JPH07115081A - Treatment apparatus - Google Patents

Abstract

PURPOSE:To make it possible to fully remove treatment solution for a wafer surface by providing a solution removing portion for releasing the treatment solution to a wafer holding portion adjoined to a peripheral end portion of a wafer. CONSTITUTION:A chuck pin 45 has a L-shaped section and has a projected portion 56 supporting a rear face of a wafer 5 on a horizontal surface 54, and a small through hole 57 for water drain is formed at a central part of a vertical plane 55. The bottom surface 57A of the through hole 57 is so formed that the surface is flush with a top surface 5A of the wafer. Water drops remaining at the central part of the chuck pin 45 at the time of spin drying of the wafer 5 can be removed through the small through hole 57, so that no solution remains at a holding portion of the wafer, thereby permitting the complete removal of the treatment solution and the production of high reliability devices with excellent yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus used for cleaning semiconductor wafers in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art The miniaturization of MOS memory has advanced, and 64M
Research and development is progressing from DRAM to 256 MDRAM and beyond. Under such circumstances, the wafer cleaning technology is considered to be very important in the future for ensuring the reliability and yield of semiconductor devices.

As a wafer cleaning method, for example, cleaning of an organic substance by a chemical solution of ammonia hydrogen peroxide (NH ₄ OH + H ₂ O ₂ + H ₂ O), for example, hydrochloric acid hydrogen peroxide (HCl + H ₂ O ₂ +)
H ₂ O) is used for cleaning metal contamination with a chemical solution, for example, natural oxidation is removed by light etching of a chemical solution of buffered hydrofluoric acid and a rinsing process (chemical solution washing) between them (commonly called RCA cleaning) is performed. In general, the cleaning apparatus was of a batch type in which wafers were immersed in a processing tank.

However, there are problems such as the size of the cleaning device becoming larger due to the larger diameter of the wafer (increasing the footprint) and the contamination from the back surface of the wafer to the front surface of the wafer, and the single-wafer automatic cleaning device has been reviewed. .

FIG. 6 shows a single-wafer automatic cleaning device. The single-wafer automatic cleaning apparatus 1 is equipped with an alkaline chemical solution chamber 2, an acid chemical solution chamber 3, and a rinse / spin drying chamber 4 for rinsing pure water and spin drying. The wafer 5 is held by the wafer chuck 7 at the peripheral end portion in each of the chambers 2, 3 and 4.

In the alkaline chemical chamber 2, for example, a chemical nozzle 8 capable of discharging a chemical solution of ammonia-hydrogen peroxide and a rinse nozzle 9 capable of discharging pure water are installed so as to face the front and back surfaces of the wafer 5.

In the acid-based chemical liquid chamber 3, a chemical liquid nozzle 11 capable of discharging a chemical liquid of hydrochloric acid / hydrogen peroxide, a chemical liquid nozzle 12 capable of discharging, for example, buffered hydrofluoric acid, and a rinse nozzle 13 capable of discharging pure water are provided on the surface of the wafer. It is installed so as to face the back surface.

In the rinse / spin dry chamber 4, a rinse nozzle 14 for discharging pure water for performing a final rinse.
Are installed so as to face the front and back surfaces of the wafer 5.

In the cleaning method, the wafer 5 is sequentially transported through the alkaline, acid and rinse drying chambers 2, 3 and 4, and the alkaline and acid chambers 2 and 3 are used.
In the chamber 4 of the rinse / spin drying system, the wafer chuck 7 holds the peripheral edge portion of the wafer 5, that is, the edge portion, and the chemical liquid is discharged from the front and back surfaces of the wafer 5 while rotating at a speed of, for example, about 1000 r / m. The final rinse with pure water and the wafer drying by rotating off are performed.

As shown in FIG. 7, the wafer chuck 7 has chuck pins 18 [18A, 18B] for holding the peripheral edge portion of the wafer 5 by sandwiching it at each tip of the radially extending arm 7 of the chuck base 16. Configured to have. A plurality of chuck pins 18, six in this example, are provided.
Three of them are fixed pins 18A, and the remaining three are movable pins 18B, and the movable pins 18B and the fixed pins 18A can be held together. Movable pin 18B
Although not shown, the cam presses and releases the wafer 5.

