JPH05299332A - Resist coating method for semiconductor wafer and suction jig - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent fine particles on the back surface of a semiconductor wafer, which cause pattern blurring, from being brought into a pattern transfer process by an exposure apparatus. [Structure] In step (a), the semiconductor wafer 1 is loaded on a mechanical carrier 7. In steps (b), (c) and (d), the upper suction jig 2u is held and the mechanical carrier 7 is withdrawn, and then the lower suction jig 2d is held. In (e), the resist is applied to the entire surface by the resist nozzle 4 while rotating the semiconductor wafer 1. In (f), the resist on the surface periphery is removed by the solvent nozzle 5. In (g), the upper suction jig 2u is held and changed, and the whole back surface is covered with solvent while rotating.
The back rinse nozzle 6 is used for cleaning in order of pure water or the like.
After drying (h) and (i), the mechanical transfer tool 9 is introduced, the suction of the upper suction jig 2u is released, and the semiconductor wafer 1 is placed on the mechanical transfer tool 9 and carried out and sent to the exposure device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist coating method for a semiconductor wafer and a suction jig used for resist coating in a resist process in a manufacturing process of a semiconductor device, which is placed in a pre-process of an exposure process such as reduction projection. ..

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a conventional semiconductor wafer resist coating method and a suction jig. The semiconductor wafer 1 having an orientation flat (hereinafter also referred to as OF) 1a for positioning in each step is attracted on the back surface by an upward stick-shaped suction jig 42 having a plurality of suction small holes 43 connected to a vacuum source. The resist which is rotated and discharged from the resist nozzle 4 is applied to the surface. Since the resist on the peripheral edge of the semiconductor wafer 1 is thicker than the resist on the entire other surface and the thickness is not uniform, the resist is removed by the solvent discharged from the solvent nozzle 5, and at the same time or after that, the solvent is discharged from the rinse nozzle 46 to the peripheral edge of the back surface of the semiconductor wafer 1. Next, water is discharged to clean the periphery of the back surface. After that, semiconductor wafer 1
To a stage of a reduction projection exposure apparatus (not shown),
Position with F and expose with a reticle (also called a photomask). In addition, backside scrubber may be performed by brushing using water or the like in a step before the resist coating step.

[0003]

In the submicron IC process, the reduction projection exposure apparatus has a depth of focus of 1 or less.
It is around μm. In the step of transferring a fine pattern by the reduction projection exposure apparatus after the resist coating step, when the semiconductor wafer 1 having fine particles attached to it is placed on the stage of the exposure apparatus, the thin semiconductor wafer 1 on the stage Is partially raised by particles, and as shown in FIG. 5, a good reticle 1 g
In addition, a reticle 1b with a defocused pattern is generated around the particles. The fine particles on the back surface of the semiconductor wafer 1 may be left on the stage, which causes the same pattern defect in many semiconductor wafers 1 in continuous processing. Even if this pattern defect is found in the inspection, it takes time and effort to wash and regenerate the stage by stopping the transfer process, and if it is not found in the inspection, it becomes a defective semiconductor device in the final test and all the processes in the meantime are wasted. become. Pattern blurring due to particles is greatly reduced by the backside scrubber, but contamination of the backside progresses due to contact with various transport tools after the backside scrubber and the pattern blurring cannot be extinguished, and the backside scrubber process becomes an economic loss. ..

An object of the present invention is to provide a semiconductor wafer resist coating method and a suction jig which can prevent fine particles on the back surface of a semiconductor wafer, which cause pattern blurring, from being brought into a pattern transfer process by an exposure apparatus. To do.

