JP2602766B2 - Wafer edge processing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for processing a wafer edge for etching or applying a chemical solution only to the edge of a wafer having a disk, square, polygon or other various shapes.

[0002]

2. Description of the Related Art A wafer is obtained by cutting a silicon single crystal into thin slices and grinding the surface. Single crystal silicon wafers are widely used for various purposes, for example, as a raw material for solar cells and as a raw material for various integrated circuits. For integrated circuit wafers, for example, surface mirror polishing, photoresist coating, pattern baking, etc.
Handling is performed each time. However, since the wafer is a thin single-crystal plate, the wafer is very likely to be chipped. If something touches the sharp edge during handling, there is a problem that the wafer edge is chipped or the wafer is severely broken. Therefore, the edges of both sides of the wafer are beveled in advance to cut corners. Traditionally,
The beveling machine (BM ') shown in Fig. 10 mechanically grinds the edges of both sides of the wafer (1') with a grindstone. And the so-called damage layer
(S ′) is formed. This damaged layer (S ′) is not only easily chipped, but also serves as a place for absorbing impurities.
At present, it is regarded as a problem because it causes impurities to be mixed in a later process and is a troublesome existence. or,
Dust generated in large quantities at the time of beveling is cumbersome and poses a serious problem in the subsequent process.

On the other hand, in an application such as a solar cell, an n-layer is formed on the surface of a p-type single-crystal silicon wafer by a method such as vapor phase diffusion, coating diffusion, and ion implantation. The formation of the n-layer extends not only to the front surface of the wafer but also to the side surface and the back surface. Therefore, after the formation of the pn junction is completed, a so-called "junction separation" operation is performed, in which the edge of one side of the wafer is scraped over the entire circumference and the p layer is exposed over the entire circumference of the wafer. Wiring electrodes are formed on both sides. Even in this case, the problem of damage layer (S ′) due to beveling occurs when grinding one side edge in mechanical grinding with a grindstone as described above.

Therefore, grinding damage caused by the beveling is considered.
In order to remove the layer (S ′) , a method has been proposed in which, after beveling, the entire wafer is immersed in an etchant to etch the entire surface, but the damaged layer (S ′) can be removed, but the front and back surfaces of the wafer are removed. Is also etched at the same time, and furthermore, it is etched unevenly, which is a major cause of quality deterioration.
Further, in the whole-surface etching, there is also an economical problem that a large amount of an etching solution is required since etching is performed simultaneously on unnecessary portions such as the front and back surfaces of a wafer.

As shown in FIG. 11, a method of spraying an etching solution from below toward the edge of a rotating wafer to etch the wafer edge has been proposed. In this method, as shown in FIG. In the case of a rectangular or nearly rectangular wafer, since the etching is performed in a circular shape, the etching amount at the side portions is small, and the corner portions are large, and the etching thickness varies depending on the location.
Further, in the use of a solar cell, if the etching area is too large to form an electrode also on the peripheral portion of the back surface, there is a problem that the electrode cannot be formed. The etched portion is shown by oblique lines.

[0006]

The problem to be solved by the present invention is as follows.
It is an object of the present invention to be able to etch only a peripheral portion of a wafer edge with a substantially constant width without generating a damage layer or the like.

[0007]

A first method of processing a wafer edge according to the present invention is as follows: a contact arm (3) containing a chemical (2) while rotating a wafer (1);
Is a predetermined angle range in a plane parallel to the main surface of the wafer (1).
And a predetermined angle range in a plane perpendicular to the main surface of the wafer (1).
The wafer edge is always in contact with the wafer edge from an oblique direction, and the chemical solution (2) is applied at the corner (1a) of the wafer edge. " Thereby, the contact arm (3)
A water curtain (H) occurs due to surface tension in a narrow width between the wafer edge and the wafer edge, and the chemical solution (2) is uniformly applied over the entire circumference of the wafer edge.

A second aspect of the present invention is a method of applying a chemical solution to the method of the first aspect, wherein a continuity test is added. "The wafer (1) is rotated and the contact arm (3) containing the chemical solution (2) is inclined obliquely to the wafer edge. And a chemical solution (2) is applied to the protruding corner (1a) of the wafer edge, and then a continuity test electrode (4) is applied to both front and back surfaces of the wafer (1).
{(4a) and (4b)} are brought into contact with each other to pass through the wafer (1).
If it is electrically insulated , finish the chemical application work,
Conversely, if the electrical conductivity remains , the chemical solution application operation is restarted. " Thereby, complete application of the chemical solution can be performed automatically.

