JP3917393B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to various substrates to be typified by semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magneto-optical disk substrates, magnetic disk substrates, etc. It relates to substrate processing equipment for processing the supply to the surface (especially the periphery) (cleaning process or etching process, etc.) the processing liquid (chemical liquid or pure water) to.
[0002]
[Prior art]
Conventionally, aluminum has been used as a wiring material for semiconductor devices, but copper has been used instead of aluminum in order to meet the demand for lower resistance of wiring accompanying higher signal speeds. . For this reason, in the semiconductor manufacturing process, a copper thin film is formed on one surface (device forming surface) or both surfaces of a semiconductor wafer (hereinafter simply referred to as “wafer”).
[0003]
When handling a wafer in a semiconductor manufacturing apparatus, if the hand of the transfer robot is contaminated by contact with a copper thin film or copper ions, this hand becomes a new source of contamination, leading to a decrease in the yield of the semiconductor device.
Therefore, for the wafer after the copper thin film is formed, an etching process or a cleaning process for removing the copper thin film or the copper ions on the peripheral portion (including the peripheral end surface) of the back surface and the front surface is indispensable.
[0004]
A substrate processing apparatus for performing such etching processing or cleaning processing includes, for example, a spin chuck that holds a wafer by gripping the peripheral edge of the wafer with chuck pins, and a rotational drive for driving the spin chuck. A rotation driving mechanism and a processing liquid nozzle for supplying a processing liquid such as an etching liquid or pure water to the wafer held by the spin chuck are provided.
The processing liquid nozzle is configured to supply the processing liquid toward the center of the back surface of the wafer, for example. The processing liquid supplied to the center of the back surface of the wafer is guided outward in the rotational radial direction by centrifugal force and spreads over the entire back surface of the wafer, and then circulates to the front surface side along the peripheral end surface, and enters the peripheral portion of the surface. Is also supplied.
[0005]
In order to prevent the spray of the processing liquid from reaching the device formation region, a blocking plate that rotates together with the spin chuck may be provided to face the wafer held by the spin chuck. Furthermore, an inert gas such as nitrogen gas is blown out from the center of the shielding plate toward the center of the wafer surface, thereby preventing the processing liquid from reaching the device formation region and the processing width at the peripheral edge of the wafer. (Radial width) may be controlled in some cases.
[0006]
[Problems to be solved by the invention]
When the wafer is rotated at a high speed by the spin chuck, the processing liquid that jumps out of the wafer under centrifugal force receives a large kinetic energy. When such splashes of the processing liquid bounce off the surface of the wafer from the spin chuck or the chamber wall, it is not easy to completely prevent the device from reaching the device formation surface.
[0007]
As a countermeasure, it may be considered to increase the flow rate of the inert gas supplied between the shielding plate and the wafer, but the result is that the running cost increases as the consumption of the inert gas increases. As a result, the manufacturing cost of the semiconductor device increases. Although it may be effective to reduce the distance between the shielding plate and the wafer, it is difficult to ensure the required reliability mainly due to mechanical design limitations and changes with time of the shielding plate.
[0008]
It is an object of the invention is to solve the technical problems described above, without increasing the running cost, with good reliability, the substrate processing equipment that can prevent the arrival of the treatment liquid droplets to the substrate surface Is to provide.
[0009]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above object, the invention according to claim 1 is arranged on a side opposite to the substrate rotating means as viewed from the substrate, and a substrate rotating means (1) for rotating the substrate about a predetermined rotation axis. A hollow rotating member (4) rotating around a rotating shaft provided substantially coaxially with the predetermined rotating shaft and having a blow-out port (43) formed at the peripheral edge, and the inside of the rotating member provided, the process by the rotation of the rotating member, the air flow generating means (42) for the air flow directed from at least the peripheral portion of the substrate outside the substrate blown from the air outlet, the substrate being rotated by the substrate rotation means A substrate processing apparatus including a processing liquid supply mechanism (3, 31, 32, 33) for supplying a liquid. The alphanumeric characters in parentheses indicate corresponding components in the embodiments described later. The same applies hereinafter.
