JPH056665U - Ion implanter - Google Patents

Abstract

(57) [Summary] [Structure] A wafer is irradiated with a scanned ion beam by applying a scanning voltage having a voltage waveform V _{b to} the scanning electrode, and the implantation dose distribution of the ion-implanted wafer is measured. The wafer is segmented into a plurality of regions (segmented region E
_{1 to} E ₉ ), based on the above measurement results, each divided area E
Correcting the voltage waveform V _b for each ₁ to E _9. Division area E ₁
Then, the voltage waveform V _b is shaped into the voltage waveform V _C1 . [Effect] Since the ion beam is scanned and the ion implantation is performed by the scanning voltage of the voltage waveform obtained based on the measurement result that can comprehensively judge the variation of the ion implantation amount caused by the overlapping of various factors. Therefore, the uniformity of the amount of ion implantation can be improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention is an ion that uniformly implants impurity ions into an ion irradiation target such as a wafer. Injection device.

[0002]

[Prior art]

  An ion implanter ionizes the impurities that it wants to diffuse, and these impurity ions are magnetically Selectively extracted by mass spectrometry using a magnetic field and accelerated by an electric field By irradiating the elephant, impurities are injected into the ion irradiation target. So This ion implanter determines the device characteristics in the semiconductor process. Since it is possible to inject impurities into a desired amount and depth with good controllability, It has become an important device in the production of roads.

[0003]   The above-mentioned ion implanter is used to irradiate a large ion such as an 8-inch wafer. An ion beam can be emitted in the X direction (for example, the horizontal direction) so that it can respond to the target object. Along with the air scanning, the ion irradiation target side is orthogonal to the X direction in the Y direction (for example, There is a so-called hybrid scan type that mechanically scans in the vertical direction. . In addition, conventionally, when there is a trench structure on the surface of the ion irradiation target, To ensure uniform ion implantation without being affected, the ion beam is scanned in parallel (pattern The method of doing (relall scan) is adopted.

[0004]   The parallel beam type hybrid scan type ion implanter is shown in the figure. Spots that have been extracted from a non-ion source and have been subjected to mass spectrometry, acceleration, etc. as needed. As shown in FIG. 14, the ion beam 73 in the shape of a beam is transmitted from the scanning power source 72 to each other. The first scan electrodes 61, 61 to which a scan voltage having a triangular waveform having a phase difference of 0 degrees is applied, and the first scan electrodes 61. So as to perform parallel scanning in the X direction by using the second scanning electrodes 62 located on the downstream side of Has become.

[0005]   The ion irradiation target 66 is held by the holding member 63 at the implantation position. Driven by the drive mechanism 67, the reciprocating motion (scanning) in the Y direction (direction perpendicular to the paper surface) is performed. ).

[0006]   The irradiation mask 6 having an opening 65a having a predetermined area is provided on the upstream side of the holding member 63. 5 are arranged. The opening 65a of the irradiation mask 65 is in the beam scanning area. Only the ion beam 73 formed on the rear side and passing through the opening 65a is retained behind it. The ion irradiation target 66 held by the member 63 is irradiated.

[0007]   In addition, the beam current is measured beside the opening 65a in the beam scanning region. A dose farade 68 is provided. Measured by the above dose Farade 68 The obtained beam current value data 69 is output to the control device 70. This controller 7 0 is a holding member based on the beam current value data 69 from the dose farade 68. The operation of the drive mechanism 67 is controlled (a control signal 71 is output), and the ion irradiation target 66 is controlled. The Y direction scanning speed is controlled. By controlling the Y-direction scanning speed Therefore, the variation of the injection amount is reduced.

[0008]

[Problems to be solved by the device]

  However, after being scanned by the scan electrodes 61, 61, the scan electrodes 62, 62 are passed through. The passing ion beam 73 is substantially free when it passes through the central portion between the scanning electrodes 62. Although it is a parallel beam, as the distance from the central portion approaches the scanning electrodes 62 The deflection angle θ becomes large due to the influence of the high potential portions of the poles 62. That is, the ion beam 7 No. 3 bends inward as the distance from the central portion approaches the scanning electrodes 62, 62 side, and the parallelism is poor. Become

[0009]   Therefore, the scanning speed of the ion beam 73 is higher in the central portion of the scanning region, It gets slower as you move away from it. Thus, in the conventional ion implanter, the beam The non-uniform scanning speed causes deterioration in the uniformity of the ion implantation amount.

