Dicing apparatus and wafer processing method

Abstract

The present invention provides a dicing apparatus and a wafer processing method that can reduce the impact of the protective film on the cutting process while also suppressing an increase in processing costs. [Solution] This dicing apparatus comprises a dicing unit for dicing a wafer having a non-water-soluble protective film applied to its surface, an ultraviolet irradiation unit for irradiating the protective film with ultraviolet light after dicing by the dicing unit to modify the protective film to be water-soluble, and a cleaning unit for cleaning the protective film after it has been modified to be water-soluble to remove the protective film from the wafer.

Description

Technical Field

[0001] The present invention relates to a dicing device and a method for processing a wafer. relates to.

Background Art

[0002] In the semiconductor manufacturing process, a dicing device for cutting a semiconductor wafer into chips is used (see, for example, Patent Document 1). The dicing device has a blade that rotates at high speed, and cuts the wafer by moving the blade along a dicing street. The semiconductor wafer cut out in chip units is transferred to its cleaning section, cleaned, and then returned to the cassette. <00000?14> [[ID=1?]]

[0004] [[ID=2?]] In the cutting process of the dicing device, in order to prevent cutting chips from adhering to the surface of the semiconductor wafer, it is necessary to apply a protective film to the surface of the semiconductor wafer so that the surface of the semiconductor wafer is not exposed. At this time, the protective film includes a water-soluble protective film and a water-insoluble protective film.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In view of the above problems, the present invention aims to provide a dicing apparatus and a wafer processing method that can reduce the influence of the protective film on the cutting process while also suppressing an increase in processing costs. [Means for solving the problem]

[0007] The dicing apparatus according to the present invention comprises a dicing unit for dicing a wafer having a non-water-soluble protective film applied to its surface; an ultraviolet irradiation unit for irradiating the protective film with ultraviolet light after dicing by the dicing unit to modify the protective film to be water-soluble; and a cleaning unit for cleaning the protective film after it has been modified to be water-soluble to remove the protective film from the wafer.

[0008] The wafer processing method according to the present invention comprises the steps of: applying a water-insoluble protective film to the surface of the wafer; dicing the wafer to which the protective film has been applied; irradiating the protective film with ultraviolet light to modify the protective film to be water-soluble; and washing the protective film after it has been modified to be water-soluble to remove the protective film from the wafer. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a dicing apparatus and a wafer processing method that can reduce the influence of the protective film on the cutting process while also suppressing an increase in processing costs. [Brief explanation of the drawing]

[0010] [Figure 1A] This is an external perspective view of the dicing apparatus 1 according to the first embodiment. [Figure 1B] This is a schematic diagram illustrating the internal structure of the dicing apparatus 1 according to the first embodiment. [Figure 2] An example of the configuration of the cleaning unit 17 will be described. [Figure 3] An example of a protective film 31 configured in a roll shape will be described. [Figure 4] The procedure for processing wafer W using dicing apparatus 1 will be explained. [Figure 5] The procedure for processing wafer W using dicing apparatus 1 will be explained. [Figure 6] This is a perspective view of the dicing apparatus 1 according to the second embodiment. [Figure 7] This is a perspective view of the second transport mechanism 14 in a state where it is gripping the UV illumination unit 18A. [Figure 8] This is a perspective view of the second transport mechanism 14 in a state where it is gripping the UV illumination unit 18B. [Modes for carrying out the invention]

[0011] This embodiment will be described below with reference to the attached drawings. The attached drawings show embodiments in accordance with the principles of this disclosure, but they are for the purpose of understanding this disclosure and are not to be used in any way to restrict the interpretation of this disclosure. The descriptions herein are merely typical examples and do not limit in any way the claims or applications of this disclosure. Although this embodiment is described in sufficient detail for those skilled in the art to implement this disclosure, other implementations and forms are possible, and it is important to understand that the configuration and structure can be changed and various elements replaced without departing from the scope and spirit of the technical idea of ​​this disclosure. Accordingly, the following description should not be interpreted as limiting to this.

