JPH0713659B2 - Charged particle distribution measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charged particle distribution measuring apparatus, for example, a charged particle distribution measuring apparatus used in an ion mixing apparatus, an ion implantation apparatus, etc. The present invention relates to a charged particle distribution measuring device that measures a two-dimensional distribution of a large-area beam with high resolution without using beam deflection.

[Conventional technology]

For example, when performing high-current / large-area ion implantation on a semiconductor, it is important to have uniformity on the implantation surface of the ion beam.

As a simple method to measure this current density distribution, there is a method of irradiating a fluorescent substance with an ion beam and measuring from the light emission, but it is difficult to measure with high accuracy, and the deterioration and consumption of the fluorescent substance due to the ion beam Is a big problem.

Another method to measure the current distribution of the beam is to move or rotate a thin metal wire up and down, left and right, and measure the distribution from the current flowing into the metal wire (Wire Beam Probe method such as JG Siekman). etc: New
microprobe techniques for measuring the current d
istribution in an electron beam used for welding; J
There is ournal of Physics 1975 Vol.8). However, this method is limited to the measurement of only the relative current density distribution because secondary electrons are emitted from the metal line during ion irradiation.

On the other hand, the following is a conventional example having a secondary electron suppressing electrode capable of measuring the absolute amount of the beam.

9 and 10 are schematic diagrams of a conventional charged particle distribution measuring apparatus shown in page 275 of "Electron / Ion Beam Handbook" and a portion for detecting a beam current (hereinafter referred to as a Faraday cage portion). ) Is a configuration cross-sectional view of FIG.

In the figure, reference numeral (1) is an entrance diaphragm plate which is a particle passage member having a plurality of through holes, and (2) is a recoil particle trapping member having a through hole at the same position as the entrance diaphragm plate (1). Secondary electron suppressing electrode, (3) is a collector electrode which is a cylindrical tubular particle trapping member arranged behind the through hole of the entrance diaphragm plate (1) and the secondary electron suppressing electrode (2), and (4) is a plurality of collector electrodes. An insulating plate (5) for structurally defining the position of the collector electrode (3) and electrically insulating each collector electrode (3).
Is a measuring terminal bolt for mechanically fixing the collector electrode (3) and the insulating plate (4), (8) is a charged particle beam, (7)
Is a vacuum chamber that shuts off the vacuum atmosphere of the above device from the atmosphere,
(8a) is a lead wire which is connected to the secondary electron suppression electrode (2) and gives a negative potential to the secondary electron suppression electrode (2) from a power source (not shown), and (8b) is connected to the measurement terminal bolt (5). Connected,
The measurement line connected to the current measuring device is omitted in the figure.

Next, the operation of the above conventional device will be described.

When the charged particle beam (6) comes from a charged particle source (not shown in the figure) and reaches the entrance diaphragm plate (1), charged particles other than the through holes collide with the entrance diaphragm plate (1). Only the charged particle beam (6) at the position of the through hole which is stopped passes through the entrance diaphragm plate (1).

The charged particles passing through the entrance diaphragm plate (1) pass through the secondary electron suppressing electrode (2) and collide with the collector electrode (3),
It is measured by a current measuring device in the atmosphere through the measuring terminal bolt (5) and the measuring wire (8b).

The current distribution of the charged particle beam (6) at the position of the entrance diaphragm plate (1) fixedly arranged on the two-dimensional plane is measured by comparing the measured current values flowing from the respective collector electrodes (3).

[Problems to be Solved by the Invention]

Since the conventional charged particle distribution measuring apparatus is configured as described above, the resolution in the two-dimensional space of this charged particle distribution measuring apparatus depends on the distance between the holes of the entrance diaphragm plate (1), that is, the distance between the collector electrodes (3). Being limited,
There is a problem that the resolution cannot be improved due to these mechanical constraints, and there is a problem to solve such a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a charged particle distribution measuring apparatus capable of increasing the resolution in a two-dimensional space.

