KR20090108059A - Ion implanting apparatus - Google Patents

Abstract

An ion implanting apparatus (10) is provided with an ion source (22) for generating an ion beam; a beam shaping section (20) for shaping the beam into a strip-like beam; a beam transporting section (30) which focuses the strip-like ion beam by thinning the beam in the thickness direction and then irradiates a substrate (62) to be processed with the beam; a processing section (60) which irradiates the substrate (62) with the strip-like ion beam; and a lens element (40) which adjusts current density distribution wherein a total value of the current densities of the strip-like ion beam in the beam thickness direction is shown by distribution inthe beam width direction. The lens element (40) is arranged in a region in the vicinity of an ion beam focusing position (52) for adjusting the current density distribution of the ion beam. The current density distribution is accurately adjusted by finely bending a part of the strip-like ion beam within the strip-like ion beam surface.

Description

Ion implantation device {ION IMPLANTING APPARATUS}

This invention relates to the ion implantation apparatus which irradiates a band ion beam to a process target substrate, and performs ion implantation.

Today, the process of performing ion implantation using an ion implantation apparatus is actively performed with respect to the glass substrate or semiconductor substrate used for a flat-panel display apparatus using a liquid crystal system or an organic LED. In particular, in order to efficiently and accurately perform ion implantation on a large substrate, it is required to use a band-shaped ion beam in which the width of the ion beam irradiated with respect to the width of the substrate is wide and the current density distribution is controlled to a desired distribution. have.

By using a band-shaped ion beam in which the beam width of the ion beam is wider than the width of the substrate, the region in the width direction of the substrate can be processed at one time. As a result, the entire substrate can be ion implanted at once, resulting in increased efficiency.

On the other hand, since the band-like ion beam processes the same position in the width direction of the substrate in a direction orthogonal to the width direction, when the current density distribution of the band-shaped ion beam is not uniform in the width direction, ion implantation is unevenly performed on the substrate. The part which appears is shown in a linear form, and an accurate ion implantation process cannot be performed. For this reason, it is desired to accurately adjust the band-shaped ion beam so as to have a desired current density distribution.

Patent Literature 1 below describes an ion implantation apparatus that scans an ion beam with respect to a sample by shaping a band-shaped ion beam and moving a sample, which is an irradiated object, with respect to the ion beam. It is. In this apparatus, a longitudinally elongated band-like ion beam is generated at an ion source, the band-shaped ion beam generated from the ion source is passed through a mass spectrometer passage, and thereafter, only an ion species having a desired number of masses is passed. The sample is irradiated with an ion beam passing through a slit that blocks other mass species of ionic species. At that time, the sample is moved in the direction orthogonal to the wide longitudinal direction of the band-shaped ion beam, and ion implantation of the sample is performed.

Moreover, the position detector for irradiating the distribution of an ion beam is provided.

Similarly, the following ion implantation apparatus is described in following patent document 2. As shown in FIG. That is, in the apparatus, a large-area ion beam having a longitudinally long cross section is generated from the magnetic shielded ion source, and the ion beam is directed at 90 degrees in the short side direction by a window-frame magnet. Bend equally so as to form a near large center angle, unnecessary ions are removed through a slit plate having a longitudinally long opening, and an ion beam is irradiated to a sample translating in the beam short side direction.

Further, Patent Literature 3 below describes the following ion implantation apparatus. That is, in this apparatus, a sheet-shaped ion beam containing a desired ion species and wider than the short side width of the substrate is generated from the ion source, and the sheet-shaped ion beam is removed by the mass separation magnet. The desired ionic species are selected and derived by bending in a direction orthogonal to the sheet surface. At that time, the desired ionic species is selected and passed through in cooperation with the mass separation magnet using a separation slit. Thereafter, in the irradiation region of the ion beam passing through the separation slit, the substrate is reciprocally driven in a direction substantially perpendicular to the sheet surface of the ion beam to perform ion implantation.

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-302706

[Patent Document 2] Japanese Patent Laid-Open No. 11-126576

[Patent Document 3] Japanese Patent Laid-Open No. 2005-327713

However, in Patent Documents 1 to 3, the current density distribution of the ion beam is measured by using a position detector that examines the distribution of the band ion beam described in Patent Document 1, and according to the result, the current density of the band ion beam. Even if the distribution was adjusted, there was a problem that a good adjustment was not always possible.

