JP3638374B2 - Rotary substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary substrate processing apparatus that performs predetermined processing on a substrate while rotating the substrate while being held horizontally.
[0002]
[Prior art]
In a rotary substrate processing apparatus such as a rotary coating apparatus and a rotary developing apparatus, a substrate such as a semiconductor wafer needs to be held horizontally and rotated. As a device for holding a substrate, a suction type spin chuck that holds the back surface of the substrate by vacuum suction has been conventionally used.
[0003]
[Problems to be solved by the invention]
However, in the suction type spin chuck, strong suction is performed in order to firmly hold the substrate, and this may cause a suction mark on the back surface of the substrate, which may adversely affect the processing in the subsequent process. There is also a problem that the back surface of the substrate is easily contaminated.
[0004]
In view of this, the present inventors have devised an outer peripheral edge holding type substrate rotation holding device (mechanical spin chuck) that rotates the substrate while holding the back surface peripheral edge portion and the outer peripheral end surface of the substrate. FIG. 6 is a schematic configuration diagram of the substrate rotation holding device. The substrate rotation holding device of this structure has not been disclosed.
[0005]
In FIG. 6, the substrate rotation holding device includes a substrate holding table 41 for holding the substrate 9. The substrate holding table 41 includes a disc-shaped bottom plate 42 and a ring-shaped substrate support member 43 formed on the periphery of the bottom plate 42. The substrate support member 43 includes a plurality of pin members 46 a that support the bottom surface of the substrate 9 and a plurality of pin members 46 b that regulate the position of the substrate 9 in the horizontal direction.
[0006]
When the substrate 9 is placed on the substrate holding table 41, a substantially sealed space X is formed between the substrate 9 and the bottom plate 42 of the substrate holding table 41. Therefore, it is difficult for mist (spray) and particles (particles) floating in the vicinity of the upper surface of the substrate 9 to enter the back surface side of the substrate 9, thereby preventing contamination of the back surface of the substrate 9.
[0007]
However, if the periphery of the substrate 9 is surrounded by the substrate holding member 43, the transfer arm for delivering the substrate 9 cannot be sent to the lower surface of the substrate 9.
Therefore, in the illustrated substrate rotation holding device, a plurality of through holes 44 are provided in the bottom plate 42 of the substrate holding table 41. Further, the substrate push-up pin 45 is raised from below through the through hole 44 to push up the substrate 9. The substrate 9 can be delivered by feeding the transfer arm to the lower surface of the substrate 9 pushed up by the substrate push-up pin 45.
[0008]
However, during the rotation operation of the substrate holding table 41, the air in the space X below the substrate 9 receives centrifugal force and is pushed out of the substrate holding table 41, and the pressure in the space X decreases. When the pressure in the space X decreases, the air below the bottom plate 42 is sucked into the space X through the through hole 44. If this air is contaminated with mist or particles, the mist or particles enter the space X and adhere to the back side of the substrate 9, thereby causing a problem of contaminating the back side of the substrate.
[0009]
An object of the present invention is to provide a rotary substrate processing apparatus capable of rotating a substrate without causing contamination of the back surface of the substrate.
[0010]
[Means for Solving the Problems and Effects of the Invention]
A rotary substrate processing apparatus according to a first aspect of the present invention includes a motor having a rotary shaft extending in the vertical direction, and a bottom plate attached to the tip of the rotary shaft of the motor and formed with a through hole. A substrate holding member that rotates while holding the substrate horizontally across the space, and a gas supply that prevents a negative pressure region from being generated on the lower surface of the substrate by supplying gas into a predetermined space on the lower surface side of the substrate The gas supply means includes a nozzle cap having a discharge port for discharging gas at the center of the lower surface of the substrate and attached to the center of the upper surface of the bottom plate.
[0011]
A rotary substrate processing apparatus according to a second aspect of the present invention is the rotary substrate processing apparatus according to the first aspect, wherein the gas supply means extends in the axial direction inside the rotary shaft and the tip is a bottom plate of the substrate holding member. And a supply pipe that passes through a discharge port of the nozzle cap and communicates with a predetermined space, and a lower end of the supply pipe and a gas supply source provided outside are connected to supply gas supplied from the gas supply source. And a gas introduction pipe that leads to the road.
