JPH09187705A - Method for forming resin coating film and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a rising part without taking a long time. SOLUTION: A silicon wafer 1 is set on the upper face of a chuck stage 13, a resist 16 is dropped to the silicon wafer 1 while the chuck stage 13 being rotated, and the resist 16 is dispersed to the whole upper face of the silicon wafer 1 based on the centrifugal force, so that the resist 16 is applied to the silicon wafer 1. After the resist 16 applied to the silicon wafer 1 is temporarily pre-baked, the rising part 17 in the peripheral part of the resist 16 is heated by a spot heater 21 while the chuck stage 13 being rotated and when the heating is carried out sufficiently, a resist dissolving agent is supplied to the rising part 17 by a nozzle 18 for supplying the resist dissolving agent. In this case, the film thickness of the temporarily pre-baked resist 16 does not alter even if the silicon wafer 1 is rotated at high speed and the rising part 17 can be dissolved and removed while the silicon wafer 1 being rotated at high speed and consequently, the rising part 17 can be removed without taking a long time.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin coating method and an apparatus therefor.

[0002]

2. Description of the Related Art For example, when a protruding electrode made of a solder is formed by electrolytic plating on a connection pad provided on a silicon wafer for forming a semiconductor chip such as an IC chip, as shown in FIG. First, the connection pad 3 is formed on the insulating film 2 formed on the silicon wafer (substrate) 1.
A protective film 4 is formed on a portion of the upper surface thereof except the central portion of the connection pad 3, and the central portion of the connection pad 3 is exposed through the opening 5 formed in the protective film 4 is prepared. Then, the underlying metal layer forming layer 6 is formed on the entire upper surface. Next, a film thickness of 50 to 150 is formed on the upper surface of the base metal layer forming layer 6.
A relatively thick resist layer 7 of about μm is formed, and then an opening 8 is formed in the resist layer 7 in a portion corresponding to the connection pad 3, and electrolytic plating of solder is performed using the underlying metal layer forming layer 6 as a plating current path. By doing so, the protruding electrode 9 made of solder is formed on the upper surface of the underlying metal layer forming layer 6 in the opening 8 of the resist layer 7.

By the way, the thickness of the resist layer 7 is 50 to 1
Forming a relatively thick layer of about 50 μm makes the final height of the protruding electrode (not shown) after the heat treatment sufficiently high, and the shape of the protruding electrode does not become distorted. This is to achieve That is, as shown in FIG. 2B, the film thickness of the resist layer 7 is 3
When the thickness is about 0 μm, which is relatively thin, the solder plating is isotropically deposited on the resist layer 7, so that the shape of the protruding electrode 9 becomes a mushroom shape. Therefore, the resist layer 7
When peeling off, the resist layer 7 existing under the umbrella portion of the mushroom-shaped protruding electrode 9 may not be completely removed. In such a case, the shape of the final protruding electrode after the heat treatment becomes distorted, and the height of the protruding electrode becomes nonuniform. Further, since the initial shape of the protruding electrodes 9 is a mushroom shape, it is necessary to widen the interval between the adjacent protruding electrodes 9 in order to prevent a short circuit, which makes it difficult to achieve a fine pitch.

FIG. 3 shows an example of a conventional resin coating device used in such a case. This resin coating device includes a spindle chuck base 11. The spindle chuck base 11 is provided with a chuck base 13 having a horizontal upper surface on an upper portion of a spindle 12 which is horizontally rotated by a motor (not shown), and is connected to a hollow passage 14 provided inside the spindle 12. When the vacuum pump is driven, the upper surface of the chuck table 13 is set to a negative pressure. A resist dropping nozzle 15 is arranged above the center of rotation of the chuck table 13.