That is, the adjustment is performed by making a part of the band-shaped ion beam bent small in the plane of the band-shaped ion beam to compensate for the current density of the part with the low current density. In order to bend a portion of the band-shaped ion beam in the plane of the band-shaped ion beam, an electric field or a magnetic field is used in a region of the portion of the ion beam. At this time, for example, in the case of the electric field, the electric field has a gradient in the in-plane direction of the band-shaped ion beam, and in the case of the magnetic field, it is necessary for the magnetic field to have a magnetic field component perpendicular to the plane of the band-shaped ion beam. However, since the band-shaped ion beam at this time has a thickness, and the electric field and the magnetic field are three-dimensionally distributed, the thickness of the band-shaped ion beam becomes uneven under the influence of the components of the electric field and the magnetic field which are not necessary for the bending. For this reason, the sorting performance at the time of sorting the desired ionic species in the separating slit is lowered, and furthermore, only the part of the band-shaped ion beam to be bent is wrongly removed so that the separating slit is removed. Ion implantation with an ion beam of non-uniform current density distribution. In this way, it is not possible to bend the portion of the band-shaped ion beam small enough in the desired direction.

In recent years, the ion implantation is required to further control the implantation angle of the ion beam and to control the temperature. However, the nonuniformity in the thickness of the band-shaped ion beam is further difficult to manage.

Thus, in order to solve the above problem, the present invention adjusts the current density distribution to a good degree by bending a portion of the band-shaped ion beam within the plane of the band-shaped ion beam, for example, to adjust the current density distribution to a good and uniform degree. It is an object of the present invention to provide an adjustable ion implantation apparatus.

In order to achieve the above object, the present invention is an ion implantation apparatus for irradiating a band-shaped ion beam having a beam width wider than the width of the substrate to be processed to ion implantation, and to generate an ion beam. A beam shaping unit having a circle and shaping the generated ion beam into a band-shaped ion beam, a processing unit for irradiating the band-shaped ion beam to a substrate to be processed, and band-shaped ions orthogonal to the direction of the beam width of the band-shaped ion beam The mass separation magnet which bends the traveling direction of the band-shaped ion beam so as to have a curvature in the thickness direction of the beam, and the total value of the current density in the thickness direction of the band-shaped ion beam is expressed by the distribution of the beam width direction. An adjustment unit for adjusting the current density distribution of the band-shaped ion beam, and reducing the thickness in the band direction by reducing the thickness in the thickness direction of the band-shaped ion beam. After converging the on beam, the beam transport unit guides the band ion beam to the processing unit, and the thickness of the band ion beam is greater than the thickness of the band ion beam when passing through the mass separation magnet. The adjustment unit is arranged so as to adjust the current density distribution of the band-shaped ion beam in a region near the convergence position of the band-shaped ion beam which is thinned.

At that time, the mass separation magnet converges the band-shaped ion beam in the thickness direction and is provided with a separation slit for passing predetermined ion particles to the location where the convergence is performed, and the adjustment unit is provided with a position of the separation slit. It is preferable to be installed at the overlapped position or the adjacent position.

Moreover, it is preferable that the said adjustment unit is comprised by the magnet provided in the pair in the thickness direction on both sides of the said strip | belt-shaped ion beam in the said width direction, and the said separation slit is comprised with the nonmagnetic substance.

Alternatively, the adjustment unit is constituted by electrodes formed in pairs on both sides of the band-shaped ion beam in the thickness direction and provided with a plurality of pairs along the width direction, and provided adjacent to the position of the separation slit. It is also similarly preferable that the side of the adjacent separation slit be provided with an electric shield that shields an electric field formed by the electrode.

The beam shaping unit includes a plurality of ion sources for generating the band-shaped ion beams, and the plurality of ion sources to converge the band-shaped ion beams generated from these ion sources at one point in the thickness direction of the ion beam. The adjustment unit is also preferably in a form in which the adjustment unit is arranged so as to adjust the current density distribution of the ion beam in a region near the position converged at the one point.

Effect of the Invention

In the ion implantation apparatus of the present invention, after the band-shaped ion beam is converged by thinning the thickness in the thickness direction of the band-shaped ion beam, the band-shaped ion beam is irradiated onto the substrate to be treated. At this time, the adjustment unit adjusts the current density distribution of the ion beam in the region near the converging position of the ion beam, in which the thickness of the band ion beam is thinner than the thickness of the band ion beam passing through the mass separation magnet. Therefore, the magnetic field component and the electric field component acting on the thin band-shaped ion beam have a substantially constant value in the thickness direction of the ion beam, and the value is also at the center position in the beam thickness direction of the band-shaped ion beam. Is close to the value of. For this reason, each part of the beam thickness direction in a strip | belt-shaped ion beam can be bent at the same angle in the same direction under the action of a constant magnetic field. For this reason, adjustment of the current density distribution of an ion beam with high precision, for example, a uniform current density distribution can be performed. In addition, since the current density distribution of the ion beam is adjusted in a region where the thickness of the ion beam is thin, the electric field and the magnetic field component which are not necessary for the deflection of the ion beam are small. For this reason, the nonuniformity of the thickness of a strip | belt-shaped ion beam falls compared with the former.

1 is a plan view of an ion implantation apparatus, which is an embodiment of the ion implantation apparatus of the present invention.

FIG. 2 is a side view of the ion implantation apparatus shown in FIG. 1.

