TWI220154B - Apparatus and method for detecting deviations of incident angles of ion beam - Google Patents

Abstract

An apparatus for detecting deviations of incident angles of ion beam is provided. The apparatus comprises an ion beam source, a means for fixing wafers and an ion beam sensor. A method for detecting deviations of incident angles of ion beam is provided. The ion beam source is configured opposite to where the means for fixing wafers is configured. The ion beam sensor receives the ion beam beside the means for fixing wafers, which is emitted from the ion beam source. Compare the values of current of the deviated incident angles to the non-deviated incident angles would get the deviations of incident angles of ion beam.

Description

1220154 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a semiconductor device, and more particularly to a detection device and method for detecting an incident angle of an ion beam. "[Previous technology] Ion implantation (i ο ni in p 1 antati ο η) technology began to be applied to semiconductor production about half a century ago. After years of research and development, the current ion implantation technology can not only provide a variety of The requirements of semiconductor doping process can more accurately control the content and distribution of doping (d ooping), so it has become the most important doping pre-measurement in Very Large Scale Integration (VLSI) process. Generally speaking, in order to make the implanted ion beam (ion beam) have a more uniform momentum, usually in the ion implanter (im planter) f a set of angle corrector with focusing function (Angle corrector), so that the ion beam can be implanted with the smallest range of incident angles. This is because the incident angle of the ion beam will affect the implantation efficiency of doped ions, which may change the conductivity of the wafer ( cnnductivity), etc. Therefore, in the process of ion implantation, it is an important subject to understand the deviation of the incident angle of the ion beam. There are two conventional methods for detecting the deviation of the incident angle of the ion beam, including V-curve in eth 〇d and Trave 1 ing Profile method. 1A to 1 Figure B is a schematic diagram showing the V-curve method. As shown in Figure 1A, the detection method of the ion beam incident angle with or without offset is to mount the wafer 1 2 a on Electrostatic chuck

11689t.wf. Ptd Page 6 1220154 V. Description of the invention (2) 100 (E-chunk), and the surface of the wafer 102a is perpendicular to the incident ion beam 104, and the inclination angle of the wafer surface at this time is defined 0 is zero. When the ion beam 1 04 is irradiated to the surface of the wafer 102a, the crystal lattice on the wafer 102a will be destroyed / the tempering process is then used to make the lattice in the wafer 102a again. Array, and then measure and record the resistance value of wafer 102a at this time. Then, as shown in FIG. 1B, the wafer 102b is tilted, so that the surface of the wafer 102b has an inclination angle 0, and the angle may be -2, -1, 1, and 2. Then, the above steps are repeated, and the resistance value of a large number of wafers 10 2 b with different tilt angles 0 is measured. After that, using the angle 0 of the wafer surface tilted during the ion implantation process as the horizontal axis, and finally measuring the resistance value on the wafer surface as a vertical axis, a graph is obtained as shown in Figure 1C. Shown as a V-shaped curve. In the continuous ion implantation process, according to the measured wafer resistance value, the V-shaped curve can be compared with this to obtain the tilted angle of the wafer in the ion implantation process, and then the ion beam or wafer can be adjusted. Hold the device so that the ion beam is implanted vertically on the wafer surface. FIG. 2 is a schematic diagram of a device for the active contour detection method (T r a v e 1 i n g P r 0 f i 1 e method). Please refer to Figure 2. This method is to arrange several fixed Faraday cups 2 0 0 at the relative position of the ion beam emission source, and arrange a piece between the Faraday cup 2 0 0 and the ion beam emission source in the direction 2 0 An obstacle 202 moving in directions 6 and 208 blocks the course of the ion beam 204. Finally, it is determined whether the incident angle of the ion beam 2 0 4 is shifted depending on the number of ions received by the obstacle 2 2 corresponding to the Faraday cup 2 0 0. When the incident angle of the ion beam 2 0 4 is not shifted, the Faraday cup 2 0 0 corresponding to this obstacle 2 2 will not be able to receive the number of ions. If the incident angle of the ion beam 2 0 4 is shifted, the Faraday cup 2 0 0 corresponding to this obstacle 2 0 2 will still receive a small amount of ionization.