Claim 3 defines the rotational direction of the wafer (1) and the contact position of the contact arm (3) with respect to the wafer (1) in the first and second claims. Rotate 1) in the horizontal plane to expose the bottom corner of the wafer
(1a) is brought into contact with the contact arm (3). "
As a result, the chemical solution (2) does not spread to the front surface side of the wafer (1) due to gravity, and is applied only to the back surface edge portion.

[0010] Claim 4 is a further improvement of the "wafer".
(1) is rotated in a horizontal plane, and the contact arm (3) containing the chemical (2) is brought into oblique contact with the wafer edge, and the chemical (2) is applied to the lower corner (1a) of the wafer edge. And flowing the gas (5) toward the peripheral edge of the upper surface of the wafer (1). " Thereby, the upper surface of the wafer (1) is protected by the airflow (5), and application of the chemical (2) to the upper surface of the wafer (1) is prevented.

[0011] Claim 5 relates to a processing apparatus (B) for carrying out the method, wherein "a wafer rotating means (6) for rotating a wafer (1) in a horizontal plane, and a chemical solution (2) at the tip end. the contact arm having a rolling contact member (7) and (3), the vertical and horizontal contact arm (3) its
Rotating contact body pivotally supported within a predetermined angle range
And (7) a support leg (8) for supporting the lower corner (1a ) of the wafer (1) so as to be in contact with the diagonal direction. As a result, even when a rectangular or nearly polygonal wafer (1) is rotated, the contact arm (3) in contact with the wafer edge can move according to the movement of the contact point with respect to the wafer edge. Due to the rotation of 1), an excessive force is not applied to the contact arm (3), and the chemical solution (2) can be smoothly and uniformly applied to the wafer edge.

A sixth aspect of the present invention is a rotary contact body of the processing device (B).
It specifies the contact direction to the wafer edge of (7),
`` Rotating contact body (7) for lower corner (1a) of wafer (1)
The angle of contact (α) between the lower surface of the wafer (1) and the contact surface of the rotating contact body (7) is acute and
The range between the direction in which the rotation center axis (C) of (7) passes through the rotation center (P) of the wafer (1) and the direction that coincides with the tangent (T) to the minimum circular locus (MIN) at the edge of the wafer. (θ). ” As a result, a smoother and more uniform solution application operation becomes possible.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows a wafer edge processing apparatus according to the present invention.
2A is a plan sectional view, FIG. 2 is a schematic configuration diagram of the device (A), FIG. 3 is a detailed plan view thereof, and FIG. 4 is a detailed sectional view thereof. In FIG. 1, a robot hand (11) for handling a wafer (1) is installed in the center of a base (10), and five edge processing devices (B) are provided around the robot hand (of course, the number of installation is not limited. The wafer loader (12) and the wafer unloader (1) are placed in places where the edge processing device (B) is not installed.
3) is installed.

3 and 4, the wafer rotating means (6) will be described in detail. A motor (14) is provided on the lower surface of the base (10), and a wafer rotating shaft (15) is provided upright at the center. A fixed mount (16) is installed on the upper surface of the base (10),
A rotating mount (17) is mounted on the fixed mount (16). The rotation mount (17) is mounted on the wafer rotation shaft (15), and can rotate without contacting the upper surface of the fixed mount (16). The rotation speed is 1 to 5 rpm in this embodiment. The maximum does not exceed 20 rpm. The fixed mount (16) is connected to a wafer suction exhaust path (19) from a motor mount (18) that passes through the base (10) and is fixed to the lower surface of the base. It is open in the inner peripheral groove (20) of the insertion hole. The inner peripheral groove
(20) is formed on the entire inner circumference of the shaft insertion hole of the fixed mount (16).

The wafer rotating shaft (15) is provided with a wafer suction exhaust hole (19a), and the lower opening (19b) matches the inner peripheral groove (20) of the fixed mount (16). Upper opening (19c)
Is also opened on the side surface of the wafer rotation shaft (15), and coincides with the inner circumferential rotation groove (22) of the rotation mount (17). Fixed mount
A ring groove (23) is formed on the upper surface of (16), and a ring protrusion (24) formed on the lower surface of the rotary mount (17) is fitted without contacting each other. Here, as shown in FIG. 4, the back air is fed in and the back air flows out from between the ring groove (23) and the ring projection (24) so that the rotation mount (17) and the fixed mount (16) are connected. The chemical solution (2) and cleaning liquid do not flow in between. The ring groove (23)
A groove air supply passage (25) is formed through the base (10) and the motor mount (18). (26) is fixed mount (16)
Is a sebalate disk installed at the center of the upper surface of the. On the upper surface of the rotation mount (17), an appropriately thin wafer suction groove (27) is engraved in a ring shape and radially, and the wafer suction exhaust hole (19a) is rotated in the suction thin groove (27). It is connected via a side exhaust hole (19d).