(A) is a top view of the lens element of the other form used instead of the lens element used for the ion implantation apparatus shown in FIG. 1, (b) is a figure explaining the inside of the lens element shown to (a) .

It is a top view of the ion implantation apparatus of a different form from the ion implantation apparatus of this invention shown in FIG.

<Explanation of symbols for the main parts of the drawings>

10 ion implantation apparatus 20 beam shaping portion

22, 22a, 22b, 22c: ion source 24, 24a, 24b, 24c: ion beam

25a, 25b, 25c, 25d: stage 30: beam transport unit

32: mass separation magnet 34: yoke

36: stimulation 37: stimulation cross section

38: coil 40, 90: lens element

42: York 44: electromagnet

46: stimulation 48: coil

49, 52: procedure position 50: separation slit

54: border 60: processing unit

62 processing substrate 64 Faraday Cup

80 control unit 82 measuring instrument

84 controller 86 power

91 electrode 92 terminal

93: insulated terminal 94: support

95a, 95b: shield electrode 110: vacuum housing

EMBODIMENT OF THE INVENTION Hereinafter, the ion implantation apparatus of this invention is demonstrated in detail based on the suitable Example shown by an accompanying drawing.

1 is a plan view of an ion implantation apparatus 10 that is an embodiment of an ion implantation apparatus of the present invention. 2 is a side view of the ion implantation apparatus 10.

The ion implantation apparatus 10 includes, in order from the upstream side of the ion beam, a beam shaping section 20 having an ion source, a beam transport section 30 having a mass separation magnet and an adjusting unit, and a substrate to be processed (hereinafter, And a processing unit 60 for implanting ions into the processing substrate) and a control unit 80. The beam shaping section 20, the beam transport section 30, and the processing section 60 are surrounded by a vacuum housing (not shown) to maintain a constant vacuum degree (10 ^-5 to 10 ^-3 Pa) by a vacuum pump.

In the present invention, the side of the ion source is called the upstream side and the side of the process substrate is called the downstream side based on the flow of the ion beam that proceeds from the ion source toward the processing substrate.

The beam shaping portion 20 has a small ion source 22. The ion source 22 is a portion for generating an ion beam, and a Bernas-type or Freeman-type plasma generator is used, and the ion beam is emitted from the small ion source 22. Is pulled out. In the Bernard-type ion source, a filament and a reflecting plate are provided in a metal chamber, and a magnet is provided outside. The gas containing the atom used for ion implantation is supplied into the metal chamber in the vacuum of this ion source 22, an electric current flows through a filament, and a hot electron is discharged, and it reciprocates between the reflecting plates provided in the both sides of a metal chamber. In this state, arc discharge is generated by applying a predetermined arc voltage to the metal chamber, thereby ionizing the gas supplied into the metal chamber, thereby generating a plasma. The ion beam 24 is radiated from the metal chamber by drawing the generated plasma out of the extraction hole provided in the side wall of the metal chamber using the extraction electrode.

The ion source 22 of the present embodiment generates an ion beam that diverges using a small ion source. In the present invention, in addition to the small ion source, it may be configured to generate a substantially parallel band-shaped ion beam having a substantially constant beam width from a large ion source. In addition, the ion beam may be generated by a plurality of ion sources.

Since the generated ion beam 24 continuously changes from the low current density region near the end of the ion beam to the high current density region that becomes the main region of the ion beam, the current density continuously changes. The boundary is not clear. However, in the present invention, the line of the ion beam 24 is determined by using the portion where the current density near the end of the ion beam exceeding a predetermined value as the end of the ion beam.

The ion beam generated from the ion source 22 diverges at the stages 25a and 25b of the ion beam as shown in FIG. 2, but also at the stages 25c and 25d of the ion beam as shown in FIG. 1. The degree of divergence at only 25c and 25d of the beam is low. The difference in the degree of divergence of the ion beam can be determined by the shape of the extraction hole of the ion source 22 and the configuration of the extraction electrode.

The cross-sectional shape of the ion beam thus produced has a smaller shape, i.e., a band, in which the beam thickness, which is the length between the ends 25c and 25d of the ion beam, is smaller than the beam width, the length between the ends 25a and 25b of the ion beam. The beam width of this ion beam is shaped so as to have a beam width wider than the horizontal width of the processing substrate.

In addition, since the ion beam is a flow of particles having a positive charge, as shown in FIG. 1, only 25c and 25d of the band-shaped ion beam reaching the processing unit 70 are repulsive forces due to the charge of the ion beam. Divergence is indicated by the action of However, in this invention, it is applicable in this invention whether a diverging ion beam or a convergent ion beam is applicable.

The ion beam 24 generated by the ion source 22 becomes a band and advances to the beam transport part 30.

