, and a point G where the straight line 62 intersects with the other side along the x axis of the extraction hole region 32. A straight line BG connecting the two is substantially parallel to the y-axis.

  In addition, when each division | segmentation part 22 has a structure like the example shown in FIGS. 3-5, for example, and has a width | variety in the direction along an x-axis, the position of the center of the width | variety is set. What is necessary is just to consider it as the position of the division part 22 in FIGS.

  Referring to FIG. 13, since the target 14 is moved in the direction along the y axis as described above (typically substantially parallel to the y axis as described above), the target 14 is substantially parallel to the y axis. When the displacement due to thermal expansion of the ion extraction hole 9 existing on the straight line PQ crossing the dividing portion 22 is considered, the extraction hole region 9 existing at a point on the straight line PQ, for example, the points K, L, M, Are displaced by thermal expansion by an amount proportional to the magnitude of the vectors u, v, and w, respectively, in the directions of the vectors u, v, and w. That is, the ion extraction hole 9 located on the left side of the straight lines 60 and 62 is displaced to the left side, and the ion extraction hole 9 located on the right side is displaced to the right side. This is because the straight lines 60 and 62 are mechanically restrained by the fixing bolts 34 on both sides. The magnitude of the displacement is proportional to the distance between each ion extraction hole 9 and the straight lines 60 and 62.

  The vectors u, v, and w originally start from the points K, L, and M. However, in order to make the lengths easy to understand, the vectors u, v, and w are translated in the direction along the x-axis, , L and M are shown as end points.

  When the concept shown in FIG. 13 is expanded to all points on the straight line PQ, as shown in FIG. 14, the total displacement of the ion extraction holes 9 existing on the straight line AC is a size ΔABC in the + x direction. The total displacement of the ion extraction holes 9 existing on the straight line CE is a magnitude ΔCDE in the direction of −x, and the total displacement of the ion extraction holes 9 existing on the straight line EH is a magnitude in the direction of + x. □ EFGH. Here, the points A and H are the intersections between the two sides along the x-axis of the extraction hole region 32 and the straight line PQ, the points C are the intersections of the straight line 60 and the straight line PQ, the points B and G are the above-mentioned intersections, the point E Is an intersection of the straight line PQ and the dividing portion 22, points D and F are intersections of a line passing through the point E and parallel to the x axis and the straight lines 60 and 62, and points J and N are two along the x axis of the extraction hole region 32. An intersection point between one side and the dividing portion 22, a point I is an intersection point between the straight line 62 and the straight line PQ.

  As will be proved below, the area is ΔABC + □ EFGH = ΔCDE, and the signs on the left side and the right side are opposite, so that the ion extraction hole 9 existing on the straight line PQ is in the direction along the x-axis. The sum of the displacements in the direction along the y-axis (that is, the sum) is substantially zero. This fact is valid when the distance X from the point J of the straight line PQ is 0 ≦ X ≦ W. W is the distance in the direction along the x axis between points J and N.

  Accordingly, in this distance W region, the displacement in the direction along the x-axis of the ion extraction holes 9 arranged in the direction along the y-axis is added to the direction along the y-axis and is substantially equal in any row. To zero. As described above, since the target 14 is moved in the direction along the y-axis, this is equivalent to obtaining the sum of the displacements on the target 14. Therefore, even if the individual ion extraction holes 9 are displaced in the direction along the x-axis by thermal expansion, the displacement is equivalent to the cancellation on the target 14 corresponding to the region of 0 ≦ X ≦ W. . Displacement of the ion extraction hole 9 causes the uniformity of the ion beam irradiation on the target 14 and thus the uniformity of the treatment, but it is equivalent to the cancellation of the displacement on the target 14 as described above. Accordingly, a process with better uniformity can be performed on the target 14.

  If the distance in the direction along the y-axis of the extraction hole region 32 is d, the following equation is established between the angle θ and the distance W.

[Equation 2]
θ = tan ⁻¹ (d / W)

  It is proved that ΔABC + □ EFGH = ΔCDE described above. In FIG. 14, paying attention to ΔABC and ΔGHI, since AB = HG, ∠CAB = ∠IHG, and ∠ABC = ∠HGI, △ ABC and △ GHI are congruent due to the angular phase at one end. Further, paying attention to ΔCDE and ΔIFE, DE = FE, ∠CED = ∠IEF, and ∠CDE = ∠IFE, and therefore, ΔCDE and ΔIFE are congruent due to the corners of both sides. From the above, the following equation is established and the above is proved.

[Equation 3]
△ ABC + □ EFGH
= △ GHI + □ EFGH
= △ IFE
= △ CDE

  The two fixing bolts 34 on one side that sandwich each divided portion 22 in the direction along the x-axis are typically disposed at symmetrical positions in the direction along the x-axis across each divided portion 22. If the four fixing bolts 34 arranged across the dividing portion 22 are on the straight lines 60 and 62, the above relationship is established. Therefore, for example, as shown by a two-dot chain line in FIG. You may shift | deviate to the outer side (or the inner side of the other side). The same applies to the other fixing bolts 34.