[0012] [First Embodiment] A dicing apparatus of the first embodiment will be described. Figure 1A is an external perspective view of the dicing apparatus 1 of the first embodiment, and Figure 1B is a schematic diagram illustrating the internal configuration of the apparatus. In the figures, the XYZ axes are mutually orthogonal axes, with the XY axes being parallel to the horizontal direction and the Z axis being perpendicular to the horizontal direction. The dicing apparatus 1 comprises a housing 11, a load port 12, a first transport mechanism 13, a second transport mechanism 14, a wafer table 15, a processing unit 16, a cleaning unit 17, and a UV illumination unit 18.

[0013] The housing 11 constitutes the main body of the dicing apparatus 1, and houses a computer that controls the entire apparatus, a power supply device, a chemical solution storage section, a pump, various pipes, etc. A cassette storing a large number of wafers W mounted on the frame F via a dicing tape T is placed on the load port 12.

[0014] The first transfer mechanism 13 transfers the wafer W mounted on the frame F from the load port 12 to the wafer table 15. The second transfer mechanism 14 transfers the wafer W after being processed by the processing section 16 toward the cleaning section 17. The wafer table 15 is a mounting section for mounting the wafer W (frame F) to be processed. The wafer table 15 has a porous mounting surface, and the wafer W is adsorbed and fixed to the wafer table 15 by the negative pressure applied from a negative pressure generating device (not shown) to this porous portion. After mounting the wafer W, the wafer table 15 is appropriately transferred to the processing section 16 by a wafer table drive mechanism L.

[0015] The processing section 16 has a spindle that can rotate and move in the XYZ directions, and a blade attached to the rotation axis of the spindle, and processes the wafer W by moving the blade along the dicing street. The processing in the processing section 16 includes cutting processing for dividing the wafer W into individual chips, grooving processing, etc. The cleaning section 17 houses the wafer W that has been diced in the processing section 16, supplies a cleaning liquid while rotating the wafer W, and spin-cleans the wafer W.

[0016] After being cleaned by the cleaning unit 17, the wafer W is transported to the load port 12 by the second transfer mechanism 14 and stored in the cassette of the load port 12. In the cleaning in the cleaning unit 17, in the previous stage of the cleaning process, the protective film formed on the surface of the wafer W is irradiated with ultraviolet rays by the UV illumination unit 18, whereby the protective film changes from water-insoluble to water-soluble. By changing to water-soluble, the protective film can be removed by washing with water in the cleaning unit 17. The ultraviolet light source of the UV illumination unit 18 may be an LED, a fluorescent lamp, a metal halide lamp, etc., and its form is not limited as long as it can irradiate the necessary ultraviolet rays.

[0017] Referring to FIG. 2, an example of the configuration of the cleaning unit 17 will be described. This cleaning unit 17 is roughly composed of a housing 21, a motor 22, a bearing portion 23, a shaft SF, a pulley 24, a transmission belt 25, a spinner table 26, and a cleaning liquid supply unit 28. The housing 21 is the main body portion of the cleaning unit 17 that provides a cleaning space. The motor M is a power source for rotating the spinner table 26. The motor M rotates the pulley 24 attached to the shaft SF via the transmission belt 25, thereby rotating the spinner table 26.

[0018] In the implementation of the cleaning process, first, the wafer W after the processing by the processing unit 16 is transported from the wafer table 15 to the spinner table 26 of the cleaning unit 17 by the second transfer mechanism 14. When the wafer W is mounted on the spinner table 26, the UV illumination unit 18 descends above it by a vertical transfer mechanism not shown.