[0005]

According to the method for applying a resist on a semiconductor wafer of the present invention, a semiconductor wafer is arranged between a downward cup-shaped upper suction jig and an upward cup-shaped lower suction jig. First, resist is coated on the entire front surface of the semiconductor wafer held by the lower suction jig, and then the semiconductor wafer is held by the upper suction jig and changed to the entire back surface of the semiconductor wafer. The main process is a cleaning process. At this time, between the resist coating process and the cleaning process, the resist removing process is intervened in the peripheral edge of the surface of the semiconductor wafer held by the lower suction jig, or the main process is performed. Before the above, the semiconductor wafer carried on the mechanical transport tool is carried by the upper suction jig to withdraw the mechanical transport tool, and then the semiconductor wafer is held by the lower suction jig. Place the process, and after the main process,
There is a step of placing the semiconductor wafer on a mechanical carrier and carrying it out.

The semiconductor wafer suction jig of the present invention is a cup-shaped suction jig having an outer shape that matches the outer shape of the semiconductor wafer to be handled, and a plurality of vacuum jigs are connected to the peripheral edge surface of the suction jig. It has a suction small hole. At this time, the portion corresponding to the orientation flat of the semiconductor wafer forms a recess in which the suction small holes do not exist, or forms a plurality of recesses in which the suction small holes do not exist.

[0007]

Operation: Referring to FIG. According to the semiconductor wafer resist coating method of the present invention, the entire rear surface of the semiconductor wafer 1 is washed in the step (g) for the first time after the resist coating in the step (e), and then in the step (i), the mechanical transfer tool is used. 9
The semiconductor wafer 1 can be immediately placed on the stage of the exposure apparatus. Therefore, the semiconductor wafer 1 does not have a chance to come into contact with other various transport tools, and it is possible to prevent the carry-in of fine particles on the back surface of the semiconductor wafer, which causes pattern blurring in the pattern transfer process by the exposure apparatus. At this time, in the step (e), the resist removing process can be performed on the peripheral edge of the surface of the semiconductor wafer 1 while the semiconductor wafer 1 is held by the lower suction jig 2d for resist coating. And these main steps (e),
Before and after (f) and (g), steps (a), (b),
By placing (c) and (d) and steps (h) and (i), the semiconductor wafer 1 is carried in and carried out by the mechanical carriers 7 and 9 with respect to the resist coating apparatus, and all steps are completed.

Please refer to FIG. 2 (and 3). According to the semiconductor wafer suction jig of the present invention, the suction jigs 2u and 2d only come into contact with only the peripheral portion of the outer shape of the semiconductor wafer 1 including the orientation flat, and the adhesion of particles due to the contact is reduced. In particular, in step (g), since only the peripheral edge of the surface of the semiconductor wafer 1 from which the resist has been removed in step (f) is adsorbed, the adsorption jig 2u does not come into contact with the resist and generate particles at all. At this time, even if the resist is removed, the orientation flat portion of the semiconductor wafer 1 has a more irregular shape than other regular arc portions, and the resist removal is not always perfect. Therefore, it corresponds to the orientation flat of the suction jig. By forming a concave portion in the portion, generation and adhesion of particles are reduced. Recesses are also formed in the other arc portions to reduce the contact surface and reduce the generation and adhesion of particles.

[0009]

EXAMPLE FIG. 1 is a process diagram showing a resist coating method for a semiconductor wafer of Example 1, FIG. 2 is a perspective view of an adsorption jig used in FIG. 1, and FIG. 3 is an adsorption jig of Example 2. It is a perspective view. First, in FIG. 2, the upper suction jig 2u and the lower suction jig 2d are cup-shaped with an outer shape that matches the outer shape of the semiconductor wafer 1 having an orientation flat (OF) 1a. There is. This suction jig 2
u and 2d are provided with a plurality of suction small holes 3 (the suction small holes 3 do not appear in 2d in FIG. 2) connected to a vacuum source (not shown) on the peripheral edge surfaces. The suction jig 32 of the second embodiment shown in FIG.
Forms a concave portion 32f having no suction small hole 3 in a portion corresponding to the OF, and further forms a plurality of concave portions 32z having no suction small hole 3 in another portion.