[Means for Solving the Problems]

The charged particle distribution measuring device according to the present invention is. According to the first aspect of the present invention, there are provided a particle passage member having a plurality of through holes provided on a plane intersecting with the orbits of the charged particles and having a plurality of through holes parallel to the orbits, and the charged particles having passed through the through holes of the particle passage members. A particle capturing part having a particle capturing member for capturing, and a moving part for moving the particle capturing part in an arbitrary direction within the plane, and in the second invention, The particle trapping member is provided in each of the holes of the insulating plate which is provided on a plane intersecting with the trajectory of the charged particles and has a plurality of holes penetrating in the trajectory direction.

[Action]

Since the present invention is configured as described above, in the first invention, the particle capturing portion moves due to the movement, and therefore the hole of the particle passage member can also move, so that the space between the through hole and the through hole. The charged particle beam current amount at the position of is also measured, and as a result, it is possible to measure with high resolution.

Further, in the second aspect of the invention, since the particle capturing member is provided in the hole of the insulating plate and the hole can be finely processed, the hole interval can be made small, and therefore the particle capturing portion can be It is possible to dispose at high density, and it is possible to measure with high resolution.

〔Example〕

The first invention of the present invention will be described below with reference to FIG. 1 showing the case of measuring an ion beam current density distribution in an ion implantation apparatus as one embodiment thereof.

In the figure, the reference numerals (1) to (6) and (8b) are the same as or equivalent to those shown by the same reference numerals in the conventional device.

Next, reference numeral (9) is a surrounding electrode which surrounds and is electrically connected to the entrance diaphragm plate (1) which is a particle passing member, and (10) is an entrance diaphragm plate (1) and the surrounding electrode (9). Another secondary electron suppressing electrode which is positioned in front of and is supplied with a negative voltage together with the secondary electron suppressing electrode (2) by the conducting wire (8c), (11) is the entrance diaphragm plate (1), The secondary electron suppressing electrode (2), the collector electrode (3), the surrounding electrode (9), and another secondary electron suppressing electrode (10) are integrally connected to the charged particle beam (6) in the direction of flight. The movable mount, which is a movable part configured to be vertically movable in two directions, (12) is the base of the movable mount (11), (13) is the vacuum tank (7a) and the movable mount (11). ) And a flexible bellows capable of blocking the vacuum from the atmosphere. The entrance diaphragm plate (1), the secondary electron suppressing electrodes (2) and (10), the collector electrode (3) and the surrounding electrode (9) form a particle trap (14).

FIG. 2 shows the basic structure in a concrete structure.
It is FIG. 3 that extracted only the Faraday cage part. In FIG. 3, reference numeral (15) is an insulating spacer that electrically insulates the other secondary electron suppressing electrode (10) and the surrounding electrode (9).

Next, the operation of the above embodiment will be described.

When a charged particle beam (6) from a charged particle source (not shown) flies from the upper part of the figure and reaches the entrance diaphragm plate (1), charged particles in a place other than the through hole enter the entrance diaphragm plate (1). Only the charged particle beam (6) at the position of the through hole is collided and stopped, and passes through the entrance diaphragm plate (1).

The charged particles passing through the entrance diaphragm plate (1) pass through the secondary electron suppressing electrode (2) and collide with the collector electrode (3),
It is measured by a current measuring device in the atmosphere through the measuring terminal bolt (5) and the measuring wire (8b).

The current distribution of the charged particle beam (6) at the position of the entrance diaphragm plate (1) fixedly arranged on the two-dimensional plane is measured by comparing the measured current values flowing into the respective collector electrodes (3). Is similar to the conventional device.

In this invention, since the above-mentioned particle capturing section (14) is moved by the movable mounting table (11), it is possible to move the entrance diaphragm plate (1) at a distance equal to or smaller than the distance between the holes, and finally move to the distance between the holes. For example, a resolution equal to or smaller than the distance between the holes of the entrance diaphragm plate (1) can be obtained.

