JPS59220945A - Method of sticking semiconductor substrate - Google Patents

Abstract

PURPOSE:To stick the titled substrate to a holding plate with a high degree of parallelism by removing air bubbles in the adhesive by a method wherein a pressure roller is rolled by pressure contact over the substrate via elastic plate. CONSTITUTION:The pressure roller 17 is placed at the position D by rotating a screw 22. A platen 11 is heated 13, thus putting the holding plate into the state of the temperature for fusing wax 14, and the substrate 15 is mounted thereon by applying the fixed amount of wax 14. An Si rubber plate 16 is put thereon and fed by means of the screw 22, transferring the roller 17 to one end of the rubber plate 16. Then, the roller 17 is lowered F by operating a cylinder 19, and accordingly the substrate 15 is pressure- contacted with the holding plate 12 via rubber plate 16. The roller is rolled to the other end by screw-feeding while pressing the substrate by means of the roller, and next the roller is pulled up and placed at the position G. The screw 22 is reversely rotated, thus making the rubber plate 16 retrogress H while pressing it by means of the roller 17 and feedback to the position D, resulting the adhesion of the substrate 15 to the holding plate 12. This method generates the distribution of pressure at the interface between the substrate 15 and the rubber plate 16, the wax 14 being pushed out always to the direction of movement of the roller. Besides, the air bubbles in the wax is pushed out of the substrate together with the wax, leading to excellent adhesion.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to applying an adhesive material such as wax or adhesive onto a sample holding plate placed on a flat plate such as a surface plate, and then applying the adhesive material. The semiconductor substrate is bonded to the sample holding plate with the adhesive material by placing the semiconductor substrate on the sample holding plate through the substrate, and then press-bonding the semiconductor substrate to the sample holding plate. Regarding the adhesion method.

BACKGROUND TECHNOLOGY AND PROBLEMS In recent years, in semiconductor substrates used for LSI manufacturing, L
With the miniaturization of SI element dimensions, reduction of substrate thickness unevenness (hereinafter referred to as Pv value) has become an important issue. This is because if the PV value of the substrate is large, there will inevitably be areas that are out of focus within the substrate during the exposure process, which is the main process of LSI manufacturing, making it impossible to perform high-precision turning. , Therefore, the manufacturing yield of LSI is significantly lowered.

The above Pv value is approximately determined by the adhesion state when the semiconductor substrate is bonded with wax to a sample holding plate used for mirror polishing the surface of the semiconductor substrate. That is, if the semiconductor substrate is bonded to the sample time keeping plate in a non-parallel state, for example, a thickness gradient will occur in the semiconductor substrate after polishing, resulting in an increase in the Pv value.

Conventionally, when bonding a semiconductor substrate to a sample holding plate, a method as shown in FIG. 1 has been used. That is, in FIG. 1, the sample holding plate (2) is first placed on the surface plate (1), and then the sample holding plate (2) is heated using the heater (3). The plate (2) is heated above the melting temperature of the wax. In this state, the above sample holding plate (
After applying an appropriate amount of wax (4) to the surface of 2), the semiconductor substrate (5) is placed on the sample holding plate (2).

Next, constant m(1) means a pressure plate (6
) is moved in the direction of arrow A using a drive unit (not shown) to press the semiconductor substrate (5) onto the sample holding plate (2), thereby moving the semiconductor substrate (5) onto the sample. Glue it to the holding plate (2).

However, in such a method, the thickness of the wax (4) becomes thicker overall and varies greatly in the range of 1 to 5 [μm] for a semiconductor substrate (5) having a diameter of 10 [α], for example. Since the air bubbles that have entered the wax (4) are not pushed out and remain in the wax (4), the semiconductor substrate (5) is
) has the disadvantage that it is difficult to adhere parallel to the surface. Therefore, after the sample holder plate (2) to which the semiconductor substrate (5) is bonded as described above is mounted on a known polishing device and a predetermined mirror polishing is performed, the Pv value remains at about 5 [μm]. , is not practically sufficient.

Note that the above air bubbles are removed from the semiconductor substrate (5) after the semiconductor substrate (5) is bonded to the sample holding plate (2) as described above.
) can be removed to some extent by shifting the position of the sample holding plate (2), but in this case, the friction between the semiconductor substrate (5) and the sample holding plate (2) causes the This is not preferable because the back surface of the semiconductor substrate (5) will be damaged.

Purpose of the Invention In view of the above-mentioned problems, the present invention provides a method for holding a semiconductor substrate as a sample by making the thickness of an adhesive material such as wax thin and uniform, and effectively removing air bubbles that have entered the adhesive material. It is an object of the present invention to provide a method for bonding a semiconductor substrate to a plate with extremely high parallelism.

