JPH088230A - Ion milling device - Google Patents

Abstract

PURPOSE:To provide an ion milling device which etches the surface of an object to be machined such as a wafer by applying ions where manufacturing cost is reduced by enlarging an etching region. CONSTITUTION:An ion milling device is provided with a central electrode 7 which is provided at the front center of an ion gun 3 and a ring electrode 8 surrounding the periphery of the central electrode 7 and applies a DC voltage between the central electrode 7 and the ring electrode 8 when applying ions from the ion gun 3, thus causing the flow of ions which pass between the central electrode 7 and the ring electrode 8 and head from the ion gun 3 toward a rotary table 5 to deviate in the direction of an object 4 to be machined being mounted on a stage 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion milling apparatus which emits ions to etch the surface of a workpiece such as a wafer, and more particularly to an ion milling apparatus configured to simultaneously process a plurality of workpieces. Regarding the structure.

In recent years, as electronic devices have become smaller and lighter, demands for smaller and lighter various electronic components incorporated therein have become stronger and stronger. For example, even in the field of small mobile phones, which are remarkably popularized, surface acoustic wave filters have There is a strong demand for downsizing and weight reduction.

As one of the means to meet such a demand, wiring and electrodes formed inside electronic parts are being miniaturized and made more precise. In the case of a surface acoustic wave filter, the width is 1
An extremely fine electrode pattern of about μm is formed on the piezoelectric substrate with high accuracy.

In a manufacturing process of a semiconductor device, an etching process by an ion milling device is used as a means for forming a fine electrode pattern. Even in the manufacturing of the surface acoustic wave filter, a fine electrode pattern is formed with high precision by using the ion milling device. It is possible.

However, in the case of the ion milling apparatus for semiconductor devices, the target etching region is small and there is a limit to the reduction of manufacturing cost. Therefore, there is a demand for the development of an ion milling device capable of reducing the manufacturing cost by enlarging the etching region.

[0006]

2. Description of the Related Art FIG. 3 is a diagram showing the structure of a normal ion milling device, FIG. 4 is a diagram showing the shape of an extraction electrode and ion distribution, and FIG. 5 is a perspective view showing a conventional ion milling device.
FIG. 6 is an operation explanatory view of a conventional ion milling device.

In FIG. 3, an ordinary ion milling apparatus has an ion gun 3 mounted on the ceiling of a vacuum container 2 having a rotary table 1 therein, and ions generated inside the ion gun 3 are provided in a plurality of extraction electrodes 31. It is radiated into the vacuum container 2 through the holes 32.

Extraction electrode arranged in front of the ion gun 3
A work piece 4 such as a wafer is mounted on the rotary table 1 facing the work piece 31. The work piece 4 is produced by colliding the ions emitted from the ion gun 3 into the vacuum container 2.
The surface of is etched.

In the ion milling apparatus, the rotary table 1 is used to evenly etch the surface of the workpiece 4.
It is necessary to control the ion beam emitted from the ion gun 3 to make the energy applied to the surface of the workpiece 4 uniform while rotating the.

For example, if the extraction electrode 31 is flat as shown in FIG. 4 (a), the intensity distribution of the ion beam on the surface to be processed is maximum at the center and toward the peripheral edge as shown in FIG. 4 (b). Is not suitable for etching the workpiece 4 having a relatively large outer shape.

On the other hand, by making the extraction electrode 31 uneven as shown in FIG. 4 (c), the intensity distribution of the ion beam becomes almost uniform from the central part to the peripheral part as shown in FIG. 4 (d). The workpiece 4 having a relatively large outer shape can be uniformly etched.

In the ion milling apparatus, the workpiece is usually placed in front of the ion gun and processed by an ion beam having a substantially uniform intensity. However, the productivity is extremely low according to the usual processing method in which the workpieces are arranged one by one in front of the ion gun and etched.

Therefore, in order to improve the productivity, the conventional ion milling device has a rotary table 5 in front of the ion gun 3 as shown in FIG. 5, and the workpiece 4 is provided on the rotary table 5 along the periphery thereof. Are mounted and a plurality of stages 6 that rotate are arranged.

