JP2004335835A - Device for manufacturing semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for manufacturing a semiconductor capable of capturing a foreign material on a stage and suppressing an increase in leakage of inert gases. <P>SOLUTION: As a size of a budget part 13 is generally about 0.375 mm, a size of an adhesive sheet 12 is required to be 199.25 mm, and to be standardized as 199±0.25 mm because a distance 14 between the budget part 13 of a wafer 11 and an end face of the adhesive sheet 12 is required to be as close as to zero. The foreign particle 16 existing on the stage 15 regardless of its position in an central part or in the vicinity of edges can be captured by covering the whole flat surface of the wafer 11 by the adhesive sheet 12, and by absorbing the wafer 11 onto the stage 15 adhered by the adhesive sheet 12 with an electrostatic chuck. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is a semiconductor manufacturing apparatus provided with a method for removing foreign matter adhering on a wafer stage.
[0002]
[Prior art]
In a semiconductor manufacturing process such as etching and sputtering, if foreign matter adheres to the back surface of the wafer, an abnormality occurs in wafer processing, which causes a reduction in yield.
[0003]
For the purpose of improving this, there is a foreign matter removal wafer having an adhesive sheet adhered to the wafer surface as shown in Patent Document 1.
[0004]
FIG. 7 illustrates a conventional adhesive sheet bonded wafer. FIG. 7A is a top view of the entire surface of the wafer 1, and FIG. 7B is a cross-sectional view around the wafer 1.
[0005]
The size of the pressure-sensitive adhesive sheet 2 of the wafer 1 to which the pressure-sensitive adhesive sheet 2 is attached is smaller than the size of the wafer 1. At present, the size of the pressure-sensitive adhesive sheet 2 in the commercially available pressure-sensitive adhesive sheet 2 attached wafer 1 is 198 mm with respect to the wafer 1 size of 200 mm.
[0006]
FIG. 8 shows a conventional mechanism for removing foreign matter from the wafer 1 to which the adhesive sheet 2 is attached.
[0007]
As shown in FIG. 8A, when the foreign matter 4 on the stage 3 exists sufficiently inside the size of the adhesive sheet 2, the foreign matter 4 can be captured by sticking to the surface of the adhesive sheet 2. Therefore, as shown in FIG. 8B, the foreign matter 4 is removed from the stage 3 by mechanically unloading the wafer 1 with the adhesive sheet 2 attached thereto.
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 10-32488
[Problems to be solved by the invention]
Conventionally, the quality assurance on the wafer 1 has conventionally been 5 mm at the edge of the wafer 1, and the introduction portion of the inert gas on the stage 3 has existed around the edge 5 mm. In this case, there was no problem with the size of the 198 mm adhesive sheet 2 with respect to the size of the wafer 1 of 200 mm.
[0010]
However, as the quality assurance on the wafer 1 spreads to the edge of 3 mm and the outer periphery, the characteristic of the process is also to ensure the outer periphery of 3 mm. Therefore, the introduction portion of the inert gas on the stage 3 is further moved to the edge 2 mm from the conventional 5 mm. In this case, in the conventional commercially available pressure-sensitive adhesive sheet 2 sticking wafer 1, the inert gas is A new problem arises in that it is not possible to cope with the problem of increasing the amount of leakage.
[0011]
FIG. 9 is a sectional view showing the vicinity of the edge of the wafer 1.
[0012]
As shown in FIG. 9A, when the size of the adhesive sheet 2 is 198 mm, the flat portion (mirror surface) of the wafer 1 is not covered by about 0.65 mm except for the budget of the wafer 1.
[0013]
Therefore, as shown in FIG. 9B, when the foreign matter 4 exists near the edge of the stage 3, specifically, near the edge of 1 mm, the wafer 1 to which the adhesive sheet 2 is attached is attracted onto the stage 3 by the electrostatic chuck. However, even if the foreign matter 4 is out of the area where the adhesive sheet 2 is attached, the foreign matter 4 is not captured, and even if the wafer 1 with the adhesive sheet 2 attached thereto is mechanically carried out, the foreign matter 4 remains on the stage 3 as it is. As a result, it was impossible to prevent the leakage of the inert gas from increasing.