[0010]
According to this configuration, the substrate rotating means rotates the substrate on one side of the substrate, and the hollow rotating member is rotated substantially coaxially on the opposite side of the substrate. Inside the rotating member, the air flow generating means for blown air flow directed by utilizing the rotation of the rotary member from the periphery of the substrate outside the substrate from the outlet is provided. Therefore, even if the droplets of the processing liquid supplied to the substrate by the processing liquid supply mechanism are directed toward the substrate, such splashes can be eliminated by the airflow generated by the airflow generation means.
[0011]
As a result, the treatment liquid splashes on the substrate surface with good reliability without increasing the flow rate of inert gas or the like to be supplied toward the substrate or reducing the interval between the rotating member and the substrate. Can be prevented.
According to a second aspect of the present invention, the air flow generation means may include a rotary blade (42) provided integrally with the rotary member.
Further, as described in 請 Motomeko 3, the rotation shaft of the rotary member is a hollow rotating shaft air passage (48) formed therein, said rotating member, the gas inlet port to the center of rotation (44 ) has, said airflow generating means, with the rotation of the rotating member, the air taken in the internal from the air passage through the gas inlet port through the outlet from the vicinity of the peripheral edge portion of the substrate It may include an exhaust member (42) that generates a pumping action for exhausting outward. Such an exhaust member may be a rotary blade as described in claim 2.
[0012]
The invention described in claim 4 is characterized in that the substrate processing apparatus is for removing unnecessary materials at the peripheral edge of the substrate rotated by the substrate rotating means. The substrate processing apparatus according to claim 1.
According to the present invention, when the processing liquid is selectively supplied only to the peripheral portion of the substrate to remove unnecessary materials on the peripheral portion of the substrate, it is ensured that the splash of the processing liquid reaches the central region of the substrate. Can be prevented.
[0013]
The unnecessary material on the peripheral edge of the substrate may be a metal ion or the like, or may be an unnecessary portion of a thin film formed on the substrate. That is, as described in claim 5, the substrate processing apparatus may be for etching away an unnecessary thin film formed on a peripheral portion of the substrate rotated by the substrate rotating means.
In this case, the processing liquid supply mechanism is an etching liquid supply mechanism (3) that supplies the etching liquid to the peripheral edge of the substrate held by the substrate rotating means. , 31, 32).
[0014]
With this configuration, the etching solution can be supplied only to the peripheral portion of the substrate, and the splash of the processing solution can be prevented from reaching the central region of the substrate.
The invention described in claim 7 further includes an inert gas supply nozzle (7) for supplying an inert gas toward the rotation center of the substrate rotated by the substrate rotating means. The substrate processing apparatus according to any one of the above .
[0015]
By this configuration, to generate an air flow directed from the periphery of the substrate to the outside of the substrate by the airflow generating means, supplying an inert gas toward the center of rotation of the base plate, by the inert gas, the peripheral portion of the substrate controls the processing width of, it is possible to prevent the arrival of the treatment liquid droplets to the substrate center region more reliably.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an illustrative view for explaining the configuration of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus includes a peripheral portion of a semiconductor wafer (hereinafter simply referred to as “wafer”) W (a peripheral portion of the surface of the wafer W and a peripheral portion of the wafer W) on which a thin film such as a copper thin film is formed on the entire surface and on the peripheral end surface. 2 is an apparatus for removing unnecessary thin films by etching and removing unnecessary substances such as metal ions (copper ions, etc.) adhering to the back surface of the wafer W. When a thin film is formed not only on the front surface of the wafer W but also on the back surface thereof, the thin film on the back surface can also be removed by etching.
[0017]
The substrate processing apparatus includes a spin chuck 1 that rotates a wafer W while holding the surface thereof substantially upward, a chuck rotation driving mechanism 2 that rotationally drives the spin chuck 1, and a spin chuck 1. The central axis nozzle 3 that discharges a processing liquid (chemical liquid such as an etching liquid or pure water) toward the center of the back surface (lower surface) of the wafer W held on the wafer W and the upper surface of the wafer W held on the spin chuck 1 A blocking plate 4 arranged in a row, a blocking plate rotation drive mechanism 5 for rotationally driving the blocking plate 4, a blocking plate elevating drive mechanism 6 for moving the blocking plate 4 up and down relative to the spin chuck 1, An inert gas supply nozzle 7 that supplies an inert gas such as nitrogen gas toward the center of the upper surface of the wafer W held by the spin chuck 1 is provided.
