JP4339634B2 - Sample chucking apparatus in resist adhesion preventing method for sample back surface - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for preventing a resist from wrapping around a back surface of a sample when the resist is applied to the surface of a sample held on a rotating disk.
[0002]
[Prior art]
For example, when a resist is applied to the surface of a sample in a photolithography process in manufacturing a MEMS (micro electro mechanical system) element, which is a kind of sensor semiconductor device, or other semiconductor device, There has been a problem that the resist solution, resist mist, etc. wrap around. Conventionally, the sample is sucked and held by a vacuum chuck method on a rotating disk called a spinner head. However, since the first surface of the sample has a sub-micron class surface structure, the mechanical effect due to sucking and holding. Is not preferred, and sometimes the fine surface is damaged.
[0003]
[Problems to be solved by the invention]
The present invention has been made paying attention to the above situation, and the problem is that a resist can be prevented from adhering to the back surface of the sample and the resist can be prevented from being attached to the back surface of the sample without damaging the back surface of the sample. It is to provide. Another object of the present invention is to enable the resist adhesion preventing method according to the present invention to be carried out by a conventional vacuum chuck type apparatus.
[0004]
In order to solve the above-mentioned problems, the present invention provides a substantially uniform gap on the rotating plate in order to prevent the resist from wrapping around the back of the sample when applying the resist to the sample surface held on the rotating plate. Keeps the inside of the gap at a higher pressure than the outside, and prevents the resist applied to the sample surface from entering the inside of the back of the sample from the periphery based on the pressure difference created inside and outside the gap. In the method for preventing the adhesion of the resist to the back surface of the sample, a plurality of holding pieces are provided on the rotating plate, and the sample is held on the rotating plate with a substantially uniform gap by these holding pieces. of a receiving frame for supporting the sample from below, a stop piece to prevent escape from receiving frames of samples, consists of two kinds, the retaining piece is provided so as to be contact and separated from the periphery of the sample, the The receiving piece is In which it took measures that shall have substantially V-shaped groove of the holding portion engaged with the periphery of the charge.
[0005]
That is, the present invention makes it possible to hold the sample without contacting the back surface of the sample to the surface of the rotating disk, and keep the inside of the gap between the rotating disk surface and the sample generated for that purpose at a higher pressure than the outside. It creates a pressure difference inside and outside the gap. In order to keep the inside of the gap at a higher pressure than the outside, it is desirable to supply a high-pressure gas to the gap. However, the same effect can be expected even if the working environment outside the gap is reduced and atmospheric pressure can be introduced into the gap.
[0006]
The pressure difference formed inside and outside the gap prevents not only the difference in pressure but also the resist that tries to go inside the back surface of the sample not only by the airflow flowing from the inside to the outside. Although it is preferable that no wraparound of the resist is present, no problem occurs as long as the resist stays at the periphery and does not enter inward, and this wraparound meets the purpose of the present invention. . That is, the resist adhesion prevention to the back surface of the sample in the present invention includes those that reach the object even if they wrap around the back surface of the sample.
[0007]
In such a method of preventing adhesion of resist to the back surface of the sample of the present invention, a plurality of holding pieces that are in contact with the periphery of the sample and hold the sample are arranged on the rotating plate, and the holding piece has a required dimension from the rotating plate surface. A concave- angled holding part that can engage the periphery of the sample is provided at a position that is only a distance away, and a pressurized airflow is jetted into the gap between the sample held on the rotating disk and the rotating disk. It is desirable to carry out with a sample chucking device provided with a jet nozzle.
[0008]
The holding piece comes into contact with and holds the sample at the peripheral edge of the sample. Therefore, the holding piece is held on the rotating disk without touching anything on the front and back surfaces. The holding piece may have a concave holding portion that can be engaged with the periphery of the sample. For example, a pulley-like holding piece having a groove in the center can hold three pieces at intervals of 120 degrees. This holding method may be considered to have the same configuration as the holding piece in the invention of Japanese Patent Application Laid-Open No. 7-130642 related to the prior invention of the present inventor. However, in this holding method, the function of moving the position of the holding piece is It is essential. However, the holding piece can be divided into two types, a receiving piece that supports the sample from below and a stopping piece that prevents the sample from being removed from the receiving piece, and only the stopping piece can be provided so as to be able to contact and separate from the sample.