In the resist coating process shown in FIG. 1, the suction jigs 2u (or 32) and 2d are used. Process (a)
In all 9 steps from (i) to (i), the downward cup-shaped upper suction jig 2u and the upward cup-shaped lower suction jig 2d
The semiconductor wafer 1 is positioned between the two facing each other, and both suction jigs move up and down, and the semiconductor wafer 1 can be sucked and rotated. When stopped, the OF corresponding portions face each other and are the same. Try to come to the position.

First, in step (a), the semiconductor wafer 1 is loaded on the mechanical carrier 7. Process (b)
Then, the semiconductor wafer 1 is once held by the upper suction jig 2u, the mechanical carrier 7 is withdrawn in the step (c), and then the semiconductor wafer 1 is held and changed by the lower suction jig 2d in the step (d). .. In step (e), while the semiconductor wafer 1 held by the lower suction jig 2d is rotated, resist coating is performed from the center of the semiconductor wafer 1 to the entire surface by the resist nozzle 4.
Next, in step (f), a resist removal process using a solvent is performed by a solvent nozzle 5 on the peripheral edge of the surface of the semiconductor wafer 1 which is still held by the lower suction jig 2d. Then, in step (g), the semiconductor wafer 1 is held and changed to the upper suction jig 2u, the lower suction jig 2d is covered with the cover 8, and the semiconductor wafer 1 is rotated from the center to the entire surface of the back surface with a solvent, pure solvent. A back rinse nozzle 6 is used for cleaning in order of water or the like. After the spin drying, finally, in step (h), the mechanical transfer tool 9 is introduced under the semiconductor wafer 1, and in step (i), the suction of the upper suction jig 2u is released, and the mechanical transfer tool 9 receives the semiconductor wafer. Place 1 and carry it out. For example, the step (e) is 3000
In the step (g), the number of revolutions is preferably 500 to 1000 rpm, and if the resist removal width in the step (f) is 3 mm in the outer circumference, the width of the peripheral edge surface of the suction jig 2u is preferably 2 mm.

According to the resist coating method of this embodiment, the entire back surface of the semiconductor wafer 1 is washed in the step (g) for the first time after the resist coating in the step (e), and then,
In step (i), the semiconductor wafer 1 can be placed on the mechanical carrier 9 and immediately placed on the stage of the exposure apparatus. Therefore, the semiconductor wafer 1 does not have a chance to come into contact with other various transport tools, and it is possible to prevent the carry-in of fine particles on the back surface of the semiconductor wafer, which causes pattern blurring in the pattern transfer process by the exposure apparatus. At this time,
The semiconductor wafer 1 is placed under the suction jig 2 for resist application.
While being held at d, the step of resist removal processing can be intervened on the peripheral edge of the surface of the semiconductor wafer 1. And before and after these main steps (e), (f) and (g),
By placing the steps (a), (b), (c) and (d) and the steps (h) and (i), the semiconductor wafer 1 is loaded and unloaded by the mechanical transport tools 7 and 9 with respect to the resist coating apparatus. All processes are completed.

Further, according to the cup-shaped suction jig of such an embodiment, the suction jigs 2u, 2d only come into contact with only the peripheral edge portion of the outer shape of the semiconductor wafer 1 including the orientation flat, and the particles due to the contact are generated. Adhesion is reduced. In particular, in step (g), since only the peripheral edge of the surface of the semiconductor wafer 1 from which the resist has been removed in step (f) is adsorbed, the adsorption jig 2u does not come into contact with the resist and generate particles at all. At this time, even if the resist is removed, the orientation flat portion of the semiconductor wafer 1 has a more irregular shape than other regular arc portions, and the resist removal is not always perfect. Therefore, it corresponds to the orientation flat of the suction jig. By forming a concave portion in the portion, generation and adhesion of particles are reduced. Recesses are also formed in the other arc portions to reduce the contact surface and reduce the generation and adhesion of particles.