[0018]
The spin chuck 1 includes a hollow rotary shaft 11 arranged along the vertical direction, a spin base 12 fixed horizontally to the upper end of the rotary shaft 11, and a spin base 12 erected on the spin base 12. A plurality of chuck pins 13 to be gripped are provided.
A processing liquid supply pipe 31 is inserted through the hollow rotating shaft 11, and the central axis nozzle 3 is coupled to the upper end of the processing liquid supply pipe 31. The processing liquid supply pipe 31 can be supplied with the etching liquid from the etching liquid supply source via the etching liquid supply valve 32 and can be supplied with pure water from the pure water supply source via the pure water supply valve 33. it can.
[0019]
The blocking plate 4 includes a rotation shaft 41 that is disposed coaxially with the rotation shaft 11 of the spin chuck 1. The rotary shaft 41 is formed in a hollow shape, and an inert gas supply pipe 71 is inserted through the rotary shaft 41. The tip of the inert gas supply pipe 71 forms an inert gas supply nozzle 7. The inert gas supply pipe 71 is supplied with nitrogen gas from a nitrogen gas supply source via an inert gas supply valve 72.
[0020]
When the wafer W is loaded into or unloaded from the substrate processing apparatus, the blocking plate lifting / lowering driving mechanism 6 raises the blocking plate 4 to a standby position far above the spin chuck 1. On the other hand, when processing is performed on the wafer W, the blocking plate 4 is lowered to a processing position set very close to the surface of the wafer W held by the spin chuck 1. The blocking plate rotation drive mechanism 5 is controlled to synchronize with the chuck rotation drive mechanism 2 and rotationally drives the blocking plate 4 at the same rotation direction and the same rotation speed as the spin chuck 1.
[0021]
When the processing liquid is supplied from the central axis nozzle 3 to the center of the back surface of the wafer W while the spin chuck 1 and the blocking plate 4 are rotationally driven, the processing liquid receives a centrifugal force on the wafer W, and the wafer W Spreads across the entire backside. This processing liquid further goes around the peripheral end surface of the wafer W and reaches the surface of the wafer W. At this time, if the inert gas is ejected from the inert gas supply nozzle 7, the amount of the processing liquid flowing into the surface of the wafer W can be controlled, and the peripheral portion of the surface of the wafer W can be set to a desired processing width. (Width along the rotational radius direction). At this time, the blocking plate 4 assists in controlling the processing width by the inert gas and prevents the processing liquid splashing outward from the wafer W from reaching the central region of the wafer W.
[0022]
FIG. 2 is a perspective view of the blocking plate 4, and FIG. 3 is a partial cross-sectional view of the blocking plate 4 in the vicinity of the chuck pin 13. FIG. 4 is a cross-sectional view of the blocking plate 4. The blocking plate 4 is formed in a hollow disk shape, and the rotary blades 42 are formed therein at substantially equal angular intervals. More specifically, the blocking plate 4 has an upper plate portion 45 coupled to the lower end of the rotation shaft 41, and a lower plate portion 46 coupled to the upper plate portion 45 via a rotary blade 42, A lower surface of the lower plate portion 46 is configured to face the upper surface of the wafer W held by the spin chuck 1 at a close distance. The upper plate portion 45 and the lower plate portion 46 are opposed to each other with a minute gap at the peripheral edge portion, and a blowing port 43 that is opened over the entire circumference is formed in the gap portion. On the peripheral edge of the lower surface of the upper plate 45, a step 45 a is formed at a position corresponding to the upper edge of the wafer W held by the spin chuck 1. Thereby, the blowout port 43 is disposed above the peripheral edge of the wafer W.
[0023]
An air intake port 44 is opened at the center of the upper plate portion 45. Rotary blades 42 are formed radially from the air intake port 44. Each rotating blade 42 has a shape that curves in a direction opposite to the rotation direction of the shielding plate 4 as it goes outward in the radial direction of the shielding plate 4. And between the adjacent rotary blades 42 and 42, the air flow path 47 which spreads as it goes to radial direction outward is formed.
With such a configuration, when the blocking plate 4 is rotationally driven, the rotary blade 42 takes in air from the air intake port 44 and generates a pump action that exhausts it to the air outlet port 43 through the air flow path 47. It will be. Therefore, air is taken in from the air passage 48 formed between the inert gas supply pipe 71 and the rotary shaft 41 through the air intake port 44, and the air flows outward from the blowout port 43 in the rotational radial direction. Will be blown out.