[0009]
The rotating disk is provided with an air nozzle that ejects a pressurized airflow in the gap between the sample and the rotating disk surface. As the gas, an inert gas such as nitrogen is used in addition to dry air. The fusible nozzle can take various forms such as one at the center or plural around the nozzle or a ring-shaped nozzle. For this reason, a conventional vacuum chuck type rotating disk having a vacuum suction port on the disk surface is used as the rotating disk, a holding piece is provided on the surface of the rotating disk, and a pressure pipe is connected to the vacuum suction port. The chuck device of the present invention can be configured to supply pressurized gas.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail based on the illustrated embodiments. 1 to 5 show Example 1 of the embodiment of the present invention. A rotating disk 11 is circular and attached to a boss 12 at the center, and the boss 12 serves as a vacuum suction port at the center of the rotating disk. It has an air passage that leads to the designed jet nozzle 13.
[0011]
As a holding piece for holding the sample 14 in contact with the periphery of the circular sample 14, a receiving piece 15 for supporting the sample 14 from below and a stop piece 16 for preventing the sample 14 from coming off are provided at the periphery of the rotating disk 11. A plurality of each is provided on a nearby board surface. The receiving piece 15 supports the sample 14 in point contact with a holding portion 17 having a concave corner at the boundary between the tapered slope of the lower large diameter portion and the cylindrical straight line of the upper small diameter portion (FIG. 3). The upper small-diameter portion does not interfere with the attachment / detachment of the sample 14, but a stopper piece 16 that engages the peripheral edge portion 19 of the sample 14 by point contact with a substantially V-shaped holding portion 18 for preventing the sample 14 from coming off. (FIG. 5).
[0012]
The receiving piece 15 is fixed to the surface of the turntable 11 with screws as attachment means 21 accurately near the periphery of the turntable 11 so that the upper small diameter portion contacts the sample 14 . Further, the stop piece 16 is also rotatably attached by the screw of the attachment means 22 exactly near the periphery. The stop piece 16 includes a portion 23 excluding a circular portion and the V-shaped groove-shaped holding portion 18, and is rotated by pushing and moving the outer portion 24 with a fingertip, and is engaged with the peripheral portion 19 of the sample 14. In the combined state, the sample 14 is fixed by point contact and stopped by the frictional resistance. In the case of the illustration, a total of 6 pieces are provided at intervals of 120 degrees for each piece.
[0013]
Therefore, a substantially uniform gap 20 is formed between the rotating disk surface and the sample 14 that is floated from the rotating disk surface and held by the holding piece. On the other hand, a piping from pressure gas is connected to the piping system 25 leading to the vacuum suction port / fountain nozzle 13. Reference numeral 26 denotes a motor as a rotational power unit, and 27 denotes a resist nozzle for a resist coating.
[0014]
Therefore, the sample 14 is placed on the support piece 15 of the holding piece on the turntable and the sample 14 is held on the turntable 11 by turning the stop piece 16 and engaging the holding portion 18 with the peripheral edge portion 19 of the sample 14. (See FIGS. 1 and 2). In this state, while the rotating disk 11 is driven, the resist solution can be ejected from the liquid nozzle 27 toward the sample 14, but the resist solution supplied from above to the center of the sample is moved outward by centrifugal force. And reaches the peripheral edge 19 of the sample surface and is shaken off by centrifugal force.
