JPH07161785A - Semiconductor wafer fixing jig - Google Patents

Abstract

PURPOSE:To prevent an external force from being applied to a wafer so as to protect it against deformation by a method wherein the inner edge of a ring-shaped holding member protrudes inwards more than that of a ring-shaped pressing board, the periphery of a wafer is set smaller than the inner edge of the pressing board but larger than the inner edge of the holding member. CONSTITUTION:A ring-shaped holding pad 2 attracted to a stage 6 by vacuum suction, an elastic ring-shaped holding section 3 composed of an upper and a lower holder holding a wafer 1 between them on the holding pad 2, a ring- shaped pressing board 4 which holds the holding section 3 pressing it from above, and a bolt 5 which screws the pressing board 4 to the holding pad 2 are provided. The inner edge (3) of the holding section 3 protrudes inwards more than the inner edge (4) of the pressing board 4 and is adequate in size to hold the periphery of the wafer 1. The inner edge (4) of the pressing board 4 is located outside of the periphery of the wafer 1, so that the pressing board 4 is restrained from applying a compressive force directly to the wafer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for fixing a semiconductor wafer on a stage when measuring the electrical characteristics of the semiconductor wafer.

[0002]

2. Description of the Related Art The quality before dicing is checked by measuring the electrical characteristics of ICs formed on a semiconductor wafer, and unnecessary work in the subsequent steps is omitted.
For this purpose, as shown in FIG. 3A, the semiconductor wafer 1 is placed on the stage 6, vacuum is drawn through a small hole provided in the stage to be fixed by suction, and the probe 8 is brought into contact with an electrode on the wafer from above. Then, the electrical characteristics are evaluated by the measuring device. By the way, since an IC and an insulating film are formed on the element surface 1'of the wafer and an Au-based adhesive film is applied on the back surface of the wafer, the wafer will be either as shown in FIG. 3 (b) or (c). It often turns back. The wafer thus warped is placed on the stage 6 and vacuum-adsorbed so that the wafer is horizontally fixed and its electrical characteristics are measured.

[0003]

When the electrical characteristics are measured by such a method, the warping of the wafer is forced to be horizontal by applying an external force, so that the piezo effect disappears and the state of current flow changes. Then, there is a problem that the result measured in the state of the wafer does not match the value measured in the state where the chip is cut and the external force is not applied. Therefore, the present invention is
It is an object of the present invention to provide a jig for fixing a semiconductor wafer that solves the above problems.

[0004]

The present invention is a jig for fixing a wafer to a stage when measuring the electrical characteristics of an IC formed on a disk-shaped semiconductor wafer, and a vacuum is provided on the stage. A ring-shaped holding base that is adsorbed and fixed, two upper and lower ring-shaped elastic holding members that hold the wafer on the holding base, and a ring-shaped holding member that presses and holds the holding member from above. A pressing plate, and a bolt for fastening the holding base and the pressing plate by screwing, the inner edge of the ring-shaped gripping member is projected inward from the inner edge of the ring-shaped pressing plate, The outer periphery of the wafer is smaller than the inner edge of the pressing plate and larger than the inner edge of the gripping member. Here, it is preferable that the upper gripping member is bonded to the pressing plate and the lower gripping member is bonded to the holding base.

Further, the present invention is a jig for fixing an IC formed on a disk-shaped semiconductor wafer to a stage when measuring the electrical characteristics of the IC, which is vacuum-adsorbed and fixed onto the stage. Ring-shaped holding table, a holding tool having an L-shaped cross section for holding a wafer, which is arranged inside the holding table, and a holding tool rotatably with the holding tool through a screw provided in a radial direction. It is equipped with a bolt that is connected to move the holder in the radial direction, and a driver that idles when the bolt receives a rotational stress of a specified value or more. It is characterized in that it is retained through.

[0006]

According to the above structure, the first aspect of the present invention is such that even if a compressive force is applied between the pressing plate and the holding base by the bolt, the wafer is separated from the pressing plate and the two holding members having elasticity. Since it is held between the two, the compressive force applied to the wafer is almost determined by the elasticity of the gripping member, and the force that deforms the wafer can be eliminated. According to a second aspect of the invention, the wafer is held on an L-shaped holder, and the distance between the holders is adjusted by bolts, but when the driver that rotates the bolts is loaded with a stress of a specified value or more, the driver idles. Since it is configured, it is possible to eliminate the force that deforms the wafer.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 is a sectional view (a) and a plan view (b) showing the configuration of the present embodiment. The disc-shaped semiconductor wafer 1 includes two ring-shaped gripping members 3,
The outer peripheral portion is gripped by 3, while the gripping members 3, 3 are held between the ring-shaped holding table 2 and the ring-shaped pressing plate 4 which are vacuum-adsorbed on the stage 6, and the pressing plate 4 bolt It is fixed to the holding table 2 by 5.

Since the pressing plate 4 and the holding base 2 must maintain their shapes even when an external force is applied, they are made of metal or hard plastic such as Bakelite, whereas the holding members 3 and 3 hold them. A soft, elastic rubber, a silicon resin, or the like is used so that an excessive force is not applied to the existing wafer.