[0014]
That is, since the size of the pressure-sensitive adhesive sheet 2 described above is smaller than the size of the wafer 1, foreign substances 4 attached near the edge of the stage 3 cannot be captured, and leakage of the inert gas cannot be prevented. .
[0015]
Further, the pressure-sensitive adhesive sheet 2 has a charge amount much weaker than that of the Si wafer 1, and when the electrostatic chuck is attracted, if the time is short, a desired attracting force cannot be obtained, and the foreign matter 4 on the stage 3 is removed. Sometimes they cannot be caught.
[0016]
In such a state, it is impossible to improve the increase of the leakage of the inert gas due to the foreign matter 4, and therefore, it is necessary to open the vacuum chamber to the atmosphere and remove the foreign matter 4 on the stage 3 by wet maintenance. In some cases, the merits of the wafer 2 with the sheet 2 attached thereto cannot be utilized.
[0017]
[Means for Solving the Problems]
A first semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus comprising a semiconductor substrate and an adhesive sheet formed on a back surface of the semiconductor substrate, wherein the adhesive sheet covers a portion other than the budget portion of the semiconductor substrate. is there.
[0018]
The first semiconductor manufacturing apparatus according to the present invention is characterized in that the size of the adhesive sheet is reduced by 1 mm from the diameter of the semiconductor substrate.
[0019]
In the first semiconductor manufacturing apparatus according to the present invention, it is more preferable that the semiconductor substrate has a circular shape of 200 mm and the pressure-sensitive adhesive sheet has a size of 199 mm.
[0020]
A second semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus comprising a semiconductor substrate and an adhesive sheet formed on the back surface of the semiconductor substrate, wherein the adhesive sheet comprises a first adhesive sheet and an outer periphery of the first adhesive sheet. And a second pressure-sensitive adhesive sheet covering the second adhesive sheet.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
A first embodiment of the present invention will be described with reference to FIG.
[0022]
As shown in FIG. 1A, the size of the adhesive sheet 12 needs to be a size that covers the entire flat surface of the wafer 11.
[0023]
Ideally, the manufacturing method is to apply the material of the adhesive sheet 12 by spin coating. However, the size of the wafer 11 in the current punching is obtained by subtracting the size of the budget portion 13 of the wafer 11 as shown in FIG. Must be size.
[0024]
Since the size of the budget part 13 is usually about 0.375 mm, the size of the adhesive sheet 12 needs to be 199.25 mm, and the distance 14 between the budget part 13 of the wafer 11 and the end face of the adhesive sheet 12 is: Since it is necessary to make the value as close to 0 as possible, it is necessary to standardize it to 199 ± 0.25 mm (hereinafter abbreviated as 199 mm).
[0025]
As a result, as shown in FIG. 2, the entire flat surface of the wafer 11 is covered with the adhesive sheet 12, and as shown in FIG. By doing so, it becomes possible to capture the foreign matter 16 existing on the stage 15 irrespective of the central part or the vicinity of the edge.
[0026]
In addition, as shown in FIG. 2B, the foreign matter 16 on the stage 15 is removed from the stage 15 by unloading the wafer 11 with the adhesive sheet 12 attached thereto from the vacuum chamber, thereby increasing the leakage of the inert gas. Can be prevented.
[0027]
A recovery experiment of the amount of inert gas leakage was performed between the case of the conventional adhesive sheet 12 having a size of 198 mm and the case of 199 mm. The result data is shown in FIG.
[0028]
When the size of the adhesive sheet 12 is 198 mm, the leakage amount of the inert gas of 30 sccm is only improved by 5 sccm even when the adhesive sheet 12 bonded wafer 11 of 5 sl is used. : 16 sccm) cannot be satisfied.
[0029]
However, when the pressure-sensitive adhesive sheet 12 has a size of 199 mm, the leakage amount of the inert gas of about 30 sccm initially becomes 13.9 sccm by the 1 sl treatment, and the leakage amount of the inert gas can be suppressed within the standard.
[0030]
The 3sl treatment further improved the normal processing state to 12.8 sccm. By setting the size of the adhesive sheet 12 to 199 mm, it is shown that the foreign matter 16 in the vicinity of the edge is surely removed, and thereafter, even if the number of processed sheets is increased, the reduction in the amount of inert gas leakage is hardly observed.