The workpiece 4 mounted on the stage 6 on the rotary table 5 naturally protrudes from the region where the intensity of the ion beam is uniform, but as shown in FIG. 6A, the rotary table 5 is rotated and the stage 6 is rotated. By rotating the machine, uniform processing is possible.

That is, by optimizing the intensity distribution of the ion beam and rotating the rotary table 5 to rotate the stage 6, the intensity of the ion beam applied to each part of the workpiece 4 is averaged and a plurality of workpieces are processed. The object 4 can be processed uniformly at the same time.

[0016]

However, as the size of the workpiece such as the wafer increases, the rotary table and the stage also increase in size as shown in FIG. 6 (b). However, there is a limit to increasing the diameter of the ion gun, and the conventional method cannot correct the intensity distribution of the ion beam to expand the processing area.

As a result, the etching progresses in the region facing the front of the ion gun, and the etching does not progress in the region away from the front. Even if the rotary table is rotated and the stage is rotated, the machining amount of the workpiece varies. There was a problem that it would occur.

It is an object of the present invention to provide an ion milling device capable of reducing the manufacturing cost by enlarging the etching region.

[0019]

FIG. 1 is a perspective view showing an ion milling device according to the present invention. Note that the same object is denoted by the same symbol throughout the drawings.

The above-mentioned problem is solved by the rotary table 5 having a plurality of stages 6 on which the workpiece 4 is mounted and which rotates, and the ion gun 3 disposed in front of the rotary table 5.
An ion milling device having an ion gun 3
Has a central electrode 7 disposed in the center of the front surface of the cell and a ring electrode 8 surrounding the central electrode 7, and applies a DC voltage between the central electrode 7 and the ring electrode 8 when the ions are emitted from the ion gun 3. By doing so, the flow of ions passing through between the central electrode 7 and the ring electrode 8 toward the rotary table 5 from the ion gun 3 causes the workpiece 4 mounted on the stage 6 to move.
This is accomplished by an ion milling device of the present invention configured to deflect towards.

[0021]

In FIG. 1, there is no workpiece 4 at the center of the rotary table 5, and the ion beam emitted to this portion does not contribute to the machining. On the other hand, it is a well-known technique that the direction of an ion beam is changed by applying an electric field in a direction orthogonal to the ion beam.

Therefore, the central electrode 7 is provided at the center of the front surface of the ion gun 3, and the ring electrode 8 is provided so as to surround the periphery of the central electrode 7, and when the ions are emitted from the ion gun 3, the central electrode 7 and the ring electrode 8 are combined. A DC voltage is applied between them to achieve the purpose.

That is, by applying a DC voltage between the central electrode 7 and the ring electrode 8, the flow of ions is deflected toward the workpiece 4, and the apparent diameter of the ion gun 3 is increased to increase the ion gun 3. Uniform etching is possible even in a region away from the front surface of the.

As a result, it is possible to realize an ion milling apparatus which can reduce the manufacturing cost by enlarging the etching region.

[0025]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 2 is a perspective view showing a modified example of the present invention.

As shown in FIG. 1, in the ion milling apparatus according to the present invention, a rotary table 5 is arranged in front of the ion gun 3 similarly to the conventional apparatus, and a workpiece 4 is provided on the rotary table 5 along the peripheral edge thereof. Are mounted and a plurality of stages 6 that rotate are arranged.

On the other hand, a center electrode 7 is disposed in the center of the front surface of the ion gun 3, and a ring electrode 8 is disposed so as to surround the center electrode 7. When the ions are emitted from the ion gun 3, the center electrode 7 and the ring electrode 8 are arranged. It is configured to apply a DC voltage between and.

Although a ring-shaped electrode which completely surrounds the center electrode 7 is described as the ring electrode 8 in FIG. 1, for example, an electrode piece which is composed of a plurality of electrode pieces and surrounds the center electrode 7 is described. The ring electrode 8 may be an electrode provided with an appropriate gap therebetween.

In FIG. 1, there is no workpiece 4 at the center of the rotary table 5, and the ion beam emitted to this portion does not contribute to the processing. On the other hand, it is a well-known technique that the direction of an ion beam is changed by applying an electric field in a direction orthogonal to the ion beam.

