JP4371391B2 - Wafer backside processing apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer backside processing apparatus and method that can efficiently perform a process such as rinsing or etching on the backside of a wafer held by rotation.
[0002]
[Related technologies]
Conventionally, when rinsing the back surface of a wafer that is rotated and held by a rotating disk, a method of applying a liquid from the outside of the rotating disk to the edge portion of the wafer with a fixed nozzle is generally performed.
[0003]
However, with this method, in the case of wafers of different sizes, it was necessary to change the position of the nozzle by changing the nozzle, and it took time and effort. In addition, the amount of the rinsing liquid to be placed on the back side of the wafer cannot be controlled, and rinsing is always performed with a certain amount of rinsing liquid.
[0004]
For this reason, the amount of the rinsing liquid relative to the rinsing of the back side portion of the wafer cannot be controlled, and rinsing according to the state of contamination on the back surface of the wafer cannot be performed freely.
[0005]
Also, there is no apparatus that can efficiently and freely etch the back surface of the wafer. Therefore, the appearance of an apparatus that can freely perform processing such as rinsing and etching on the back surface of the wafer is awaited.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems. When a process such as rinsing or etching is performed on the back surface of the wafer held by rotation, it is not necessary to change the nozzle depending on the size of the wafer. It is possible to provide a processing apparatus and method for a wafer back surface that can freely change the amount of contact of the processing liquid with respect to the wafer and perform processing such as rinsing and etching according to the situation on the wafer back surface. Objective.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a wafer back surface processing apparatus according to the present invention comprises a rotating disk having a diameter larger than the diameter of a wafer to be processed and rotating and holding the wafer , and an upper center portion of the rotating disk. And the center of the wafer is positioned so that the outer peripheral portion of the back surface of the wafer faces the upper surface of the rotating disk at a predetermined interval and the outer peripheral portion of the rotating disk is located outside the outer peripheral edge of the wafer. A wafer holding unit for holding the substrate and a flow nozzle for supplying and flowing the processing liquid on the upper surface of the outer peripheral portion of the rotating disk, and allowing the processing liquid to flow down on the outer peripheral surface of the rotating disk while rotating the rotating disk. A wave of the treatment liquid is formed on the top surface of the part, and the back surface of the wafer is processed by bringing the wave into contact with the back surface of the wafer.
[0008]
If the flow nozzle and / or the rotating disk are provided so as to be movable in the vertical direction and the horizontal direction, the flow position and flow height of the processing liquid can be freely determined, so the amount of the processing liquid flowing into the back side of the wafer can be reduced. It is possible to adjust, and various processing modes can be set.
[0009]
By providing the flow-down nozzle so as to be capable of swinging, there is an advantage that a treatment such as rinsing can be sufficiently performed up to the orientation flat portion particularly when processing the back surface of the wafer with an orientation flat (hereinafter referred to as orientation flat).
[0010]
The distance between the upper surface of the rotating disk and the back surface of the wafer is preferably about 0.5 to 2 mm, preferably about 1 mm in consideration of the height of the wave of the processing liquid to be formed.
[0011]
Examples of the treatment on the back surface of the wafer include rinsing and etching.
[0012]
The wafer back surface processing method of the present invention uses the wafer back surface processing apparatus of the present invention to form a wave by flowing down the processing liquid, and to process the wafer back surface by bringing the wave of the processing liquid into contact with the wafer back surface. It is characterized by performing.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings, but it goes without saying that various changes or modifications can be made to these embodiments without departing from the spirit of the present invention.
[0014]
As shown in FIGS. 1 and 2, the wafer back surface processing apparatus 12 of the present invention has a rotating disk 14. A wafer holder 16 is provided at the center of the upper surface of the rotating disk 14. When the wafer holding unit 16 holds the wafer W, the outer peripheral portion of the back surface of the wafer W can be opposed to the upper surface of the rotating disc 14 at a predetermined interval. The upper surface is provided with a predetermined height.
[0015]
Reference numeral 18 denotes a flow-down nozzle that feeds the processing liquid 20 to the upper surface 14a of the rotating disk 14 to form a wave 20a of the processing liquid 20, and is provided so as to be movable in the vertical and horizontal directions with respect to the rotating disk 14. Yes. The wave height of the treatment liquid 20 flowing down to the upper surface 14a of the rotating disk 14 can be set by moving the flow down nozzle 18 in the vertical direction.
