JPH042754Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention applies resists, etc. to photomask substrates in which a light-shielding thin film is coated on a transparent glass plate, and to substrates in which a semiconductor oxide is coated on a semiconductor substrate. After the resist is applied, the resist is exposed to light in a predetermined pattern to form a pattern on these substrates. The present invention relates to a spin chuck for applying a processing liquid of a spin device used for processing liquids, etc., and particularly to a spin chuck for applying a processing liquid (hereinafter simply referred to as a spin chuck) that uses suction to attract and hold the substrate.

[Conventional technology]

Conventionally, this type of spin chuck is shown in Fig. 3a,
The item shown in b was found. In addition, the same figure a shows a top view, and the same figure b shows the _X3 - _X3 enlarged sectional view of the same figure a. This spin chuck consists of a disk-shaped substrate holder 2 integrally molded with an annular protrusion 1 on which a substrate is placed.
and a cylindrical rotation bearing part 4 provided with a fitting part 3 into which a rotation shaft (not shown) for rotating the substrate holding part 2 is fitted. Four holes 5, 5, 5, 5 are provided near the center of the substrate holding portion 2 on the annular protrusion 1 side.
On the other hand, a center hole 6 is also provided on the rotation bearing section 4 side of the substrate holding section 2, and the hole 5 and the center hole 6 are connected by a through hole 7 passing through the inside of the substrate holding section 2. Furthermore, an upper hole 8 having substantially the same size as the center hole 6 is provided on the upper surface of the rotation bearing section 4 (the surface on which the substrate holding section 2 is fixed), and the upper hole 8 has substantially the same size as the center hole 6. The rotation bearing part 4 includes a central hole 6 and an upper hole 8.
be fixed so that they substantially coincide with each other.

Next, the use of this conventional spin chuck will be described below using a resist coating process as an example.

First, a glass wafer 11 (diameter 76.4 mm, thickness 0.55
mm) (Fig. 3c) to the annular protrusion 1 of the substrate holder 2.
(diameter 65 mm, height 0.5 mm), and then, using a vacuum suction machine (not shown), pass the glass wafer through the upper hole 8, the center hole 6, the through hole 7, and the hole 5. 1
Aspirate and hold 1. Next, while rotating the rotating shaft fitted in the rotary bearing part 4, a resist solution (processing solution) is dropped to form a resist film (processing solution) with a desired thickness.

[Problem that the invention attempts to solve]

However, in the conventional spin chuck, the substrate is placed on the annular protrusion 1, and the substrate is broken into the holding part 2.
Since the hole 5 provided near the center of the substrate is suction-held, a thin substrate, such as the glass wafer 11 shown in FIG. 3c, is curved as shown in FIG. 3b. Finally, there was a drawback that the thickness of the resist film near the center of the substrate was different from that in other parts. In extreme cases, there was a drawback that the board could be damaged. Furthermore, since the spin chuck simply places the substrate on it, there is a drawback that even if the spin chuck moves a little before suction, the substrate will shift and fall off the annular protrusion 1.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to firmly hold the board by vacuum suction without damaging or even bending the board when it is mounted. Another object of the present invention is to provide a spin chuck that allows the substrate to be easily removed when the substrate is removed. Furthermore, it is an object of the present invention to provide a spin chuck capable of suppressing non-uniformity in the thickness of a formed treatment film in a process of applying a treatment liquid for resist or the like.

