JPH08287863A - Ion implantation device - Google Patents

Abstract

PURPOSE: To improve the efficiency of an ion beam, and realize uniform implantation of ions over the whole surface of a board. CONSTITUTION: An ion beam of a large cross sectional surface extended from a beam extension electrode system 6 of an ion source 1 is implanted on a subjected board 14 of a rectangular form without mass separation. Each electrode in the extension electrode system is a multi-slit electrode by slits 18, and its cross sectional surface gives rectangular beams to the board. Strength of the beams on the board pulsates corresponding to a slit disposition pitch of the multi-slit electrode. By vibrating the subject board at a similar vibration width to the slit disposition pitch, strength of the beams on the board is equalized, and ions can be uniformly implanted to the whole surface of the board. When the beam strength gas pulsive distribution components of an integer- multiplication of twice or more the slit disposition pitch, the board vibration width is set to be similar to the integer-multiplication of the slit disposition pitch, where an integer (n)>=2, thereby the pulsation distribution components, and pulsive distribution components for each slit disposition pitch can be equalized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for injecting an ion beam, which is extracted from a beam extraction electrode system of an ion source and has a large cross section, into a substrate to be injected without mass separation.
The present invention relates to an ion implanter with improved utilization efficiency.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a device for implanting ions into a substrate to be implanted with an ion beam having a large cross-section, for example, an ion implanter for forming a thin film transistor (TFT) array as a drive circuit of a liquid crystal device. is there. The plasma generation chamber 2 in the high-frequency ion source 1 has a cylindrical container member 3 and a high-frequency flange member 4 attached to the cylindrical container member 3 via an insulating material.
The tubular container member and the high frequency flange member are connected to the high frequency power source 5. The beam extraction electrode system 6 of the ion source is composed of a plasma electrode (plasma grid) 7, an extraction electrode 8, a suppression electrode 9 and a ground electrode 10 in the case of, for example, four electrodes, and the plasma electrode is a cylindrical container member 3. At the same time, the accelerating power supply 11 biases it to a positive potential, the extraction electrode is biased to a negative potential with respect to the plasma electrode by the extraction power supply 12, and the suppression electrode is biased to a negative potential by the suppression power supply 13. The ion beam extracted from the beam extraction electrode system 6 is injected into the injected substrate 14 without mass separation.

Each electrode in the extraction electrode system 6 is shown in FIG.
As shown in (a), it is composed of a multi-hole electrode having a large number of holes 15 through which a beam passes in the xy plane.
The plasma distribution in the plasma generation chamber 2 of the ion source is uniform over the entire beam extraction surface, so that the beam intensity finally obtained from each hole 15 of the ground electrode 10 is equal. The beam from each hole of the ground electrode spreads and reaches the substrate 14 to be injected. However, since the holes are provided at intervals, the centers of the rows of holes in FIG. The beam intensity i on the surface of the substrate to be injected corresponding to the position of the passing x-axis pulsates as shown in FIG. 7 (a). Therefore, the substrate to be injected 14 is held by the rotation / holding mechanism 16, and the substrate to be injected is rotated to make the injection amount D in the arbitrary radius r direction from the center of the substrate uniform as shown in FIG. 7B. ing.

[0004]

An ion beam extracted and accelerated from the extraction electrode system 6 has a substantially circular cross section so that ions can be injected into the entire surface of the substrate by rotating the substrate 14 to be injected. In this respect, even in the hole arrangement of the multi-hole electrode shown in FIG. 6A, the beam cross section is almost circular as a whole, but in order to make the cross section more circular, the outermost hole in the multi-hole electrode is formed. There is also one that is placed on the circumference. On the other hand, the injected substrate 1
In the case of the glass substrate of the liquid crystal device, 4 is a rectangle, and as shown in FIG. 7B, the beam cross-section portion with hatching in the circular cross-section 17 of the ion beam is wasted.

An object of the present invention is to provide an ion implantation apparatus which eliminates such a wasteful portion of the ion beam and improves the utilization efficiency of the ion beam.