[0016]
Further, the wave 20 a formed by moving the flow nozzle 18 in the horizontal direction can be moved on the upper surface 14 a of the rotating disk 14.
[0017]
The wave 20a can be moved in the direction of the wafer W held by the wafer holder 16 to flow the processing liquid 20 into the back surface of the wafer W, and the back surface of the wafer W can be processed. The amount of the processing liquid 20 that flows into the back surface of the wafer W can be controlled by controlling the position where the wave 20a is brought close to the wafer W.
[0018]
If the treatment liquid 20 is a rinse liquid, the back surface of the wafer W can be rinsed, and if it is an etchant, the wafer W can be etched.
[0019]
It is also possible to install the flow-down nozzle 18 so as to be swingable with respect to the rotating disk 14. In this case, it is particularly suitable when rinsing the back surface of the wafer with orientation flat (OF). For example, the orientation flat portion of the wafer W (by placing the falling nozzle 18 near the outer peripheral edge of the wafer W and swinging it) ( Since the rinsing liquid sufficiently wraps around the back surface of OF), good rinsing can be performed.
[0020]
When the supply flow of the processing liquid 20 is performed from the flow-down nozzle 18 to the upper surface of the outer peripheral portion of the rotating disk 14, a wave 20 a of the processing liquid 20 is generated by the flow rate of the processing liquid 20 and the rotation of the rotating disk 14. The height of the wave 20a is about 1 to 2 mm. In order to process the back surface of the wafer W using the wave 20a, it is necessary to hold the wafer W on the upper surface of the wafer holding unit 16 so that the back surface of the wafer W is located at a position lower than the height of the wave 20a. is there. Therefore, the wafer holder 16 may be installed so that the upper surface of the wafer holder 16 is about 0.5 to 2 mm higher than the upper surface of the rotating disk 14.
[0021]
The operation of the above configuration will be described. First, the wafer W is held on the upper surface of the wafer holder 16 of the rotating disk 14. Next, the rotating disk 14 is rotated at a high speed. The flow-down nozzle 18 is brought close to the upper surface 14a of the rotating disk 14 during high-speed rotation, and the processing liquid 20 is supplied to the outer peripheral portion of the rotating disk 14 by flowing down.
[0022]
At this time, a wave 20 a of the processing liquid 20 is formed on the upper surface 14 a of the outer peripheral portion of the rotating disk 14 in accordance with the outflow amount and outflow speed of the processing liquid flowing out from the downflow nozzle 18.
[0023]
For example, the pipe diameter of the flow-down nozzle 18 is 3/8 inch, the inner diameter is 0.635 cm, the flow rate of the treatment liquid 20 is about 1.5 liters / minute, the flow rate is about 4.74 cm / minute, and the rotational speed of the rotating disk 14 is 800. When the processing liquid 20 is caused to flow down to the upper surface of the rotating disk 14 under the condition of ~ 1000 rpm, the rising height h of the wave 20a is about 1 mm. When the rising height of the wave 20a is about 1 mm, as shown in FIG. 6, if the distance d between the lower surface of the wafer W and the upper surface of the rotating disk 14 is set to about 0.8 mm, the wave 20a is moved to the wafer W. Difference between the rising height h of the wave 20a and the distance d (about 1 mm) -d (about 0.8 mm) = about 0.2 mm portion of the processing liquid 20 on the lower surface of the wafer W. It will be in contact and good rinsing and etching can be performed.
[0024]
The formed wave 20a of the processing liquid 20 is moved in the direction of the wafer W by moving the flow nozzle 18 in the direction of the wafer W, and the wave 20a is brought into contact with the wafer W. Further, the wave 20a, that is, the processing liquid 20 enters the back side of the wafer W. Thus, the jet of the processing liquid can be continuously brought into contact with the back surface of the wafer W rotating at high speed, and efficient processing such as rinsing and etching can be performed.