Summary of the Invention A semiconductor substrate bonding method according to the present invention includes applying an adhesive material onto a sample holding plate placed on a flat plate, and then mounting the semiconductor substrate on the sample holding plate via the adhesive material. Place,
Next, in the semiconductor substrate bonding method, the semiconductor substrate is bonded to the sample holding plate with the adhesive material by pressing the semiconductor substrate onto the sample holding plate, and an elastic plate is placed on the semiconductor substrate. After that,
By rolling the pressure roller 2 while pressing the pressure roller against the semiconductor substrate via the elastic plate,
The semiconductor substrate is bonded to the sample holding plate. By doing so, the thickness of the adhesive material can be made thin and uniform, and air bubbles that have entered the adhesive material can be effectively removed, so that the semiconductor substrate can be placed against the sample holding plate. Bonding can be performed with extremely high parallelism.

EXAMPLE Hereinafter, an example of the method for bonding semiconductor substrates according to the present invention will be described with reference to the drawings.

In the semiconductor substrate bonding apparatus (c) shown in FIGS. 2 and 6, a ceramic ring sample holding plate a21 is placed on a metal surface plate αυ having a flat surface. The surface plate μυ can be heated by a heater tt31. The semiconductor substrate u1 is placed on the sample holding plate (3) via wax Q41 as an adhesive material. Also, on the semiconductor substrate u51 is a silicone rubber plate (1, (2) as an elastic plate. 9 is placed.The cylindrical metal pressure roller (17) pulls the support member o and the central axis A
. It is rotatably supported around the This pressure roller (17) is movable up and down by moving the support member a8 in the direction of arrow B along the cylinder rod (2o) by the action of the pressure cylinder (L9). A pair of guide shafts (2I) are connected to each other, and these guide shafts C! are slidingly guided by the drive member (c), so that the horizontal swing of the support member α mallet and therefore the pressure It is possible to prevent the roller (17) from rolling laterally.

Also, the driving member (c) is moved by the arrow C by the guide rod C24).
A feed screw (which is driven in the direction of the arrow C by two functions and a pressure roller α7) which is supported so as to be movable in the direction and rotationally driven by a drive device (not shown). The supporting member supporting the drive member (
23). Therefore, when the drive member (2 molten metals) is driven in the direction of arrow C above by the feed screw, the pressure roller side similarly moves in the direction of arrow C above.

Next, a method of bonding the semiconductor substrate ([ω) to the sample holding plate α using the adhesive device (25) constructed as described above will be explained.

First, in FIGS. 2 and 6, the above-mentioned drive unit rotates the feed screw (221) to control the pressure roller.
After positioning it at the position indicated by the imaginary line in Fig. 6,
Place the sample holding plate (I7J) on the surface plate σD. Next, by heating the surface plate I by energizing the heater (131), the sample holding plate (I7J) is heated to the wax (melting temperature of 1,41, e.g. 120 (''C).Next, after melting and applying a predetermined amount of wax (14I) onto the upper surface of the sample holding plate (tZ), place one semiconductor substrate (one) on top of this wax θa. So, semiconductor substrate (wax α under the first phrase)
The thickness of the shank is usually thick and uneven.

Next, the semiconductor substrate tt! Place the rubber plate θG) on top of i). In this state, the drive device rotates the feed screw shifter to move the pressure roller 0η from position D to near one end of the silicone rubber plate ([6)] in the direction of arrow E, and then operates the pressure cylinder (2). By moving the pressure roller (17) in the direction of arrow F, the semiconductor substrate (Iω
is pressed onto the sample holding plate (121). While pressing the silicone rubber plate (10) with the pressure roller aη, continue the above-mentioned movement using the feed screw (2) and press this pressure roller (lη). Roll the silicone rubber plate (lω) in the direction of arrow E to near the other end of the plate, then stop the operation of pressure cylinder 0 and roll the pressure roller η in the opposite direction to arrow F. Then, the feed screw (2314 continues the above-described movement and the pressure roller Q7) is positioned at the position G shown by the imaginary line.Next, the drive device rotates the feed screw 4 in the opposite direction to that described above. Then pressurize roller α in the same way as above.
While pressing the silicone rubber plate αQ with η, the pressure roller is moved in the direction opposite to the direction of the arrow E, that is, in the direction of the arrow H, so that it is positioned at the initial position. In this way, the semiconductor substrate 4 is bonded to the sample holding plate α.

In addition, when polishing the semiconductor substrate u5 bonded as described above, the sample holding plate a is removed from the surface plate and the wax is removed by cooling the sample holding plate (lz) with another cooling device. After solidifying the sample holder 141 and removing the excess wax that was not used for bonding the semiconductor substrate 151, the sample holding plate 141 may be mounted on a polishing device and polished as desired.

FIG. 4 is an enlarged vertical cross-sectional view of a part of FIG. 6 for explaining details of the bonding method of the semiconductor substrate u1 in FIGS. 2 and 6. FIG. In FIG. 4, the pressure roller (17)
A constant pressure P is applied by the pressure cylinder l1g1. (For example, 3 (kg/α2)) is applied and this pressure P.