[0010]   The factor that impedes the uniformity of the ion implantation amount is the nonuniform beam scanning speed. However, various factors overlap each other, resulting in ion implantation dose. Therefore, it is not possible to control the scanning speed in the Y direction as in the conventional case. It is difficult to ensure a satisfactory implantation uniformity.

[0011]   The present invention has been made in view of the above, and its purpose is to provide a uniform ion implantation amount. An object of the present invention is to provide an ion implanter capable of improving the property.

[0012]

[Means for Solving the Problems]

  Therefore, in order to solve the above-mentioned problems, the ion implantation apparatus according to claim 1 of the present invention solves the above problems. , Ionize the scanned ion beam by applying a scan voltage to the scan electrodes In the ion implantation device that irradiates the irradiation target with uniform implantation of impurity ions, The scanning voltage is based on the measurement result of the implantation amount of the ion-implanted ion irradiation target. It is characterized in that it has a voltage waveform that has been shaped.

[0013]   In order to solve the above-mentioned problems, the ion implantation apparatus according to claim 2 of the present invention is In the ion implantation apparatus according to claim 1, the actual measurement result is divided into a plurality of regions. It is characterized in that each of the divided regions of the ion-irradiated object is formed.

[0014]

[Action]

  According to the structure of claim 1, the voltage waveform of the scanning voltage applied to the scanning electrode is It is shaped based on the measured result of the implantation amount of the ion-implanted target. is there. In this way, variations in the ion implantation dose caused by various factors overlapping The scanning voltage of the voltage waveform obtained based on the measured results that can be comprehensively judged Since the on-beam is scanned and the ion implantation is performed, the uniformity of the ion implantation amount is improved. You can go up.

[0015]   According to the structure of claim 2, the voltage waveform of the scanning voltage is divided into a plurality of regions. Shaped based on the measurement results of each divided area of the differentiated ion irradiation target It is a thing. That is, the scanning voltage is different for each divided area of the ion irradiation target. It has multiple shaped voltage waveforms, and the scanning voltage of the voltage waveform corresponding to each divided area Because the ion beam is scanned and the ion implantation is performed, the entire ion irradiation target The uniformity of the amount of ion implantation can be improved over the surface.

[0016]

【Example】

  An embodiment of the present invention will be described below with reference to FIGS. 1 to 13. It is Ri.

[0017]   As shown in FIG. 6, the ion implantation apparatus of this embodiment has an X direction (for example, a horizontal direction). The ion beam 12 is electrically scanned in parallel (parallel scan) on the The wafer 6 as the irradiation object in the Y direction (for example, the vertical direction) orthogonal to the X direction. A so-called parallel beam type hybrid scan type that mechanically scans Of.

[0018]   This ion implanter, as shown in FIG. Ion source part 41 to be extracted as the dome 12 (see FIG. 3) and only predetermined implanted ions The mass separation section 42 for selecting and extracting the ions, if necessary during transportation of the ion beam 12. Includes the functions of accelerating the ion beam 12 and shaping, focusing, and scanning the beam shape Beam line unit 43, the wafer 6 as the ion irradiation target is set, and implantation processing is performed. It is composed of an end station unit 44 that performs

The ion source section 41 is provided with a gas box 45 for supplying an ion source substance gas (for example, BF ₃ etc.), an ion source 40 for ionizing the implanted elements, and an extraction power source 46 for extracting the ion beam 12. Has been. The inside of the ion source unit 41 is kept in a vacuum state by an ion source unit vacuum pump 47. The ion source 40 is, for example, a hot cathode PIG type equipped with a solid oven, and has a filament, an arc electrode, and a source magnet, which are not shown, respectively, and an arc is triggered by thermionic emission from the filament in the arc chamber. Plasma is generated by discharging, and the ion beam 12 is extracted from an ion extraction electrode (not shown) to which a voltage is applied from the extraction power source 46. As the ion source substance, not only gas but also solid (As etc.) can be used. When using solid, the solid ion source substance is vaporized in the solid oven and guided to the arc chamber, and the gas box is used. From 45, a carrier gas (Ar or the like) is introduced into the arc chamber to ionize the solid ion source material.