The beam transport section 30 has a mass separation magnet 32, a lens element 40 and a separation slit 50. The beam transporter 30 narrows the thickness of the ion beam 24 in the beam thickness direction (thickness direction between only 25c to 25d in FIG. 1) and converges the ion beam 24, and then the ion beam 24. Is irradiated to the processing substrate of the processing unit 60.

As shown in FIG. 2, the mass separation magnet 32 has a pair of magnetic poles 36 facing each other inside the rectangular cylindrical structure formed of the yoke 34 and the magnetic poles 36. ) Is an electromagnet formed by winding the coil 38 around it. The coils 38 are connected in series so that the magnetic fields generated by the pair of magnetic poles 36 are in the same direction, and are connected to a power source (not shown) to supply current.

As can be seen from the trajectories of stages 25c and 25d of the ion beam shown in FIG. 1, the ion beam 24 becomes a slightly diffused ion beam 24 and enters the mass magnet 32. The ion beam 24 passes between the pair of magnetic poles 36, and the traveling direction of the ion beam 24 is bent so as to have a curvature in the thickness direction of the band-shaped ion beam, and thus the position of the separation slit to be described later. It is structured to process in.

The inwardly facing surface between the pair of magnetic poles 36 is partially inclined, and by changing and adjusting the inclined position, a complex continuous such as a continuous surface or a torus surface of a cylindrical surface having different curvatures. It is composed of curved surfaces. Moreover, it is comprised so that a part of magnetic pole 36 may operate and the angle which the magnetic pole cross section 37 of both sides with respect to the ion beam 24 makes is adjusted. In addition, a field clamp may be provided in the mass separation magnet 32 that extends beyond the coil 38 from the yoke 34 to the ion beam 24. In addition, the shape of the coil 38 may be adjusted to have a desired ion beam shape.

The ion beam 24 which has passed through the mass separation magnet 32 has a current density difference of not more than a constant under the influence of the plasma density of the ion source 22 and the magnetic fields of the lead electrode and the mass separation magnet 32 which are not shown. For example, the plasma density, the voltage of the lead electrode and the magnetic field of the mass separation magnet 32 are adjusted to be 5% or less. This ion beam 24 is reduced by the lens element 40 which will be described later, so that the current density gap is reduced to about 1%.

Here, the current density of the ion beam is an integrated value, that is, the sum total of the integration of the current density along the thickness direction of the ion beam 24, that is, the beam thickness direction, which is the direction of the length between the ends 25c and 25d of the ion beam. to be. The gap of the current density is the deviation width of the current density distribution, which is a distribution in the beam width direction of the current density (the longitudinal direction between only 25a to 25b in FIG. 2), for a distribution (for example, a uniform distribution) to be targeted. The degree of the standard deviation is referred to, and more specifically, the difference of 1% or less means that the ratio of the standard deviation of the deviation width to the value of the average current density is 1% or less.

In addition, in the present invention, the current density distribution may be a non-uniform desired distribution in addition to the uniform distribution. For example, in order to intentionally change the amount of ion implantation depending on the location in accordance with the unevenness of the thin film formed by the CVD method or the like on the processing substrate 62, the uneven distribution aiming at the current density distribution is performed. It may be adjusted.

The lens element 40 bends a part of the band-shaped ion beam 24 in the direction of the beam width in the plane of the band-shaped ion beam 24, so that the ion beam 24 is in the beam width direction. Adjusting unit for adjusting the current density distribution. The lens element 40 is disposed in an area near the converging position 52 of the ion beam, in which the thickness of the ion beam 24 is thinner than the thickness of the ion beam 24 passing through the mass separation magnet 32. In this region, the current density distribution of the ion beam 24 is adjusted.

In the lens element 40, the electromagnets 44 are paired to the yokes 42 on both sides with the ion beams 24 interposed therebetween, and a plurality of the magnets are arranged in the beam width direction of the ion beams 24. It is. These electromagnets 44 are provided at symmetrical positions on both sides with respect to the center plane in the beam thickness direction of the band-shaped ion beam 24. The electromagnet 44 is composed of a magnetic pole 46 made of electromagnetic soft iron and a coil 48 wound around the magnetic pole 46, and the electromagnet 44 of one side of the paired electromagnet 44 is rotated. The lines of the coils 48 are connected in series to the pair of electromagnets 44 so that the magnetic field to be made is directed to the other electromagnet 44. In this way, a plurality of sets of opposing pairs of electromagnets 44 are provided on the yoke 42 so as to traverse the entire beam width. The number of pairs of electromagnets 44 is about 10-20.

In addition, the lens element 40 shown in FIGS. 1 and 2 is an example, It is not limited to this. Since the ion beam 24 is adjusted to some extent by the ion source 22 and the extraction electrode which is not shown of the ion source 22, and also the mass separation magnet 32 to become close to a predetermined current density distribution, Adjustment by the lens element 40 may be a smooth adjustment. For this reason, the generation of the magnetic field by the lens element 40 is also gentle.