  The shape and arrangement of the ion extraction holes 9 may be, for example, a square arrangement of circular holes as shown in FIGS. 2, 6, and 7 as described above. For example, the circular holes as shown in FIGS. A zigzag arrangement may be used, or a slit shape as shown in FIGS. 10 and 11 may be used.

  As the structure of each division part 22, you may employ | adopt the structure shown, for example in FIGS. 3-5 similarly to the above.

  The arrangement structure of the fixing bolt 34 shown in (3) may be used in combination with the structure in which the total area of the ion extraction holes 9 shown in (2) is made constant. Since the effect can be obtained, the target 14 can be subjected to a process with better uniformity.

  As means for fixing the electrode piece 82 to the fixing portion, a fixing pin or the like may be employed instead of the fixing bolt 34. The fixing portion is the support frame 26 in the above example, but other flanges or the like may be employed.

  As described above, regarding the second electrode 10 as well, in addition to the structure in which the divided portion shown in (1) above is inclined with respect to the first electrode 8, the total area of the ion extraction holes shown in (2) above is set. You may employ | adopt one or both of the structure made constant, and the arrangement | positioning structure of the fixing bolt near the division | segmentation part shown to said (3).

  The number of electrodes of the ion source 2 may be two as in the above example, or three or more. For example, the third electrode and the fourth electrode may be provided on the downstream side of the second electrode 10. In that case, a negative voltage is applied to the second electrode 10 with respect to the plasma generation unit 4 and is called an extraction electrode, a third electrode is called a suppression electrode with a negative voltage applied thereto, and the fourth electrode is a ground potential. It is sometimes called a ground electrode. When the ion source 2 has a plurality of electrodes in this way, a desired one of the structures shown in the above (1) to (3) may be adopted for at least one of them. In addition, it may be adopted for a plurality of sheets or may be adopted for all sheets, and the above-described effects can be achieved with respect to the employed electrodes. In particular, since the first electrode 8 on the most upstream side is closest to the plasma generation unit 4 and is easily heated by heat from the plasma generation unit 4, the effect of adopting the structures (1) to (3) is great. .

  When the divided structure shown in the above (1) is adopted for a plurality of electrodes, each divided part has a structure like the example shown in FIGS. 3 to 5 and the ion beam 12 is extracted from each divided part. If not, it is preferable to arrange the divided portions of the electrodes at positions overlapping in the ion beam extraction direction. By doing so, the number of locations where the ion beam 12 is not drawn out can be reduced, so that the amount of ion beam can be increased.

  When the divided structure shown in the above (1) is adopted for a plurality of electrodes, each divided portion is a gap penetrating vertically, and when the ion beam 12 is drawn from each divided portion, the divided portion of each electrode is It is preferable to arrange them at positions that do not overlap each other in the ion beam extraction direction (ie, shifted positions). By doing so, even if the ion beam 12 is extracted from the divided portion, the portion having a high ion beam density is dispersed, and the ion beam passing through the divided portion of one electrode passes through the portion other than the divided portion of the other electrode. Since the peak is somewhat relaxed, the density distribution of the ion beam 12 in the direction along the x axis can be made uniform. Further, when attention is paid to two of the plurality of electrodes, for example, if these are the first electrode 8 and the second electrode 10, the divided portion of the first electrode 8 is as shown in the example shown in FIG. The ion extraction hole nonexistent region 59 of the second electrode 10 exists immediately below the second electrode 10, and the ion extraction hole nonexistent region 58 of the first electrode 8 exists immediately above the dividing portion 24 of the second electrode 10. You may do it. By doing so, the ion beam leaking from the upper divided portion 22 is blocked by the lower nonexistent region 59, and the ion beam does not leak from the upper nonexistent region 58 to the lower divided portion 24. , The density distribution of the ion beam 2 in the direction along the x-axis can be made more uniform. The same applies to three or more electrodes.

  When the ion source 2 has one electrode, a desired one of the structures shown in the above (1) to (3) may be adopted as the electrode.

