JP2674572B2 - Anodic bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anodic bonding apparatus for a silicon wafer and a glass substrate in the production of semiconductor devices.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor device, the conventional method for bonding a silicon wafer and a glass substrate is shown in FIG.
An anodic bonding apparatus as shown in is usually used.

Referring to FIG. 3, after a silicon wafer 31 is placed on an electrode plate 34 via an insulating plate 33 on a heater 32, a glass substrate 35 (generally silicon and thermal expansion are placed on the silicon wafer 31). Borosilicate glass having a similar coefficient is used), and the needle-shaped electrode 36 is further contacted on the glass substrate 35.

When the positioning and fixing of the silicon wafer 31 and the glass substrate 35 are completed, the heater 32 is heated to about 400 ° C., and then the electrode plate 34 in contact with the silicon wafer 31 is used as an anode to serve as an anode and the needle electrode in contact with the glass substrate 35. Three
When a DC voltage of about 500 V is applied through 6 as a cathode, bonding is started centering on the contact portion of the needle-shaped electrode 36, and the bonding of the entire silicon wafer 31 is performed over time.

However, such a fixed needle electrode 36 requires a great amount of bonding time.

In order to shorten the joining time, for example, Japanese Patent Application Laid-Open No. 4-280618 proposes an anodic joining apparatus in which an electrode can be moved by controlling a robot equipped with a needle electrode.

[0007]

SUMMARY OF THE INVENTION In a conventional device,
When joining is performed with the device of the needle electrode 36 fixed as shown in FIG. 3, the joining portion spreads in a ripple pattern sequentially from the contact point between the needle electrode 36 and the glass substrate 35 as a core, so that the unjoined portion ( Although there are few occurrences of "voids", it took a long time, for example, several hours to completely bond a 4-inch wafer.

On the other hand, when joining is performed by a needle electrode device that can be moved by using a robot like the device described in Japanese Patent Laid-Open No. 4-280618, the joining time can be saved to some extent. When the needle-shaped electrode moves, the joint portion spreads in a ripple shape with the moving point as a nucleus, which causes a problem that voids are easily generated at points where the ripples interfere with each other.

Further, if the same portion of the needle-shaped electrode is constantly in contact with the glass substrate, it reacts with Na ions inside the glass substrate to deposit Na precipitates on the electrode surface of the needle-shaped electrode, resulting in poor bonding. As a result, there is a problem that a new electrode must be always replaced at each joining.

Therefore, the present invention solves the above problems and provides an anodic bonding apparatus which does not generate voids in the step of anodic bonding a silicon wafer and a glass substrate, which can extend the life of the electrode and shorten the bonding time. The purpose is to do.

[0011]

In order to achieve the above-mentioned object, the present invention is to bring a glass substrate into contact with a silicon wafer, apply a DC voltage to the silicon wafer as an anode and use the glass substrate as a cathode, and heat the glass substrate. Then, in the apparatus for anodic bonding the silicon wafer and the glass substrate, the cathode in contact with the glass substrate is a cylindrical electrode,
There is provided an anodic bonding apparatus characterized by rotating on the surface of the glass substrate and applying a predetermined voltage to perform bonding.

In the present invention, preferably, the cylindrical electrode is moved in parallel with respect to the glass substrate, and the glass substrate and the silicon wafer are bonded from one end to the other end. Is performed.

In the present invention, preferably, the cylindrical electrode is pressed toward the glass substrate via a predetermined elastic member.

In the present invention, preferably, the cylindrical electrode is rotatably attached to the supporting member via a shaft and is configured to smoothly rotate via a predetermined bearing means. Characterize.

In the present invention, preferably, the support member controls the movement of the cylindrical electrode in the direction from the one end where the glass substrate and the silicon wafer overlap each other on the glass substrate to the other end. It is connected to a driving device that operates.

[0016]

According to the present invention, by using the rotatable cylindrical electrode as the cathode in contact with the glass substrate, a continuous large joint portion having the same length as the electrode is formed under the glass substrate in contact with the electrode. In addition, since the joints are sequentially expanded in parallel in the direction in which the electrodes are rotated, not only the joints with extremely few voids are obtained, but also the joint time is much shorter than that of the apparatus using the robot.

Further, since the contact portion of the cylindrical electrode which is in contact with the glass substrate is constantly changed by the rotation, the Na inside the glass is changed.
Reaction with ions is avoided and the life of the electrode is significantly extended.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the construction of an embodiment of the anodic bonding apparatus of the present invention, and a part thereof is shown as a partial sectional view for explanation. FIG. 2 is a plan view for explaining a bonded state of a silicon wafer and a glass substrate.

In FIG. 1, 1 is a base 3 via a base 2.
And is connected to the heater power supply 4.

Further, an insulating plate 5 and an electrode plate 7 connected to the anode of the DC power source 6 are mounted on the heater 1, and a silicon wafer 8 and a glass substrate 9 are housed on the electrode plate 7, A storage plate 20 that is electrically insulated from the cylindrical electrode 11 that rotates by driving the motor 10 is mounted.