In addition to the adjustment using the magnetic field, the lens element 40 may also adjust the ion beam 24 using the full length as described later. However, from the following points, it is preferable that the lens element 40 uses a magnetic field. That is, the characteristic that the ion beam 24 itself tries to diverge by the repulsive force between positive charges in the ion beam 24 causes electrons which move around the ion beam 24 unevenly and unevenly at low speed. However, the lens element 40 preferably uses a magnetic field so as not to have a large influence on the electrons.

A separation slit 50 is provided between the electromagnets 44 that make up the pair of lens elements 40. Although not shown in FIG. 2, the separation slit 50 is composed of a nonmagnetic member provided with thin elongated holes (slits) to traverse ends 25a and 25b of the ion beam 24. The ion beam 24 bent at the mass separation magnet 32 converges at the convergence position 52 in the beam thickness direction on the downstream side of the mass separation magnet 32, but at the convergence position 52, the separation slit 50 is formed. ) Is provided to pass only ionic particles having a predetermined mass and charge. That is, the separation slit 50 is provided at the convergence position 52 where the ion beam 24 converges in the beam thickness direction, and the lens element 40 is provided at the position overlapped with the separation slit 50. have.

Since the ion particles which do not have a predetermined mass and charge in the ion beam 24 do not converge at the converging position, they collide with the wall surface of the separation slit 50 and the movement to the downstream side is prevented. For this reason, it is necessary for the separation slit 50 to use the material which has tolerance to the abrasion by the collision of an ion particle, For example, graphite is used suitably. Since the collision of the ion particles has an inclination angle with respect to the vertical and the wear is intense when colliding with the wall surface, the separation slit 50 preferably has a shape such that the ion particles collide substantially perpendicularly to the wall surface. .

In the separation slit 50, at the time of collision of the ion particles, a part of the material of the separation slit 5 receives the collision energy of the ion particles and physically scatters as particles, and becomes a gas by vaporization by heat. At this time, since the beam transport section 30 is in a low pressure atmosphere, the scattering may spread linearly. For this reason, it is necessary to determine the shape of the separation slit 50 so that the part where an ion particle collides is not seen from a process board | substrate so that material components, such as scattered particle | grains and gas, may not reach a downstream process board | substrate. For example, as shown in FIG. 1, the edge 54 which has a collision surface with a large area is provided in the part which the ion particle of the upstream side of the separation slit 50 collides, and by this edge 54 This prevents the scattering material component from reaching the processing substrate. Further, the ion particles collide with the inner wall surface of the hole of the separation slit 50 through which the ion beam 24 passes, so that the scattering material component does not directly reach the processing substrate even if the ion particles collide with the inner wall surface. The surface to be made is a shape which cannot be seen from a process board | substrate. It is preferable that a shape is a saw-shaped uneven | corrugated shape which has a 90 degree stepped surface inclined to an upstream, for example.

The separation slit 50 needs to be nonmagnetic so as not to affect the magnetic field produced by the lens element 40. Furthermore, the separation slit 50 may be arranged so that the separation slit 50 and the lens element 40 are adjacent to each other without being superimposed at the position of the lens element 40.

As described later, when the lens element 90 is used instead of the lens element 40 to adjust the ion beam 24 using the electric field, it is difficult to select a material that does not affect the electric field, and the separation slit ( In consideration of the fact that a conductive film is deposited on the surface of 50 to affect the electric field, the lens element 90 is preferably disposed adjacent to the separation slit 50. In this case, since the separation slit 50 needs to be disposed at the converging position 52 of the ion beam 24, the lens element 90 is disposed adjacent to the separation slit 50.

Furthermore, although the opening width of the slit in the thickness direction of the ion beam 24 of the separation slit 50 may be fixed, it is preferable that it can be adjusted variably. The opening width of the slit can be adjusted in accordance with the amount of ions to be implanted into the processing substrate and in accordance with the necessity of implantation of ions with high purity, whereby the separation performance of the ion particles can be appropriately adjusted. In addition, the thickness of the ion beam 24 in the converging position 52 may be made thinner by about 10 mm, while the trajectory of the ion beam 24 may vary the type of ions, the energy of the ion beam, and the ion particles. Influenced by an electric charge, it is not always constant. For this reason, it is preferable that the opening width of a slit can be adjusted with context.

The ion beam 24, which is composed of only predetermined ion particles separated from unnecessary ion particles in the separation slit 50 and whose current density distribution is adjusted in the lens element 40, advances to the processing unit 60 while increasing the beam thickness. Goes.

The processing unit 60 includes a moving mechanism (not shown) that performs ion implantation while transferring the processing substrate 62 from the lower side to the upper side in FIG. 1, and the Faraday cup 64 that measures the current density distribution of the ion beam 24. Has

The processing substrate 62 is exemplified by a semiconductor wafer or a glass substrate. The beam width of the ion beam 24 is wider than the width of the processing substrate 62 as shown in FIG. 2 by the adjustment by the mass separation magnet 32.