(D) is an upper mechanism installed directly above the rotary mount (17), and has an air blowing function, a wafer centering mechanism, and an upper electrode (4a). A blow ring groove (28) is formed on the lower surface of the upper mechanism (D), and a blow path (29) is connected to the blow ring groove (28). Upper mechanism (D)
The upper electrode (4a) is housed in the center of
Furthermore, four crab-foot-shaped centering arms (37) are provided on the side surface of the upper mechanism (D) (the number is of course not limited to this).
Are installed, and the centering arm (3) is moved by the arm drive cylinder (38) that constitutes the side part of the upper mechanism (D).
7) scales. That is, the centering arm (37) is constantly urged in the expanding direction by, for example, a torsion coil spring (not shown) installed on the shaft.
As shown in the left half, when the arm drive cylinder (38) moves upward, it closes with spring force and the wafer (1)
The center of rotation of the rotary mount (17) is matched with the center of the wafer (1).

FIGS. 5 and 6 show an etching arm mechanism (E) in which a cylindrical rotary contact body (7) is rotatably inserted at the tip of a contact arm (3) as a component. (30) is a Teflon seat that holds the rotating contact body (7), and (31) is a fixed seat that prevents the Teflon seat (30) from falling off. A balance weight (32) is slidably attached to the other end of the contact arm (3), and the balance weight (32) is moved back and forth so as to balance the rotary contact body (7) at the tip. I have. The material of the rotary contact body (7) is not particularly limited, but it is desirable that the material is hardly corroded by the etching solution and can impregnate the liquid to some extent. In this embodiment, "bamboo" is used. Of course, a porous corrosion-resistant metal material (for example,
Stainless steel powder metallurgy) or fibrous Teflon can also be used. The arm member (3a) of the contact arm (3) is
It is composed of a hollow corrosion-resistant metal pipe with a closed end, and a protective Teflon tube (33) is placed over the end. The fitting portion of the Teflon tube (33) is inserted into the through hole of the rotary contact body (7), and the Teflon tube
(33) also serves as a bearing for the rotary contact body (7). The chemical solution (2) may be supplied from the chemical solution nozzle (39) disposed close to the rotary contact body (7) to the rotary contact body (7), or supplied through the arm member. You may.

Reference numeral (34) denotes a rotating hinge for holding the contact arm (3), which is fixed to a support shaft (35) inserted at the upper end of the support leg (8). It is connected to a rotating device (36) such as a rotary actuator.
The support legs (8) are fixed on the base (10) and
At (36), the contact arm (3) moves lightly in the vertical direction. The fixing position of the arm portion (3a) can be slid in the through hole of the rotating hinge (34) by loosening the screw, and can be freely changed.

The installation direction of the etching arm mechanism (E) is as follows.
This will be described with reference to FIGS. In this embodiment, the wafer (1)
The angle of contact (α1) to (α2) between the lower surface of the wafer (1) and the contact surface of the rotating contact member (7) is an acute angle ( Usually, the rotation angle is selected within the range of 15 ° to 45 °, but is not limited to this.) And at the same time, the rotation center axis (C) of the rotary contact body (7) is set at the rotation center (P) of the wafer (1). ), The minimum circular locus of the wafer edge from the direction passing through
It is oriented within the range (θ) between the directions coinciding with the tangent (T) to (MIN). Usually, (1/2) θ is selected.
Further, the length (L) of the rotating contact body (7) is, for example, a rectangular wafer.
In the case of the edge processing of (1), a length that can cover the maximum circular locus (MAX) and the minimum circular locus (MIN) is selected. Although one etching arm mechanism (E) may be provided, a plurality of etching arm mechanisms (E) may be provided as shown in FIG. Thereby, the chemical solution application operation can be performed at a higher speed.