[0012]
A rotary substrate processing apparatus according to a third aspect of the present invention is the rotary substrate processing apparatus according to the second aspect of the present invention, wherein the lower end of the supply line is connected to a cleaning liquid supply source provided outside, and a cleaning liquid supply source is connected. The cleaning liquid introduction line for guiding the cleaning liquid supplied from the supply line to the supply line, the state where the supply line and the gas introduction line are connected, and the state where the supply line and the cleaning liquid introduction line are connected And a switching means.
[0013]
A rotary substrate processing apparatus according to a fourth aspect of the present invention is the rotary substrate processing apparatus according to the second aspect of the invention, wherein the supply pipe line has a first passage and a second passage extending independently of each other. The gas introduction pipe is connected to the first passage of the supply pipe, and the second passage of the supply pipe is connected to the cleaning liquid supply source provided outside, and supplied from the cleaning liquid supply source. A cleaning liquid introduction pipe for guiding the cleaning liquid to be supplied to the second passage of the supply pipe.
[0014]
In the rotary substrate processing apparatus according to the first to fourth inventions, the gas supply means supplies gas to the lower surface side of the substrate during the substrate rotation processing. For this reason, even when a centrifugal force due to the rotation of the substrate acts on the gas on the lower surface side of the substrate, this region is prevented from being filled with gas and becoming negative pressure. Accordingly, the air on the lower side of the substrate holding member is prevented from entering the back surface side of the substrate through the through hole of the bottom plate, and contamination of the back surface of the substrate is prevented.
[0015]
In particular, in the rotary substrate processing apparatus according to the second invention, a supply pipe is provided inside the rotary shaft, and gas is guided to the lower surface side of the substrate through this supply pipe. For this reason, the generation of a negative pressure region on the lower surface side of the substrate can be prevented with a simple configuration without requiring an extra space for the gas supply conduit.
[0016]
In particular, the rotary substrate processing apparatus according to the third aspect of the invention is configured to switch between the gas guided to the supply pipe and the cleaning liquid using a switching means. For this reason, the cleaning liquid supply process and the gas supply process can be performed by one supply line provided in the rotating shaft.
[0017]
In the rotary substrate processing apparatus according to the fourth aspect of the present invention, a first passage through which gas passes and a second passage through which the cleaning liquid passes are provided in the supply pipe line. Therefore, the gas supply operation and the cleaning liquid supply operation can be controlled independently.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram of a rotary coating apparatus according to a first embodiment of the present invention. In FIG. 1, only the structure of the main part of the rotary coating apparatus is schematically shown. FIG. 2 is a plan view of the substrate support in FIG.
[0019]
As shown in FIG. 1, the rotary coating apparatus includes a substrate holder 1 that holds and rotates a substrate 9 and a spin motor 14 that rotates the substrate holder 1.
The periphery of the substrate holder 1 is surrounded by a hollow cup (not shown). This cup is provided mainly to prevent the processing liquid from splashing outward.
[0020]
The substrate holder 1 includes a bottom plate 2, a substrate support member 3 and an annular member 6 attached on the bottom plate 2.
The bottom plate 2 is formed in a disc shape, and a shaft portion 2 a formed at the center thereof is fitted and fixed to the tip of the rotating shaft 10 of the spin motor 14. Further, as shown in FIG. 2, the bottom plate 2 is provided with through holes 7 at three positions on a concentric circle.
[0021]
The substrate support member 3 is formed in a ring shape, and includes a plurality of bottom surface support pins 4 that support the bottom surface of the substrate 9 and a plurality of end surface supports that are in contact with the outer peripheral end surface of the substrate 9 to restrict horizontal movement. A pin 5 is formed.
[0022]
An annular member 6 is disposed around the substrate support member 3. The annular member 6 is provided to prevent turbulence from being generated around the substrate 9 by the bottom surface support pins 4 and the end surface support pins 5 of the substrate support member 3 during rotation. Thus, a substantially sealed space X is formed between the bottom plate 2 and the lower surface of the substrate 9.