[0020]   The mass separation unit 42 includes a mass analysis magnet (not shown) (90 degree deflection electromagnet). ) Is provided. This mass analysis magnet is extracted from the ion source unit 41. Selected ions from the ion beam 12 and the magnetic focusing effect is utilized. To narrow down the ion beam 12 to the analysis slit 48 to the beam line section 43. It is designed to guide you.

[0021]   The beamline section 43 has an image output from the analysis slit 48 of the mass separation section 42. An accelerating tube 49 that accelerates the on-beam, an electrostatic lens that focuses the ion beam 12 ( Triple quadrupole lens) 50, two sets of first beams for scanning the ion beam 12 in parallel in the X direction Deflection the scanning electrodes 1.1 and the second scanning electrodes 2.2 and the ion beam 12 in the Y direction. A pair of deflection electrodes 31, 31 are provided. Also, within the beamline section 43 The part is kept in a vacuum state by a beamline vacuum pump 55.

[0022]   The first scan electrode 1.1 and the second scan electrode 2.2 serving as the scan electrodes are As shown in FIG. 3, the scanning power source 14 is connected, and the scanning power source 14 causes the electrodes to The above-mentioned scan voltage Vsweep is applied. In addition, the deflection electrodes 31 and 31 (see FIG. 5 and FIG. A deflection power source (not shown) is connected to 6).

The scanning power supply 14 includes a waveform generator 15 that generates a waveform signal having a voltage waveform corresponding to the scanning waveform data 21 based on scanning waveform data 21 supplied from a controller 13 described later, and a waveform signal from the waveform generator 15. The high voltage amplifiers 16 and 17 which boost the voltage and output scanning voltages Vswee p having opposite polarities are provided. As shown in FIG. 4, the waveform generator 15 is provided with an area for storing data for generating waveform signals of voltage waveforms V _{c1 to} V _c9 obtained by an operation described later, for example, a memory such as a RAM. The device 15a is incorporated.

[0024]   As shown in FIG. 6, the ion beams 12 are separated from each other by a scanning power source 14 (see FIG. 3). The scanning voltage Vsweep having a phase difference of 180 degrees applied to the first scanning electrode 1.1. After being scanned in the X direction, the deflection electrode 31 to which a predetermined voltage is applied from the deflection power source 31 is deflected by a predetermined angle in the Y direction, and the scanning power source 14 further sets them to 1 The second scan electrodes 2.2 to which the scan voltages Vsweep having a phase difference of 80 degrees are applied flatten The beam 6 is made into a linear beam and is irradiated onto the wafer 6 which is scanned in the Y direction described later. ing.

[0025]   The end station section 44 holds the wafer 6 as shown in FIG. A wafer holding member (hereinafter referred to as a platen) 3 is provided, and a target chuck is provided. The inside of the chamber is kept in a vacuum state by the end station vacuum pump 51. . A swing arm 4 shown in FIG. 6 is attached to the platen 3. So Then, the platen 3 is driven by the platen drive mechanism 18 (see FIG. 3) to move in the direction of arrow B. By reciprocating in the direction, scanning in the Y direction is performed.

[0026]   Further, on the upstream side of the platen 3, there is an opening 5a having a predetermined area shown in FIG. The irradiation mask 5 is arranged. The opening 5a of the irradiation mask 5 is beam-scanned. Only the ion beam 12 formed in the region and passing through the opening 5a is The wafer 6 held by the platen 3 is irradiated. In addition, in the figure The arrow A indicates the scanning trajectory of the ion beam 12.

[0027]   A beam current is measured outside the opening 5a in the beam scanning area. A dose Farade 7 is provided. Io incident on this dose Farade 7 The dose is calculated from the measured beam current of the beam 12 and the dose From the area ratio of the opening portion of the array 7 and the opening portion 5a of the irradiation mask 5, the opening portion 5a is determined. The dose amount of the passing ion beam 12 is converted and displayed on a monitor (not shown). It is supposed to be done.

[0028]   In addition, the beam current value data 24 measured by the dose Farade 7 is 3 is output to the control device 13. This control device 13 Operation of the platen drive mechanism 18 based on the beam current value data 24 from the radar 7 (Control signal 25 is output) to control the scanning speed of the wafer 6 in the Y direction. It has become. Specifically, if the beam current value decreases, the control device 13 By decreasing the swing speed of the swing arm 4 in proportion to If the beam current value increases on the contrary, the swing arm 4 The control is performed so as to increase the swing speed of and increase the Y-direction scanning speed. This Y direction By controlling the scanning speed, variations in the amount of ion implantation into the wafer 6 in the Y direction are reduced. It is supposed to be.