[0024]
If the blocking plate 4 is rotated at a high speed together with the spin chuck 1, the pumping action by the rotating blades 42 is strengthened, so that the blowout flow rate from the blowout port 43 increases. Therefore, even if the processing liquid that has obtained a large momentum by rotating the spin chuck 1 at high speed collides with the chuck pin 13 or the inner wall of the chamber, the splashing of the processing liquid is generated from the outlet 43. Air flow 50 ensures that it is eliminated. Therefore, the splash of the processing liquid does not reach the central area of the wafer W. Of course, the inert gas supplied from the inert gas supply nozzle 7 not only contributes to the control of the processing width by the processing liquid, but also plays the role of removing the processing liquid splash together with the air flow 50.
[0025]
As described above, according to this embodiment, the rotating blade 42 is provided inside the blocking plate 4, and the air flow 50 is formed outward from the peripheral edge of the wafer W by using the rotation of the blocking plate 4. I have to. As a result, it is possible to reliably prevent the splash of the processing liquid from reaching the central region of the wafer W without increasing the flow rate of the inert gas or reducing the distance between the blocking plate 4 and the wafer W. The running cost of the substrate processing apparatus can be reduced.
[0026]
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, in the above embodiment, the inside of the blocking plate 4 is cut out to form the rotary vane 42. However, instead of the rotary vane 42, the flow passage cross-sectional area increases from the center of rotation toward the outer side in the radial direction. By forming the tubular air flow path to be radially formed in the blocking plate 4, it is possible to cause a pump action as the blocking plate 4 rotates.
[0027]
In addition, various design changes can be made within the scope of matters described in the claims.
[Brief description of the drawings]
FIG. 1 is an illustrative view for explaining the configuration of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view of a blocking plate.
FIG. 3 is a partial cross-sectional view of a blocking plate in the vicinity of a chuck pin.
FIG. 4 is a cross-sectional view of a blocking plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spin chuck 13 Chuck pin 2 Chuck rotation drive mechanism 3 Center axis nozzle 31 Processing liquid supply pipe 32 Etching liquid supply valve 33 Pure water supply valve 4 Shut-off plate 41 Rotating shaft 42 Rotor blade 43 Outlet 44 Air intake port 45 Upper plate part 46 Lower plate portion 47 Air passage 48 Air passage 50 Air flow 5 Shutter plate rotation drive mechanism 7 Inert gas nozzle 71 Inert gas supply pipe 72 Inert gas supply valve W Wafer

Claims (7)

Substrate rotating means for rotating the substrate around a predetermined rotation axis;
A hollow which is disposed on the opposite side of the substrate rotating means as viewed from the substrate, rotates around a rotation shaft provided substantially coaxially with the predetermined rotation shaft, and has a blowout port at the peripheral edge. A rotating member;
Arranged inside the rotating member, the rotation of the rotary member, and the air current generating means for blown air flow directed from at least the peripheral portion of the substrate outside the substrate from the outlet,
A substrate processing apparatus comprising: a processing liquid supply mechanism that supplies a processing liquid to a substrate rotated by the substrate rotating means.   The substrate processing apparatus according to claim 1, wherein the airflow generation unit includes a rotary blade provided integrally with the rotary member. The rotating shaft of the rotating member is a hollow rotating shaft having an air passage formed therein,
Said rotary member has a gas inlet port to the center of rotation, the airflow generating means, with the rotation of the rotating member, the air taken in the internal from the air passage through the gas inlet port of the substrate 3. The substrate processing apparatus according to claim 1, further comprising an exhaust member that generates a pumping action for exhausting outward from the vicinity of the peripheral portion through the blowout port .   4. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is for removing unnecessary materials at a peripheral portion of the substrate rotated by the substrate rotating means.   5. The substrate processing apparatus according to claim 4, wherein the substrate processing apparatus is for etching away an unnecessary thin film formed on a peripheral portion of the substrate rotated by the substrate rotating means.   6. The substrate processing apparatus according to claim 4, wherein the processing liquid supply mechanism includes an etching liquid supply mechanism that supplies an etching liquid to a peripheral portion of the substrate held by the substrate rotating means.   7. The substrate processing apparatus according to claim 1, further comprising an inert gas supply nozzle that supplies an inert gas toward a rotation center of the substrate rotated by the substrate rotating means.

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