[0006]

According to the present invention, an ion beam extracted from a beam extraction electrode system of an ion source and having a large cross section is implanted into a rectangular substrate to be implanted without mass separation. The injection apparatus is provided with a beam extraction electrode system having a multi-slit electrode, and a mechanism for vibrating a substrate to be injected with a vibration width of about the slit arrangement pitch of the multi-slit electrode. .

Since the intensity of the beam extracted from the multi-slit beam extraction electrode system and reaching the substrate to be injected has a pulsating distribution with the slit arrangement pitch as a period, the substrate to be injected is vibrated with a vibration width of about the slit arrangement pitch. By doing so, the beam intensity on the substrate is averaged, and the ion implantation amount on the entire surface of the substrate to be implanted is made uniform.

The present invention further provides a multi-slit electrode for an ion implantation apparatus for implanting an ion beam having a large cross section extracted from a beam extraction electrode system of an ion source into a rectangular substrate to be implanted without mass separation. And a mechanism for vibrating the substrate to be injected with a vibration width of an integer multiple (where integer n ≧ 2) of the slit arrangement pitch of the multi-slit electrode. It is a thing.

When the intensity of the beam reaching the substrate to be implanted has a pulsation distribution component that is an integral multiple of twice or more the slit arrangement pitch, the oscillation width of the substrate to be injected is an integer multiple of the slit arrangement pitch (where integer n ≧ 2) By setting it to about
Since the pulsation distribution component having the beam intensity is averaged, and the pulsation distribution component of one slit arrangement pitch can be averaged, the ion implantation amount on the entire surface of the substrate to be implanted can be made uniform.

[0010]

Embodiments of the present invention will be described with reference to the drawings. 1A is a configuration diagram of the embodiment, FIG. 1B is a plan view of a multi-slit electrode in a beam extraction electrode system, and the same reference numerals as those in FIGS. The plasma generation chamber 2 in the high frequency ion source 1 is formed of a cylindrical container member 3 and a high frequency flange member 4 attached to the cylindrical container member 3 via an insulating material. In the case of the four-electrode system, the beam extraction electrode system 6 of the ion source is composed of a plasma electrode 7, an extraction electrode 8, a suppression electrode 9 and a ground electrode 10.

Each electrode in the beam lead-out electrode system 6 is formed as a multi-slit electrode in which a plurality of slits 18 are formed in parallel, as shown in the plan view of FIG. 1 (b). The intensity of the ion beam extracted from each slit 18 in the multi-slit electrode of the beam extraction electrode system 6 is uniform in the slit longitudinal direction because the plasma density distribution in the plasma generation chamber 2 is uniform. The intensity of each ion beam extracted from each slit is also uniform. The ion beam extracted from each of these slits is injected into the entire surface of the injection target substrate 14.

The beam from each slit 18 in the ground electrode 10 spreads in the direction of the adjacent slit and reaches the substrate 14 to be injected, and this reaching beam has a cross section that can greatly reduce the unused portion. Although it is a rectangular beam, the beam intensity i in the y-axis direction, which is the slit arrangement pitch direction in the substrate 14 to be injected, is as shown in FIG. 2 because the slits are arranged at intervals. Pulsates. Therefore, by vibrating the implantation target substrate 14 in the y-axis direction by the holding / vibrating mechanism 19, the beam intensity on the substrate is averaged and ions are uniformly implanted into the entire surface of the substrate.

The beam intensity i is pulsatingly distributed with the slit arrangement pitch as a period. Therefore, by oscillating the substrate to be injected with a vibration width Δy corresponding to the slit arrangement pitch, actually, with a vibration width of about the slit arrangement pitch, the beam intensity with respect to the substrate to be injected 14 is averaged, and the injection amount on the entire surface of the substrate to be injected is Can be made uniform. This is because the pulsation distribution of the beam intensity is affected by the processing accuracy of the slits 18 and the arrangement pitch thereof, and the vibration width of the implanted substrate is designed so that the ion implantation amount on the entire surface of the substrate is made uniform. This is due to the fact that there is an adjustment range for the slit arrangement pitch.

