TWI473911B - Method and apparatus for removing thick metal on wafer of photovoltaic element - Google Patents

Description

Method and device for removing thick metal on photovoltaic element wafer

The present invention relates to a semiconductor process, and more particularly to a method and apparatus for removing thick metal on a photovoltaic element wafer.

With the advancement of modern technology, more and more electronic products are used, and wafers are required inside these electronic products, and these wafers are made through semiconductor manufacturing. Among them, the conventional method of fabricating the metal wires required for the circuit components of the semiconductor process is to implant a layer of metal on the substrate, and then remove unnecessary metal, and only retain the desired metal.

There are three main methods of metal removal: manual removal of metal, removal of metal with adhesive tape, and removal of metal by ultrasonic grooves. Among them, the manual method is to remove unnecessary metal directly by people's hands or simple tools. In addition, the method of removing the metal by the adhesive tape is to adhere to the unnecessary metal by using a tape, and then peeling off the tape and the attached metal by hand or by machine. In addition, ultrasonic waves can be used to generate ultrasonic waves to remove unnecessary metals. However, conventional metal removal methods have resulted in low wafer yields due to the inability to automate. In addition, the conventional metal removal method is to manually remove unnecessary metal and easily break the wafer, thereby increasing the damage rate of the wafer.

In view of the various problems of the prior art, in order to be able to solve the problem, the inventor has proposed to remove a thick layer of the photovoltaic element wafer based on years of research and development and many practical experiences. The method of metal and its equipment are used as an implementation and basis for improving the above disadvantages.

In view of the above-mentioned problems of the prior art, it is an object of the present invention to provide a method and apparatus for removing thick metal on a photovoltaic element wafer to prevent scratching of the wafer.

Therefore, in order to achieve the above object, the method for removing thick metal on a photovoltaic element wafer according to the present invention comprises at least the following steps. First, the wafer to be processed is placed on a rotatable tray to rotate the wafer by the tray to provide the required rotation speed of the wafer. The photoresist layer and the first metal layer are sequentially stacked on the substrate of the wafer, and the photoresist layer has at least one opening, and the second metal layer is located on the substrate in the opening. Next, a spraying device is provided above the tray, and the first pipeline in the spraying device, the second pipeline and the third pipeline having a plurality of nozzles are sequentially used, thereby completely removing the unnecessary thickness on the photovoltaic component wafer. metal.

The method for removing thick metal on the photovoltaic element wafer of the present invention is to first apply a first solution on the rotating wafer by the first pipeline to dissolve the photoresist layer on the substrate of the wafer, and first The solution is, for example, a photoresist, wherein the photoresist is, for example, acetone or N-Methyl-2-Pyrrolidone (NMP).

Then, the second solution is simultaneously sprayed by a nozzle of the second pipeline at a pressure on the wafer rotating at a rotation speed to flush part of the photoresist layer and the first metal layer. Or the pressure of the second solution is sprayed by the second pipe to remove part of the photoresist layer and the first metal layer. Wherein, the rotation speed is, for example, less than 500 revolutions per minute (rpm). In addition, the plurality of nozzles of the second conduit are arranged in a row, for example, in a row that is linear with respect to the wafer. Wherein the width of the nozzle distribution of the second pipeline is, for example, greater than or equal to the diameter of the wafer Or the second solution ejected by the second tube completely covers the surface of the wafer. And the second line sprays the second solution at a pressure in the range of, for example, about 5 pounds per square inch (psi) to about 40 pounds per square inch. Alternatively, the second solution may be, for example, a photoresist removal solution, wherein the photoresist removal solution may be, for example, acetone or nitrogen methyl 2-cyclopropanone (NMP).

One of the features of the present invention is that when the width of the nozzle distribution of the second conduit is larger than the diameter of the wafer or the second solution ejected by the second conduit completely covers the surface of the wafer, thereby removing the first metal layer, The first metal layer does not form a cloud on the wafer and rolls around, or the first metal layer is prevented from contacting the substrate of the wafer and the second metal layer, thereby preventing scratching of the wafer.

Then, the third solution is sprayed on the wafer by the third pipeline to remove the residual photoresist layer and the first metal layer on the wafer. Wherein, the movement of the third conduit may be, for example, a sweeping movement over the wafer, and the third conduit spraying the third solution may have a pressure range of, for example, less than about 50 psi. Further, the third solution may be, for example, a photoresist removal liquid, wherein the photoresist removal liquid may be, for example, acetone or nitrogen methyl 2-cyclopropanone (NMP).