As the wafer, a wafer obtained by cutting a silicon single crystal rod into a circle is used, and there are various kinds of wafers, such as a thin disk-shaped wafer, a square wafer, and a substantially rectangular wafer having arc-shaped corners. For solar cells, those having a square or substantially rectangular shape are used to increase the installation area. As the etching chemical, for example, hydrogen fluoride, nitric acid, or the like is used, and as the edge masking chemical, for example, water glass is used.

First, the case of the solar cell wafer (1) will be described. As described in the conventional example, when the pn junction is performed by the diffusion process, the solar cell wafer (1) forms an n-layer on both the front and rear surfaces and the entire side surface of the wafer (1). Therefore, the edge is etched on one side to insulate the front and back surfaces. First, the edge-unprocessed wafer (1) after the diffusion processing step is transferred to the rotary mount (17) by the robot hand (11), and the arm driving cylinder (38) is raised to fix the tip of the centering arm (37). The center of the wafer (1) is moved in the direction of the center of the rotation mount (17) to coincide with the center of rotation of the rotation mount (16). After the centering is completed, when the arm drive cylinder (38) is pushed down, the base of the centering arm (37) is pushed and the centering arm (37) moves in the opening direction.

Subsequently, the evacuation operation is started and the rotating mount is mounted.
The wafer (1) is suction-fixed by the suction narrow groove (27) on the upper surface of (17). After fixing in this manner, the motor (14) is driven, and the rotation mount (17) is rotated while holding the wafer (1). At this time, pure compressed air supplied through the air passage (29) is jetted from the air blowing ring groove (28) to the upper surface side of the wafer (1), and flows toward the edge of the wafer (1). I have. This shield air prevents the chemical (2) from flowing into the upper surface of the wafer (1) during edge processing described later. In addition, as shown in FIG. 2, it is also possible to eject back air from the edge of the rotary mount (17) so that the chemical solution (2) does not flow to the back side of the wafer (1).

Thereafter, the rotating device (36) is operated to move the contact arm (3) in the direction of the edge of the wafer (1), and lightly contact the rotating contact body (1a) on the lower surface side corner (1a) of the wafer (1). (7) Make contact. The contact pressure is set by the balance weight (32). The contact direction of the rotating contact body (7) with respect to the lower corner (1a) is as described above, and the most suitable condition is selected from the above range. As a result, not only a circular wafer (1) but also a rectangular or nearly polygonal wafer
Even in (1), edge processing can be easily performed.

Here, the case of the rectangular wafer (1) will be described in detail with reference to FIGS. 7 and 8. The distance from the center of rotation (O) of the rectangular wafer (1) to be processed to the edge of the wafer (1) ( M) constantly changes in a sine curve with the rotation, and the contact arm (3) moves up and down accordingly. As described above, when the rotation axis (C) of the rotary contact body (7) is out of the rotation center axis (O) of the wafer (1) and is within the range of (θ), the contact arm (3 ) Can easily move up and down, and the rotation of the rotating contact body (7) can be smoothly performed (in other words, the rotating contact body (7) is attached to the edge of the rotating wafer (1)).
The chemical solution (2) is applied to the lower edge of the wafer (1) with a substantially constant width.

The chemical (2) is always supplied to the rotary contact body (7), and is applied to the edge of the wafer (1) with a substantially constant width. The back side edge of the wafer (1) is gradually dissolved by the applied etching solution (2),
The p layer which is the ground of (1) is exposed. When the wafer (1) is a disk, the contact arm (3) can contact the rotating contact body (7) with the lower side edge of the wafer (1) with almost no vertical movement and rotate the wafer (1). When the wafer (1) is not disc-shaped, the rotating contact body (7) also rotates.
The contact arm (3) moves up and down with the rotation of the wafer (1), and the rotating contact body (3) also rotates with the rotation of the wafer (1). In this case, the angle between the lower surface of the wafer (1) and the rotating contact body (7)
(α) changes slightly to cause variations in the etching widths (N1) to (N2).
This is an amount that does not interfere with the formation of the wiring electrode on the back surface of (1). The wiring electrode is generally formed 2 m from the edge.
m inside.