From the viewpoint of the design of the ion source 1 and the beam extraction electrode system 6 having the multi-slit electrodes, the pulsation distribution period of the beam intensity i should basically correspond to the slit arrangement pitch. As a result of measurement, it may have a pulsation distribution component that is an integral multiple of twice or more the slit arrangement pitch. The reason for this is not clear at present, but for example, the processing precision of the slit 18 and its arrangement, the electrodes of the beam extraction electrode system are arranged with a gap, and the electrode system and the substrate to be implanted are arranged. It can be understood that the influence of the distance interval of 1 and the beam emitted from each slit are uniform, but some non-uniformity exists.

When the beam intensity i has a pulsation distribution component which is an integral multiple of the slit arrangement pitch (where integer n ≧ 2), the vibration width of the substrate 14 to be injected is also an integral multiple of the slit arrangement pitch. The degree. This allows
Since the pulsation distribution component having the beam intensity is averaged, and also the pulsation distribution component of one slit arrangement pitch can be averaged, the ion implantation amount on the entire surface of the implanted substrate 14 can be made uniform.

3A and 3B are structural views of the holding / vibrating mechanism 19 for the substrate 14 to be injected. FIG. 3A is a sectional view and FIG. 3B is a plan view seen from the line AA in FIG. It is a figure. The substrate 14 to be injected is attached to the substrate holder 20 using the substrate pressing member 21. The substrate holder 20 is attached to an arm member 23 extending from the support block 22,
The support block is supported by two vibration guide rods (shafts) 25 via sliding bearings 24 attached to the side surfaces. Both ends of the vibration guide rod 25 are fixed to frame plates 26 and 26 ', and these guide rods and frame plates form a vibration support frame for the substrate holder 20 and the support block 22.

A hollow tilt shaft 27 is connected to one frame plate 26. A bearing member 29 that pivotally supports the tilt shaft 27 is attached to the vacuum chamber 28, and the tilt shaft 27 is rotatably supported by bearings 30 arranged at two positions of the bearing member. A hollow vibration drive shaft 31 is coupled to the support block 22 by a mounting flange portion 31 ′. The vibration drive shaft is a frame plate 26 and a tilt shaft 27.
And extends outside the tilt axis. The bellows 3 is provided between the frame plate 26 and the flange portion 31 ′ of the vibration driving shaft 31.
2 is provided so that the tilt shaft 27 and the vibration drive shaft 31 can relatively move under a vacuum sealed state.

A supporting member 33 is attached to an end of the vibration driving shaft 31, and a guide shaft 35 is slidably supported by a sliding bearing 34 attached to the supporting member. The end portion of this guide shaft is fixed to the side surface of the operation portion 27 'by the belt pulley of the tilt shaft 27. Also, the support member 3
A screw shaft 37 for vibration driving is screwed into the screw bearing 36 provided on the third shaft 3. One end of this screw shaft is rotatably attached to the operating portion 27 ′ of the tilt shaft 27, and the other end is It is connected to the vibration motor 38. The motor has a guide shaft 34.
It is supported by a fixing member 39 attached to the tilt shaft 27 and moves integrally with the tilt shaft 27.

By repeating the required forward and reverse rotations of the vibration driving screw shaft 37 by the vibration motor 38, the supporting member 33 is moved in the left and right direction, and the hollow vibration driving unit to which the supporting member 33 is connected is driven. The support block 22 of the substrate holder 20 vibrates through the shaft 31 with a required vibration width Δy.

The angle of incidence of the ion beam on the substrate 14 to be implanted can be adjusted by rotating the hollow tilt shaft 27 with the operating portion 27 '. The heat generated by the substrate 14 during ion implantation is generated by the substrate holder 20.
It is removed by flowing cooling water through the passage provided inside,
Cooling water is supplied to this passage through a pipe provided in the hollow vibration drive shaft 31.

As slits of the multi-slit electrode in the beam extraction electrode system 6, a large number of holes 40 are arranged in two rows adjacent to each other as shown in FIG. By arranging with the pitch shifted, it is possible to equivalently form one slit 41. Since the cooling water passage can be provided between the adjacent equivalent slits 41, the electrode can be easily cooled even when the beam is drawn out from the hole.