That is, when a DC voltage is applied between the central electrode 7 and the ring electrode 8 when the ions are emitted from the ion gun 3, the direct current voltage passes between the central electrode 7 and the ring electrode 8 toward the rotary table 5. The ion beam is deflected and moves toward the workpiece 4.

In other words, in the conventional ion milling apparatus, the ion beam is emitted to the area facing the ion gun 3, whereas in the ion milling apparatus according to the present invention, ions are directed toward a ring-shaped area larger than the diameter of the ion gun 3. The beam is emitted.

By thus radiating the ion beam toward the ring-shaped area larger than the diameter of the ion gun 3, the apparent diameter of the ion gun 3 is increased and even in the area away from the front of the ion gun 3. Uniform etching becomes possible.

On the other hand, the incident angle of the ion beam is changed by deflecting the ion beam toward the rotary table 5 toward the workpiece 4. The modification of the present invention shown in FIG. 2 comprises means for absorbing the variation in the incident angle of the ion beam due to the deflection of the ion beam.

That is, in the modification of the ion milling apparatus according to the present invention, as shown in FIG. 2, the rotary table 5 is arranged in front of the ion gun 3, and the workpiece 4 is provided on the rotary table 5 along the peripheral edge thereof. Are mounted and a plurality of stages 6 that rotate are arranged.

On the other hand, a center electrode 7 is disposed in the center of the front surface of the ion gun 3, and a ring electrode 8 is disposed so as to surround the center electrode 7. When the ions are emitted from the ion gun 3, the center electrode 7 and the ring electrode 8 are arranged. It is configured to apply a DC voltage between and.

However, unlike the above-described embodiment, the stage 6 on the rotary table 5 has a rotary shaft 61 having the ion gun 3 respectively.
The angle of incidence of the ion beam with respect to the workpiece 4 on the stage 6 can be optimized by inclining in the center direction and selecting the angle of inclination of the rotating shaft 61.

As described above, the central electrode 7 and the ring electrode 8 are provided on the front surface of the ion gun 3 to increase the apparent diameter of the ion gun 3, and the rotary shafts 61 of the stage 6 are respectively inclined toward the center of the ion gun 3. Can further increase productivity.

[0038]

As described above, according to the present invention, it is possible to provide an ion milling apparatus capable of reducing the manufacturing cost by enlarging the etching region.

[Brief description of drawings]

FIG. 1 is a perspective view showing an ion milling device according to the present invention.

FIG. 2 is a perspective view showing a modified example of the present invention.

FIG. 3 is a diagram showing a configuration of a normal ion milling device.

FIG. 4 is a diagram showing the shape of an extraction electrode and the distribution of ions.

FIG. 5 is a perspective view showing a conventional ion milling device.

FIG. 6 is an operation explanatory view of a conventional ion milling device.

[Explanation of symbols]

 3 Ion gun 4 Workpiece 5 Rotary table 6 Stage 7 Central electrode 8 Ring electrode 61 Rotation axis

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01J 37/305 A 9172-5E

Claims (2)

[Claims] 1. A rotary table (5) having a plurality of stages (6) on which a workpiece (4) is mounted and which rotates about its own axis, arranged along the periphery of the rotary table (5).
And an ion gun placed in front of the turntable (5)
(3) An ion milling device having a central electrode (7) arranged in the center of the front of the ion gun (3).
And a ring electrode (8) surrounding the central electrode (7), and a direct current is applied between the central electrode (7) and the ring electrode (8) when the ions are emitted from the ion gun (3). By applying a voltage, the flow of the ions passing between the central electrode (7) and the ring electrode (8) and flowing from the ion gun (3) to the rotary table (5) is changed to the stage (6). An ion milling device, characterized in that it is configured to deflect toward a workpiece (4) mounted on. 2. The rotating shafts (61) of a plurality of stages (6) arranged around the periphery of the rotary table (5) and rotating about the rotation axis (61) are inclined toward the center of the ion gun (3). 1. The ion milling device according to 1.