11689t.wf.ptd Page 7 1220154 V. Description of the invention (3) Number of children. · However, in the V-curve detection method, since it requires many wafers to make this V-curve, the cost is excessive. In addition, the wafer also needs to be tempered, which not only takes a long time for the manufacturing process, but also is more likely to cause inconsistent lattice arrangement in the wafer due to improper control of the parameters during the tempering process. The measured resistance value is incorrect. On the other hand, in the active contour detection method, if the obstacle is not positioned properly (for example, the obstacle itself is tilted), it will affect the measurement result. In addition, the graphite in the Faraday cup is easy to wear and may affect the measured results. In addition, in the method, since the detection system is not related to the electrostatic chuck, the detection system cannot reflect the actual condition of the electrostatic chuck. That is, the angular displacement of the electrostatic chuck itself will cause the incident angle of the ion beam to shift, which will make it impossible to detect whether the ion beam is truly shifted. [Summary of the Invention] In view of this, the object of the present invention is to provide a detection device and method for the deviation of the incident angle of an ion beam, which can accurately measure the deviation of the incident angle of the ion beam, so as to make it appropriate. Adjust to make the implantation process more accurate. The invention provides a detection device for the deviation of the incident angle of an ion beam. The device is composed of an ion beam emission source, a wafer fixing device, and an ion beam sensing device. Among them, the ion emission source is used to emit an ion beam required for ion implantation, and the wafer fixing device is arranged at a relative position of the ion beam emission source to fix the wafer. In addition, a sensor is arranged at the bottom of the ion beam sensing device to measure the number of ions received. This ion beam sense

11689t.wf.ptd Page 8 1220154 V. Description of the invention (4) The measuring device is in a cylindrical shape and is set on one side of the wafer fixing device, and the opening is directed toward the ion beam emission source. Because the ion beam incident angle deviation detection device of the present invention uses a cylindrical ion beam sensing device, when the ion beam is shifted, part of the ion beam will be blocked by the side wall of the ion beam sensing device, and Make the current value measured by the bottom of the ion beam sensing device small (that is, less ion beams are sensed), and then use the current value when the current value does not deviate from the incident angle of the ion beam By comparing the current values, the deviation angle of the ion beam can be calculated. Moreover, the present invention directly disposes the ion beam sensing device on one side of the wafer holding device (ie, an electrostatic chuck), so the relationship between the wafer holding device and the ion beam emission can be actually reflected. In addition, the detection device for the deviation of the incident angle of the ion beam of the present invention has a simple structure, does not need to modify the ion implantation device, and does not waste the wafer, thus saving costs. In addition, the detection device for the deviation of the incident angle of the ion beam of the present invention does not need to use other auxiliary tools, and can avoid affecting the measurement accuracy due to the error of the auxiliary tools. The invention proposes a method for detecting the deviation of the incident angle of an ion beam. This method firstly installs an ion beam sensing device on one side of a wafer fixing device of an ion beam implantation device, and the ion beam sensing device is formed into a cylinder. Shape, and the opening is toward the ion beam emission source, and a sensor is provided at the bottom of the ion beam sensing device. An ion beam is then emitted to the above-mentioned ion beam sensing device, and the current value of the ion beam is measured by the ion beam sensing device, and then another current value measured when the ion beam enters the ion beam sensing device vertically , And the first time

11689t.wf. Pt.d Page 9 1220154 V. Description of the invention (5) The measured current value is compared to judge the deviation of the incident angle of the ion beam. · The ion beam incident angle detection method of the present invention uses a cylindrical ion beam sensing device, so when the ion beam is shifted, part of the ion beam will be blocked by the side wall of the ion beam sensing device, and Make the current value measured by the bottom of the ion beam sensing device smaller (that is, the number of ions sensed is smaller), and then use the current value when the current value does not deviate from the angle of incidence of the ion beam By comparing the current values, the deviation angle of the ion beam can be calculated. Moreover, the method of the present invention uses an ion beam sensing device to directly detect an ion beam on one side of a wafer holding device (ie, an electrostatic chuck), so the relationship between the wafer holding device and the ion beam emission source can be actually reflected. . In addition, the method for detecting the deviation of the incident angle of the ion beam of the present invention does not require modification of the ion implantation device, and does not waste the wafer, thus saving costs. In addition, the method for detecting the deviation of the incident angle of the ion beam of the present invention does not need to use other auxiliary tools, and can avoid affecting the measurement accuracy due to the errors of the auxiliary tools. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings for detailed description as follows: [Embodiment Mode] FIG. A schematic diagram of a detection device for shifting the incident angle of an ion beam in a preferred embodiment of the invention. FIG. 4A and FIG. 4B are schematic diagrams respectively showing a state in which an incident angle of an ion beam is not shifted and an incident angle of an ion beam is shifted in a preferred embodiment of the present invention.