[0015]
However, a part of the resist solution tends to go around from the peripheral edge portion 19 to the back surface of the sample. Therefore, pressurized gas is supplied to the gap 20 through the piping system 25, and the inside of the gap is kept at a higher pressure than the outside to prevent the resist solution from entering (see FIG. 4). A pressurized air flow is constantly supplied to the gap 20 from the jet nozzle 13 so that the gap 20 is maintained at a higher pressure than the outside, and the excess air flow is indicated by arrows in FIG. It flows out to the outside. This flow of airflow to the outside is effective for eliminating resist mist.
[0016]
FIGS. 6 and 7 show Example 2 of the embodiment of the present invention, which is not diverted by vacuum suction chucking and has a configuration for floating the sample 14 from the beginning and holding it by the holding piece 35. Three holding pieces 35 are provided at equal intervals so as to be movable inward and outward in the radial direction from the center of the turntable 31. Each holding piece 35 has a substantially drum-shaped outer shape provided with a concave-shaped holding portion 36 on the outer side so as to contact and hold the peripheral edge portion 19 of the sample 14, and its upper portion 37 is relatively lower than the lower portion 38. The small diameter makes it easy to set the sample, and even if it is slightly opened, it is supported by the lower portion 38 so as not to fall.
[0017]
Each holding piece 35 is attached to the upper end of a support shaft 32 that is parallel to the central axis of the turntable, and the support shaft 32 is attached to a slider 33 of a movable mechanism incorporated in the turntable. The movable mechanism moves the three holding pieces 35 inward and outward in the radial direction by the same distance simultaneously, and has a biasing force that biases all the holding pieces 35 inward in the radial direction. The peripheral edge portion 14 of the 14 is pressed inward and is automatically held. This urging force includes a base portion 39 having a guide groove 34 formed of a circular arc directed in the radial direction of the rotating disk 31 as a whole, and an engaging protrusion 41 attached to the support shaft 32 so as to engage with the guide groove 34. And have. Further, a spring 42 is disposed in the annular space 40 between the turntable 31 and the base 39, one end of which is attached to the lever 43, and the other end is positioned with respect to the base 39. It is attached to locking means 44 for locking.
[0018]
Further, the movable mechanism is provided with a partition plate 45 interposed between the turntable 31 and the base portion 39, and is provided with a long groove 47 in the same direction as the long groove 46 in the radial direction formed on the surface of the turntable. . Reference numeral 48 denotes an operation port provided on the base portion side. When the lever 43 is operated in this opening range, the holding piece 35 near the center of FIG. 6 has the engagement projection 41 having a radius along the guide groove 34. Since it moves outward in the direction, the chucking diameter by the three holding pieces 35, 35, 35 can be changed in size. Since the other structure may be the same as that of Example 1, reference numerals are used and detailed description is omitted.
[0019]
In the case of Example 2, the position of the holding piece 35 is adjusted by operating the lever 43 to hold the sample 14. At this time, the sample 14 can be supported by the holding unit 36 if only the upper portion 37 of each holding piece 35 is opened to a diameter that allows the sample 14 to pass. In this state, the rotating disk 31 can be rotated and the resist solution can be ejected from the liquid nozzle 27 toward the center of the sample 14. The resist solution moves outward by centrifugal force and reaches the peripheral edge 19. Then it is shaken off.
[0020]
A part of the resist solution remains on the peripheral edge portion 19 of the sample 14, and the resist mist tends to go from the sample surface to the sample back surface. However, since a pressurized airflow is supplied to the gap 50 between the back surface of the sample and the surface of the rotating disk, and the pressure in the gap 50 is kept higher than the outside and there is an airflow going outward from the gap 50, the resist solution is also resist. It is only a part that the mist can wrap around the back of the sample, and it does not cause harm in practice.
[0021]
FIG. 8 is a schematic view of an optical microscope showing test results obtained by stopping the method of the present invention in order to grasp and compare the wraparound of the resist solution using the chuck device of the present invention shown in Example 1. . According to FIG. 8 (a), wraparound is recognized at the holding position by the six holding pieces on the back surface of the sample. As shown in FIG. 8 (b), the wraparound includes the resist solution indicated by the line and the resist mist. And streaks extending like a string. On the other hand, as a result of carrying out the resist adhesion preventing method of the present invention, the wraparound to the extent shown by the chain line M in FIG.