Further, in this ion implantation apparatus, as shown in FIGS. 9 and 10, a plurality (16 in this embodiment) of front farads f _{1 to} f ₁₆ and a plurality (11 in this embodiment) are used. Back farades b _{1 to} b ₁₁ , dump farade 10, dose farade 52, and beam farade 11. These are for receiving the ion beam 12 and measuring the beam current thereof, and are used when correcting the waveform of the scanning voltage Vsweep applied from the scanning power supply 14 to the scanning electrodes 1.1 and 2.2. . Therefore, during ion implantation into the wafer 6, it is removed from the scanning trajectory of the ion beam 12, and is set within the scanning trajectory of the ion beam 12 when performing the waveform correction operation of the scanning voltage Vsweep described later.

The plurality of front farads f _{1 to} f ₁₆ are arranged in the X direction, which is the scanning direction of the ion beam 12, upstream of the implantation position T ₁ where the wafer 6 is provided. The plurality of back farads b _{1 to} b ₁₁ are also arranged in the X direction downstream of the injection position T. The front farads f _{1 to} f ₁₆ and the back farads b _{1 to} b ₁₁ are used to obtain the beam incident angle α to the wafer 6, and detect the peak of the beam current of the ion beam 12 as described later. That is the main purpose.

[0031]   The dump farade 10 obtains a trapezoidal waveform from the measured value, It is used to recognize the shape of No. 2.

[0032]   The dose Farade 52 counts the dose like the above-mentioned Dose Farade 7. It is used to

[0033]   The beam farade 11 has a beam scanning area (overscan as much as necessary). Is done).

The dump farade 10 is located at a position where the ion beam 12 in the horizontal direction can be measured, and the front farades f _{1 to} f ₁₆ are located at positions where the ion beam 12 deflected by 4 ° from the horizontal direction can be measured. The back farads b _{1 to} b ₁₁ , the dose farad 52, and the beam farad 11 are provided, for example, at positions where the ion beam 12 deflected by 7 ° from the horizontal direction can be measured. Then, while the respective Farades are fixed at the above positions, the deflection angles of the ion beam 12 are switched by the deflection electrodes 31 and 31 (see FIG. 6) and sequentially measured.

Waveform correction of the scanning voltage Vsweep using the above-mentioned front farads f _{1 to} f ₁₆ and back farads b _{1 to} b ₁₁ is performed by arranging the respective farads on the scanning trajectory of the ion beam 12 as shown in FIG. The above is performed as follows.

First, the control device 13 outputs the scanning waveform data 21 corresponding to the basic voltage waveform V _a (see FIG. 13B) to the scanning power supply 14. The basic voltage waveform V _a is a triangular wave or _a waveform close to it. A waveform signal is generated by the waveform generator 15 in response to the scanning waveform data 21, and the first scanning electrode 1.1 and the second scanning electrode 2.2 are connected to each other via the high voltage amplifiers 16 and 17 between the parallel electrodes. A scanning voltage Vsweep having _a voltage waveform Va of 180 ° out of phase is applied, and the ion beam 12 is scanned in the X direction.

At this time, the control device 13 switches the front farades f _{1 to} f ₁₆ and the back farades b _{1 to} b ₁₁ individually, and while the ion beam 12 is scanned once, the control device 13 detects the detection points in the X direction. The beam current is sampled in synchronism with the change in position (address), and the X-direction address having a peak at each farade and the waveform data value (scanning voltage Vsweep) at that address are obtained. Incidentally, X-direction address of the front Faraday f ₁ ~f ₁₆ and Bakkufarade b ₁ ~b ₁₁ is known in advance.

[0038]   At this time, the dump farade 10 and the beam farade 1 shown in FIG. 9 and FIG. 1. Dose Farade 52 determines the shape and scanning state of the ion beam 12 and the dose amount. Etc. are confirmed.

The control device 13 performs a predetermined calculation based on the collected data obtained from the above-mentioned front farades f _{1 to} f ₁₆ and back farades b _{1 to} b ₁₁ , and determines the incident angle of the ion beam 12 at the implantation position T. Figure out α. This will be described below with reference to FIG.