[0031]
From this, it can be confirmed that the adhesive sheet 12-attached wafer 11 is improved by increasing the inert gas leakage by treating the adhesive sheet 12-attached wafer 11 of 3 sl.
[0032]
When the size of the pressure-sensitive adhesive sheet 12 is larger than 199.25 mm, the budget portion 13 is covered, and the foreign matter 16 in the wafer 11 cassette is captured by the pressure-sensitive adhesive sheet 12, and is transported onto the stage 15 in that state. In this case, the possibility that the foreign matter 16 falls on the stage 15 on the contrary and contaminates the vacuum chamber increases.
[0033]
In addition, in that part, a gap exists between the stage 15 and the foreign matter 16 on the stage 15 cannot be captured when there is a gap therebetween, and there is no effect on the increase of the leakage of the inert gas.
[0034]
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG.
[0035]
In FIG. 4, two types of adhesive sheets 12 are used.
[0036]
The adhesive force of the adhesive sheet 12 is generally represented by an elastic modulus (Young's modulus). That is, the elasticity refers to a load required for the adhesive sheet 12 to extend 100%, and the smaller the elasticity of the adhesive sheet 12, the stronger the adhesive force of the adhesive sheet 12.
[0037]
The adhesive force of the conventional pressure-sensitive adhesive sheet 12 is about 300 to 600 MPa in elasticity. In order to improve the effect of removing the foreign matter 16 on the stage 15 in the pressure-sensitive adhesive sheet 12 bonded wafer 11 in the first embodiment. Since the surface of the stage 15 is processed to have a groove for introducing an inert gas or the like, the surface is often uneven. To 299 MPa to improve the foreign matter 16 removal rate on the stage.
[0038]
However, improving the adhesive strength of the adhesive sheet 12 requires that the wafer 11 be moved from the stage 15 in the vacuum chamber, particularly when the surface roughness (roughness Ra) Ra of the stage 15 is 1.0 μm or less, such as atomic force. Due to the influence, it is stuck to the stage 15 and cannot be peeled off, so that a trouble that cannot be carried out from the stage 15 occurs.
[0039]
Therefore, in the adhesive sheet 12 on which the two types of adhesive sheets 12 are attached as shown in FIG. 4, a conventional adhesive sheet 12a having an elastic modulus of 300 to 600 MPa is attached on the silicon wafer 11 and the elastic modulus is applied to the outer periphery thereof. An adhesive sheet 12b reinforced to about 150 to 299 MPa is attached. The method of determining the area to which the pressure-sensitive adhesive sheet 12 is to be applied is determined by the integrated value of the attraction force per unit area.
[0040]
FIG. 5 illustrates the characteristics of the stage surface shape and the attraction force. FIG. 5B shows the in-plane distribution of the attraction force of the wafer 11 on the stage 15 with respect to the shape of the stage 15 shown in FIG.
[0041]
In the stage 15, the distance from the wafer 11 to the outer periphery is increased toward the outer periphery, so that the force at which the wafer 11 is attracted to the stage 15 is reduced as compared with the center. Accordingly, in order to obtain the same adhesive strength as the center of the wafer 11, it is necessary to strengthen the adhesive sheet 12b at the outer peripheral portion.
[0042]
The design of the adhesive force and the determination of the area to which the adhesive sheet 12 is attached are desirably determined based on the integrated value of the suction force of the wafer 11 per unit area.
[0043]
Since the shape and the like of the stage 15 differ depending on the individual equipment, the characteristics of the attraction force of the wafer 11 as shown in FIG. 5B are respectively obtained, and based on the results, the adhesive force of the adhesive sheets 12a and 12b is determined. By designing the pressure-sensitive adhesive sheet 12a <the pressure-sensitive adhesive sheet 12b and determining the area where the stage 15 and the pressure-sensitive adhesive sheet 12 are stuck, the releasability from the stage 15 is improved, and even in the peripheral portion where the suction power of the stage 15 is weak, the foreign matter is not removed. By effectively improving the removal rate of No. 16, an increase in leakage of the inert gas can be suppressed.
[0044]
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.
