JP2005174870A - Ion implantation method and ion implantation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion implantation method and an ion implantation device capable of preventing increase of the height of the device and the occupation area of the device, in an ion implantation device for executing ion implantation to a large substrate of 1 m to 2 m square. <P>SOLUTION: This ion implantation device 10 is provided with: an ion source 11 for generating an ion beam B1; beam deflection mechanisms 12 and 13 for changing the ion beam 11 into a ribbon-like ion beam B3; and a substrate scan mechanism 14 for moving a substrate 20 in a direction intersecting with the radiation direction of the ribbon-like ion beam B3. The ion beam B1 generated by the ion source 11 is changed into the ribbon-like ion beam B3 expanding nearly in the vertical direction by the beam deflection mechanisms 12 and 13, and the substrate 20 is moved nearly in the horizontal direction by the substrate scan mechanism 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to an ion implantation method and an ion implantation apparatus used for introducing impurities in a manufacturing process of a semiconductor element, a liquid crystal display device, and the like. More specifically, the present invention relates to an ion implantation method and an ion implantation apparatus that can perform ion implantation on a large substrate of 1 m to 2 m square and can suppress an increase in the height of the apparatus and the installation area of the apparatus.

  Flat display devices (FPDs) such as liquid crystal displays and organic electroluminescence (EL) are widely used for mobile phones, personal digital assistants, personal computer displays, large television screens, and the like. In recent years, this FPD has been used for large-sized televisions and tends to increase in size. From the viewpoint of improving productivity, a plurality of products are manufactured from a single substrate (mother glass substrate). It is becoming. Therefore, the size of the substrate in the manufacturing stage has been increased from several tens of cm square to 1 m to 2 m square.

  Of these FDPs, thin film transistors (TFTs) such as amorphous silicon TFTs and low-temperature polysilicon TFTs are used in the active type, which is expected to grow significantly in the future.

  In the process of manufacturing TFTs on this large substrate, impurities are introduced by ion implantation in order to control the properties of the semiconductor. As one of the ion implantation devices used for this ion implantation and using a high current wide beam, the ion source that generates a large amount of ions and the ion beam drawn from this ion source are expanded and deflected. And a mass magnet for converging, a decomposition slit that blocks inconvenient beams among the converged beams, and a second magnet that further deflects and collimates the beam that has passed through the decomposition slit, A small high-current wide-beam ion implantation apparatus that forms a highly uniform wide ribbon beam with an electric current of 1 mA or more and energy of several keV or more has been proposed (for example, see Patent Document 1).

  Further, when a large energy is required for ion implantation, as schematically shown in FIG. 3, a ribbon-like ion beam that spreads in a horizontal plane is generated, and the substrate is irradiated with the ribbon-like ion beam. An ion implantation apparatus has been proposed in which the substrate is moved in the vertical direction with respect to the horizontal beam (lateral beam) and ion implantation is performed on the entire surface of the substrate (see, for example, Patent Document 2 and Patent Document 3).

  However, in the method of scanning the substrate by moving the substrate in the vertical direction with respect to the horizontal beam while radiating the ribbon-like ion beam spreading in the horizontal plane as in the conventional ion implantation method, a space for moving the substrate up and down is used. Is required. Therefore, when the substrate is enlarged, the necessary apparatus height is remarkably increased due to the movement space of the substrate, the holding of the substrate, and the scanning mechanism.

  Therefore, when the height of the substrate reaches 1 m to 2 m, the height of the ion implantation apparatus becomes 4 to 6 m, and there arises a problem that the existing factory building having a height of 3 m to 4 m cannot be accommodated. The problem of the height of the ion implantation apparatus is a serious problem because it becomes necessary to design a special building when the building is remodeled or newly constructed when the height is higher than the normal factory building height.