When a relatively thick resist layer 7 having a film thickness of about 50 to 150 μm is formed on the silicon wafer 1 by using this resin coating apparatus, the silicon wafer 1 is first placed on the upper surface of the chuck table 13. The vacuum pump is driven to make the upper surface of the chuck table 13 have a negative pressure so that the silicon wafer 1 is attracted to the upper surface of the chuck table 13. At this time, since the upper surface of the chuck table 13 is horizontal, the silicon wafer 1 is arranged in the horizontal direction. next,
The spindle chuck base 11 is horizontally rotated at a relatively low speed of about 500 rpm or less. Then, when a resist 16 having a relatively high viscosity of 1500 to 2000 cP is dropped from the resist dropping nozzle 15 onto the central portion of the upper surface of the silicon wafer 1, the resist 16 is diffused over the entire upper surface of the silicon wafer 1 by centrifugal force. As a result, the resist 16 is applied on the silicon wafer 1, and the resist layer 7 is formed thereby. Next, the resist 16 is dried by prebaking at about 120 to 130 ° C. for about 5 to 6 minutes using a hot plate (not shown) or the like.
Next, an opening 8 is formed in the resist layer 7 in a portion corresponding to the connection pad 3 by exposing and developing using a predetermined mask (see FIG. 2A). In this case, the exposure method includes contact exposure in which the mask is in contact with the resist layer 7 and proximity exposure in which the mask is separated from the resist layer 7 by about 10 to 20 μm.

However, in such a conventional resin coating method, when the rotation of the spindle chuck base 11 is stopped after the resist 16 is applied to the upper surface of the silicon wafer 1,
Although depending on the type of the resist 16, the thickness of the resist layer 7 corresponding to the peripheral edge of the silicon wafer 1, that is, the peripheral edge of the resist layer 7 is about 30 to 100 μm thicker than the predetermined thickness. The rising part 17 may be formed. In this case, even if the mask is brought into contact with the resist layer 7 in the exposure of the subsequent step, the mask is brought into contact with the raised portion 17, so that the distance between the portion of the resist layer 7 other than the raised portion 17 and the mask is 30 to 30 mm. It will be separated by about 100 μm,
The alignment gap that is a gap during alignment and the print gap that is a gap during exposure are 30 to 1
It also requires about 100 μm, and there is a problem that the alignment accuracy and the resolution deteriorate. Therefore, as a solution to this problem, as shown in FIG. 4, after the resist 16 is applied to the upper surface of the silicon wafer 1, the spindle chuck table 11 is rotated before the pre-baking while rotating the spindle chuck table 11 at a predetermined position on the peripheral portion of the silicon wafer 1. A method called edge rinse is used to dissolve and remove the rising portion 17 by supplying the resist dissolving agent to the rising portion 17 from the resist dissolving agent supply nozzle 18 arranged above the.

[0007]

However, when the resist layer 7 is formed to have a thickness of about 50 to 150 μm, the highly viscous resist 1 of about 1500 to 2000 cP is formed.
6, using the spindle chuck table 11 at 500 rpm
Since the rotation is performed at a low speed equal to or lower than the above, when the raised portion 17 is dissolved and removed by using the resist dissolving agent, when the spindle chuck table 11 is rotated at a high speed, the film thickness of the resist layer 7 is changed, and thus the high speed rotation is performed. However, there is a problem in that it takes time to make the raised portion 17 below a predetermined height. An object of the present invention is to make it possible to remove a raised portion in a short time.

[0008]