[0014]

According to the semiconductor wafer resist coating method of the present invention, the semiconductor wafer is mounted on the stage of the exposure apparatus by the mechanical transfer tool immediately after the entire back surface of the semiconductor wafer is cleaned after the resist coating. You can Therefore, the semiconductor wafer has no opportunity to come into contact with other various transport tools, and there is an effect that it is possible to prevent carry-in of fine particles on the back surface of the semiconductor wafer, which causes pattern blurring in the pattern transfer process by the exposure apparatus. There is an effect that the defective rate of the apparatus is reduced, the labor for cleaning and reproducing the stage is reduced, and so-called in-line can be realized by connecting the resist coating apparatus and the exposure apparatus. At this time, all the steps are completed by interposing a resist removal process on the peripheral edge of the surface or carrying in and out.

According to the semiconductor wafer suction jig of the present invention, the suction jig only comes into contact with only the peripheral portion of the outer shape of the semiconductor wafer, which has the effect of reducing the adhesion of particles due to the contact. In particular, in the step of cleaning the entire back surface, only the peripheral edge of the front surface of the semiconductor wafer from which the resist has been removed is adsorbed, so that the adsorption jig does not contact the resist and generate particles at all. At this time, there is an effect that a concave portion is formed in a portion corresponding to the orientation flat of the suction jig or another circular arc portion to reduce a contact surface, thereby reducing generation and adhesion of particles.

[Brief description of drawings]

FIG. 1 is a process diagram showing a method for applying a resist on a semiconductor wafer according to a first embodiment.

FIG. 2 is a perspective view of a suction jig used in FIG.

FIG. 3 is a perspective view of a suction jig according to a second embodiment.

FIG. 4 is a perspective view showing a conventional semiconductor wafer resist coating method and a suction jig.

FIG. 5 is a plan view of the semiconductor wafer manufactured according to FIG.

[Explanation of symbols]

 1 semiconductor wafer 1a orientation flat 1b reticle 1g reticle 2u suction jig 2d suction jig 3 suction small hole 4 resist nozzle 5 solvent nozzle 6 back rinse nozzle 7 mechanical transport tool 8 cover 9 mechanical transport tool 32 suction jig 32f recess 32z recess 42 Adsorption jig 43 Adsorption small hole 46 Rinse nozzle

Claims (6)

[Claims] 1. A semiconductor wafer is placed between a lower cup-shaped upper suction jig and an upper cup-shaped lower suction jig, and the semiconductor wafer is first held by the lower suction jig. A resist is applied to the entire front surface of the semiconductor wafer, and then the semiconductor wafer is held and changed to the upper suction jig, and the entire back surface of the semiconductor wafer is subjected to a cleaning process, which is a main process. Wafer resist coating method. 2. The semiconductor wafer resist coating method according to claim 1, wherein a surface peripheral edge of the semiconductor wafer held by the lower suction jig is provided between the resist coating step and the cleaning step. A resist coating method for a semiconductor wafer, wherein the main step is to intervene the step of resist removal processing. 3. The method of applying a resist to a semiconductor wafer according to claim 1, wherein before the main step, the semiconductor wafer carried on a mechanical carrier is held by the upper suction jig. Then, a step of holding the semiconductor wafer on the lower suction jig after changing the mechanical carrier is removed, and after the main step, a step of placing the semiconductor wafer on the mechanical carrier and carrying it out is placed. A method for applying a resist to a semiconductor wafer, comprising: 4. A cup-shaped suction jig having an outer shape that matches the outer shape of a semiconductor wafer to be handled, characterized in that a plurality of suction small holes connected to a vacuum source are provided on the peripheral end surface of the suction jig. A semiconductor wafer suction jig. 5. The suction jig for a semiconductor wafer according to claim 4, wherein the portion corresponding to the orientation flat of the semiconductor wafer forms a recess in which the suction small hole does not exist. Ingredient 6. The suction jig for a semiconductor wafer according to claim 4, wherein a plurality of recesses in which the suction small holes are not present are formed.