[0045]
FIG. 6 shows the adsorption time of the wafer 11 with the adhesive sheet 12 attached thereto to the electrostatic chuck and the voltage characteristics. The dielectric constant of the sheet of the wafer 11 to which the adhesive sheet 12 is attached is about 2 to 10.
[0046]
However, the pressure-sensitive adhesive sheet 12 has a thickness of 100 μm to 200 μm. Therefore, even if a voltage is applied to the electrostatic chuck, the suction force is small because the capacity is small. Weaker than wafer 11. Therefore, when the wafer 11 with the adhesive sheet 12 adhered thereto on the stage 15 is suctioned by using the electrostatic chuck, a predetermined suction force is not obtained, and the foreign matter existing on the stage 15 cannot be completely captured. .
[0047]
Specifically, when the voltage applied to the stage 15 was set to 700 V, the Si wafer 11 was able to obtain a desired suction force within one second. However, even when 700 V is applied to the stage 15, it takes a considerable amount of time to obtain the desired suction force on the wafer 11 to which the adhesive sheet 12 is attached, and the semiconductor manufacturing equipment is recognized as abnormal and cannot be used.
[0048]
Then, the time required for the adhesive sheet 12-attached wafer 11 to obtain a desired suction force on the stage 15 was investigated. As a result, it was found that when a voltage of 700 V was applied to the stage 15, a desired suction force could be obtained after 30 seconds.
[0049]
In addition, it is understood that in order to obtain a desired suction force by the voltage applied to the stage 15, the suction must be performed for a time longer than the time indicated by the characteristic curve. Although the foreign matter 16 has been captured, the foreign matter on the stage 15 can be reliably captured with a smaller number of sheets, and leakage of the inert gas can be reliably prevented.
[0050]
【The invention's effect】
In the present invention, as described above, the size of the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive sheet-attached wafer is increased by 1 mm from 198 mm of the conventional product to 199 ± 0.25 mm, and covers all flat surfaces other than the wafer budget portion. Existing foreign substances can be reliably removed, and leakage of inert gas can be prevented.
[0051]
In addition, by specifying the processing time by the voltage applied to the stage, a desired adsorption force is obtained, the number of foreign objects on the stage is reliably captured with a smaller number of sheets, and leakage of inert gas is prevented. can do.
[Brief description of the drawings]
FIG. 1 is a schematic view of the pressure-sensitive adhesive sheet-attached wafer of the present invention and its cross-sectional structure. FIG. 2 is an explanatory view of the size of the pressure-sensitive adhesive sheet of the present invention and foreign matter removal. FIG. Characteristic diagram of leakage amount [Fig. 4] Diagram of wafer with two types of adhesive sheets attached [Fig. 5] Stage shape and characteristic diagram of wafer suction force and adhesive force of adhesive sheet [Fig. 6] Adhesion FIG. 7 is a diagram showing the adsorption time and voltage characteristic of the sheet-attached wafer to the electrostatic chuck. FIG. 7 is a conventional adhesive sheet-attached wafer and its cross-sectional structure. FIG. 1)
FIG. 9 is an explanatory view of a conventional pressure-sensitive adhesive sheet size and foreign matter removal (part 2).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wafer 2 Adhesive sheet 3 Stage 4 Foreign matter 11 Wafer 12 Adhesive sheet 13 Budget part 14 Distance between budget part and adhesive sheet end 15 Stage 16 Foreign matter

Claims (4)

In a semiconductor manufacturing apparatus comprising a semiconductor substrate and an adhesive sheet formed on a back surface of the semiconductor substrate,
The semiconductor manufacturing apparatus, wherein the pressure-sensitive adhesive sheet covers a portion other than a budget portion of the semiconductor substrate. The semiconductor manufacturing apparatus according to claim 1,
A semiconductor manufacturing apparatus, wherein the size of the pressure-sensitive adhesive sheet is reduced by 1 mm from the diameter of the semiconductor substrate. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the semiconductor substrate has a circular shape of 200 mm, and the adhesive sheet has a size of 199 mm. In a semiconductor manufacturing apparatus comprising a semiconductor substrate and an adhesive sheet formed on a back surface of the semiconductor substrate,
The semiconductor manufacturing apparatus according to claim 1, wherein the pressure-sensitive adhesive sheet includes a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet covering an outer periphery of the first pressure-sensitive adhesive sheet.

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