The silicone rubber plate αe is pressurized by. At this time, due to the elasticity of this silicone rubber plate αQ, the interface CI between the semiconductor substrate (151 and the silicone rubber plate αe)
'[9ICPl, P2, P5 (Pl > P2 >
A pressure distribution as shown in P5) occurs. As is clear from this, the wax (I4) is always applied to the pressure roller α.
Along the movement direction of η, it is pushed out one after another in the direction from P to P3, and finally it is pushed out to the outside of the semiconductor substrate (10. At this time, the bubbles in the wax α are also pushed out. The thickness of the wax (14) after bonding the semiconductor substrate 0ω as described above is at the pressure P described above.

It goes without saying that the thickness changes depending on the size of Po, and the larger Po is, the thinner it is.

In this way, in the above embodiment, the pressure roller (I
Since the pressure roller (1?) is moved while pressing the silicone rubber plate (1, 6) with η, as is clear from the above explanation, the thickness of the wax ([4] And it can be made uniform. That is, for example, when the diameter of the semiconductor substrate is 10 (t, The thickness is 1 to 5 [
μm] range (varies, whereas wax α
In this example, the probability that air bubbles remain in the wax αa after adhesion is approximately 1 [chi], and the thickness can be made extremely thin (and uniform). The above probability is 5 [chi] when using the above probability, which is extremely small.
4) The thickness, its uniformity, and the reproducibility of the bubble remaining probability are extremely good compared to conventional bonding methods.

Therefore, in the above-described embodiment, since the semiconductor substrate (151) can be bonded to the sample holding plate α in an extremely high degree of parallelism with respect to the sample holding plate α, the semiconductor substrate (The Pv value of the semiconductor substrate (c) after polishing the old one can be reduced to 6 [μm] or less. This value is higher than the Pv value of 5 [μm] when using the conventional bonding method. extremely small compared to

Note that in the conventional bonding method, as the diameter of the semiconductor substrate 41 layer to be bonded increases, the thickness of the wax α and the non-uniformity of the thickness increase significantly, whereas the bonding method of the above-mentioned embodiment In this case, the thickness of the wax (14) is sufficiently thin (
Moreover, it has the advantage that it is uniform, and therefore the Pv value mentioned above can be made sufficiently small.

In addition, in the above embodiment, since air bubbles in the wax I can be effectively removed, there is no need to shift the position of the semiconductor substrate (151) on the sample holding plate α as described above. Therefore, it is possible to prevent the back surface of the semiconductor substrate u5) from being scratched.

In the above-mentioned embodiment, the semiconductor substrates (4) are bonded using wax, but they may also be bonded (glued) using a commonly used adhesive. When gluing 151, it is necessary to use a heater (
13I does not necessarily need to be provided.

Further, instead of the silicone rubber plate Qt9 in the above-described embodiment, a plate made of another elastic material such as Python rubber may be used. Furthermore, the material of the sample holding plate (12+) may be other than ceramics, such as metal, and the material of the pressure roller (17) may also be other than metal, such as Teflon. .

Further, in the above embodiment, the pressure p-ra a'? ) on the silicone rubber plate (16) once to remove the semiconductor substrate (
151 is attached to the sample holding plate α2, but it is of course possible to attach it by simply moving the pressure lawn (17) one way, or by applying the force of the pressure lawn a back and forth two or more times to attach it to the sample holding plate α2. I'm not even good at saying good things.

Effects of the Invention According to the method for bonding semiconductor substrates according to the present invention, the thickness of the bonding material can be made thin and uniform, and air bubbles that have entered the bonding material can be effectively removed. It can be bonded to the sample holding plate with extremely high parallelism.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional bonding apparatus for explaining a conventional method for bonding semiconductor substrates, and FIG. 2 is a longitudinal cross-sectional view of a conventional bonding apparatus for explaining a conventional bonding method for semiconductor substrates, and FIG. FIG. 6 is a side view of the main part of the bonding device shown in FIG. 2, with a portion of the bonding device shown in FIG.
FIG. 4 is an enlarged vertical cross-sectional view of a part of FIG. 3 for explaining details of the method of bonding semiconductor substrates in FIGS. 2 and 6. FIG. In addition, in the codes used in the drawings, (1)■ ・-・・Surface plate (2X121 ・・・Sample holding plate (4X14)
... Wax (5) TL group ... Semiconductor substrate (6) ... Pressure plate 06) ... ... With elastic plate a ... Pressure row 2 12■ ... ...It is an adhesive device. Agent Masaru Doashi

Claims (1)

[Claims] After applying an adhesive material onto a sample holding plate placed on a flat plate, placing a semiconductor substrate on the sample holding plate via the adhesive material, and then pressing the semiconductor substrate onto the sample holding plate. In the semiconductor substrate bonding method, the semiconductor substrate is bonded to the sample holding plate by the adhesive material, after placing the elastic plate on the semiconductor substrate, a pressure roller is moved to the elastic plate. A method for adhering a semiconductor substrate, characterized in that the semiconductor substrate is adhered to the sample holding plate by rolling the pressure roller while pressing the semiconductor substrate through the sample holding plate.