In addition, the present invention further provides an apparatus for removing thick metal on a photovoltaic element wafer, the apparatus being a device for providing the foregoing method, comprising at least a tray and a spraying device, wherein the tray is used to rotate the wafer to provide crystal The required speed of the circle. The spraying device is located above the carrier tray and includes at least a first conduit, a second conduit having a plurality of nozzles, and a third conduit. The first conduit can be, for example, a conduit in a fixed position, and the first conduit applies a first solution to the rotating wafer. The second pipeline sprays the second solution at a pressure on the wafer rotating at a rotation speed, and the plurality of nozzles of the second pipeline are arranged in a straight line, and the nozzle distribution width of the second pipeline can be, for example, large Is equal to or equal to the diameter of the wafer. Wherein, the rotational speed of the wafer may be, for example, less than about 500 rpm, and the pressure of the second conduit to eject the second solution is, for example, between about 5 psig and about 40 psig. In addition, the third conduit is, for example, a moveable conduit for mobilely ejecting a third solution onto the wafer, and the third conduit ejects a third solution at a pressure of, for example, less than about 50 psi.

As described above, the method and apparatus for removing thick metal on a photovoltaic element wafer according to the present invention may have one or more of the following advantages:

(1) blasting the photoresist layer and the first metal layer by spraying a second solution on the rotating wafer with a second tube having a plurality of nozzles arranged in a line to avoid the first metal layer being crystallized Form a ball on the circle and roll around.

(2) completely covering the surface of the wafer by the second solution ejected by the second pipeline, so as to prevent the first metal layer from contacting the substrate of the wafer and the second metal layer, thereby preventing the first metal layer from scratching the crystal circle.

For a better understanding and understanding of the technical features and the efficacies of the present invention, the preferred embodiments and the detailed description are as follows.

100‧‧‧ wafer

110‧‧‧Substrate

120‧‧‧ photoresist layer

131‧‧‧First metal layer

132‧‧‧Second metal layer

140‧‧‧ openings

210‧‧‧Solution step

220‧‧‧Removal steps

230‧‧‧Clearing steps

300‧‧‧Thick metal removal equipment

301‧‧‧Spray device

310‧‧‧Tray

321‧‧‧First line

331‧‧‧Second line

332‧‧‧ nozzle

341‧‧‧ third pipeline

1 is a schematic cross-sectional view of a photovoltaic element wafer to be processed; FIG. 2 is a flow chart of a method for removing thick metal on a photovoltaic element wafer of the present invention; and FIG. 3 is a photovoltaic element wafer of the present invention. Schematic diagram of a device for removing thick metal; FIG. 4 is a second tube of a thick metal removal device for a photovoltaic element wafer of the present invention The top view is a schematic view; and the fifth figure is a schematic cross-sectional view of the processed photovoltaic device wafer.

Hereinafter, a method for removing thick metal on a photovoltaic element wafer according to a preferred embodiment of the present invention and an apparatus thereof will be described with reference to the related drawings. For ease of understanding, the same components in the following embodiments are denoted by the same reference numerals. Description.

Please refer to FIG. 1 , which is a schematic cross-sectional view of a wafer of photovoltaic elements to be processed. As shown in FIG. 1 , a wafer 100 is first provided, wherein a photoresist layer 120 and a first metal layer 131 are sequentially stacked on a substrate 110 of the wafer 100 , wherein the photoresist layer 120 has at least one The opening 140 and a second metal layer 132 are located on the substrate 110 in the opening 140. The adhesion between the photoresist layer 120 and the substrate 110 is substantially smaller than the adhesion between the second metal layer 132 and the substrate 110.

Please refer to FIG. 2 to FIG. 4, FIG. 2 is a flow chart of a method for removing thick metal on a photovoltaic element wafer of the present invention, and FIG. 3 is a device for removing thick metal on a photovoltaic element wafer of the present invention. FIG. 4 is a schematic top view of the second pipeline of the thick metal removal device on the photovoltaic component wafer of the present invention. As shown in FIGS. 2 to 4, the wafer 100 to be processed provided in the above FIG. 1 is placed on the tray 310 of the thick metal removal apparatus 300, and the thick metal removal apparatus 300 has the tray 310. The spraying device 301 above, wherein the spraying device 301 is composed of at least a first pipe 321 , a second pipe 331 and a third pipe 341 , and the receiving tray 310 can adjust the rotating speed to rotate on the receiving tray 310 according to requirements. Wafer 100.