  Also, regarding the depth of the ion implantation apparatus, when mass separation (mass analysis) of ions is performed between the horizontal distance from the outlet of the analyzer magnet to the substrate, a beam line of 3 m or more even when the beam width is 1 m. However, when the beam width is 2 m, a beam line of 6 m or more is required, and there is a problem that the space occupied by the ion implantation apparatus becomes very large if this distance is to be gained by a horizontal distance.

Furthermore, in the conventional ion implantation apparatus that moves the substrate in the vertical direction, when the substrate is enlarged to 1 to 2 m square, the substrate is held upright while the periphery of the substrate is held up and scanned in the vertical direction. (Scanning) That is, when reciprocating, there is a problem that a very thin substrate having a thickness of about 0.5 mm to 1.0 mm swells like a drum skin.
Japanese Patent Laid-Open No. 6-342639 Japanese Patent Laid-Open No. 11-163092 JP 2003-277771 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ion implantation apparatus for performing ion implantation on a large substrate having a size of 1 m to 2 m square. It is an object of the present invention to provide an ion implantation method and an ion implantation apparatus that can prevent an increase in the area occupied by the ion implantation.

  In order to achieve the above object, an ion implantation method of the present invention includes an ion source that generates an ion beam, a beam deflection mechanism that changes the ion beam into a ribbon ion beam, and an irradiation direction of the ribbon ion beam. In an ion implantation apparatus including a substrate scanning mechanism that moves a substrate in a crossing direction, the beam deflection mechanism changes the ion beam generated in the ion source into a ribbon-like ion beam that spreads in a substantially vertical direction, and A substrate scanning mechanism is used to move the substrate in a substantially horizontal direction.

  The ribbon-like ion beam that spreads in the vertical direction refers to a flat ion beam that has a thin ion beam shape in the horizontal direction, has a width in the vertical plane, and is irradiated in parallel.

  With this configuration, since the substrate is scanned in the horizontal direction, even if the size of the substrate is increased, the height of the apparatus does not have to be significantly increased as in the case of scanning the substrate in the vertical direction.

  In the ion implantation method described above, when the ion beam generated by the ion source is bent into an S shape by passing through two or more magnet portions and irradiated onto the substrate by the beam deflection mechanism, the trajectory of the ion beam The horizontal distance is reduced, and not only the height of the apparatus but also the depth of the apparatus is reduced.

  Further, in the above ion implantation method, the substrate scan mechanism tilts the substrate 5 ° to 30 ° rearward from the vertical direction, supports the back surface of the substrate with a support, and uses the beam deflection mechanism to provide a ribbon. When the substrate ion beam is deflected in a direction of 80 ° to 100 °, preferably perpendicular to the substrate, and irradiated on the substrate, the substrate swells when scanned or reciprocated. Flapping is prevented.

  When the above-described ion implantation method is used as a substrate manufacturing method, a manufacturing system having a relatively small height and depth is obtained.

  In addition, an ion implantation apparatus of the present invention for achieving the above object includes an ion source that generates an ion beam, a beam deflection mechanism that changes the ion beam into a ribbon-like ion beam, and irradiation of the ribbon-like ion beam. In an ion implantation apparatus including a substrate scanning mechanism that moves a substrate in a direction crossing the direction, the beam deflection mechanism is changed to a ribbon-like ion beam that expands an ion beam generated in the ion source in a substantially vertical direction. The substrate scanning mechanism is configured to move the substrate in a substantially horizontal direction. With this configuration, since the substrate is scanned in the horizontal direction, even if the size of the substrate is increased, the height of the apparatus does not have to be significantly increased as in the case of scanning the substrate in the vertical direction.

  In the ion implantation apparatus described above, the beam deflection mechanism is configured to have two magnet parts, and the trajectory of the ion beam generated from the ion source is passed through two or more magnet parts to form an S-shape. The substrate is configured to be bent into a shape and irradiated onto the substrate. According to this configuration, since the trajectory of the ion beam is S-shaped, the horizontal distance is shortened, and not only the height of the apparatus but also the depth of the apparatus is reduced.