According to a first aspect of the present invention, there is provided a resin coating method, wherein a substrate is arranged in a horizontal direction, a resin coating material is dropped on the substrate while the substrate is rotated in the horizontal direction, and centrifugal force is applied. By diffusing the resin coating material over the entire upper surface of the substrate, the resin coating material is applied on the substrate, and after the resin coating material applied on the substrate is pre-baked, the resin coating material Only the raised portion is heated, and the resin coating material dissolving agent is supplied to the heated raised portion while rotating the substrate, whereby the raised portion is dissolved and removed. 3. The resin coating method according to claim 2, wherein the substrate is arranged in a horizontal direction, the resin coating material is dropped on the substrate while rotating the substrate in the horizontal direction, and the resin coating material is placed on the upper surface of the substrate by centrifugal force. By diffusing the whole, apply the resin coating material on the substrate, after provisionally pre-baking the portion of the resin coating material applied on the substrate except the ridges formed in the peripheral portion, The resin film material dissolving agent is supplied to the raised portion while rotating the substrate to dissolve and remove the raised portion. The resin coating device according to claim 3 is arranged so as to be rotatable in a horizontal direction, and a chuck table on which a substrate is placed on an upper surface,
Rotating means for rotating the chuck base, a resin coating material dropping nozzle for dropping the resin coating material on the substrate mounted on the upper surface of the chuck base, the rotating means being disposed above the chuck base; A pre-baking means for temporarily pre-baking the resin coating material applied on the substrate, and a heap of the resin coating material applied on the substrate placed above the chuck table and mounted on the upper surface of the chuck table. Heating means for heating an ascending portion, and resin film material melting which is disposed above the chuck table and supplies a resin film material dissolving agent to the rising portion of the resin film material applied to the substrate on the chuck table. And a nozzle for supplying the agent. The resin coating apparatus according to claim 4, wherein the chuck table is rotatably arranged in a horizontal direction, and a substrate is placed on an upper surface of the chuck table, and rotating means for rotating the chuck table.
Of the resin coating material dropping nozzle that is disposed above the chuck table and that drops the resin coating material onto the substrate that is placed on the upper surface of the chuck table, and the resin coating material that is applied onto the substrate A pre-baking means for temporarily pre-baking a portion other than the rising portion, and a resin film material dissolving agent supplied to the rising portion of the resin film material which is disposed above the chuck table and is applied to the substrate on the chuck table. And a nozzle for supplying a resin coating material dissolving agent.

According to the first or third aspect of the invention, after the resin coating material applied on the substrate is pre-baked,
The resin film material dissolving agent is supplied to the heated ridges while the substrate is rotated by heating only the ridges of the resin film material, so the film thickness of the temporarily prebaked resin film material rotates the substrate at high speed. There is no change even when the substrate is rotated, and the raised portion can be dissolved and removed while rotating the substrate at a high speed, and the raised portion can be quickly removed without taking time. According to the invention of claim 2 or 4, after temporarily pre-baking the portion of the resin coating material applied on the substrate excluding the raised portion, the resin is applied to the raised portion which is not temporarily pre-baked while rotating the substrate. Since the film material dissolving agent is supplied, the film thickness of the temporary pre-baked resin film material does not change even when the substrate is rotated at high speed, and the raised portion can be removed while rotating the substrate at high speed. The upstream part can be removed promptly without taking time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a schematic configuration diagram of a resin coating device according to an embodiment of the present invention, and FIG. 1B is a plan view thereof. In these figures, parts having the same names as those in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. In this resin coating device, a resist dropping nozzle 15 is arranged above the center of rotation of the chuck table 13. A resist dissolving agent supply nozzle 18 is provided above a predetermined portion of the outer peripheral portion of the chuck table 13, that is, above a predetermined portion of the peripheral edge portion of the silicon wafer 1 mounted on the chuck table 13.
Is arranged. In addition, a plurality of spot heaters (heating) that irradiate infrared rays are provided above another predetermined location on the outer peripheral portion of the chuck table 13, that is, above another predetermined location on the peripheral edge of the silicon wafer 1 mounted on the chuck table 13. Means) 21
Are arranged at predetermined intervals in the circumferential direction.