[Means for solving problems]

The present invention has been made to achieve the above object, and includes a substrate holding section and a rotation bearing section, and the substrate holding section has a substrate mounting surface on which a substrate is placed, and a substrate mounting surface on which the substrate is placed. a ring-shaped groove provided along the periphery of the mounting surface, a suction hole provided in the bottom surface of the groove, and a fixing surface facing the substrate mounting surface for fixing the rotary bearing part; The fixing surface includes a central hole provided on the fixed surface, and a through hole connecting the suction hole and the central hole, and the substrate is vacuum-adsorbed to the substrate mounting surface and processed on the substrate. In a spin chuck for coating a processing liquid, the outer shape of the plate mounting surface is selected to be smaller than the substrate, and the side surface of the peripheral edge of the substrate protruding from the substrate holding part is held by the preliminary holding surface. A plurality of preliminary holding means for holding the substrate are provided in the substrate holding part, and the preliminary holding means includes a sliding part that slides along the fixed surface so as to move away from or approach the rotation bearing part, and the preliminary holding surface is A spin chuck for applying a processing liquid, characterized in that it is provided with a preliminary holding part extending from the sliding part toward the substrate mounting surface so as to be located above the substrate mounting surface.

Further, it is preferable that the groove is provided near the periphery of the substrate mounting surface.

Here, the term "substrate" refers to a photomask substrate in which a light-shielding thin film is coated on a transparent glass plate, a semiconductor substrate such as Si, a substrate in which a semiconductor oxide such as SiO ₂ is coated on a semiconductor substrate such as Si, and a substrate formed on these substrates. This includes a substrate coated with a resist and a resist coated with a resist that is exposed to light in a predetermined pattern.

In addition, the spin chuck is used in the resist coating process,
This includes those used in spin devices used in developing processes, etching processes, cleaning processes, etc.

[Effect]

According to the spin chuck for applying processing liquid of the present invention, since the outer diameter of the substrate mounting surface is smaller than the substrate, the substrate can be held without curving when the substrate is mounted, and the substrate can be easily removed from the mounting surface when the substrate is removed. I can do it. This effect becomes more pronounced as the substrate becomes thinner. By the way, when the outer shape of the board mounting surface is made smaller,
When the substrate is placed on the substrate mounting surface, the substrate mounting surface is blocked from view by the substrate, making it difficult to align the rotation center of the substrate holder with the geometric center of the substrate. Furthermore, even if the center points of both substrates are close to each other when placed, the substrates may move before being vacuum-adsorbed. These factors lead to non-uniformity in the thickness of the treated film.

However, in the present invention, since the above-mentioned deviation of both centers is suppressed in advance by the preliminary holding means before vacuum suction, the substrate can be vacuum suctioned with the deviation of both centers suppressed.
Further, movement of the substrate before vacuum suction can also be prevented. As a result, when the processing liquid is applied onto the substrate while rotating the substrate, it is possible to prevent the thickness of the processing film formed on the substrate from becoming non-uniform.

In addition, the above-mentioned pre-holding means not only contributes to uniformity of film thickness, but also reduces the suction force caused by making the mounting surface smaller than the substrate by providing a pre-holding portion on the peripheral side of the substrate. This can be compensated for by contact, which allows for firm substrate holding.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

Fig. 1 shows the spin chuck of the present invention; Fig. 1a is a perspective view, Fig. 1b is a plan view, and Fig. 1c is a top view.
is a bottom view, d is an enlarged cross-sectional view taken along X ₁ -X ₁ of figure b, and figure e is an enlarged sectional view taken along Y ₁ -Y ₁ of figure b.

The spin chuck of this embodiment first includes a disk-shaped substrate holding section 9 and a cylindrical rotation bearing section 4. As shown in FIG.

The substrate holder 9 is a disk-shaped glass wafer 11 (diameter 76.4 mm, thickness 0.55 mm,
It has a circular substrate mounting surface 91 (diameter 70 mm) on which a substrate (made of soda lime glass) is placed. A ring-shaped groove 93 (width: 0.5 mm, depth: 1 mm, inner diameter of the groove is 63 mm) is provided on this circular substrate mounting surface 91, approximately concentrically with this mounting surface 91. Four suction holes 94 (diameter 0.5 mm) are provided on the bottom surface of this groove 93 at approximately 90° intervals. or,
A center hole 96 (diameter 2 mm) is provided at the center of a fixing surface 95 (diameter 70 mm) on which the rotary bearing section 4 of the substrate holding section 9 is fixed, and a central hole 96 (diameter 2 mm) is provided in the center of the fixing surface 95 (diameter 70 mm) on which the rotation bearing section 4 of the substrate holding section 9 is fixed. two through holes 97 with circular cross sections that connect the two suction holes 94 and the center hole 96;
(cross-sectional diameter of 2 mm) is provided in the substrate holding portion 9.