  In the ion implantation apparatus, in the substrate scanning mechanism, the substrate is inclined 5 ° to 30 ° rearward from the vertical direction, and the back surface of the substrate is supported by a support. The substrate is configured to irradiate the substrate with the ion beam deflected in a direction of 80 ° to 100 °, preferably perpendicular to the substrate. This configuration prevents the substrate from bulging or fluttering when the substrate is scanned, that is, reciprocated.

  When the substrate manufacturing system is configured to include the above-described ion implantation apparatus, a compact manufacturing system having a small height and depth is obtained.

  According to the ion implantation method and the ion implantation apparatus of the present invention, impurities can be stably introduced into a large substrate, and the height of the apparatus and the depth of the apparatus can be reduced. In other words, in the conventional ion implantation apparatus that vertically moves the substrate, the height of the building becomes a problem in order to insert the device, and a special building design is required for remodeling or new building. In the ion generator of the invention, the influence of the increase in the size of the substrate on the height of the apparatus can be remarkably reduced by rotating the relationship between the ion beam and the substrate by 90 degrees from the conventional horizontal beam / longitudinal movement to the vertical beam / lateral movement. .

  Also, if the ion beam generated by the ion source is bent into an S shape by passing through two or more magnet parts and irradiated onto the substrate, the horizontal distance of the trajectory of the ion beam is shortened. In addition, the depth of the apparatus can be reduced.

  Therefore, there is no problem of restriction on the size of the building, particularly the height when installing the ion implantation apparatus, and transportation is facilitated.

  Furthermore, the substrate is inclined 5 ° to 30 ° backward from the vertical direction, and the back surface of the substrate is supported by a support, and in the beam deflection mechanism, the ribbon-like ion beam is directed in the direction of 80 ° to 100 ° with respect to the substrate. In addition, when the substrate is preferably deflected in the vertical direction and irradiated onto the substrate, it is possible to prevent swelling and fluttering when scanning a substrate that is very thin compared to the size and has an unstable shape.

  Embodiments of an ion implantation method and an ion implantation apparatus according to the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, an ion implantation apparatus 10 of this embodiment includes an ion source 11 that generates an ion beam B1, and a beam deflection mechanism that mass-separates the ion beam B1 and changes the ion beam B1 into a ribbon-like ion beam B3. 12, 13, a multipole (uniform control mechanism) 14 for adjusting to a desired ion current density distribution, and an arbitrary angle (hereinafter referred to as substantially vertical) close to perpendicular to the irradiation direction of the ribbon-like ion beam B3, for example , And a substrate scanning mechanism 15 that scans (scans) a substrate (a wafer in a semiconductor and a glass substrate in a liquid crystal) 20 in a horizontal direction at 80 ° to 100 °.

  The ion source 11 is configured to extract and accelerate an ionized impurity supplied from a gas source (not shown) by an extraction electrode to which an acceleration voltage (for example, 10 to 100 kV) is applied to form an ion beam B1. Is done.

  In addition, the beam deflection mechanisms 12 and 13 are formed by a mass separation magnet unit 12 and a vertically long parallel beam that expands the ion beam B2 selected by the mass separation magnet unit 12 in the vertical direction and has a narrow horizontal width. And a converging magnet part (collector magnet part) 13 for changing to a ribbon-like ion beam B3.

  The magnet part 12 for mass separation deflects the ion beam B1 from the ion source 11 by approximately 90 ° and passes only the ion beam B2 having a predetermined mass through the decomposition slit, thereby allowing ions having a light mass or heavy ions to pass. Excluded, only ions having a predetermined mass are selected and taken out, and a flat ion beam B2 that is thin in the horizontal direction and has a width in the vertical plane is configured. The range of the mass to be passed is preset by the opening width of the decomposition slit.