Next, a dissolution step 210 is performed on the wafer 100 on the carrier tray 310. In the dissolving step 210, the first solution is applied by the first line 321 in the spraying device 301. On the wafer 100, and rotating the wafer 100 by the tray 310, the first solution can uniformly contact the photoresist layer 120 of the wafer 100, wherein the first pipeline 321 is, for example, a fixed tube fixed in position. Since the first solution is, for example, a photoresist, the photoresist layer 120 is dissolved when the first solution contacts the photoresist layer 120. Wherein, the photoresist is, for example, acetone or nitrogen methyl 2-cyclopropanone (NMP).

Next, a flushing step 220 is performed. In the flushing step 220, the rotational speed of the tray 310 and the wafer 100 thereon is, for example, less than about 500 revolutions per minute (rpm). Subsequently, a second solution is sprayed onto the wafer 100 by a second line 331 of the spray device 301, wherein the second line 331 has a plurality of nozzles 332, and the nozzles 332 are, for example, arranged in a row. For example, the second conduit 331 can have ten nozzles 332 arranged in a straight line. Additionally, the width of the nozzle 332 of the second conduit 331 may be, for example, greater than or equal to the diameter of the wafer 100.

Since the nozzles 332 are arranged in a row with respect to the wafer 100, and the width of the nozzles 332 of the second conduit 331 is, for example, greater than or equal to the diameter of the wafer 100, the nozzles are opened when the second conduit 331 is opened. The 332 system simultaneously ejects the second solution toward different regions of the wafer 100, and the nozzles 332 spray the second solution onto the wafer 100 by high pressure, thereby flushing most of the photoresist layer 120 on the wafer 100 and most of the photoresist layer 120. The first metal layer 131. In addition, the second solution ejected by the second pipeline can completely cover the surface of the wafer 100, and does not limit the form of the second pipeline, and then removes the pressure of the second solution by the second pipeline to remove the wafer 100. Most of the photoresist layer 120 and most of the first metal layer 131.

Moreover, since the nozzle 332 of the second line 331 sprays the second solution toward the wafer 100 at a high pressure, or the second solution ejected by the second line completely covers the surface of the wafer 100. Therefore, the first metal layer 131 that is movable due to the dissolution of the photoresist layer 120 is not on the wafer. 100 is rolled up and rolled around, or rolling, but does not touch the substrate 110 and the second metal layer 132 of the wafer 100, so that the present invention can prevent the first metal layer 131 from scratching the wafer 100. situation. Wherein, the second line 331 sprays the second solution at a pressure ranging, for example, between about 5 psig and 40 psig. Further, the second solution may be, for example, a photoresist removal liquid, wherein the photoresist removal liquid may be, for example, acetone or nitrogen methyl 2-cyclopropanone (NMP).

Finally, a clearing step 230 is performed. In the cleaning step 230, the third conduit 341 of the spray device 301 is a movable device. The third conduit 341 can sweep back and forth over the wafer 100, for example, and spray a third solution toward the wafer 100. And the pressure at which the third conduit 341 sprays the third solution is, for example, less than about 50 pounds per square inch. The cleaning step 230 is performed by spraying the third solution to the wafer 100 in the direction of the wafer 100 by the third conduit 341, so that a small portion of the light remaining on the wafer 100 after the step 220 is removed. The resist layer 120 and a small portion of the first metal layer 131 are completely removed. In addition, the third solution ejected by the third line may be, for example, a photoresist removal liquid, wherein the photoresist removal liquid may be, for example, acetone or nitrogen methyl 2-cyclopropanone (NMP).

Please refer to FIG. 5 , which is a schematic cross-sectional view of the processed photovoltaic device wafer. As shown in FIG. 5 , the processed wafer 100 only has the substrate 110 and the second substrate 110 . The metal layer 132 thus completes the method of removing thick metal from the photovoltaic element wafer of the present invention.