[0023]
A substrate push-up pin 17 and an elevating mechanism unit (not shown) for raising and lowering the substrate push-up pin 17 are provided below the substrate holding table 1. The substrate push-up pins 17 push the substrate 9 upward through the through hole 7 of the bottom plate 2 when the substrate 9 is discharged. Further, when the substrate 9 is mounted, the substrate push-up pins 17 rise above the substrate holding table 1 to support the back surface of the substrate 9 and then descend to mount the substrate 9 at a predetermined position on the substrate holding table 1. Further, the substrate push-up pin 17 descends and returns to a predetermined standby position.
[0024]
In addition to the function of spin-coating the processing liquid on the surface of the substrate 9, the above-described rotary coating apparatus has a function of supplying the cleaning liquid to the back surface of the substrate 9 to perform back surface cleaning, and an inertness in the space X below the substrate 9. And a function of supplying gas. In order to fulfill such a function, the following configuration is provided.
[0025]
In FIG. 1, a shaft passage 11 penetrating along the axial direction is formed in the rotating shaft 10 of the spin motor 14. Similarly, a shaft passage 2 b communicating with the shaft passage 11 of the rotary shaft 10 is formed in the shaft portion 2 a of the bottom plate 2 of the substrate support 1. A supply conduit 13 is inserted into the shaft passage 11 of the rotating shaft 10 and the shaft passage 2 b of the bottom plate 2.
[0026]
The front end of the supply pipe 13 is fixed to the center of the nozzle cap 8 attached to the center of the upper surface of the bottom plate 2. Further, the vicinity of the tip of the supply pipe 13 is supported by a rotary bearing 12 provided in the shaft portion 2 a of the bottom plate 2. Even when the substrate support 1 is rotated by the rotary bearing 12, the supply pipeline 13 does not rotate and can remain stationary.
[0027]
Further, the lower end of the supply pipeline 13 is connected to the manifold 15. The manifold 15 is fixed inside the rotary coating apparatus. One end of the connection path 16 formed inside the manifold 15 is connected to the lower end portion of the supply pipe line 13. The other end of the connection path 16 is connected to the inert gas supply line 25 and the cleaning liquid supply line 28 via the common line 20.
[0028]
The common line 20 includes an automatic two-way valve 21 and is connected to an inert gas supply line 25 and a cleaning liquid supply line 28 via an automatic three-way valve 22.
The inert gas supply line 25 has a pipe connected to a nitrogen gas (N ₂ gas) supply source (not shown) provided outside the rotary coating apparatus, and in the pipe, a filter 24 and A flow meter 23 is provided. The cleaning liquid supply line 28 has a pipe connected to a cleaning liquid supply source (not shown) provided outside, and a flow meter 26 and a filter 27 are provided in the pipe. The automatic two-way valve 21 and the automatic three-way valve 22 are controlled by a controller 29.
[0029]
The controller 29 performs not only control of the supply operation of the inert gas supply line 25 and the cleaning liquid supply line 28 but also, for example, rotation control of the spin motor 14.
[0030]
In the rotary coating apparatus configured as described above, the supply pipeline 13, the common line 20, and the inert gas supply line 25 constitute the inert gas supply means of the present invention, and the automatic two-way valve 21 and the automatic three-way valve. 22 and the controller 29 constitute the switching means of the present invention.
[0031]
Here, the operation of the rotary coating apparatus will be described. FIG. 3 is a diagram showing temporal changes in the number of substrate rotations in the spin coating process.
Referring to FIGS. 1 and 3, in the resist processing step, controller 29 sets automatic two-way valve 21 to a closed state. Therefore, neither the inert gas (nitrogen gas) nor the cleaning liquid is discharged from the tip of the supply pipe 13. In this state, a resist solution is dropped on the surface of the substrate 9 and a spin coating process is performed at a high speed (for example, 3000 rpm).
[0032]
Next, in the back surface cleaning step, the controller 29 sets the automatic two-way valve 21 to an open state and switches the automatic three-way valve 22 to a state in which the automatic three-way valve 22 communicates with the cleaning liquid supply line 28. As a result, the cleaning liquid is discharged from the front end of the supply conduit 13 toward the back surface of the substrate 9. The substrate 9 is rotated at a low speed (for example, 1200 rpm). Thereby, the back surface of the substrate 9 is rotationally cleaned with the cleaning liquid, and contaminants on the back surface of the substrate 9 are removed.