[0025]
If the optimum position of the wave 20a of the processing liquid 20 formed on the upper surface 14a of the rotating disk 14 can be set in advance according to the diameter of the wafer W, the wave 20a of the processing liquid 20 is formed at a far position and flows down. The wave 20a of the processing liquid 20 is formed at the optimum position from the beginning without taking the time-consuming method of gradually moving the wave 20a closer to the wafer W by moving the nozzle 18, and the back surface of the wafer W is processed. Of course it is also possible.
[0026]
Further, when the back surface of the wafer W with orientation flat (OF) shown in FIG. 5 is processed, in particular, rinsed, the wave 20a of the processing liquid 20 formed below the flow-down nozzle 18 is brought closest to the outer peripheral portion of the wafer W. Even if the wave 20a of the processing liquid 20 is formed with the falling nozzle 18 positioned on the outer peripheral edge of the wafer W as shown in FIG. 5, the wave 20a does not reach the lower surface of the orientation flat portion (OF). In addition, rinsing of the orientation flat part (OF) cannot be performed well.
[0027]
Therefore, when rinsing or the like of the wafer W with orientation flat (OF) is performed, a function of swinging in the radial direction is added to the flow-down nozzle 18, and the flow-down nozzle 18 is connected to the wafer W as shown in FIG. When the falling nozzle 18 is swung in the radial direction in this state, the wave 20a of the treatment liquid 20 formed on the upper surface 14a of the rotating disk 14 is also swung in the radial direction, and is fixed. Since the wave 20a swings also on the back surface of the orientation flat portion (OF) that cannot be reached by the wave 20a, the treatment liquid 20 enters and good rinsing or the like can be performed.
[0028]
【The invention's effect】
As described above, according to the present invention, when rinsing, etching or the like is performed on the back surface of the wafer held by rotation, it is not necessary to change the nozzle depending on the size of the wafer. The amount of contact can be freely changed, and processing such as rinsing and etching can be freely performed according to the situation on the back surface of the wafer.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a wafer back surface processing apparatus according to the present invention.
FIG. 2 is an explanatory schematic side view of FIG. 1;
FIG. 3 is an explanatory plan view showing a state of formation of a wave of the treatment liquid on the upper surface of the rotating disk.
4 is an explanatory side view of FIG. 3; FIG.
FIG. 5 is an explanatory plan view showing a state in which an orientation flat wafer is held on a rotating disk.
FIG. 6 is a side explanatory view of the main part showing an example of the relationship between the wave height of the processing liquid on the upper surface of the rotating disk and the arrangement of the wafer.
[Explanation of symbols]
12: Wafer back surface processing apparatus, 14: rotating disk, 14a: upper surface of rotating disk, 16: wafer holding unit, 18: falling nozzle, 20: processing liquid, 20a: wave, W: wafer.

Claims (6)

A rotating disk having a diameter larger than the diameter of the wafer to be processed and rotating and holding the wafer ; and an outer peripheral portion provided on the center of the upper surface of the rotating disk with respect to the upper surface of the rotating disk. A wafer holding unit that holds the center of the wafer so that the outer peripheral part of the rotating disk is opposed to the outer periphery of the wafer and is positioned outside the outer peripheral edge of the wafer, and processing is performed on the upper surface of the outer peripheral part of the rotating disk. A flow nozzle for feeding the liquid down and rotating the rotating disk to cause the processing liquid to flow down on the upper surface of the outer peripheral portion, forming a wave of the processing liquid on the upper surface of the outer peripheral portion, and the wave on the back surface of the wafer An apparatus for processing a wafer back surface, wherein the wafer back surface processing is performed by contacting the wafer.   2. The wafer back surface processing apparatus according to claim 1, wherein the flow-down nozzle and / or the rotating disk are provided so as to be movable in a vertical direction and a horizontal direction.   3. The wafer back surface processing apparatus according to claim 1, wherein the flow-down nozzle is provided so as to be swingable.   The wafer back surface processing apparatus according to any one of claims 1 to 3, wherein a facing distance between the upper surface of the rotating disk and the wafer back surface is 0.5 to 2 mm.   The wafer back surface processing apparatus according to claim 1, wherein the processing of the wafer back surface is rinsing or etching. Using the wafer backside processing apparatus according to any one of claims 1 to 5, a wave is formed by flowing a processing solution down, and the processing of the wafer backside is performed by bringing the wave of the processing solution into contact with the wafer backside. A method for processing a back surface of a wafer, which is performed.

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