When a relatively thick resist layer 7 having a film thickness of about 50 to 150 μm is formed on the silicon wafer 1 by using this resin coating apparatus, first, the silicon wafer (substrate) 1 is used as the horizontal surface of the chuck table 13. Placed on the upper surface of the chuck 1, and the vacuum pump is driven to bring the upper surface of the chuck table 13 to a negative pressure, whereby the silicon wafer 1 is chucked.
Adsorb to the upper surface of 3. Next, spindle chuck stand 1
1 is rotated in the horizontal direction at a relatively low speed of about 500 rpm or less. When a resist (resin coating material) 16 having a relatively high viscosity of 1500 to 2000 cP is dropped from the resist dropping nozzle 15 onto the central portion of the upper surface of the silicon wafer 1, the resist 16 is removed from the silicon wafer 1 by centrifugal force. The resist 16 is applied on the silicon wafer 1 by diffusing it over the entire upper surface, whereby the resist layer 7 is formed.

Next, the rotation of the spindle chuck base 11 is stopped, the silicon wafer 1 is removed from the chuck base 13, and 120 to 13 are formed by using a hot plate or the like (not shown).
Temporary pre-bake at 0 ° C for about 2 to 3 minutes to form resist 1
Temporarily dry 6 Next, the silicon wafer 23 is placed on the upper surface of the chuck base 13 again, and the vacuum pump drives the negative pressure on the upper surface of the chuck base 13 to attract the silicon wafer 1 to the upper surface of the chuck base 13. Next, while rotating the spindle chuck base 11 in the horizontal direction at a relatively high speed of about 1000 rpm or more, the raised portion 17 formed on the peripheral portion of the resist layer 7 is heated to about 150 to 160 ° C. by the spot heater 21. When the heating portion 17 is sufficiently heated and the rising portion 17 is softened, when the resist dissolving agent is supplied to the rising portion 17 from the resist dissolving agent supply nozzle 18, the rising portion 17 is dissolved and removed. In this case, since the resist 16 is provisionally prebaked and provisionally dried, the film thickness does not change even if it is rotated at a relatively high speed of about 1000 rpm or more. On the other hand, the raised portion 17 is heated by the spot heater 21 and softened, so that it is easily dissolved in the resist dissolving agent. Next, using a hot plate or the like, 120 to 130 ° C
Main pre-baking is performed for about 2 to 3 minutes, and the resist 16 is main dried.

As described above, in this resin coating method, after the resist 16 applied on the silicon wafer 1 is temporarily pre-baked, the chuck base 13 is rotated in the horizontal direction and the protrusions formed on the peripheral edge of the resist 16 are rotated. Since the resist dissolving agent is supplied to the heated rising portion 17 while heating the portion 17 and rotating the chuck table 13, the film thickness of the temporarily prebaked resist 16 changes even when the silicon wafer 1 is rotated at a high speed. Instead, the raised portion 17 can be dissolved and removed while rotating the silicon wafer 1 at a high speed,
The raised portion 17 can be quickly removed without taking time.

Although a plurality of spot heaters 21 are arranged above the peripheral edge of the silicon wafer 1 in the above embodiment, the present invention is not limited to this, and the spot heater 21 is not limited to this, and is limited to the case where the silicon wafer 1 is rotated and heated. It is not necessary to dispose a plurality of units and only one unit may be disposed. In addition, in the above-described embodiment, after the resist 16 applied to the silicon wafer 1 is pre-baked, the rising portion 17 formed on the peripheral portion of the resist 16 is heated and the heated rising portion 17 is coated with a resist dissolving agent. However, the present invention is not limited to this, and after the portion of the resist 16 applied to the silicon wafer 1 excluding the raised portion 17 is pre-baked, the resist dissolving agent may be fed to the raised portion 17. .
In this case, since it is not necessary to heat the rising portion 17 using the spot heater 21, it is possible to simplify the equipment and the process. Furthermore, in the above-described embodiment, the case where the method is applied to the resist coating method has been described, but the present invention is not limited to this and can be applied to a method of forming a resin film made of polyimide or the like.