The glass wafer 11 is held in the substrate holding section 9.
Three claws 92 are provided as preliminary holding means for positioning the glass wafer 11 so that the center thereof substantially coincides with the center of the circular substrate mounting surface 91 and for preventing the glass wafer 11 from moving from this central position. ing. As shown in FIG. 1, each claw 92 has an L-shaped cross section and consists of a sliding part and a preliminary holding part. The sliding part is one surface 921 (hereinafter referred to as "sliding surface") on the fixed surface 95 side for sliding from the rotary bearing 4 toward the side surface of the substrate holding part 9 (or in the opposite direction). The other preliminary holding part protrudes about 0.45 mm from the substrate mounting surface 91 in order to temporarily hold the substrate as will be described later. Hereinafter, it has a "preliminary holding surface"). Note that this claw 92 is attached to the fixed surface 95 with a screw 98.
They are movably stopped at , and are spaced at approximately 120° intervals. On the other hand, the rotary bearing part 4 has a fitting part 3 and an upper hole 8 (diameter 2 mm), as in the conventional case, and is arranged so that the center hole 96 of the fixed surface 95 and the upper hole 8 almost coincide with each other. Then, the rotary bearing portion 4 is fixed to the fixed surface 95.

Next, a usage example of this embodiment will be explained in detail based on FIG. 2. In addition, figure a is a plan view, figure b is a bottom view, and figure c is a _Y2 - _Y2 enlarged partial sectional view of figure a.

First, loosen the screws 98 of each of the three claws 92, slide the three claws 92 fully outward, and then use these claws 92 as indicators to place the glass wafer 11 on the substrate mounting surface 91. glass wafer 11
and the center of the substrate mounting surface 91 substantially coincide with each other. Next, the three claws 92 that have been slid fully outward are slid inward, and the preliminary holding surfaces 922 of the claws 92 are held against the glass wafer 1.
1 and is fixed with screws 98 to temporarily hold the glass wafer 11. Next, a hollow part (not shown) in the rotating shaft 10 (fixed by a screw 101) fitted into the rotating bearing part 4, an upper hole 8, a central hole 96, a through hole 97, By a vacuum suction machine (not shown) through the suction hole 94 and the groove 93,
The glass wafer 11 preliminarily held on the substrate mounting surface 91 is attracted. In this way, the glass wafer 11
By applying the resist (processing liquid) onto the glass wafer 11 while rotating the spin chuck while adsorbing the resist film (processing liquid), it is possible to suppress the difference in film thickness of the resist film (processing film).

According to this embodiment, since the ring-shaped groove 93 is provided on the substrate mounting surface 91, the groove 93 is more effective than simply suctioning the glass wafer 11 using the suction hole 94.
3, the flatness of the glass wafer 11 can be better maintained. Further, since the glass wafer 11 is preliminarily held by the claws 92, even if the substrate holding part 9 moves slightly before suction, the glass wafer 11 will not move and the glass wafer 11 will not be moved to the desired position. can be retained.
Furthermore, in this embodiment, since the claws 92 suppress mismatch between the geometric center of the glass wafer 11 and the center of rotation, variations in the resist film thickness exist only around the glass wafer 11 and are normally It is possible to satisfy the required standards when forming a pattern. Furthermore, in this example,
Since the groove 93 is located around the substrate mounting surface 91,
The above-mentioned film thickness uniformity effect is promoted. Further, in this embodiment, since the amount of protrusion of the preliminary holding surface 922 of the claw 92 is not greater than the thickness of the glass wafer 11, the claw 92
There is no change in the resist film thickness near the contact portion on the side surface of the glass wafer 11.