In addition, the ion beam 24 irradiated to the process board | substrate 62 inclines below in the figure so that a position may fall as it progresses to the process board | substrate 62 of a downstream side as shown in FIG. This is maintained by gravity from the back of the processing substrate 62 due to the base (not shown) of the processing substrate 62, and the ion beam 24 is applied to the processing substrate 62. It is to be incident vertically with respect to. The holding of the processing substrate 62 from the back is because a holding mechanism such as a clamp jig cannot be provided on the front surface of the processing substrate 62 exposed to the ion beam.

When the process board | substrate 62 is a glass plate, many board | plates of one side are 1 m square and 0.5 mm in thickness, and it is easy to bend easily. Furthermore, since processing for a fine circuit element etc. is provided in the front surface of a glass plate, in order to avoid that a minute dust and particle adhere, it cannot contact with the process surface side by a clamp etc. Therefore, as shown in FIG. 2, it is preferable to incline the process board | substrate 62 and to hold | maintain from the back surface using gravity.

The Faraday cup 64 is provided in the downstream side of the arrangement position of the processing board 62. The Faraday cup 64 is provided in multiple numbers in the range larger than the beam width of the ion beam 24 in the beam width direction. The length of the beam thickness direction of the surface receiving the ion beam 24 of each Faraday cup 64 is longer than the beam thickness of the ion beam 24, and the current density distribution along the beam thickness direction of the ion beam 24. It is configured so that the total value of is measured at one time. In the beam width direction, a plurality of Faraday cups 64 are arranged adjacent to each other. Therefore, in the beam width direction, the total value of the current density is measured discretely at each position of the Faraday cup 64.

The Faraday cup 64 has a cup part which receives an ion particle, and the secondary electron trap mechanism not shown. The secondary electron trapping mechanism is a trapping mechanism that prevents secondary electrons generated by collision of ion particles on the inner surface of the Faraday cup 64 to leak out of the Faraday cup 64. This is because when secondary electrons leak out of the Faraday cup 64, an error is caused in the measurement of the current density. The secondary electron capture mechanism may use any of the capture functions using the electric field in addition to the capture function using the magnetic field.

The number of Faraday cups 64 may be increased as necessary. If the measurement accuracy is increased, the number of Faraday cups 64 may be increased. Although the number of Faraday cups 64 is preferably about 100 in order to measure the difference of several percent of the current density, the adjustment of the ion beam 24 from the current density distribution is good enough even if the number of Faraday cups 64 is about 100. I can do it.

Faraday cup 64, as shown in Fig. 1, 2, in addition to the form of a plurality of lines, a single Faraday cup in the beam width direction of the ion beam 24, from the end to the end to move across the position and current density You may measure in pairs. In this method, it can measure to a good extent only by using one Faraday cup.

The processing unit 60 according to the present embodiment moves the processing substrate 62 in the vertical direction to perform ion implantation. However, in the present invention, in addition to this, the processing substrate is moved in an arc shape or in the disk shape. It may also be a method of irradiating an ion beam by rotating it and placing it on a thing. In the case of circular arc motion or rotational motion, since the radius of rotation is different at the place, each position of the processing substrate moves with respect to the ion beam. Therefore, in order to perform uniform ion implantation, it is necessary to adjust the current density distribution of an ion beam in consideration of the movement of each position of a process board | substrate.

In addition, each of the Faraday cups 64 shown in FIG. 1, 2 is connected with the measuring device 82 in the control part 80, and the total value of the current density measured by each Faraday cup 64 is the measuring device 82 Is sent to.

The control unit 80 has a measuring instrument 82, a controller 84, and a power source 86.

The measuring instrument 82 is a part which calculates a current density distribution using the data sent from each Faraday cup 64. The result of the obtained current density distribution is a part of the controller 84 that determines, together with the current value, which current to flow in the coil 48 of the electromagnet 44 of which lens element 40. The position of the electromagnet 44 to which electric current should flow, and its current value may be comprised so that it may be set automatically by the controller 84, and an operator may input it manually. Further, for each pattern of the current density distribution, the information on the position of the electromagnet 44 to which current should flow and its current value are stored in a memory (not shown), and the information may be sequentially called and set. It's okay.

The power supply unit 86 is a portion for supplying current to the corresponding electromagnet 44 based on the position and current value of the electromagnet 44 determined by the controller 84. As a result, the position and current value of the electromagnet 44 to be made to flow the current are determined, and the current is allowed to flow through the electromagnet 44 so as to correspond to the position corresponding to the electromagnet 44 in the ion beam 24. Thus, the current density distribution can be adjusted by bending the moving direction of the ion particles by the magnetic field.