From the above collected data, the relationship between the address in the X direction and the scanning voltage Vsweep is shown at the position where the front farads f _{1 to} f ₁₆ are arranged and the position where the back farads b _{1 to} b ₁₁ are arranged. A characteristic curve is obtained. A curve f in the figure shows the characteristic at the position where the front farades f _{1 to} f ₁₆ are arranged, and a curve b shows the characteristic at the position where the back farades b _{1 to} b ₁₁ are arranged. Then, the distance L ₁ between the position and the injection position T of the front Faraday f ₁ ~f _16, the ratio of the distance L ₂ between the position of the injection position T and Bakkufarade b ₁ ~b ₁₁ is l _1: l If it is ₂ , the curve t showing the characteristic at the injection position is obtained by connecting the points dividing the curve f and the curve b into l ₁ : l ₂ as shown in FIG.

Therefore, the incident angle α of the ion beam 12 incident on the arbitrary point H _x at the implantation position T is obtained as follows.

That is, the deflection angle θ of the ion beam 12 incident on the point H _x after passing through the second scanning electrodes 2 and 2 is H _x f at the front Faraday position of the ion beam 12 and at the back Farade position at the address. the When H _x b, tanθ = from _{(H x b -H x f)} / (l 1 + l 2), θ = tan -1 (H x b -H x f) / (l 1 + l 2) than this , The incident angle α is α = 90 ° -tan ⁻¹ (H _x b −H _x f) / (l ₁ + l ₂ ), and the control device 13 controls the ion beam 12 on the implantation position T obtained as described above. From the relationship between the irradiation position (H _x ) of the ion beam and the incident shift angle | α-90 ° | (shown in FIG. 13A), the scanning speed of the ion beam 12 should be constant as shown in FIG. given waveform shaping instruction 23 to the voltage waveform V _a temporally relocated to the waveform generator 1 5 . Since the beam scanning speed corresponds to the time change of the scanning voltage Vsweep, that is, the slope of the voltage waveform (dVsweep / dt), the voltage waveform V _a is changed by the waveform shaping command 23 as shown in FIG. The larger α is, the larger the dVsweep / dt becomes. For example, the voltage waveform V _b is formed.

In the present embodiment, beam scanning is performed using the voltage waveform V _b obtained as described above, ion implantation is actually performed on the wafer 6, and the voltage waveform V _b of the voltage waveform V _b is further described below. Perform correction again. First, the implantation operation of the ion implantation apparatus using the voltage waveform _Vb will be described below.

As shown in FIG. 3, the controller 13 outputs the scanning waveform data 21 corresponding to the voltage waveform V _b to the scanning power supply 14. A waveform signal is generated by the waveform generator 15 in response to the scanning waveform data 21, and is transmitted to the first scanning electrode 1.1 and the second scanning electrode 2.2 through the high-voltage amplifiers 16 and 17 between the parallel electrodes. A scanning voltage Vsweep having a voltage waveform _{Vb having} a phase difference of 180 ° is applied, and the ion beam 12 is scanned in parallel in the X direction. The ion beam 12 passes through the opening 5 a of the irradiation mask 5 and is irradiated onto the wafer 6.

[0045]   On the other hand, the platen 3 on which the wafer 6 is set is driven by the platen drive mechanism 18. And is scanned in the Y direction. This causes the ion beam 12 to illuminate the entire surface of the wafer 6. Is shot. Further, during the ion implantation operation, the controller 13 controls the dose Farade 7 Based on the measured beam current value data 24, the operation of the platen drive mechanism 18 The swing speed of the swing arm 4, that is, the scanning speed of the wafer 6 in the Y direction is controlled. Do your best.

[0046]   As described above, the voltage waveform is set so that the beam scanning speed becomes constant in the X direction. Is corrected, and the actual beam measurement value is fed back in the Y direction to scan speed. The injection uniformity is improved to some extent by controlling the above. But Naga In addition, there are factors that cannot be covered by these factors, which causes variations in injection. There is a case.

[0047]   Therefore, in this embodiment, the injection uniformity is further improved by the following method. .

[0048]   With respect to the wafer 6 that has been actually ion-implanted as described above, Measure the cloth condition. An example of this measurement result is shown in FIG. The figure shows the wafer 6 FIG. 7 is an injection amount distribution map obtained by measuring the electrical resistance. The solid line in the wafer 6 in the figure is the average value. It is a line, and the numerical value represents the deviation from the average value as a percentage (%). still In the sheet resistance value variation data, the part with a large injection amount is negative (-) or small. There is a plus (+) in the part that does not exist, but in this example, the part with a large injection amount is plus, The small part is negative.