In summary, one of the features of the present invention is that the second conduit 331 of the apparatus of the present invention has a plurality of nozzles 332 aligned in a row with respect to the wafer 100, and the nozzle distribution width of the second conduit 331 is, for example, The first metal layer 131 on the photoresist layer 120 is prevented from being lumped on the wafer 100 and is circumscribed by the nozzles. scroll Further, the case where the first metal layer 131 scratches the wafer 100 is eliminated. Or the second solution sprayed by the second line 331 completely covers the surface of the wafer 100, and the second line 331 is sprayed with the pressure of the second solution to remove the photoresist layer 120 and the first metal layer 131. Since the surface of the wafer 100 is completely covered with the second solution, the first metal layer 131 is prevented from contacting the substrate 110 and the second metal layer 132, thereby eliminating the situation in which the first metal layer 131 scratches the wafer 100.

In addition, in order to confirm that the method of removing thick metal on the photovoltaic element wafer of the present invention and its apparatus do have the effect of reducing the wafer damage rate, the inventors have further proposed experimental data to support the effect. If the method and apparatus of the present invention are used to remove thick metal from a photovoltaic element wafer, the wafer fragmentation rate is 0.5%, compared to 10% of the wafer fragmentation rate using conventional techniques. In addition, if the thick metal is removed from the photovoltaic element wafer using the method and apparatus of the present invention, the wafer scratch rate is less than 1%, and the wafer scratch rate using conventional techniques is 10%. Therefore, the use of the method and apparatus of the present invention to remove thick metal on the photovoltaic element wafer has a significant drop in wafer fragmentation rate or wafer scratch rate. In addition, the time required to remove thick metal on a photovoltaic element wafer using conventional techniques is about 10 minutes. However, if thick metal is removed from the photovoltaic element wafer using the method and apparatus of the present invention, the time required can be reduced to about 3 minutes. Therefore, the method and apparatus of the present invention can indeed reduce the damage rate of the wafer and have the dual effect of automation.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

210‧‧‧Solution step

220‧‧‧Removal steps

230‧‧‧Clearing steps

Claims (7)

A method for removing thick metal on a wafer of a photovoltaic element, comprising: providing a wafer on a tray to rotate the wafer by the tray, wherein one of the substrates of the wafer is sequentially stacked with a photoresist And a first metal layer, wherein the photoresist layer has at least one opening, and a second metal layer is located on the substrate in the opening; providing a first pipeline, a second tube having a plurality of nozzles a third pipeline is located above the tray, wherein the width of the nozzles of the second conduit is greater than or equal to the diameter of the wafer; and the first conduit is applied to rotate by the first conduit Disposing the photoresist layer on the wafer; spraying a second solution on the wafer at a rotation speed by the second pipeline for punching out part of the photoresist layer and the first a metal layer, or a pressure of the second solution sprayed by the second line or the second solution ejected by the second line completely covers the surface of the wafer to avoid the photoresist layer and the first metal The layer scratches the wafer; and the third pipe is used to spray a third solution On the wafer to remove the residue of the photoresist layer on the wafer and the first metal layer. A method of removing thick metal from a photovoltaic element wafer as described in claim 1 wherein the rotational speed is less than 500 rpm. A method of removing thick metal from a photovoltaic element wafer as described in claim 2, wherein the second line sprays the second solution at a pressure of between 5 psi and 40 psi. . The method for removing thick metal on a photovoltaic element wafer according to claim 3, wherein the third pipeline is swept back and forth over the wafer, and the third pipeline ejects the third solution. The pressure is less than 50 psi. A device for removing thick metal on a photovoltaic element wafer, comprising: a tray for rotating a wafer; and a spraying device, the spraying device is located above the tray, wherein the spraying device comprises at least: a first a conduit for applying a first solution to the rotating wafer to dissolve the photoresist layer; a second conduit having a plurality of nozzles, wherein the widths of the nozzles of the second conduit are greater than or equal to a diameter of the wafer, the second tube is sprayed with a second solution at a pressure on the wafer rotating at a speed to flush a portion of the photoresist layer and the first metal layer, or the second tube The second solution ejected from the road completely covers the surface of the wafer to prevent the photoresist layer from scratching the wafer with the first metal layer; and a third conduit for moving a third solution to the mobile solution The wafer is disposed to remove the photoresist layer and the first metal layer remaining on the wafer. The apparatus for removing thick metal on a photovoltaic element wafer as described in claim 5, wherein the rotation speed is less than 500 rpm. The apparatus for removing thick metal on a photovoltaic element wafer according to claim 6, wherein the second line injects the second solution at a pressure of 5 psi to 40 psi. The third conduit is swept back and forth over the wafer, and the third conduit sprays the third solution at a pressure of less than 50 psi.