11689twf.ptd Page 10 1220154 V. Description of the invention (6) Please refer to FIG. 3, FIG. 4A to FIG. 4B at the same time, the detection device for the ion and beam incident angle shift of the present invention includes at least an ion emission source 3 0 0, wafer fixing device 302 and ion beam sensing device 304. ‘Among them, the ion beam emission source 300 is used to emit the ion beam required for ion implantation. The wafer fixing device 300 is, for example, disposed at a relative position of the ion beam emission source 300 to fix a wafer. In this embodiment, the wafer fixing device 3 02 is, for example, an electrostatic chuck, and the wafer fixing device 3 2 has, for example, an opening 3 0 8. Through this opening 308, the wafer can be suction-fixed on the wafer holding device 302. Of course, the wafer fixing device 302 may also be a device for holding, fixing, and holding a wafer in a semiconductor process equipment, such as a robot arm. The ion beam sensing device 304 is provided on one side of the wafer holding device 302. The ion beam sensing device 3 0 4 is cylindrical, for example, and the opening faces the ion beam emission source 3 0 0. The ion beam sensing device 304 may be cylindrical, quadrangular cylindrical, or other cylindrical objects. In this embodiment, the ion beam sensing device 300 is described by taking a rectangular tube shape as an example. The bottom of the ion beam sensing device 3 0 4 is, for example, provided with a sensor 4 0 0 to detect the number of ions received (ie, the current value). In the present invention, the ion beam emitted by the ion emission source 3 0 0 is directed toward the opening 3 0 8 of the wafer fixing device 3 0 2 and the opening 3 1 0 of the ion beam sensing device 3 0 4. The opening 3 1 0 of the ion beam sensing device 3 0 4 is, for example, coplanar with the opening 308 of the wafer fixing device 302, so that the two act synchronously. Then, a sensor 400 at the bottom of the ion beam sensing device 300 is used to detect the number of ions emitted from the ion emission source 300 to the sensing device 300.

1 1689t.wf. Ptd Page 11 1220154 V. INTRODUCTION TO THE INVENTION (7) The detection device for the deviation of the incident angle of the ion beam in the above embodiment has a simple structure, which can save the cost of remanufacturing the testing machine. Moreover, in the present invention, the ion beam sensing device 3 0 4 is directly disposed on one side of the wafer fixing device 3 2 2 (that is, the electrostatic chuck), so it can actually reflect the emission between the wafer fixing device and the ion beam. relationship. In addition, the detection device for the deviation of the incident angle of the ion beam of the present invention can directly detect the number of ions received by directly measuring the fixed position of the wafer, and derive the offset of the incident angle of the ion beam. Since wafers are not required, costs can be saved. In addition, the detection device for the deviation of the incident angle of the ion beam of the present invention does not need to use other auxiliary tools, and can avoid affecting the accuracy of the measurement due to the errors of the auxiliary tools. The above description explains the ion beam incident angle deviation detection device of the present invention, and then the following will describe a method for detecting the ion beam incident angle deviation using the above device. First, referring to FIG. 3, the ion beam sensing device 3 0 4 is arranged on one side of the wafer fixing device 3 2 2 and the two are operated in synchronization. The wafer fixing device 3 0 2 is, for example, an electrostatic chuck having an opening 3 0 8, and the ion beam sensing device 3 0 4 has an opening 3 1 0 that is, for example, an opening 3 0 8 with the wafer fixing device 3 0 2 Coplanar. Next, an ion beam 3 0 6 is emitted from the ion emission source 300 toward the wafer fixing device 3 2 so that the ion beam sensing device 3 0 4 provided on one side of the wafer fixing device 3 0 2 can receive ions. Beam 3 0 6 and measure a current value. After that, adjust the ion emission source 3 0 ◦ or the wafer fixing device 3 2 so that the ion beam 3 0 6 emitted from the ion emission source 3 0 0 is perpendicular to the wafer fixing device 3 0 2