In the ion implantation apparatus 10 as described above, the ion beam 24 generated by the ion source 22 is shaped into a band-shaped ion beam 24 having a wide beam width in the mass separation magnet 32. In the separation slit 50, only the ion beam 24 made of ion particles having a predetermined mass and charge passes and is supplied to the processing unit 60. In the processing unit 60, ion implantation is performed in the processing substrate 62, but the current density of the ion beam 24 is measured in the Faraday cup 64 before the ion implantation, and the current density distribution is obtained in the measuring instrument 82. . If this current density distribution is not the desired distribution, the controller 84 determines which electromagnet 44 of the lens element 40 is allowed to flow the current, and based on this determination, the power source 86 Silver is supplied to the electromagnet 44 which determined the electric current.

On the other hand, since the lens element 40 is provided near the convergence position of the ion beam 24, the beam thickness of the ion beam 24 passing through the lens element 40 passes through the mass separation magnet 32. When compared with the beam thickness of the ion beam 32 at the time of making it thinner. Since the lens element 40 creates a magnetic field in the vicinity of the converging position 52 where the beam thickness is thin, the magnetic field component acting on the thinner ion beam 24 is approximately in the thickness direction of the ion beam. With a constant value, the value is also close to the value at the center position in the beam thickness direction of the ion beam 24. For this reason, each part of the beam thickness direction in the ion beam 24 is bent at the same angle in the same direction under the action of a constant magnetic field. For this reason, the current density distribution of the ion beam with high precision can be adjusted.

As described above, in the present invention, since the thickness of the ion beam 24 acting on the magnetic field produced by the lens element 40 is thin, the component of the magnetic field to be bent in the beam width direction is the thickness direction in the ion beam 24. Irrespective of the position of the ion beam 24, the ion beam at a desired position in the beam width direction in the ion beam 24 can be bent as desired. Therefore, the current density distribution of the ion beam 24 can be adjusted to a good extent.

In addition, in the said embodiment, although the lens element 40 is the adjustment of the ion beam 24 using the magnetic field by the electromagnet 44, as shown to (a), (b) of FIG. The ion beam 24 may be adjusted.

FIG. 3A is a plan view of the lens element 90 used in place of the lens element 40, and FIG. 3B is a view for explaining the inside of the lens element 90. As shown in FIG.

The lens element 90 is provided on the downstream side of the convergence position 52 of the ion beam 24.

In the present invention, the lens element 90 is located near the converging position 52 of the ion beam, which is thinner than the beam thickness of the ion beam 24 passing through the mass separation magnet 32 located on the upstream side. In the area, the current density distribution of the ion beam should be provided so as to be adjusted, and as shown in Figs. 3A and 3B, they are provided at positions adjacent to the position of the separation slit 50.

The lens element 90 is connected to the terminal 92 on the outside of the vacuum housing 110 and the support 94 on the inner side through the insulating introduction terminal 93, and has an electrode on the front end side of the support 94. 91 is provided. The terminal 92 is connected to the power source 86 of the control unit 80 shown in FIG. 1. As shown in FIG. 3B, the pairs of the electrode 91, the terminal 92, the insulating terminal 93, and the support 94 are beam widths from only 25a to 25b of the ion beam 24. A plurality of rows are arranged in the direction. Corresponding to the electrode 91, a plurality of electrodes 91 having the same structure are arranged in the beam width direction at symmetrical positions on the opposite side with the ion beam 24 interposed therebetween. The number of electrodes 91 is about 10-20, similarly to the number of pairs of electromagnets 44 in the lens element 40 mentioned above.

The same voltage of the same pole of DC voltage is applied to the electrode 91 of the lens element 90, and the electric field which is linearly symmetrical with respect to the center plane of the beam thickness direction of the ion beam 24 between the electrodes 91 is created. For example, the positive voltage is applied to the electrode 91, and the ion beam 24 adjusts the current density of the ion beam by using the deflections on both sides of the electric field so as to avoid the electric field.

As illustrated in FIGS. 3A and 3B, shield electrodes 95a and 95b are placed on the upstream side and the downstream side of the lens element 90 from the vacuum housing 110. The shield electrodes 95a and 95b are provided at positions symmetrical with respect to the electrode 91, and the electric field produced by the lens element 90 is applied to the ion beam 24 outside the region of the lens element 90. Shield the battlefield so it doesn't affect you.

The shape of the cross section 56 on the downstream side of the separation slit 50 is processed in the same shape as that of the shield electrode 95a, and extends to the inner surface of the vacuum housing 110, thereby similar to the shield electrode 95a. It can also have the function of. At this time, it is preferable to provide the shield electrode 95b at a position symmetrical with the position of the end face 56 of the separation slit 50 with the electrode 91 as the center.

Furthermore, this invention may comprise the ion implantation apparatus shown in FIG.