For example, assuming that the entrance diaphragm plate (1) is provided with holes with a diameter of 1 mm at intervals of 10 mm in a grid pattern, the axis connecting the holes at intervals of 10 mm is the X axis, and the axis orthogonal to the X axis is the Y axis. It is possible to measure the distribution of the charged particle beam (6) with a resolution of 1 millimeter by moving 10 times in the X-axis direction and 10 times in the Y-axis direction, that is, 100 times in the 1 mm pitch in the axial direction and the Y-axis direction. it can.

As can be seen from the above example, since the movable mounting base (11) can be moved within the range of the holes of the maximum entrance diaphragm plate (1), the flexible bellows (13) having a function of blocking vacuum from the atmosphere. Deformation can be reduced.

Due to the use of bellows (13) has no air entrainment, such as the shaft seal in the vacuum sealing of a mechanism for moving particle capture unit (14), without vacuum pressure rises during the movement, always 10 ^- Can maintain a high vacuum of ⁶ _Torr or less.

For example, when using toxic substances such as As and P for semiconductor ion implantation, adhesion to each part of the charged particle distribution measuring device occurs and it is necessary to consider safety during maintenance. The parts other than the part directly exposed to the toxic ions such as the particle trap can be placed in the atmosphere.

In addition, as in this embodiment, the entrance diaphragm plate (1) is surrounded by the electrode (9), and the secondary electron suppression electrode (10) is installed in front of the entrance diaphragm plate (1) so that the entrance diaphragm plate (1) receives a current. If a meter is connected, the total current and distribution of the beam can be measured simultaneously and accurately.

Although the bellows (13) is used in the above embodiment, other flexible vacuum seals such as O-rings can be used for those having a low degree of vacuum.

Furthermore, although the bellows (13) having a large diameter is used in the above-mentioned embodiment, as shown in FIG. 4, by providing one or more bellows (13a) having a small diameter, the bellows (13a) It is also possible to increase the flexibility and prevent the charged particle beam (6) from directly irradiating the bellows (13).

Next, as shown in the second invention, in order to further enhance the two-dimensional measurement resolution, as shown in FIGS. 5 and 6 showing an embodiment of the second invention, an insulating plate (16) is used. To form a hole at the same position as the hole of the entrance diaphragm plate (1), the collector electrode (3) which is a particle trapping member is inserted into the hole, and the measurement terminal bolt (5) is attached to the end thereof. Can be achieved by reducing the hole diameter and the interval of the entrance diaphragm plate (1) together with the collector electrode (3) and the gap therebetween. That is, the entrance diaphragm plate (1)
The size of the through hole and the collector electrode (3) formed in the substrate is 0.2 mm, and if this is moved at intervals of 0.2 mm, the resolution becomes 5 times that of the above example. The method is shown in FIGS. 5 and 6. In the figure, (17) is a collector electrode plate which is a general term for the secondary electron suppressing electrode (2), collector electrode (3), insulating plate (16) and measuring terminal bolt (5), and (18) Is a terminal for secondary electron suppressing electrode.

The manufacturing process of the collector electrode plate (17) is as follows.

For example, a collector electrode (3) is attached to one surface of an insulating plate (16) made of a difficult-to-machine material such as alumina by an energy beam of an electron beam or a laser beam (2)
Micromachine the insertion hole in 8). However, the insulating plate (16) that can be machined may be drilled.
The minimum hole size by energy beam and drill is 0.
Since it is about 2 millimeters, it can be processed with high positional accuracy.

Collector electrode (3) on the surface that has undergone fine processing in the process
Ring-shaped masking is applied to the circumferential surface of, and the entire surface is metallized by vacuum deposition or the like. This film thickness is set to several μm to several tens μm in consideration of the function of the secondary electron suppressing electrode (2) and the bonding or brazing process in the subsequent step.

The contact portion with the measuring terminal bolt (5) is masked, and the other surface of the insulating plate (16) is metallized as in the process.

The measurement terminal bolt (5) and the secondary electron suppressing electrode terminal (18) are inserted and hermetically joined to the insulating plate (16) with, for example, gold solder.