[0049]   Then, the data of the measurement result of the implantation result distribution over the entire surface of the wafer 6 (below (Hereinafter referred to as actual measurement data) 22 is the data of the personal computer shown in FIG. Data is input to the control device 13 via the input device 19.

The controller 13 divides the wafer 6 into a plurality of regions in the Y direction (in this embodiment, nine regions) (see FIGS. 2 and 8), and the measured data 22 is obtained. based on performed as follows recalibration of the voltage waveform V _b (the shaping) for each segmented region E ₁ to E _9.

[0051]   In consideration of overscan, the beam scanning range (scan in the X direction) is set for each divided area. Start address and end address).

Taking the partitioned area E ₁ as an example, a detailed description will be given with reference to FIG. During the drawing, V _xA: scanning voltage value of the start address of the voltage waveform V _b (existing value) V _xB: scanning voltage value of the end address of the voltage waveform V _b (existing value) V _xC: Start Voltage waveform V _c1 Address scanning voltage value V _xD : End address scanning voltage value of voltage waveform V _c1 V _{x1 to} V _x7 : Scanning voltage value of voltage waveform V _b (existing value) β ₁ : Beam scanning region β _{2 of} voltage waveform V _c1 Β ₃ is an overscan region based on the voltage waveform V _c1 . The voltage waveform V _c1 is a voltage waveform corresponding to the divided area E ₁ which is obtained by correcting the voltage waveform V _b by the following method.

When the specified overscan value is β = [(β ₂ + β ₃ ) / β ₁ ] × 100 (%), β / 100 = (| V _xD −V _x7 | + | V _x1 −V _xC | ) / | V _xD -V _xC | than, obtaining the scanning voltage value V _xD scan voltage V _xC and the end address of the start address of the voltage waveform V _c1.

[0054]   However, like this ion implanter, it does not measure the beam current during ion implantation. If Zufarade 7 is on the side of Platen 3, the address of Dose Farade 7 side (End address in this case) is not corrected.

[0055]   By correcting the beam scanning range in this way, beam utilization efficiency and implantation The processing speed can be improved. The correction of the beam scanning range is It is performed only when considering the utilization efficiency and the injection processing speed, and these are taken into consideration. The above procedure may be omitted if it is not necessary to do so.

The slope (dVsweep / dt) of the voltage waveform V _b is corrected based on the actual measurement data 22 from the data input device 19 as follows.

In the 0% region, dVsweep / dt of the voltage waveform V _b is used as it is.

[0058]   In the + n% area, dVsweep / dt is increased by n%.

[0059]   In the -n% area, dVsweep / dt is reduced by n%.

That is, the control device 13 increases the dV sweep / dt by 0.13% in the V _{xC to} V _x1 region with respect to the voltage waveform V _b , and sets the dV sweep / dt to 0 in the V _{x1 to} V _x2 region. ． Increased by 13%, the V _x2 ~V _x3 area increases dVsweep / dt 0.09%, accept the dVsweep / dt in V _x3 ~V _x4 region, the dVsweep / dt in V _x4 ~V _x5 area 0 .15%, dVsweep / dt is reduced by 0.20% in the V _{x5 to} V _x6 region, dVsweep / dt is reduced by 0.13% in the V _{x6 to} V _x7 region, and dVsweep is reduced in the V _{x7 to} V _xB region. A waveform shaping instruction 23 that directly uses / dt is given to the waveform generator 15 (see FIG. 4). As a result, the voltage waveform _Vb is shaped like the voltage waveform _Vc1 .

At this time, the waveform generator 15 stores the data for generating the waveform signal corresponding to the voltage waveform V _c1 in a predetermined area of the built-in storage device 15 a (see FIG. 4).

Although only the segmented region E ₁ has been described above, the measured data 22 from the data input device 19 is processed by the control device 13 in the same manner as described above for the segmented regions E _{2 to} E ₉ , and the voltage waveform V _b is , And the voltage waveforms V _{c2 to} V _c9 (not shown) corresponding to each of the divided areas E _{2 to} E ₉ are corrected. Then, in the waveform generator 15, data for generating waveform signals corresponding to the voltage waveforms V _{c2 to} V _c9 are stored in predetermined areas of the storage device 15a, respectively.