The ion implantation apparatus 100 shown in FIG. 4 is similar to the ion implantation apparatus 10 shown in FIG. 1, and includes a beam shaping portion 20, a beam transport portion 30 including a mass separation magnet and an adjustment unit. And a processing unit 60 for implanting ions into the processing substrate and a control unit 80. The beam shaping section 20, the beam transport section 30, and the processing section 60 are surrounded by a vacuum housing (not shown) to maintain a constant vacuum degree (10 ^-5 to 10 ^-3 Pa) by a vacuum pump.

The beam transport unit 30 has a mass separation magnet 32, a lens element 40, and a separation slit 50, and the processing unit 60 carries the ions while conveying the processing substrate 62 from the lower side in FIG. 4 to the upper side. It has a moving mechanism (not shown) which performs implantation, and a Faraday cup 74 which measures the current density distribution of the ion beam 24. Since the lens element 40 differs only in the point provided in the upstream side of the mass separation magnet 32, and the structure of each part other than this is the same, description is abbreviate | omitted.

In addition, the lens element 40 may adjust the ion beam 24 using a magnetic field, and may adjust using the full length as shown to FIG. 3 (a), (b). .

On the other hand, the beam shaping section 20 has ion sources 22a, 22b and 22c having a plurality of similar performances, and the ion beams 24a to 24c generated from these ion sources 22a to c are positioned ( Each ion source 22a-22c is arrange | positioned so that it converges in 49). The lens element 90 adjusts the ion beam in the region near the position 49. That is, in the ion implantation apparatus 100, since the ion beam 24 converges on the upstream side of the mass separation magnet 32, adjustment of an ion beam can be made very favorable in the region near the position 49. FIG. have.

In this case, since the lens element 40 and the separation slit 50 are separated, the magnetic field or the electric field made of the lens element 40 does not affect the separation slit 50, It is advantageous in that there are no restrictions such as materials. Furthermore, when trying to bend the ion beam at a predetermined position in the beam width direction by using the lens element 40, the distance from the lens element 40 to the processing substrate 62 is long. The degree of adjustment of the current density distribution by this is also small and does not have an extra influence on the ion beam 24. In addition, since the current supplied to the lens element 40 is also low, in addition to the lens element 40 itself, the capacity of the power source 86 may also be small, thereby reducing the manufacturing cost.

As mentioned above, although the ion implantation apparatus of this invention was demonstrated in detail, this invention is not limited to the said Example, A various improvement and modification may be made in the range which does not deviate from the main point of this invention. Of course.

Claims (5)

It is an ion implantation apparatus which irradiates a to-be-processed board | substrate with an ion beam by irradiating the strip | belt-shaped ion beam which has a beam width larger than the width | variety of this process target substrate, A beam shaping part including an ion source for generating an ion beam, and shaping the generated ion beam into a band-shaped ion beam; A processing unit for irradiating the band-shaped ion beam to a substrate to be processed; Mass separation magnet which bends the traveling direction of the band-shaped ion beam so as to have a curvature in the thickness direction of the band-shaped ion beam perpendicular to the direction of the beam width of the band-shaped ion beam, and the current in the thickness direction of the band-shaped ion beam. An adjustment unit for adjusting the current density distribution of the band-shaped ion beams in which the total value of the density is expressed by the distribution in the direction of the beam width, and converging the band-shaped ion beams by thinning the thickness in the thickness direction of the band-shaped ion beams. (Iv), and has a beam transport section for directing the band-shaped ion beam to the processing section, To adjust the current density distribution of the band-shaped ion beam in the region near the converging position of the band-shaped ion beam, in which the thickness of the band-shaped ion beam becomes thinner than the thickness of the band-shaped ion beam when passing through the mass separation magnet. And the adjustment unit is disposed. The method of claim 1, The mass separation magnet is provided with a separation slit for converging the band-shaped ion beam in the thickness direction and passing predetermined ion particles at a position where the convergence is performed. And the adjustment unit is provided at a position overlapping with or in a position overlapping with the position of the separation slit. The method of claim 2, The said adjustment unit is comprised by the magnet provided in the pair in the said width direction by making a pair in the both sides of the said thickness direction of the said strip | belt-shaped ion beam, The separation slit is an ion implantation device composed of a nonmagnetic material. The method of claim 2, The adjustment unit is constituted by pairs on both sides of the band-shaped ion beam in the thickness direction and constituted by electrodes provided with a plurality of pairs along the width direction, and are provided adjacent to the position of the separation slit, The said adjustment unit is an ion implantation apparatus provided with the electric field shield which shields the electric field formed by the said electrode in the adjoining side of the said separation slit. The method of claim 1, The beam shaping unit includes a plurality of ion sources for generating the band-shaped ion beams, and arranges the plurality of ion sources to converge the band-shaped ion beams generated from these ion sources at one point in a thickness direction of the ion beam. Doing The adjustment unit is an ion implantation device in which the adjustment unit is arranged to adjust the current density distribution of the ion beam in a region near the position converged at the one point.

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