It is the schematic which shows one Embodiment of the ion beam irradiation apparatus which concerns on this invention. It is a top view which shows an example of the 1st electrode in FIG. 1 with a lower target. It is sectional drawing which expands and shows an example of the structure of the division part of a 1st electrode. It is sectional drawing which expands and shows the other example of the structure of the division part of a 1st electrode. It is sectional drawing which expands and shows another example of the structure of the division part of a 1st electrode. It is a top view which shows partially the other example of the 1st electrode in FIG. FIG. 10 is a plan view partially showing still another example of the first electrode in FIG. 1. FIG. 10 is a plan view partially showing still another example of the first electrode in FIG. 1. FIG. 10 is a plan view partially showing still another example of the first electrode in FIG. 1. FIG. 10 is a plan view partially showing still another example of the first electrode in FIG. 1. FIG. 10 is a plan view partially showing still another example of the first electrode in FIG. 1. It is a figure which shows an example of the position of the fixing bolt near the division part of the 1st electrode. It is a figure for demonstrating the displacement in the division part vicinity by the thermal expansion of a 1st electrode. It is a figure for demonstrating the displacement in the division part vicinity by the thermal expansion of a 1st electrode. It is the schematic which shows an example of the conventional ion beam irradiation apparatus. It is a top view which shows an example of the division structure of the conventional electrode with a lower target. It is a top view which shows partially an example of positional relationship, such as a division part of the 1st electrode and the 2nd electrode, and shows both electrodes side by side for convenience.

Explanation of symbols

2 Ion source 8 1st electrode 9 Ion extraction hole 10 2nd electrode 11 Ion extraction hole 12 Ion beam 14 Target 18 Target driving device 22, 24 Dividing part 26, 28 Support frame (fixed part)
32 Drawer hole area 34 Fixing bolt (fixing means)
82, 102 electrode pieces

Claims (5)

Assuming that two axes orthogonal to each other are an x-axis and a y-axis, an ion source having a plurality of ion extraction holes and having at least one electrode along the xy plane in the ion beam extraction direction is extracted from the ion source. An ion beam irradiation apparatus comprising: a target driving device that moves the target in a direction along the y axis when viewed in plan in the ion beam irradiation region;
The extraction hole region, which is the region where the plurality of ion extraction holes are distributed, of each electrode of the ion source is a rectangle whose long side is substantially parallel to the x axis and whose short side is substantially parallel to the y axis. The shape
At least one of the electrodes of the ion source is divided into a plurality of electrode pieces in a direction substantially parallel to the x axis, and each divided portion is disposed obliquely with respect to the y axis. An ion beam irradiation apparatus characterized by that. Assuming that two axes orthogonal to each other are an x-axis and a y-axis, an ion source having a plurality of ion extraction holes and having at least one electrode along the xy plane in the ion beam extraction direction is extracted from the ion source. An ion beam irradiation apparatus comprising: a target driving device that moves the target in a direction along the y axis when viewed in plan in the ion beam irradiation region;
At least one of the electrodes of the ion source is divided into a plurality of electrode pieces in a direction along the x-axis, and each divided portion is arranged obliquely with respect to the y-axis,
Further, the ion extraction holes of the divided electrodes are arranged so that the total area of the plurality of ion extraction holes in the direction along the y-axis is substantially constant in the direction along the x-axis. An ion beam irradiation apparatus characterized by that. Assuming that two axes orthogonal to each other are an x-axis and a y-axis, an ion source having a plurality of ion extraction holes and having at least one electrode along the xy plane in the ion beam extraction direction is extracted from the ion source. An ion beam irradiation apparatus comprising: a target driving device that moves the target in a direction along the y axis when viewed in plan in the ion beam irradiation region;
At least one of the electrodes of the ion source is divided into a plurality of electrode pieces in a direction along the x-axis, and each divided portion is arranged obliquely with respect to the y-axis,
Furthermore, each divided portion of the divided electrode is linear, and is sandwiched at a substantially equal distance from each other in the direction along the x-axis and substantially parallel to the divided portion. Fixing means for fixing the electrode pieces to the fixing portions are respectively arranged at four positions on two straight lines and outside the extraction hole region where the ion extraction holes are distributed. A featured ion beam irradiation apparatus. Assuming that two axes orthogonal to each other are an x-axis and a y-axis, an ion source having a plurality of ion extraction holes and having at least one electrode along the xy plane in the ion beam extraction direction is extracted from the ion source. An ion beam irradiation apparatus comprising: a target driving device that moves the target in a direction along the y axis when viewed in plan in the ion beam irradiation region;
At least one of the electrodes of the ion source is divided into a plurality of electrode pieces in a direction along the x-axis, and each divided portion is arranged obliquely with respect to the y-axis,
Further, the ion extraction holes of the divided electrodes are arranged so that the total area of the plurality of ion extraction holes in the direction along the y-axis is substantially constant in the direction along the x-axis. ,
Each of the divided portions of the divided electrode has a linear shape, and is sandwiched between the divided portions at a substantially equal distance in the direction along the x axis and substantially parallel to the divided portions. Fixing means for fixing the electrode pieces to the fixing portion are respectively arranged at four positions on the straight line of the book and outside the extraction hole region where the ion extraction holes are distributed. Ion beam irradiation device.   The electrode pieces on both sides of each divided portion of the divided electrode are arranged so as to have a gap between each other in the direction along the x axis and overlap each other in the ion beam extraction direction. 2. The ion beam irradiation apparatus according to 2, 3 or 4.

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