Then, in the actual ion implantation operation, the voltage waveforms V _{c1 to} V _c9 of the scanning voltage Vsweep are controlled by the controller 13 at the timing when the wafer 6 passes through the opening 5 a of the irradiation mask 5 which is the ion implantation region. Is selectively switched by and the injection process is performed.

Specifically, when the platen 3 is moved from the upper side to the lower side, the controller 13 controls the upper end position C (see FIG. 7) of the opening 5 a of the irradiation mask 5 to the wafer 6 shown in FIG. The voltage waveforms V _{c1 to} V _c9 of the scanning voltage Vsweep are switched every time the waveform switching addresses B _{1 to} B _{8 of the above} are passed. Incidentally, the waveform switching address B ₁ .about.B ₈ is a boundary segment regions E ₁ to E _9.

Further, the platen drive mechanism 18 outputs a position signal 20 indicating the position of the wafer 6 to the controller 13, as shown in FIG. Then, the control device 13 determines the position of the wafer 6 in the Y direction based on the position signal 20, and until the waveform switching address B ₈ of the wafer 6 passes the upper end position C of the opening 5 a of the irradiation mask 5, The scanning waveform data 21 corresponding to the voltage waveform V _c9 is output to the waveform generator 15. At this time, the waveform generator 15 receives the scanning waveform data ₂₁ corresponding to the voltage waveform V _c9 and generates a waveform signal corresponding to the voltage waveform V _c9 . As a result, the scan voltage Vswee p having the voltage waveform V _c9 is applied to the first scan electrode 1.1 and the second scan electrode 2.2 to perform beam scanning.

Next, the controller 13 causes the waveform switching address B ₈ of the wafer 6 to pass through the upper end position C of the opening 5 a of the irradiation mask 5, and then the waveform switching address B _{7 of the} wafer 6 to open. Until passing through the upper end position C of 5a, the scanning waveform data 21 corresponding to the voltage waveform V _c8 is output to the waveform generator 15. As a result, beam scanning with the voltage waveform V _c8 is performed as in the above.

Similarly, the waveform switching address B ₇ of the wafer 6 passes through the upper end position C of the opening 5 a of the irradiation mask 5 until the next waveform switching address B ₆ passes by the voltage waveform V _c7. , Until the next waveform switching address B ₅ passes, by the voltage waveform V _c6 , and until the next waveform switching address B ₄ passes by the voltage waveform V _c5 , and then the waveform switching address B. _The voltage waveform V _c4 is used until ₃ passes, the voltage waveform V _c3 is used until the waveform switching address B ₂ is passed next, and the voltage waveform V _c2 is passed until the waveform switching address B ₁ is passed next. Then, after passing the waveform switching address B _1, beam scanning is performed by the voltage waveform V _c1 .

Similarly, when the platen 3 moves from the lower side to the upper side, the controller 13 causes the lower end position D (see FIG. 7) of the opening 5 a of the irradiation mask 5 to move to the waveform switching address B _{1 of the} wafer 6. each time .about.B ₈ passes, the voltage waveform V _c1 ~V _c9 scan voltage Vsweep is switched.

In the present embodiment, as described above, the voltage waveform V _b in which the triangular wave has been corrected is further corrected based on the actual measurement result of the implantation amount of the ion-implanted wafer 6. As described above, the ion beam 12 scans with the scanning voltage Vsweep of the voltage waveforms V _{c1 to} V _c9 obtained based on the actual measurement result that can comprehensively judge the variation in the ion implantation amount caused by the overlapping of various factors. Since the ion implantation is performed, the uniformity of the ion implantation amount can be improved.

Further, the voltage waveforms V _{c1 to} V _c9 of the scanning voltage Vsweep are selectively switched depending on the timing at which the divided regions E _{1 to} E _{9 of} the wafer 6 pass through the opening 5 a of the irradiation mask 5 which is an implantation region. Since the implantation process is performed in this way, it is possible to improve the uniformity of the ion implantation amount over the entire surface of the wafer 6.