[0033]
Further, in the drying process, the substrate 9 is spin-dried by rotating the substrate 9 again at a high speed (for example, 3000 rpm). At the same time, an inert gas is filled in the space X below the substrate 9.
[0034]
That is, at the beginning of the drying process, the controller 29 switches the automatic three-way valve 22 from the cleaning liquid supply line 28 side to the inert gas supply line 25 side. Thereby, the inert gas is discharged from the tip of the supply pipe 13. The discharged inert gas fills the space X below the substrate 9 and prevents the space X from becoming a negative pressure. For this reason, the outside atmosphere is not sucked from the through hole 7 of the bottom plate 2, but rather the inert gas flows out from the space X through the through hole 7. Therefore, the drying process proceeds on the back surface of the substrate 9 without touching the outside air contaminated with mist or the like.
[0035]
When the drying process is completed, the rotation of the substrate support 1 is stopped. The supply of the inert gas is continued for a while after the rotation of the substrate support 1 is stopped.
In addition, since both the inert gas supply line 25 and the cleaning liquid supply line 28 have flow meters 23 and 26 and filters 24 and 27, it is possible to send out clean inert gas and cleaning liquid in appropriate amounts.
[0036]
As described above, the rotary coating apparatus according to the present embodiment performs a rotation process in the drying process in a state where the back surface side of the substrate 9 is filled with the inert gas, thereby causing a contamination source such as mist on the back surface side of the substrate 9. Prevent intrusion. Thereby, the back surface of the substrate 9 after cleaning can be kept clean.
[0037]
FIG. 4 is a schematic configuration diagram of a rotary coating apparatus according to a second embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line AA in FIG. The rotary coating apparatus according to the second embodiment is different from the rotary coating apparatus according to the first embodiment in that an inert gas supply line and a cleaning liquid supply line are individually provided. Therefore, the same components as those in the rotary coating apparatus according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0038]
In FIG. 4, the rotating shaft 10 of the spin motor 14 has an axial passage 11 penetrating in the axial direction. A double supply conduit 30 is inserted into the shaft passage 11. As shown in FIG. 5, the double supply pipeline 30 has a first passage 31 and a second passage 32 that are partitioned by a partition wall.
[0039]
In FIG. 4, the distal end side of the double supply pipe 30 is held inside the shaft passage 2 b of the bottom plate 2 via the rotary bearing 12. In addition, the lower end of the double supply pipe 30 is connected to the manifold 35. In the manifold 35, an inert gas connection path 36 and a cleaning liquid connection path 37 are individually formed. The first passage 31 of the double supply conduit 30 is connected to the inert gas connection passage 36, and the second passage 32 is connected to the cleaning liquid connection passage 37.
[0040]
An inert gas supply line 25 is connected to the inert gas connection path 36 of the manifold 35, and a cleaning liquid supply line 28 is connected to the cleaning liquid connection path 37. The inert gas supply line 25 is connected to an inert gas supply source (not shown), and includes an automatic two-way valve 38, a flow meter 23, and a filter 24 in the line. The cleaning liquid supply line 28 is connected to a cleaning liquid supply source (not shown), and includes an automatic two-way valve 39, a flow meter 26, and a filter 27 in the line. The controller 29 controls the opening / closing operation of the automatic two-way valves 38 and 39.
[0041]
Referring again to FIG. 3, in the resist processing step, the controller 29 closes both automatic two-way valves 38 and 39.
Next, in the substrate back surface cleaning step, the controller 29 sets the automatic two-way valve 39 of the cleaning liquid supply line 28 to an open state, and sets the automatic two-way valve 38 of the inert gas supply line 25 to a closed state. As a result, the cleaning liquid is discharged to the back surface of the substrate 9 through the second passage 32 of the double supply conduit 30. The cleaning liquid is spread from the center of the back surface of the substrate 9 toward the outer peripheral side as the substrate 9 rotates, and the back surface of the substrate 9 is cleaned.