As shown in FIG. 8, the chuck pins 18 [18A, 18B] are sectioned so that the upper portion holding the wafer 5 has a horizontal surface 20 for receiving the back surface of the edge portion of the wafer 5 and a vertical surface 21 for receiving the edge side surface. It is formed in an L shape, and a protrusion 22 is provided on the horizontal surface 20 so as to support the wafer 5 at a point.

For spin drying, as shown in FIG. 7, the wafer edge portion is pressed and fixed by chuck pins 18 [18A, 18B], and the wafer 5 is rotated at 3000 r / m.
It is rotated by about m to remove moisture by the centrifugal force generated during rotation and dried.

[0013]

By the way, in the spin-drying in the above-mentioned single-wafer automatic cleaning apparatus 1, since the wafer 5 is fixed by the chuck pins 18, the centrifugal force generated during the rotation removes the water to dry the wafer 5. The dry state changes greatly depending on whether the surface of the wafer 5 is hydrophilic or hydrophobic. If an insulating film such as SiO ₂ is deposited on the wafer surface, it becomes a hydrophilic surface, and if it is a silicon surface, it becomes a hydrophobic surface.

That is, since the centrifugal force is less likely to be exerted on the water in the central portion of the wafer, it is necessary to draw it to the water remaining around it. However, since water is repelled on the hydrophobic surface, water drops are likely to remain in the central portion of the wafer, resulting in poor drying.

Therefore, the wafer surface is rotated at an extremely low rotation speed (about 70 r / m) before the spin-drying to move the water droplets in the central portion of the wafer to the periphery of the wafer, thereby eliminating the drying failure.

However, regarding the wafer edge,
On the hydrophobic surface, there is no problem because the water droplets fly off during acceleration, but on the hydrophilic surface, it is shaken off depending on the rotation speed and the holding time. Therefore, as shown in FIG. 7, the chuck pins 18 [18A, 18
In the portion B], the escape of water becomes worse, and the water drop residue 24 is generated.

Since this poor drying finally remains as particles, there is a possibility that when a CVD film or the like is deposited in the next step, it will be enlarged and become huge particles, or a problem will occur in surface flatness.

In view of the above points, the present invention provides a processing apparatus capable of sufficiently achieving so-called removal of a processing liquid on a wafer surface, such as a drying process.

[0019]

According to the present invention, in a processing apparatus for removing a processing liquid on the surface of a wafer by rotation, a liquid removing portion 57 for letting the processing liquid escape to a wafer holding portion 45 in contact with a peripheral edge portion of the wafer 5. , 58 or 59 is provided.

This removal of the treatment liquid can be used for the drying treatment.

The liquid removing portion provided on the wafer holding portion 45 can be formed by the through holes 57 and 58 or the groove 59.

Then, the through holes 57 and 58 constituting the liquid removing portion.
Alternatively, the groove 59 is formed such that its lower surface 57A, 58A or 59A is flush with the upper surface 5A of the wafer 5 held by the wafer holding portion 45.

[0023]

In the present invention, the liquid removing portions 57 and 5 for releasing the processing liquid to the wafer holding portion 45 which is in contact with the peripheral edge portion of the wafer 5.
Since 8 or 59 is provided, when the processing liquid attached to the wafer surface, particularly the hydrophilic surface is shaken off and removed by centrifugal force due to the rotation, the remaining liquid 24 in the wafer holding unit 45 is removed by the liquid removing unit 57, 58 or 59. Be removed through. Therefore, the processing liquid on the wafer surface can be sufficiently removed.

When used in the drying process, defective drying of the wafer holding portion is eliminated, and complete drying is possible.

By forming the liquid removing portion by the through holes 57, 58 or the groove 59, the remaining liquid 24 in the wafer holding portion can be easily released.

The through holes 57, 58 or the groove 5 constituting the liquid removing portion
9 is formed so that its lower surface 57A, 58A or 59A is flush with the held wafer upper surface 5A, the residual liquid 24 in the wafer holding portion is passed through the through holes 57, 58.
Or it can be surely escaped through the groove 59.

[0027]

Embodiments of the processing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a case where the present invention is applied to a single-wafer automatic cleaning device. The single-wafer automatic cleaning apparatus 31 of the present example includes an alkaline chemical solution chamber 32, an acid chemical solution chamber 33, and a rinse / spin drying chamber 34 that performs final pure water rinse and spin drying.