[0071] In the ion implantation apparatus of the present embodiment, the wafer 6 is divided into nine sections areas E ₁ to E _9, nine voltage waveform V _c1 ~V corresponding to each segmented region E ₁ to E _{9 c9} The beam scanning is performed by the scanning voltage Vsweep of, but not limited to this, the accuracy and resolution of the measured data 22 of the injection result distribution, the resolution of the voltage waveform of the device, and the accuracy of the injection uniformity. Is required, the number of voltage waveforms to have and the correction accuracy of each voltage waveform are determined.

[0072]   In addition, in this embodiment, a parallel beam type hybrid scan type ion injection is used. Although the input device has been described, the present invention is not limited to this, and the scanning voltage is applied. Beam scanning is performed by an additional scanning electrode (not necessarily a parallel beam) All on-injection devices are included in this summary.

[0073]

[Effect of device]

  As described above, the ion implanter according to the invention of claim 1 is applied to the scan electrodes. The scanning voltage is based on the measurement result of the implantation amount of the ion-implanted ion irradiation target. It is a configuration of a voltage waveform that has been shaped according to the above.

[0074]   Therefore, the variation in ion implantation amount caused by various factors overlapping is comprehensively evaluated. The ion voltage is determined by the scanning voltage of the voltage waveform obtained based on the actual measurement results The ion beam is scanned and the ion implantation is performed, so the uniformity of the ion implantation amount is improved. There is an effect that can be.

[0075]   The ion implanter according to the invention of claim 2 is, as described above, the invention of claim 1. In the ion implantation apparatus according to the above, the actual measurement result is divided into a plurality of regions. The ion irradiation target is in each divided area.

[0076]   Therefore, the scanning voltage was individually shaped for each sectional area of the ion irradiation target. It has multiple voltage waveforms, and the ion is generated by the scanning voltage of the voltage waveform corresponding to each divided area. Since the beam is scanned and the ion implantation is performed, the entire surface of the ion irradiation target is covered. Therefore, it is possible to improve the uniformity of the amount of ion implantation.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is an explanatory diagram showing a method of shaping a voltage waveform based on data of actual measurement results.

FIG. 2 is a schematic injection amount distribution chart showing an example of the actual measurement result.

FIG. 3 is a schematic explanatory view showing a main part of a parallel beam type hybrid scan type ion implantation apparatus according to an embodiment of the present invention.

FIG. 4 is a block diagram showing how the data of the actual measurement results is input to the control means of the ion implantation apparatus.

FIG. 5 is a schematic explanatory view showing an example of a configuration of the ion implantation apparatus.

FIG. 6 is an X of an ion beam in the above-mentioned ion implantation apparatus.
FIG. 3 is a schematic explanatory diagram showing scanning in a direction and scanning in a Y direction on a wafer.

FIG. 7 is a schematic explanatory view showing a positional relationship between an opening of an irradiation mask of the ion implantation apparatus and a wafer.

FIG. 8 is an explanatory diagram showing an example in which a wafer is divided into a plurality of areas.

FIG. 9 is an explanatory diagram showing an arrangement of farads (front, back, dump, beam, dose) of the ion implantation apparatus when viewed from the side.

FIG. 10 is an explanatory diagram showing the arrangement of the Farade when viewed from above.

FIG. 11 is an explanatory diagram showing a state in which the Farade (front, back) is arranged on a scanning trajectory of an ion beam.

FIG. 12 is an explanatory diagram showing a method of obtaining an incident angle from measurement data by the Farade (front, back).

FIG. 13 is an explanatory diagram showing a method of shaping a voltage waveform based on a relationship between a beam irradiation position and an incident shift angle.

FIG. 14 shows a conventional example and is a schematic explanatory view showing a main part of a hybrid beam type ion implanter of a parallel beam system.

[Explanation of symbols]

1 the first scanning electrode (scanning electrode) 2 second scan electrodes (scanning electrodes) 6 wafer (ion irradiation target object) 12 ion beam 13 controller 14 scanning power source 15 waveform generator 15a memory 19 data input device E ₁ to E _9- segment area

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/265

Claims (2)

[Scope of utility model registration request] 1. An ion implanter for irradiating an ion irradiation target with an ion beam scanned by applying a scan voltage to a scan electrode to uniformly implant impurity ions, wherein the scan voltage is the ion-implanted ion. An ion implanter having a voltage waveform shaped based on a measurement result of an implantation amount of an irradiation target. 2. The ion implantation apparatus according to claim 1, wherein the actual measurement result is for each of the divided regions of the ion irradiation target divided into a plurality of regions.