When the one-side etching of the edge is completed in this manner, the cleaning / blowing ring groove (2) is passed through the blowing passage (29).
Spray pure water from 8) to wash off the chemical solution (2) from the upper surface of the wafer (1), and then dry it by blowing dry air from the cleaning / blast ring groove (28) through the ventilation path (29). After that, the upper electrode (4a) is lowered, the wafer (1) is sandwiched between the upper electrode (4a) and the rotary mount (17), and an electric current is applied to test the insulation state between the front and back surfaces. At this time, the rotation mount (17) serves as a lower electrode (4b). If the edge etching is insufficient and even a very small portion of the conductive portion remains, it is determined that the etching is defective and the edge etching is restarted. After re-etching for a predetermined time, a recheck is performed. As a result of the test, if sufficient insulation was obtained, etching was completed, and the rotation mount (17)
Stop, and then release the vacuum suction to rotate mount (1
Release the wafer from 7), then operate the robot hand (11) to remove the wafer (1) from the rotary mount (17) and store it in the wafer storage box (not shown) installed on the unloader (13) I do.

When the processed wafer is full in the wafer storage box, it is removed from the unloader and replaced with a new empty wafer storage box. The wafer storage box in which the processed wafers are stored is transferred to a cleaning device, where the etching solution adhering to the edges is washed away with pure water, and then dried and transferred to an electrode forming step.

Next, the etching of the lower surface side edge will be described in more detail with reference to FIG. The rotating contact body (7) is in oblique contact with the wafer (1) rotating in the horizontal plane. Rotating contact body (7) constantly etch chemical (2)
Is gradually supplied, and the surface is in a wet state. Accordingly, a water curtain (H) of the chemical solution is formed with a certain width between the back surface of the wafer (1) and the rotating contact body (7) due to the surface tension.
Then, one side of the edge is etched by the water curtain (H). When the angle (α) of the rotating contact body (7) with respect to the wafer (1) is raised, the formation of the water curtain (H) becomes smaller and the etching width (N) becomes smaller. (H) becomes large, and wide etching is performed.

What is important in the present invention is that the wafer (1) is rotated in a horizontal plane, and the rotating contact body (7) is in contact with the edge on the lower surface side. Thereby, most of the water curtain (H) is formed between the lower surface of the wafer (1) and the rotating contact body (7) due to gravity, and the side of the wafer (1) and the rotating contact body (7) are formed. Only a very small water curtain (H) is generated between them, and the chemical solution (2) does not flow into the upper surface side of the wafer (1). This allows
A state where the upper surface of the wafer (1) is not etched is secured.

In order to protect the upper surface of the wafer (1), compressed air (5) is blown from the upper mechanism (D) containing the upper electrode (4a) so that the upper surface of the wafer (1) is moved from the center. The wind is allowed to flow toward the periphery. With this, the drug solution (2)
Does not adhere to the surface of the wafer (1).

When processing the edges of both surfaces of the wafer (1), the same operation as described above may be performed by inverting. In the case of edge treatment on both sides of the wafer (1), the application of an electric current check is not necessarily required, since the application is not for a solar cell.

Other applications include the following. A protective material such as water glass is applied to the edge of the wafer (1) in advance by the above-mentioned method as a chemical solution (2), and thereafter, an n layer is formed on the entire surface of the wafer (1) by diffusion treatment,
Finally, the protective material (2) can be dissolved and removed by the method of the present invention, and an edge treatment can be performed.

[0033]

According to the present invention, since the wafer is rotated and the contact arm containing the chemical liquid is brought into contact with the wafer edge from an oblique direction, and the chemical liquid is applied to the protruding corner of the wafer edge, the rotary contact body is formed on the edge of the wafer. A water curtain is formed with a very small width between the wafer edge and the rotating contact body due to surface tension. As a result, as the wafer rotates, the water curtain moves along the edge of the wafer while maintaining a substantially constant width, and the edge is coated with the chemical solution with a substantially uniform width.

Further, a chemical solution is applied to the protruding corner of the wafer edge. Thereafter, electrodes are brought into contact with the front and rear surfaces of the wafer to measure the electrical characteristics of the wafer. If the electrical characteristics are satisfied, the chemical solution is applied. When the application operation is completed and conversely, when the electrical characteristics are not satisfied, when the chemical application operation is restarted, the complete chemical application operation can be automatically performed.

When the wafer is rotated in a horizontal plane and the contact arm is brought into contact with the lower corner of the lower surface of the wafer, most of the water curtain is moved between the lower surface of the wafer and the rotating contact body due to gravity. Only a very small water curtain is generated between the side surface of the wafer and the rotating contact body, so that the chemical does not flow into the upper surface side of the wafer and the upper surface of the wafer is not etched. Become.

In the case where the gas is caused to flow toward the peripheral edge of the upper surface of the wafer, a chemical mist or the like can be eliminated, so that the cleanness of the upper surface of the wafer can be further maintained.