[0042]
Further, in the drying process, the controller 29 closes the automatic two-way valve 39 of the cleaning liquid supply line 28 and opens the automatic two-way valve 38 of the inert gas supply line 25. As a result, the supply of the cleaning liquid through the second passage 32 of the double supply conduit 30 is shut off, and the inert gas is supplied through the first passage 31. The inert gas is filled in the space X on the back side of the substrate 9. Thereby, generation | occurrence | production of the negative pressure in the space X is prevented. Therefore, it is possible to prevent air including mist from entering the space X from the outside through the through hole 7.
[0043]
As described above, by separately providing the supply path for supplying the cleaning liquid and the supply path for supplying the inert gas, the cleaning liquid and the inert gas can be switched and supplied instantaneously.
[0044]
In the second embodiment, the first passage 31 and the second passage 32 are formed in one double supply conduit 30. For this reason, it can be efficiently inserted into the narrow shaft passage 11 in the rotary shaft 10. However, the first and second passages 31 and 32 may be inserted into the rotary shaft 10 using different pipes.
[0045]
Further, a first pipe 31 and a second pipe 32 may be formed by using a double pipe as the double supply pipe 30.
Moreover, in the said Example, the same effect can be acquired even if it uses clean air instead of an inert gas.
[0046]
Furthermore, the configuration for supplying an inert gas according to the present invention can be applied to a rotary cleaning device, a rotary developing device, and the like.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a rotary coating apparatus according to a first embodiment of the present invention.
2 is a plan view of the substrate holder shown in FIG. 1. FIG.
FIG. 3 is a diagram showing temporal changes in the number of rotations of a substrate in a spin coating process.
FIG. 4 is a schematic configuration diagram of a rotary coating apparatus according to a second embodiment of the present invention.
FIG. 5 is a cross-sectional view taken along line AA in FIG.
FIG. 6 is a schematic configuration diagram of a conventional rotary coating apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate holding base 2 Bottom plate 3 Substrate support member 7 Through-hole 8 Nozzle cap 9 Substrate 10 Rotating shaft 11 Axis passage 12 Rotating bearing 13 Supply pipe 14 Spin motor 15 Manifold 16 Connection passage 17 Substrate push-up pins 21, 38, 39 Automatic two Directional valve 22 Automatic three-way valve 25 Inert gas supply line 28 Cleaning liquid supply line 30 Double supply line 31 First passage 32 Second passage

Claims (4)

A motor having a rotating shaft extending in the vertical direction;
A substrate holding member that is attached to the tip of the rotating shaft of the motor and has a bottom plate formed with a through hole, and that rotates by holding the substrate horizontally with a predetermined space above the bottom plate;
Gas supply means for preventing a negative pressure region from being generated on the lower surface of the substrate by supplying gas into the predetermined space on the lower surface side of the substrate;
The rotary substrate processing apparatus, wherein the gas supply means includes a nozzle cap that has a discharge port for discharging gas at the center of the lower surface of the substrate and is attached to the center of the upper surface of the bottom plate. . The gas supply means includes
A supply pipe line extending in the axial direction inside the rotating shaft and having a tip communicating with the predetermined space through the bottom plate of the substrate holding member and the discharge port of the nozzle cap;
A gas introduction pipe that connects a lower end of the supply pipe and a gas supply source provided outside to guide a gas supplied from the gas supply source to the supply pipe is provided. Item 2. The rotary substrate processing apparatus according to Item 1. A cleaning liquid introduction pipe that connects a lower end of the supply pipe and a cleaning liquid supply source provided outside, and guides the cleaning liquid supplied from the cleaning liquid supply source to the supply pipe;
A switching means for switching between a state in which the supply line and the gas introduction line are in communication and a state in which the supply line and the cleaning liquid introduction line are in communication are further provided. The rotary substrate processing apparatus according to 2. The supply line has a first passage and a second passage extending independently of each other;
The gas introduction line is connected to the first passage of the supply line;
A cleaning liquid introduction pipe that connects the second passage of the supply pipe with a cleaning liquid supply source provided outside and guides the cleaning liquid supplied from the cleaning liquid supply to the second path of the supply pipe The rotary substrate processing apparatus according to claim 2, further comprising:

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