  The converging magnet unit 13 is a device for deflecting and collimating the beam. Here, the ion beam B2 is deflected by approximately 70 ° to be a parallel beam, and is configured to be a ribbon-like ion beam B3. The ribbon-like ion beam B3 is thin in the first direction (thickness) where the ion beam shape in the portion irradiated on the substrate 20 is substantially perpendicular to the irradiation direction, and the second ion beam B3 is substantially perpendicular to both the first direction and the irradiation direction. It is a flat ion beam that is long in the direction (width) and irradiated in parallel, and has a rectangular or line-shaped cross section, and each cross section has the same shape.

  The ribbon-like ion beam B3 can be applied to the substrate 20 substantially vertically. Since the substrate 20 is held at an inclination angle α with respect to the vertical direction, the ion beam B3 is configured to have an angle of attack α with respect to the horizontal plane.

  In the present invention, the beam deflection mechanisms 12 and 13 are divided into a mass-separation magnet unit 12 that specializes in mass separation and a beam called a collector to form a ribbon-like beam. An ion beam B1, B2 is formed by two magnet parts of a converging magnet part 13 for guiding the beam B3 to a target (substrate), and passing the ion beam B1 generated from the ion source 11 through both magnet parts 12,13. , B3 trajectory is bent into an S-shape to irradiate the substrate 20.

  By dividing the function of this magnet and having the two magnet sections 12 and 13 share the roles of mass separation and beam widening, both high ion implantation quality and beam widening can be realized. Further, since the trajectory of the ion beam is bent twice into an S shape, the height of the beam lines B1, B2, B3 is suppressed. Therefore, it is not necessary to increase the height of the ion implantation apparatus 10, and the depth of the ion implantation apparatus 10 is shortened, so that space is saved.

  This double magnet system also enables higher resolution of ion species to be implanted, so that it can handle higher performance of low-temperature polysilicon TFT panels in parallel with support for large substrates. It becomes a device.

  The multipole (uniform control mechanism) 14 is formed by arranging a plurality of sets (for example, 15 sets) of small electromagnets on the left and right. Then, the ribbon-like ion beam B3 formed by the converging magnet unit 13 is allowed to pass, and the excitation current to the coil of each small electromagnet is controlled to be adjusted to a predetermined ion current density distribution, so that ion implantation is made uniform. Plan.

  The substrate scanning mechanism 15 is configured to have a substrate holding function that holds the substrate 20 tilted backward (tilt back) so as to be substantially perpendicular to the irradiation direction of the ribbon-like ion beam B3. The In this embodiment, the substrate scanning mechanism 15 is further configured to have a substrate scanning function for scanning the substrate 20 in the horizontal direction, and is disposed in the process chamber (end station) 16.

  In the substrate scanning mechanism 15, the support 15 b grips the periphery of the substrate 20 and supports the back surface of the substrate 20. The support 15b is formed of a flat plate, a lattice plate, a perforated plate or the like, and is supported by a support bracket 15d via a hinge 15c. The support bracket 15d is fixed to a support bed 15e.

  An example of the support 15b is shown in FIG. 4, and this support 15b has a frame 15ba and a back surface agent 15bb, and is used to hold the periphery of the substrate 20 on the front of the frame 15ba. Claws (gripping members) 15bc are arranged at substantially equal intervals. The claw 15bc holds and supports 2 to 3 mm on the inner side from the edge of the substrate 20 (not shown in FIG. 4) that contacts the frame body 15ba from the front surface. Further, the back member 15bb is formed in a cross-girder structure having an opening for weight reduction, and the weight balance is taken by the position and size of the opening. Further, support pins 15bd are planted at the intersections of the cross beams, and the back surface of the substrate 20 is supported by substantially point contact with the tip portions of the support pins 15bd.

  The support 15b has an inclination angle α from the vertical direction so as to be substantially perpendicular to the irradiation direction of the ribbon-like ion beam B3 irradiated in parallel, that is, the edge B3a of the ribbon-like ion beam B3. The angle is adjusted to incline to the rear side. The inclination angle α is 5 ° to 30 °, preferably 15 ° to 25 °.