In the alkaline chemical chamber 32, a chemical solution nozzle 36 capable of ejecting a chemical solution required for cleaning organic substances, for example, a chemical solution of ammonia hydrogen peroxide (NH ₄ OH + H ₂ O ₂ + H ₂ O) and pure water can be ejected. Rinse nozzle 37
Are installed so as to face the front and back surfaces of the wafer 5.

In the acid type chemical solution chamber 33, a chemical solution necessary for cleaning metal contamination, for example, hydrochloric acid / hydrogen peroxide (HC) is used.
1 + H ₂ O ₂ + H ₂ O), a chemical solution nozzle 38 capable of ejecting a chemical solution, a chemical solution nozzle 39 for ejecting a chemical solution of, for example, buffered hydrofluoric acid for removing natural oxidation, and a rinse nozzle 40 capable of ejecting pure water. It is installed so as to face the front and back surfaces of the wafer 5.

In the rinse / spin drying chamber 34,
Rinse nozzle 4 that discharges pure water for the final rinse
1 is installed so as to face the front and back surfaces of the wafer 5.

In each of the chambers 32, 33 and 34, as shown in FIG. 2, the wafer 5 is chucked with a chuck pin 45 [which presses the peripheral edge portion of the wafer 5 onto the tip of the radially extending arm 44 of the chuck base 43. 45A, 4
5B] is held by a so-called wafer chuck 46. The wafer chuck 46 in each of the chambers 32, 33 and 34 is constructed so as to be rotatable about a shaft 47 while holding the wafer 5. Chuck pin 45
Are provided in plurality, six in this example, three of which are fixed pins 45A, and the other three are movable pins 45B. The wafer 5 is clamped and held by the cooperation of the fixed pin 45A and the movable pin 45B.

The flow of the wafer 5 in FIG. 1 will be described. The wafer 5 carried out from the loader unit 51 is introduced into the chemical chamber 32, and is rotated at about 1000 r / m, and is subjected to an organic matter and particle cleaning process by ammonia hydrogen peroxide from the chemical nozzle 36, and then in the same chamber 32. Then, a rough rinse with pure water from the rinse nozzle 37 is performed.

Next, the wafer 5 is introduced into the chemical chamber 33 and rotated at a speed of about 1000 r / m to clean the metal contamination by hydrochloric acid / hydrogen peroxide from the chemical nozzle 38 and the buffered hydrofluoric acid from the chemical nozzle 40. The natural oxide film is removed by. Then, a rough rinse with pure water from the rinse nozzle 40 is performed in the same chamber 33.

Then, the wafer 5 is introduced into the rinse / spin drying chamber 34, and finally rinsed with pure water from the rinse nozzle 41 to sufficiently release the chemical solution adhering to the front and back surfaces of the wafer 5. , The wafer 5 itself is rotated up to, for example, about 3000 r / m to shake off water and dry. Finally, the dried wafer 5 is carried out to the unloader unit 52, and one cycle is completed.

When the final chemical treatment of the wafer 5 is other than the treatment with buffered hydrofluoric acid, the front and back surfaces of the wafer 5 are both hydrophilic.

Therefore, in this example, the chuck pin 4 for fixing the wafer edge portion of the wafer chuck 46 is used.
5 [45A, 45B] is configured as shown in FIGS.

The chuck pins 45 shown in FIGS. 3A and 3B have a horizontal surface 54 whose upper portion holding the wafer edge portion receives the back surface of the edge portion of the wafer and a vertical surface 5 which receives the side surface of the edge portion.
5, a protrusion 56 for supporting the back surface of the wafer 5 at a point is provided on a horizontal surface 54 thereof, and a minute through hole 57 for draining water is provided at the center of the vertical surface 55.
Are formed and configured.

The through hole 57 holds the wafer 5 in the chuck pin 4
The lower surface 57A of the through hole 57 and the upper surface 5A of the wafer are formed to be flush with each other while being held at 5.

According to the embodiment of FIG. 3, the chuck pins 45 [45A, 45B] are used during the spin drying of the wafer 5 having the hydrophilic surface in the rinse / spin drying chamber 34.
The remaining water droplets 24 that have not been shaken off in the central portion of the above are shaken off through the minute through holes 57, the water droplets remain, and the poor drying is eliminated.