The motor 10 rotates to rotate the shaft 1
2 is a linear motor type having a rack and a pinion that move in a linear direction, and is attached to the base 3 via a base 13 so as to be parallel to the heater 1.

An insulating block 1 is provided at the tip of the shaft 12.
4 are fixed with screws, and the shaft 1 is attached to both ends of the insulating block 14.
Arms 16 and 16 'are rotatably mounted via 5.

At the other ends of the arms 16 and 16 ', a cylindrical electrode 11 is rotatably mounted via a shaft 17, and a ceramic ring 18 having excellent heat resistance is provided for smooth rotation. ing.

The cathode of the DC power supply 6 is connected to the cylindrical electrode 11 via a brush 19 attached to the arm 16.

Next, a bonding method by the anodic bonding apparatus according to one embodiment of the present invention will be described.

First, the silicon wafer 8 and the glass substrate 9 are sequentially inserted into the storage plate 20 so as to be stacked on the electrode plate 7, and then the motor 10 is driven to position the cylindrical electrode 11 at the end portion of the glass substrate 9. And the heater 1 is heated to about 400 ° C.

Next, when a DC voltage of about 500 V is applied between the electrode plate 7 and the cylindrical electrode 11, the silicon wafer 8
2 and the glass substrate 9 have a high degree of adhesion, that is, as shown in FIG. 2, the bonding is started from the periphery of the line contact portion of the cylindrical electrode 11 and the bonding portion 21 (shaded portion) spreads.

At the same time when the joint portion 21 spreads, the motor 10
When the electrode is driven and moved in the direction of arrow A (see FIG. 1) in parallel, the joint portion 21 spreads in parallel, but the periphery of the cylindrical electrode 11 is urged by an elastic member such as a torsion coil spring 22. Pressurization makes it possible to maintain a high degree of adhesion at all times, and good bonding can be obtained.

In this way, according to the present embodiment, it is possible to join with extremely few voids. Moreover, since the cylindrical electrode 11 can move at a speed of about 1 to 2 mm / sec,
For example, in the case of a 4-inch wafer, it became possible to perform bonding in an extremely short time of about 1 to 2 minutes.

On the other hand, the cylindrical electrode 11 can be joined without rotating, but if the same portion of the electrode is constantly in contact with the glass substrate 9, it reacts with Na ions inside the glass,
Since it causes deterioration of the electrode surface, it is preferable that the electrode always rotates smoothly. For that purpose, the same effect can be obtained by using a ceramic bearing instead of the ceramic ring 18.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments,
Needless to say, various modes according to the principle of the present invention are included.

[0033]

As described above, according to the present invention,
By using a cylindrical electrode that has a long contact point and moves while rotating for the cathode that contacts the glass substrate, there is no void, and the bonding time is greatly shortened and the anodic bonding that achieves a longer electrode life is achieved. The device is realized.
The above-described effects can be similarly suitably achieved by the preferred embodiments of the present invention described in the second and subsequent aspects.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a configuration of an embodiment of the present invention.

FIG. 2 is a diagram for explaining a joined state in one embodiment of the present invention.

FIG. 3 is a diagram for explaining a configuration of a conventional example.

[Explanation of symbols]

 1, 32 Heater 2, 13 units 3 Base 4 Heater power supply 5, 33 Insulation plate 6 DC power supply 7, 34 Electrode plate 8, 31 Silicon wafer 9, 36 Glass substrate 10 Motor 11 Cylindrical electrode 12 Shaft 14 Insulation block 15, 17 Axis 16, 16 'Arm 18 Ring 19 Brush 20 Storage plate 21 Joint part 22 Torsion coil spring

Claims (5)

(57) [Claims] 1. An apparatus for anodic-bonding a silicon substrate and a glass substrate to each other, applying a DC voltage to the silicon wafer as an anode and using the glass substrate as a cathode and heating the silicon substrate as a cathode to heat the silicon wafer and the glass substrate. 2. The anodic bonding apparatus according to claim 1, wherein the cathode in contact with the glass substrate is a cylindrical electrode, and the glass substrate is rotated on the surface to apply a predetermined voltage to perform bonding. 2. The cylindrical electrode moves in parallel with respect to the glass substrate, and bonding is performed from one end portion where the glass substrate and the silicon wafer are overlapped to the other end portion. The anodic bonding apparatus according to claim 1. 3. The anodic bonding apparatus according to claim 1, wherein the cylindrical electrode is pressed toward the glass substrate via a predetermined elastic member. 4. The cylindrical electrode is rotatably attached to a support member via a shaft and is configured to smoothly rotate via a predetermined bearing means. The anodic bonding apparatus described. 5. The supporting member is connected to a driving device that controls the movement of the cylindrical electrode on the glass substrate from one end where the glass substrate and the silicon wafer overlap to the other end. The anodic bonding apparatus according to claim 4, wherein