The apparatus for processing a wafer edge includes a wafer rotating means for rotating the wafer in a horizontal plane, a contact arm having a rotating contact body impregnated with a chemical solution at a tip end, and a contact arm which is inclined obliquely to the lower corner on the lower surface side of the wafer. As described above, the liquid medicine is applied to the edge with a substantially uniform width because of the support legs that support the liquid medicine so as to come into contact therewith.

Further, the contact direction of the rotating contact body with the lower corner of the lower surface side of the wafer is an acute angle between the lower surface of the wafer and the contact surface of the rotating contact body, and the rotation center axis of the rotating contact body is If the liquid is oriented within a range between the direction passing through the center of rotation of the wafer and the direction coinciding with the tangent to the minimum circular locus of the wafer end, the liquid chemical has a substantially uniform width on the edge regardless of the shape of the wafer. Will be applied smoothly.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of a wafer edge processing apparatus according to the present invention.

FIG. 2 is a schematic front view of a wafer edge processing apparatus according to the present invention.

FIG. 3 is a plan view of an edge machining mechanism according to the present invention.

FIG. 4 is a sectional view of an edge machining mechanism according to the present invention.

FIG. 5 is a front view of an embodiment of an etching arm mechanism according to the present invention.

FIG. 6 is a sectional view of one embodiment of an etching arm mechanism according to the present invention.

FIG. 7 is a plan view for explaining the principle of edge processing according to the present invention.

FIG. 8 is a longitudinal sectional view for explaining the principle of edge processing according to the present invention.

FIG. 9 is a flowchart showing the operation procedure of the present invention.

FIG. 10 is a schematic front view of a conventional beveling operation.

FIG. 11 is a principle front view showing another conventional edge etching process.

FIG. 12 is a plan front view of the wafer showing the edge etching formed according to FIG. 11;

[Explanation of symbols]

(A) Wafer edge processing equipment (B) Edge processing mechanism (1) Wafer (2) Chemical solution (3) Contact arm

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Go Tsuyoshi Murai 3-6-16 Yanaka, Taito-ku, Tokyo M-setec Co., Ltd. (56) References JP-A-2-303759 (JP, A) JP JP-A-1-316936 (JP, A) JP-A-2-130922 (JP, A) JP-A-3-220723 (JP, A)

Claims (6)

(57) [Claims] A wafer is rotated and a contact arm containing a chemical solution is rotated in a plane parallel to a main surface of the wafer.
Within a predetermined angle range and a plane perpendicular to the main surface of the wafer.
A method for processing a wafer edge, wherein the wafer edge is oscillated within a fixed angle range to always contact the wafer edge from an oblique direction, and a chemical solution is applied to a protruding corner of the wafer edge. 2. A wafer is rotated and a contact arm containing a liquid chemical is brought into contact with the wafer edge from an oblique direction, a liquid chemical is applied to an outer corner of the wafer edge, and then electrodes are brought into contact with both front and back surfaces of the wafer. On the wafer
A method for processing a wafer edge, comprising: applying a chemical and terminating a chemical liquid application operation when insulated ; and conversely, restarting a chemical liquid application operation when electric conductivity remains . 3. The method of processing a wafer edge according to claim 1, wherein the wafer is rotated in a horizontal plane, and a contact arm is brought into contact with a lower-side projected corner of the wafer. 4. A wafer is rotated in a horizontal plane, and a contact arm containing a chemical is brought into contact with the wafer edge from an oblique direction. The chemical is applied to the lower corner of the wafer edge and the gas is directed toward the upper edge of the wafer. Wafer edge processing method characterized by flowing. 5. A wafer rotating means for rotating a wafer in a horizontal plane, a contact arm having a rotating contact body impregnated with a chemical solution at a tip portion, and a vertical and horizontal contact arm.
Rotating contact body pivotally supported within a predetermined angle range
And a support leg for supporting the lower surface of the wafer so as to come into contact with the lower corner of the lower surface of the wafer from an oblique direction. 6. The contact direction of the rotary contact body with the lower corner of the lower side of the wafer is an acute angle between the lower surface of the wafer and the contact surface of the rotary contact body, and the rotation center axis of the rotary contact body is the same as that of the wafer. 6. The wafer edge processing apparatus according to claim 5, wherein the wafer edge processing apparatus is directed within a range from a direction passing through the center of rotation to a direction coinciding with a tangent to the minimum circular locus of the wafer end.