Furthermore, in this embodiment, the preliminary holding surface 92 of the claw 92
2 preliminarily holds the glass wafer 11 by contacting the side surface of the glass wafer 11 that protrudes from the side surface of the substrate holding section 9 .
The glass wafer 11 can be easily removed by holding the side portions of the glass wafer 11 that are not in contact with each other.
In addition, the glass wafer 11 is not only held by vacuum suction, but also has its side portions held by the claws 92, so that it is held firmly even during rotation.

In the above-mentioned embodiments, the substrate holder has a disk shape, but it may have a rectangular shape, and the number of claws is not limited to three, but may be determined as appropriate to suit the shape of the substrate. Further, in the above embodiment, the number of suction holes was four, but it may be one.
Preferably, there are more than one in order to make the force with which the substrate is attracted through the groove more uniform. More preferably, three or more suction holes are provided at substantially equal positions, and the sum of the cross-sectional areas of the suction holes is greater than or equal to the cross-sectional area of the central hole. If the total cross-sectional area of the suction holes is less than the cross-sectional area of the center hole, when the board is placed on the board mounting surface, it will be as if the board is being sucked.
If the spin chuck is rotated in this state due to a misunderstanding that the substrate is truly attracted, there is a risk that the substrate will come off the substrate mounting surface. Moreover, the substrate holding part and the rotation bearing part may be integrally molded.

[Effect of idea]

According to the present invention, it is possible to prevent the substrate from curving and firmly hold it when it is mounted, and it is also possible to suppress mismatch between the geometric center of the substrate and the center of rotation, so that the processed film formed on the substrate can be It is possible to prevent the film thickness from becoming non-uniform. Further, when the substrate is detached, it can be easily removed.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the spin chuck of the present invention, in which Fig. 1a is a perspective view, Fig. 1b is a top view, Fig. 1c is a bottom view, and Fig. 1d is an X ₁ - _X1
The enlarged sectional view and the figure e are the _Y1 - _Y1 enlarged sectional views of the same figure b. Figure 2 shows an example of the use of the spin chuck of the present invention, in which figure a is a plan view and figure b is a plan view.
₁ is a bottom view, and _FIG . Figures 3a and 3b are a plan view showing a conventional spin chuck and an X ₃
-X ₃ is an enlarged sectional view, and FIG. 3c is a plan view showing an example of the substrate. 3... Fitting part, 4... Rotating bearing part, 8... Upper hole, 9... Base holding part, 11... Glass wafer,
91...Substrate placement surface, 92...Claw (preliminary holding means), 93...Groove, 94...Suction hole, 95...Fixed surface, 96...Center hole, 97...Through hole, 98... …
Screw, 921...Sliding surface, 922...Preliminary holding surface.

Claims (1)

[Claims for Utility Model Registration] The substrate holding section includes a substrate holding section and a rotation bearing section, and the substrate holding section has a substrate mounting surface on which a substrate is placed, and a substrate mounting surface along the periphery of the substrate mounting surface. a ring-shaped groove; a suction hole provided on the bottom of the groove;
The fixing surface includes a fixing surface facing the substrate mounting surface and fixing the rotary bearing part, a center hole provided in the fixing surface, and a through hole connecting the suction hole and the center hole. In a spin chuck for applying a processing liquid, which applies a processing liquid onto the substrate while the substrate is vacuum-adsorbed to the substrate mounting surface, the outer shape of the substrate mounting surface is selected to be smaller than the substrate. , a plurality of preliminary holding means are provided in the substrate holding section for holding a side surface of the peripheral edge of the substrate protruding from the substrate holding section with a preliminary holding surface, and the preliminary holding means holds the rotation along the fixed surface. A sliding part that slides away from or toward the bearing part, and a preliminary holding part that extends from the sliding part toward the substrate placement surface so that the preliminary holding surface is located above the substrate placement surface. A spin chuck for applying processing liquid.