[0022]
【The invention's effect】
Since the present invention is configured and operates as described above, it is possible to prevent the resist from wrapping around the back surface of the sample in the resist coating process on the sample surface, and the sample is held in a non-contact manner on the rotating disk. Therefore, there is no risk of damage to the sample, and the present invention can be implemented even if a conventional vacuum chuck type device is modified, so that a remarkable effect is achieved such that the cost is set to be extremely low.
[Brief description of the drawings]
FIG. 1 is a plan view showing Example 1 of a sample chuck device used in a method for preventing adhesion of a resist to a sample back surface according to the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a cross-sectional view showing a receiving piece portion of the above.
FIG. 4 is a cross-sectional view illustrating the operation of the present invention.
FIG. 5 is a cross-sectional view showing a stop piece portion.
FIG. 6 is a plan view showing Example 2 of a sample chuck device used in the method of the present invention.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8A is a backside view of a sample for comparison and explanation of the effects of the present invention.
(B) Explanatory drawing which expanded the principal part similarly.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11, 31 Rotating disk 13 Fountain nozzle 14 Sample 15 Receiving piece 16 Stopping piece 17, 18, 36 Holding part 19 Peripheral part 20, 50 of sample 25 Gap 25 Piping system 35 Holding piece

Claims (3)

When applying the resist to the sample surface held on the rotating plate, in order to prevent the resist from wrapping around the back side of the sample, hold the sample with an almost uniform gap on the rotating plate, A method for preventing the resist from adhering to the back of the sample by keeping the pressure higher than that and preventing the resist applied to the surface of the sample from entering the inside of the back of the sample from the periphery based on the pressure difference created inside and outside the gap. In this example, the holding plate is provided with a plurality of holding pieces, and the holding piece is used to hold the sample with a substantially uniform gap on the rotating plate. The holding piece includes a receiving piece for supporting the sample from below, the stop piece to prevent escape from the frame received, consists of two kinds, the retaining piece is provided so as to be contact and separated from the periphery of the sample, the receiving frame is engaged with the peripheral portion of the sample V-shaped groove Chucking device of the sample in the resist adhesion preventing method for the sample back surface having a retaining portion. When applying the resist to the sample surface held on the rotating plate, in order to prevent the resist from wrapping around the back side of the sample, hold the sample with an almost uniform gap on the rotating plate, A method for preventing the adhesion of resist to the back surface of the sample by preventing the resist applied to the surface of the sample from flowing from the peripheral portion toward the center of the back surface of the sample based on the pressure difference created inside and outside the gap. A plurality of holding pieces that are in contact with the periphery of the sample and hold the sample with a substantially uniform gap on the rotating plate, and the holding piece is placed at a position separated from the rotating plate surface by a required dimension. A configuration in which a concave-angled holding portion capable of engaging with the periphery is provided, and the rotating disk is provided with a jet nozzle for injecting a pressurized air flow into a gap between the sample held on the rotating disk and the rotating disk. Hold the holding piece under the sample A receiving piece for supporting, consists of two kinds of the stop piece to prevent escape from receiving piece of the sample, the stop piece is provided so as to be contact and separated from the periphery of the sample, the receiving frame is in the sample An apparatus for chucking a sample in a method for preventing adhesion of a resist to a back surface of a sample , comprising a holding portion having a substantially V-shaped groove that engages with a peripheral portion . The turntable is a conventional vacuum chuck type turntable having a vacuum suction port on the surface, and a holding piece is arranged on the turntable surface to supply pressurized gas to the piping system leading to the vacuum suction port. 3. A sample chucking apparatus in a method for preventing resist adhesion to the back surface of a sample according to claim 2, wherein the pressure piping is connected.

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