Wire (8a) and measurement line (8b) are joined by wire bonding or soldering. Alternatively, the measuring terminal bolt (5) and the secondary electron suppressing electrode terminal (18) are made into a pin structure and connected together by a connector.

If the collector electrode plate (17) manufactured in the above steps is used, the measurement resolution can be further increased as described above.

Further, since the collector electrode plate (17) can have a small hole diameter, the hole interval can be narrowed to about 5 mm between the hole centers. Therefore, when the resolution is not so high, the collector electrode plate (17) may be used in a fixed state without being moved. Examples thereof are shown in FIGS. 7 and 8.

In the figure, reference numeral (19) is a gasket, (20) is a holding flange, and (21) is a tightening bolt.

After assembling the collector electrode (17), the entrance diaphragm plate (1), the surrounding electrode (9), the insulating spacer (15) and another secondary electron suppressing electrode (10), the gasket (19) and the pressing flange ( It is fixed to the vacuum chamber (7) with the tightening bolts (21) through 20).

Further, as in the above-described embodiment, if the particle trapping member and the recoil trapping member are made of the same electric insulating member, there is an effect that a higher spatial resolution can be obtained.

Although the case of using an ion beam has been described in the above embodiment, an apparatus for an electron beam may be used, and the same effect as that of the above embodiment can be obtained.

〔The invention's effect〕

As described above, according to the first aspect of the invention, in the first aspect of the invention, a particle passage member provided on a plane intersecting with the trajectory of charged particles and having a plurality of through holes, and passing through each of the through holes of the particle passage member. The particle trapping member for trapping the charged particles, and the moving unit for moving the particle trapper in any direction within the plane, and in the second invention, Since the particle trapping member is installed in the hole formed in the insulating plate, there is an effect that a charged particle distribution measuring device with high spatial resolution can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the configuration of a charged particle distribution measuring apparatus according to an embodiment of the first invention, FIG. 2 is a three-dimensional sectional view of the configuration of the charged particle distribution measuring apparatus according to FIG. 1, and FIG. FIG. 4 is a three-dimensional sectional view of a configuration in which a part of the drawing is extracted, FIG. 4 is a three-dimensional sectional view of a configuration of a charged particle distribution measuring apparatus according to another embodiment of the first invention, and FIG. FIG. 6 is a schematic sectional view of a particle trap in a charged particle distribution measuring apparatus according to an example, FIG. 6 is a three-dimensional sectional view of FIG. 5, and FIG. 7 is a schematic assembly of a charged particle distribution measuring apparatus according to another embodiment of the second invention. A sectional view, FIG. 8 is a three-dimensional sectional view of FIG. 7, FIG. 9 is a schematic configuration diagram of a conventional charged particle distribution measuring apparatus, and FIG. 10 is a configuration sectional view of FIG. (1) ...... Particle passing member (incident diaphragm), (2), (1
0) ... Recoil particle trapping member (secondary electron suppression electrode),
(3) …… Particle trapping member (collector electrode), (6) ……
Charged particle beam, (11) …… Movable part (movable platform),
(14) …… Particle trap, (16) …… Insulation plate, (17) ……
Collector electrode plate. In each figure, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumiharu Yabunaka 8-1, 1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture Sanryo Electric Co., Ltd. Production Engineering Laboratory (72) Inventor Soichiro Okuda 8 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture 1-chome Sanritsu Electric Co., Ltd. Central Research Laboratory

Claims (2)

[Claims] 1. A particle passage member having a plurality of through holes provided in a plane intersecting with orbits of charged particles and penetrating in the orbit direction, and charged particles having passed through each of the through holes of the particle passage member. A charged particle distribution measuring apparatus, comprising: a particle capturing section including a particle capturing member; and a moving section that moves the particle capturing section in an arbitrary direction within the plane. 2. An insulating plate having a plurality of holes provided in a plane intersecting with the orbits of charged particles and penetrating in the orbital direction,
A charged particle distribution measuring apparatus, comprising: a particle trapping member provided in each of the holes to trap an electron beam incident on the hole.