11689twf.ptd Page 12 1220154 V. Description of the invention (8) The plane of the opening 3 0 8. Next, the ion beam sensing device 300 measures the current value received when the ions and the beam are not shifted. Then, the incident angle of the ion beam emitted by the ion beam emission source 300 is shifted by an angle, and the current values when the incident angles from the sub-beams are shifted are measured respectively. Then, the offset angle is taken as the horizontal axis, and the current value measured by the ion beam sensing device 300 is plotted on the vertical axis (as shown in FIG. 5). Please refer to FIG. 4A. When the incident angle of the ion beam 4 0 6 a has no offset, the sensor 4 0 0 at the bottom of the ion beam sensing device 3 0 4 can detect a larger number of ions. The obtained current value will also be relatively large. However, when the incident angle of the ion beam is shifted, as shown in FIG. 4B, the ion beam 4 0 6 b is incident on the ion beam sensing device 3 0 4 at an offset incident angle, because part of the ion beam 4 0 6 b will be emitted beyond the opening 3 1 0 of the ion beam sensing device 3 0 4, so the inductor 4 0 0 at the bottom of the ion beam sensing device 3 0 4 may receive only part of the ion beam 4 0 6 b, so the measured current value will be smaller than that measured when the ion beam has no offset. Therefore, when it is necessary to detect whether the incident angle of the ion beam is shifted, as long as the current value of the ion beam is measured, and then the current value is compared with the current value received when the ion beam is not shifted, it can be obtained Know the offset of the incident angle of the ion beam. In the above embodiment, the method for detecting the deviation of the incident angle of the ion beam is to make the opening of the ion beam detection device and the opening of the electrostatic chuck (wafer holding device) coplanar, and the two are operated synchronously. If there is a difference between the current values, this difference can only be related to the angle between the ion beam emission source and the electrostatic chuck (wafer holding device), which is not easily affected by other factors.

1 1689 t.wf. Pt.d Page 13 1220154 V. Description of the invention (9) Affects the measurement result. Furthermore, since the detection method of the present invention does not need to use a wafer during the detection process, the cost of the detection process can be greatly reduced. In order to prove the efficacy of the present invention, an experimental example is given for illustration. In this experimental example, the size of the cylindrical ion beam sensing device is 5 cm * 5 cm * 10 cm. When the incident angle of the ion beam is shifted by 1 degree, the ion beam sensing device The detected current value will drop by about 5.2%. Therefore, the offset of the incident angle of the ion beam can be calculated from the decrease in the current value. However, the size of the cylindrical ion beam sensing device of the present invention is not limited to the size described above, and the above data is only one of the experimental data of the present invention. More specifically, it is known from experiments that if this cylindrical ion beam sensing device is made relatively slender, its sensitivity and degree can be increased. '' The method for detecting the deviation of the incident angle of the ion beam of the present invention uses a cylindrical j-shaped ion beam sensing device, so when the ion beam is shifted, part of the ion beam will be blocked by the side wall of the ion beam sensing device. When the current value measured by the bottom of the ion beam sensing device is small (that is, the number of ions detected is small), and then the current value sensed by this does not deviate from the incident angle of the ion beam By comparing the current values, the deviation angle of the ion beam can be calculated. Moreover, the method of the present invention uses an ion beam sensing device to directly detect an ion beam on one side of a wafer holding device (ie, an electrostatic chuck), so the relationship between the wafer holding device and the ion beam emission source can be actually reflected. . In addition, the method for detecting the deviation of the incident angle of the ion beam of the present invention does not need to modify the ion implantation device, and does not waste the wafer, so the cost can be saved. In addition, the method for detecting the deviation of the incident angle of the ion beam of the present invention is not

11689t.wf. Ptd Page 14 1220154 V. Description of the invention (ίο) Other auxiliary tools must be used to avoid affecting the accuracy of the measurement due to the errors of the auxiliary tools. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.