The ring-shaped pressing plate 4, the inner edge portion of the holding base 2 and their outer peripheral portions are formed to be substantially the same.
On the other hand, the two ring-shaped gripping members 3, 3 are sized such that the outer peripheral portions thereof are held between the holding plate 4 and the holding base 2, but the inner edge portions of the holding members 3, 3 are the holding plate 4. The size is such that it projects inward from the inner edge and can grip the outer peripheral portion of the wafer 1. The inner edge of the pressing plate 4 is outside the outer periphery of the wafer 1 so that the compressive force of the pressing plate 4 is not directly applied to the wafer 1.

In this way, when the pressing plate 4 is fastened to the holding table 2 with the bolts 5, the outer peripheral portions of the gripping members 3, 3 are compressed, but the wafer 1 is inside the inner edge of the pressing plate 4 and Since it is held by the gripping members 3 and 3, the compressive force of the pressing plate 4 is not directly received,
A force determined mainly by the elasticity of the grip members 3, 3 is applied. Therefore, the wafer 1 can be fixed to the stage 6 without being directly affected by the compressive force of the bolt 5.

In the above structure, if the upper gripping member 3 is integrally bonded to the pressing plate 4 and the lower gripping member 3 is bonded to the holding base 2, the number of independent parts is reduced and the wafer 1 is fixed. It is convenient to do.

FIG. 2 is a sectional view (a) and a plan view (b) showing the structure of another embodiment. The disk-shaped wafer 1 has its outer peripheral portion placed on the holders 14 ... 14 having an L-shaped cross section. On the other hand, the holder 14 is arranged inside the ring-shaped holder 12 that is vacuum-adsorbed on the stage 6. Further, the holding table 12 is provided with bolts 15 that are rotatably connected to the holders 14 through radially provided screws and that move the holders 14 in the radial direction.

Further, the bolt 15 is rotated by a driver, and this driver has a function of idling when a stress exceeding a specified value occurs in the bolt.

Inside the L-shaped holder 14, a cushion material 13 such as soft and elastic rubber or silicon resin is applied to prevent the wafer 1 from being scratched when fixed to the holder 14. This is to prevent the wafer 1 from being damaged due to excessive force.

[0015]

As described above, according to the first aspect of the present invention, even if a compressive force is applied between the holding plate and the holding base by a bolt, the wafer is held at a position apart from the holding plate and has two elastic grips. Since it is held between the members, the compressive force applied to the wafer is almost determined by the elasticity of the gripping member, and the structure can eliminate the force that deforms the wafer. According to a second aspect of the invention, the wafer is held on an L-shaped holder, and the distance between the holders is adjusted by bolts, but when the driver that rotates the bolts is loaded with a stress of a specified value or more, the driver idles. Since it is configured, it is possible to eliminate the force that deforms the wafer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view (a) and a plan view (b) showing the configuration of the present embodiment.

FIG. 2 is a sectional view (a) and a plan view (b) showing a configuration of another embodiment.

FIG. 3 is a cross-sectional view showing a conventional configuration.

[Explanation of symbols]

 1, 1-1, 1-2: Semiconductor wafer 2, 12: Holding table 3: Gripping member 4: Holding plate 5, 15: Bolt 6: Stage 7: Vacuum suction 8: Probe 13: Cushion material 14: Holder: Inner edge of holding base: Inner edge of gripping member: Inner edge of pressing plate

Claims (3)

[Claims] 1. An IC formed on a disk-shaped semiconductor wafer
Is a jig for fixing the wafer to the stage when measuring the electrical characteristics of the wafer. It is a ring-shaped holding table that is vacuum-adsorbed and fixed onto the stage, and the wafer is sandwiched and held on the holding table. A top and bottom two ring-shaped gripping member having elasticity, a ring-shaped pressing plate for pressing and holding the gripping member from above, and a bolt for screwing and fastening the holding base and the pressing plate, The inner edge of the ring-shaped holding member projects inward from the inner edge of the ring-shaped holding plate, and the outer periphery of the wafer is smaller than the inner edge of the holding plate and larger than the inner edge of the holding member. Fixing jig for semiconductor wafers. 2. The jig for fixing a semiconductor wafer according to claim 1, wherein the upper gripping member is bonded to the pressing plate, and the lower gripping member is bonded to the holding table. 3. An IC formed on a disk-shaped semiconductor wafer
Is a jig that fixes the wafer to the stage when measuring the electrical characteristics of the wafer. It is a ring-shaped holding table that is vacuum-adsorbed and fixed onto the stage, and is placed inside the holding table to hold the wafer. For holding the L-shaped cross section, a bolt that is rotatably connected to the holder through a screw provided in the holder in the radial direction to move the holder in the radial direction. A jig for fixing a semiconductor wafer, comprising: a driver that idles when a rotational stress is applied, a cushion material is applied to an inner surface of a holder, and the wafer is held through the cushion material.