The chuck pin 45 [45 of FIG. 4A and FIG. 4B
A, 45B] is formed by forming a through hole 58 for draining water in the central portion of the vertical surface 55 so as to penetrate along the trajectory of water flowing by centrifugal force due to rotation. The lower surface 58A of the through hole 58 and the wafer upper surface 5A are formed flush with each other.

The chuck pin 45 [45A, 4 of FIG.
5B], since the through hole 58 is provided along the flow of the water to be shaken off, the water drop residue 24 at the chuck pin portion is shaken off more efficiently.

The chuck pin 45 of FIG. 5 [45A, 45
B] is formed by forming a groove 59 passing through the center of the vertical surface 55. In this case, the groove 59 can also be formed so that the groove lower surface 59A and the upper surface 5A of the held wafer 5 are flush with each other.

Also in the embodiment of FIG. 5, the chuck pins 45 [45A, 4A, 4A, 4A] are used for spin-drying the wafer 5 having the hydrophilic surface in the rinse / spin-drying chamber 34.
5B], the remaining water droplets 24 that have not been shaken off at the central portion of [5B] are shaken off through the groove 45, and the poor drying is eliminated.

According to the single-wafer automatic cleaning device 31 described above,
By providing through holes 57, 58 for draining water or grooves 59 in the central portion of the chuck pins 45 [45A, 45B] of the wafer chuck 46 holding the wafer 5, the wafer 5
When cleaning and subsequent drying treatment when is a hydrophilic surface, there is no defective drying of the wafer edge portion,
Particles can be reduced.

Further, since clean drying is possible,
The abnormality that the haze increases in the case after the drying treatment can be prevented, and the yield of semiconductor devices is improved.

In the above example, the method is applied to spin drying after cleaning, but it can also be applied to spin drying of other etching apparatuses. In addition, it can be applied to the removal of the chemical remaining on the wafer surface after the chemical treatment.

Further, in the above example, the present invention is applied to the single-wafer type cleaning device, but it can also be applied to the case of spin drying with a batch type cleaning device. Also in the case of this batch type, a liquid removing part (through hole, groove, etc.) for draining water is provided in the holding part of the wafer.

[0049]

According to the present invention, when the processing liquid on the wafer surface is removed, the liquid remains on the wafer holding portion,
It is possible to completely remove the processing liquid. Therefore, highly reliable devices can be manufactured with high yield.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a single-wafer automatic cleaning apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a wafer chuck and water droplet removal according to the present invention.

FIG. 3A is a front view showing an example of a chuck pin according to the present invention. 3B is a cross-sectional view of FIG. 3A.

FIG. 4A is a front view showing another example of the chuck pin according to the present invention. B is an enlarged sectional view taken along the line AA of FIG. 4.

5A is a front view showing another example of the chuck pin according to the present invention. FIG. B is an enlarged plan view of FIG. 5A.

FIG. 6 is a configuration diagram of a single-wafer automatic cleaning device used for a conventional description.

FIG. 7 is an explanatory diagram of a wafer chuck and a water drop residue according to a conventional example.

FIG. 8 is a front view of a chuck pin according to a conventional example. B is a cross-sectional view of FIG. 8A.

[Explanation of symbols]

1,31 Single wafer type automatic cleaning device 2,3,4,32,33,34 Chamber 5 Semiconductor wafer 7,46 Wafer chuck 8,11,12,36,38,39 Chemical solution nozzle 9,13,14,37, 40,42 Rinse nozzle 16,43 Chuck base 17,44 Arm 18 [18A, 18B], 45 [45A, 45B] Chuck pin 24 Water drop remaining 57, 58 Through hole 59 Groove

Claims (4)

[Claims] 1. A processing apparatus for removing a processing liquid on the surface of a wafer by rotation, wherein a liquid removing part for letting out the processing liquid is provided in a wafer holding part in contact with a peripheral edge part of the wafer. Processing equipment. 2. The processing apparatus according to claim 1, wherein the removal of the processing liquid is a drying process. 3. The processing apparatus according to claim 1, wherein the liquid removing portion is formed of a through hole or a groove. 4. The processing apparatus according to claim 3, wherein the lower surface of the through hole or groove forming the liquid removing section is flush with the wafer surface.