Since the beam intensity on the substrate to be injected has a pulsating distribution also depending on the lateral arrangement interval of the holes 40, in the case of the equivalent slit 41, the vibration width for one slit arrangement pitch with respect to the substrate to be injected is as shown in FIG. As shown in FIG. 4 (b), each hole has a vertical and horizontal arrangement of Δy in the diagonal direction, and the vibration width of the substrate to be injected has the same slit arrangement as that of the multi-slit electrode of FIG. 2 (b) described above. By setting the pitch to be about an integer multiple of the slit arrangement pitch (where integer n ≧ 2), the ion implantation amount on the entire surface of the substrate to be implanted can be made uniform.

[0023]

Since the present invention is configured as described above, by vibrating the substrate to be implanted with a vibration width of about the slit arrangement pitch of the multi-slit electrode, the ions are made uniform over the entire surface of the rectangular substrate to be implanted. Since the implantation can be performed, the utilization efficiency of the ion beam can be significantly improved as compared with the case where the substrate to be implanted is rotated. As the beam utilization efficiency improves, it becomes possible to reduce the power supply capacity required for extracting and accelerating the ion beam, and these power supply devices are reduced in price and downsized, which in turn lowers the cost of the ion implantation device as a whole. , Enables miniaturization.

By setting the vibration width of the substrate to be injected to an integer multiple of the slit arrangement pitch (where integer n ≧ 2),
Even when the intensity of the beam reaching the substrate to be injected has a pulsation distribution component that is an integral multiple of twice the slit arrangement pitch, the pulsation distribution component can be averaged and one slit arrangement is performed. Since the pulsation distribution component of the pitch can also be averaged, the ion implantation amount on the entire surface of the substrate to be implanted can be made uniform and the utilization efficiency of the ion beam can be improved as compared with the case of rotating the substrate to be implanted. it can.

[Brief description of drawings]

1A is a configuration diagram of an embodiment, and FIG. 1B is a plan view of a multi-slit electrode in a beam extraction electrode system.

FIG. 2 Pulsation of beam intensity i and vibration amplitude Δ of the injected substrate
It is a relationship explanatory view with y.

3A and 3B are configuration diagrams of a holding / vibrating mechanism with respect to a substrate to be injected 14, where FIG. 3A is a sectional view and FIG.
It is the top view which looked down from the -A line.

4A is a configuration diagram of an electrode equivalently forming a slit by a hole, and FIG. 4B is an explanatory diagram of vibration of a substrate to be injected.

FIG. 5 is a configuration diagram of a conventional ion implanter using a beam having a large cross section.

6A is a configuration diagram of a multi-hole electrode in a conventional beam extraction electrode system, and FIG. 6B is an explanatory diagram of a cross-sectional shape of a large-area beam and a shape of a substrate to be implanted.

FIG. 7 is an explanatory diagram showing an example of beam intensity and implantation amount characteristics in a conventional ion implantation apparatus.

[Explanation of symbols]

 1 High-Frequency Ion Source 6 Beam Extraction Electrode System 14 Injected Substrate 19 Retaining / Vibrating Mechanism of Injected Substrate 20 Substrate Holder 22 Support Block 24 Sliding Bearing 25 Vibration Guide Rod 26, 26 'Frame Plate 27 Hollow Tilt Shaft 28 vacuum chamber 29 bearing member 31 vibration drive shaft 33 support member 35 guide shaft 37 vibration drive screw shaft 38 vibration motor 40 hole 41 equivalent slit

Claims (2)

[Claims] 1. An ion implantation apparatus for implanting an ion beam having a large cross section extracted from a beam extraction electrode system of an ion source into a rectangular substrate to be implanted without mass separation, and a beam having a multi-slit electrode. An ion implantation apparatus comprising a frame extraction electrode system and a mechanism for vibrating the substrate to be implanted with a vibration width of about the slit arrangement pitch of the multi-slit electrodes. 2. An ion implanter for implanting an ion beam having a large cross-section extracted from a beam extraction electrode system of an ion source into a rectangular substrate to be implanted without mass separation, and a beam having a multi-slit electrode. An ion implantation apparatus comprising: a frame extraction electrode system; and a mechanism for vibrating the substrate to be implanted with a vibration width of an integer multiple of the slit arrangement pitch of the multi-slit electrodes (where integer n ≧ 2). .