[0019] The UV illumination unit 18 (ultraviolet irradiation unit) is held by the housing shielding cover 27A. The housing shielding cover 27A, which holds the UV irradiation unit 18, moves to a position opposite the cleaning stage of the cleaning unit 17 during cleaning, and together with the housing 21, shields the UV illumination unit 18 and the wafer W into a sealed space. As a result, before the cleaning process is executed, ultraviolet light from the UV illumination unit 18 is irradiated onto the protective film 31 that protects the surface of the wafer W transported to the cleaning unit 17, thereby changing the protective film 31 from water-insoluble to water-soluble. The UV illumination unit 18 is configured to move to a position opposite the spinner table 26 (cleaning stage) of the cleaning unit 17, and to irradiate the surface of the wafer W transported to the cleaning unit 17 with ultraviolet light. As described above, by forming a sealed space, it is prevented that ultraviolet light leaks to the outside of the cleaning unit 17.

[0020] After the UV irradiation process by the UV illumination unit 18 is completed, the housing shielding cover 27 is fitted onto the housing 21 in place of the housing shielding cover 27A, and cleaning is performed while preventing leakage of cleaning solution to the outside. If the UV illumination unit 18 is waterproofed, it is also possible to supply cleaning solution from the cleaning solution supply unit 28 and perform the cleaning process while keeping the UV illumination unit 18 in a sealed space.

[0021] Next, the wafer processing method, protective film processing method, and cleaning method using the dicing apparatus 1 of the first embodiment will be described with reference to Figures 3 to 5. In the dicing apparatus 1 of this embodiment, a protective film 31 is attached to the surface of the wafer W to protect the surface of the wafer W during the dicing process. This protective film 31 can be a protective film tape wound into a roll, for example, as shown in Figure 3. In this case, the protective film 31 has adhesive properties, but in the roll state, an upper liner film UL and a lower liner film LL are attached to both sides.

[0022] The protective film 31 is non-water-soluble before irradiation with ultraviolet light, but has the property of becoming water-soluble upon exposure to a predetermined amount of ultraviolet light. During the cutting process by the processing unit 16, the protective film 31 remains water-soluble, so even if the film thickness is approximately 10 μm, the surface of the wafer W is not exposed during the cutting process. After the cutting process is completed, the protective film 31 is irradiated with ultraviolet light and becomes water-soluble before the cleaning process is performed. By becoming water-soluble, the period required to remove the protective film 31 during the cleaning process can be shortened. Furthermore, because it becomes water-soluble, water can be used as the cleaning solution, and there is no need to use special chemicals to remove the protective film 31.

[0023] The specific process will be explained with reference to Figures 4 and 5. First, as shown in Figure 4(a), the wafer W is fixed to the frame F via dicing tape T, and the protective film 31 described above is attached to the surface of the wafer W (the device layer D formed on the surface of the wafer W) together with the top liner film UL. Then, as shown in Figure 4(b), the top liner film UL is removed. The wafer W in the state shown in Figure 4(b) is stored in the cassette of the load port 12.

[0024] The wafer W in the state shown in Figure 4(b) is transported to the wafer table 15 by the first transport mechanism 13, and as shown in Figure 4(c), a cutting process is performed in the processing unit 16 using the blade BL.

[0025] After the cutting process is complete, the wafer W is transported to the cleaning section 17 by the second transport mechanism 14 and placed on the spinner table 26. The gripping portion of the second transport mechanism 14 then retracts to a position away from the cleaning section 17. Then, as shown in Figure 5(a), as a preliminary step to the cleaning process, the UV illumination section 18 is transported to the top of the wafer W (above the cleaning section 17) by an upper / lower transport mechanism (not shown), and ultraviolet light is irradiated from the UV illumination section 18 towards the protective film 31. The amount of ultraviolet light irradiated is not particularly limited, but as an example, it is 500 mJ / cm². 2 (20mW / cm 2In this case, the irradiation time is 25 seconds. After that, as shown in Figure 5(b), a cleaning process is performed, and the protective film 31 is removed, as well as other foreign matter (cutting debris) which is also removed by cleaning (Figure 5(c)). After cleaning, the wafer W is returned to the cassette of the load port 12 together with the frame. Note that a step to clean the wafer W may be added between the dicing process in Figure 4(d) and the ultraviolet irradiation process in Figure 5(a). This process removes cutting debris generated by dicing, and then the protective film is removed, making it less likely for cutting debris to re-adhere on the protective film, thus achieving a higher degree of cleanliness.