  Thus, by holding the substrate 20 with an inclination angle α of 5 ° or more while supporting the back surface with the support 15b, the thin and unstable substrate 20 can be stably supported, and the substrate 20 swells during substrate scanning. Flapping etc. can be avoided.

  Further, by keeping the inclination angle α holding the substrate 20 small within 30 °, in order to prevent dust from adhering to the substrate 20, a mechanism or dust generation is likely to occur on the substrate 20. Although a space in which no object is arranged is taken, this space can be reduced, and a useless space in the ion implantation apparatus can be reduced.

  The support bed 15e is placed on the rail 15f and is configured to reciprocate in the horizontal direction by the drive motor 15g. The rail 15f is provided in the horizontal direction and in a direction substantially perpendicular to the irradiation direction of the ribbon-like ion beam B3. Further, the support bed 15e is provided on the rail 15f so that the entire surface of the substrate 20 can be irradiated with the ribbon ion beam B3. The drive motor 15g is precisely controlled to achieve uniform ion implantation.

  Note that the rail 15f is not necessarily limited to a straight line as long as the irradiated portion of the substrate 20 is substantially perpendicular to the irradiation direction of the ribbon-like ion beam B3. You may form in. For example, the substrate 15 may be rotated by forming the rail 15f in an arc shape having a center in the irradiation direction of the ribbon-like ion beam B3. However, when the substrate is moved in a straight line, the substrate is less deformed than when the substrate is moved in a curved line.

  Further, a profiler (not shown) for checking the uniformity of the ribbon-like ion beam B3 is disposed in the immediate front portion (?) Of the substrate 30 held by the substrate scanning mechanism 15, and the ion current density distribution of the ribbon-like ion beam B3. The multipole 14 and the substrate scanning mechanism 15 are controlled while feeding back the measurement result, and the ion implantation is made uniform.

  The path along which the ion beams B1, B2, and B3 pass is covered with a case 17, and is evacuated with a high displacement vacuum pump (not shown) to maintain a high vacuum.

  And in the ion implantation apparatus 10 of this structure, ion implantation is performed as follows.

  The substrate 20 is held by the substrate scanning mechanism 15 and the substrate 20 is accommodated in the process chamber 16. The inside of the process chamber 16 is evacuated by a vacuum pump, and the inside of the process chamber 16 and the inside of the case 17 surrounding the path through which the ion beams B1, B2, and B3 pass are kept in vacuum.

  In a state where an appropriate degree of vacuum is reached, impurity ions are generated while applying a high voltage to the extraction electrode of the ion source 11, and the ion beam B1 is extracted. By bending the extracted ion beam B1 by approximately 90 ° by the mass separation magnet unit 12 to be an ion beam B2 spreading in the vertical direction, only the ion beam B2 having a predetermined mass range is allowed to pass through the decomposition slit. Excluding light ions, heavy ions, etc., only ions with a predetermined mass are used.

  The ion beam B2 is bent by about 50 ° to 70 ° by the focusing magnet unit 13 and is converted into a ribbon-like ion beam B3 which is a parallel beam. The ribbon-like ion beam B3 is adjusted to a predetermined ion current density distribution in the multipole 14 and then irradiated onto the substrate 20.

  On the other hand, the substrate scanning mechanism 15 holding the substrate 20 is reciprocated in the horizontal direction with respect to the irradiated ribbon-like ion beam B3 to scan the substrate 20.

  The scanning of the substrate 20 is performed by detecting the ion current density distribution of the ion beam B3 by a profiler and ions by a dose monitor (not shown) installed on the inner surface of the process chamber 16 that always receives the ion beam B3 on the back side of the substrate 20. Based on the current value of the beam B3, the beam is controlled to be an appropriate ion implantation amount together with the beam homogenization control of the multipole 14.