[0015]

As described above, claim 1 or claim 3
According to the invention described, after pre-baking the resin coating material applied on the substrate, only the rising portion of the resin coating material is heated, and the resin coating material melts in the heated rising portion while rotating the substrate. Since the agent is supplied, the film thickness of the temporary prebaked resin coating material does not change even when the substrate is rotated at high speed, and the raised portion can be dissolved and removed while rotating the substrate at high speed. Can be promptly removed without taking time. According to the invention of claim 2 or 4, after temporarily pre-baking the portion of the resin coating material applied on the substrate excluding the raised portion, the resin is applied to the raised portion which is not temporarily pre-baked while rotating the substrate. Since the coating material dissolving agent is supplied, the film thickness of the temporary prebaked resin coating material does not change even when the substrate is rotated at high speed, and the ridge can be removed while rotating the substrate at high speed.
The raised portion can be quickly removed without taking time.

[Brief description of the drawings]

FIG. 1A is a schematic configuration diagram of a resin coating device according to an embodiment of the present invention, and FIG. 1B is a plan view thereof.

2A and 2B are cross-sectional views showing a method of forming a protruding electrode using a conventional resin coating device.

FIG. 3 is a schematic configuration diagram showing an example of a conventional resin coating device.

FIG. 4 is a schematic configuration diagram showing another example of a conventional resin coating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon wafer (substrate) 11 Spindle chuck stand 12 Spindle 13 Chuck stand 15 Resist dropping nozzle 16 Resist (resin coating material) 17 Rise portion 18 Resist dissolving agent supply nozzle 21 Spot heater (heating means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B05D 3/02 B05D 3/02 Z

Claims (4)

[Claims] 1. A substrate is arranged in a horizontal direction, a resin coating material is dropped onto the substrate while the substrate is rotated in the horizontal direction, and the resin coating material is diffused over the entire upper surface of the substrate by a centrifugal force. By applying the resin coating material on the substrate, after pre-baking the resin coating material applied on the substrate, while heating only the rising portion of the resin coating material, while rotating the substrate A resin coating method characterized in that the resin coating material dissolving agent is supplied to the heated raised portion to dissolve and remove the raised portion. 2. A substrate is arranged in a horizontal direction, a resin coating material is dropped on the substrate while rotating the substrate in the horizontal direction, and the resin coating material is diffused over the entire upper surface of the substrate by a centrifugal force. Thus, the resin coating material is applied onto the substrate, and the portion of the resin coating material applied onto the substrate excluding the raised portion formed on the peripheral portion is pre-baked, and then the substrate is rotated. While the resin coating material dissolving agent is supplied to the raised portion while dissolving, the raised portion is dissolved and removed. 3. A chuck table which is rotatably arranged in a horizontal direction and on which a substrate is placed, a rotating means for rotating the chuck table, and a chuck table which is arranged above the chuck table. A resin coating material dropping nozzle for dropping a resin coating material on the substrate mounted on the upper surface of the substrate, a pre-baking means for temporarily pre-baking the resin coating material applied on the substrate, and an upper portion of the chuck table. Heating means for heating a raised portion of the resin coating material applied on the substrate, which is placed on the upper surface of the chuck table, and arranged on the chuck table above the heating means. A resin coating material dissolving agent supply nozzle for supplying a resin coating material dissolving agent to a rising portion of the resin coating material applied to a substrate, and a resin coating device. 4. A chuck table which is rotatably arranged in a horizontal direction and on which a substrate is placed, a rotating means for rotating the chuck table, and a chuck table which is arranged above the chuck table. A resin coating material dropping nozzle for dropping a resin coating material on the substrate placed on the upper surface of the substrate, and a pre-baking means for temporarily pre-baking a portion of the resin coating material applied on the substrate excluding a raised portion. And a nozzle for supplying a resin film material dissolving agent, which is arranged above the chuck table and supplies a resin film material dissolving agent to the rising portion of the resin film material applied to the substrate on the chuck table. A resin coating device characterized by being provided.