1 1689twf .pt.d Page 15 1220154 Brief description of the drawings Figures 1A to 1B are schematic diagrams of the V-curve detection method of the conventional technology. Figure 1C is a graph showing the relationship between the angle of inclination and the resistance value. ‘Figure 2 is a schematic diagram of the conventional technology activity corridor detection method. FIG. 3 is a schematic diagram of a detection device for deviation of an incident angle of an ion beam according to a preferred embodiment of the present invention. Figure 4A is a schematic diagram of an ion beam incident angle without shifting according to a preferred embodiment of the present invention. FIG. 4B is a schematic diagram of an ion beam incident angle deviation according to a preferred embodiment of the present invention. Figure 5 is the offset angle and current? Straight relationship diagram. [Illustration of drawing symbols] 1 0 0, 3 0 2: Wafer holding device 10 2 a, 10 2 b: Wafer 104, 204, 30 6 • Ion beam 2 0 0:: Faraday cup 2 0 2: : Obstacle 2 0 6 • 20 8: Obstacle movable 300 Ion emission source 304 Ion beam sensing device 308 Opening of wafer fixing device 3 10 Ion beam sensing device opening 400 Inductor 406a: No incident angle Offset ion beam

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Claims (1)

1220154 VI. Patent application: Beam implantation equipment is equipped with a fixed ion beam 3, and the second electrical offset 2. Method, 3. Method, 4. Method, Fixing device 5. Method, 6. Method, A method for detecting an incident angle deviation of an ion beam, which is applicable to an ion. The method includes: a beam sensing device is formed on one of the crystals of the ion beam implanting device, the ion beam sensing device is cylindrical, and the opening is directed to the emission source An ion beam sensing device is provided at the bottom of the ion beam sensing device, and a side-beam ion beam is directed toward the ion beam sensing device; the ion beam sensing device measures a first current value of the ion beam. The off-flow value is the same as the one in which the claim is made. The one in which the claim is made. The one in which the claim is made. The sub-beam sensing device for detecting the incident angle of the ion beam according to the first range of the change angle of the first current value measured by the ion beam sensing device is a Faraday cup. Detecting the angle of incidence of the ion beam as described in item 1 of the scope of interest. The circle fixing device includes an electrostatic chuck. The detection of the incident angle of the ion beam as described in the third item of the scope of interest is the opening of the sub-beam sensing device is set to a solid plane with the wafer. The sub-beam sensing device for detecting the incident angle of the ion beam described in the first item of the scope is cylindrical. Detecting the incident angle of the ion beam according to the first item of the scope of interest The sub-beam sensing device is a quadrangular tube. Ion beam implantation device for measuring incident angle of ion beam 11689twf.ptd Page 18 1220154 6. The scope of the patent application is prepared. The device at least includes: · an ion beam emission source for emitting the ion beam required for ion implantation; a wafer fixing device arranged at the ion beam emission The relative position of the source is used to fix a wafer; and an ion beam sensing device is disposed on one side of the wafer fixing device, the ion beam sensing device is cylindrical, and the opening faces the ion beam emission source, A sensor is arranged at the bottom of the ion beam sensing device to measure a current value of the ion beam. 8. The ion beam implantation device according to claim 7, wherein the ion beam sensing device includes a Faraday cup. 9 · Detectable incident angle of ion beam as described in item 7 of the scope of patent application Degree offset ion beam implantation equipment, wherein the wafer holding device includes an electrostatic chuck. 10. The ion beam implantation device capable of detecting an incident angle deviation of an ion beam according to item 9 of the scope of the patent application, wherein the opening of the ion beam sensing device and the opening of the wafer fixing device are coplanar. 1 1. The ion beam implantation device capable of detecting the deviation of the incident angle of the ion beam as described in item 7 of the scope of the patent application, wherein the ion beam sensing device is cylindrical. 1 2. The ion beam implantation device capable of detecting the deviation of the incident angle of the ion beam as described in item 7 of the scope of the patent application, wherein the ion beam sensing device is a quadrangular cylinder. ❿ 1 1689twf.ptd Page 19