  According to the above ion implantation method and ion implantation apparatus, since the substrate 20 is moved in the horizontal direction without moving in the vertical direction (vertical direction), the height of the ion implantation apparatus 10 can be reduced.

  Also, by bending the ion beam trajectory twice into an S-shape, the height of the beam line can be suppressed, which eliminates the need to increase the height of the ion implanter 10 and shortens the horizontal distance of the ion beam. Therefore, the depth of the ion implantation apparatus 10 can be shortened, and a space saving apparatus can be obtained.

  And, by separating the functions of the magnet, the double magnet system configuration in which the two magnet sections share the roles of mass separation and beam widening, respectively, it is possible to further increase the resolution of ion species to be implanted. It is possible to achieve both high ion implantation quality and wide beam. Therefore, in parallel with the response to a large substrate, it is possible to cope with further enhancement of performance of a low-temperature polysilicon TFT panel that requires high ion implantation quality.

1 is a schematic side view showing a configuration of an ion implantation apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the irradiation direction of the ribbon-shaped ion beam which concerns on this invention, and the scanning direction of a board | substrate. It is a schematic diagram which shows the irradiation direction of the ribbon-shaped ion beam in a prior art, and the scanning direction of a board | substrate. It is a perspective view which shows an example of the structure of the support body of a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ion implantation apparatus 11 Ion source 12 Magnet part for mass separation (beam deflection mechanism)
13 Convergence magnet (beam deflection mechanism)
14 Multipole 15 Substrate scanning mechanism 15b Support 20 Substrate B1 Ion beam B2 Ion beam B3 Ribbon ion beam

Claims (8)

  Ions having an ion source that generates an ion beam, a beam deflection mechanism that changes the ion beam into a ribbon-like ion beam, and a substrate scanning mechanism that moves the substrate in a direction that intersects the irradiation direction of the ribbon-like ion beam In the implantation apparatus, the ion beam generated by the ion source is changed into a ribbon-like ion beam expanding in a substantially vertical direction by the beam deflection mechanism, and the substrate is moved in a substantially horizontal direction by the substrate scanning mechanism. Ion implantation method.   2. The ion implantation method according to claim 1, wherein the beam deflection mechanism irradiates the substrate with an ion beam generated by the ion source being bent into an S shape by passing through two or more magnet portions.   With the substrate scanning mechanism, the substrate is inclined 5 ° to 30 ° backward from the vertical direction, and the back surface of the substrate is supported by a support, and the ribbon ion beam is made to the substrate with the beam deflection mechanism. The ion implantation method according to claim 1, wherein the substrate is irradiated with the light deflected in a direction of 80 ° to 100 °.   The manufacturing method of the board | substrate using the ion implantation method of any one of Claims 1-3.   Ions having an ion source that generates an ion beam, a beam deflection mechanism that changes the ion beam into a ribbon-like ion beam, and a substrate scanning mechanism that moves the substrate in a direction that intersects the irradiation direction of the ribbon-like ion beam In the implantation apparatus, the beam deflection mechanism is configured to change the ion beam generated by the ion source into a ribbon-like ion beam that spreads in a substantially vertical direction, and the substrate scanning mechanism is moved in a substantially horizontal direction. An ion implantation apparatus characterized by being configured as follows.   The beam deflection mechanism is configured to have two magnet parts, and an ion beam trajectory generated from the ion source is bent into an S shape by passing through two or more magnet parts to irradiate the substrate. The ion implantation apparatus according to claim 5.   In the substrate scanning mechanism, the substrate is inclined 5 ° to 30 ° rearward from the vertical direction, and the back surface of the substrate is supported by a support, and in the beam deflection mechanism, a ribbon-like ion beam is applied to the substrate. The ion implantation apparatus according to claim 5 or 6, wherein the substrate is irradiated with the light deflected in a direction of 80 ° to 100 °. A substrate manufacturing system comprising the ion implantation apparatus according to claim 5.

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