[0026] As described above, the dicing apparatus 1 of the first embodiment can change the water-insoluble protective film 31 to a water-soluble one by ultraviolet irradiation in the cleaning section 17. As a result, the protective film 31 can be formed with a small thickness, and by making it water-soluble by ultraviolet irradiation, it can be easily washed off in the cleaning section 17. Therefore, with this dicing apparatus 1, it is possible to reduce the influence of the protective film 31 on the cutting process while also suppressing an increase in processing costs.

[0027] [Second Embodiment] Next, a dicing apparatus 1 according to a second embodiment of the present invention will be described with reference to Figure 6. As shown in Figure 6, the UV illumination units 18A and 18B are held by the gripping portion of the second transport mechanism 14, and the apparatus 1 is configured to irradiate the protective film 31 with ultraviolet light during the transport of the wafer W by the second transport mechanism 14.

[0028] An example of the structure of the second transport mechanism 14 in the second embodiment will be described with reference to Figures 7 and 8. Figure 7 is a perspective view of the second transport mechanism 14 holding a 12-inch diameter UV illumination unit 18A, and Figure 8 is a perspective view of the second transport mechanism 14 holding an 8-inch diameter UV illumination unit 18B.

[0029] This second transport mechanism 14 is broadly composed of a main body 41, a lighting unit holding unit 44, and a vacuum pad holding unit 45 that holds the vacuum pad BP. The main body 41 is configured to be movable by a robot arm (not shown). The lighting unit holding unit 44 is configured to fixally hold the UV lighting unit 18A or 18B below it. The method of holding (fixing) the UV lighting unit 18A or 18B by the lighting unit holding unit 44 is not limited to any particular method or structure.

[0030] A pair of vacuum pad holding units 45 are located below the main body 41 and are movable, for example, in the Y direction relative to the main body 41, and hold vacuum pads BP that adsorb the frame F below them. By making the vacuum pad holding units 45 movable in the Y direction, the distance between the pair of vacuum pad holding units 45 changes, making it possible to hold wafers W (frame F) of different sizes (e.g., 12 inches, 8 inches). When the wafer W to be processed is exchanged between a 12-inch and an 8-inch wafer, the UV illumination unit is also exchanged between the UV illumination unit 18A for 12 inches and the UV illumination unit 18B for 8 inches. In either case, in this embodiment, the UV illumination unit 18A or 18B is transported together with the second transport mechanism 14, and ultraviolet irradiation can be performed while holding the wafer W, thus shortening the processing time compared to the first embodiment. Although not shown in the diagram, the UV illumination units 18A and 18B have a downward-facing concave structure, and illumination can be performed with the wafer W, to which the protective film 31 is attached, positioned in the concave portion. The provision of the concave portion makes it possible to irradiate the wafer W without leaking ultraviolet light to the outside.

[0031] [others] The present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0032] 11…Cabinet 12…Load port 13…First conveying mechanism 14…Second conveying mechanism 15…Wafer Table 16...Processing section 17…Cleaning section 18, 18A, 18B...UV lighting section 21… Cabinet 22…motor 23...Bearing part 24...Pulley 25…Transmission belt 26... Spinner Table 27, 27A... Enclosure shielding cover 28... Cleaning fluid supply unit 31...Protective film 41...Main unit 44...Lighting part holding part 45... Vacuum pad holder

Claims

1. A dicing section for dicing wafers with a water-insoluble protective film applied to their surface, A UV irradiation unit that irradiates the protective film after dicing by the dicing unit with ultraviolet light to denature the protective film into a water-soluble form, A cleaning unit that cleans the protective film after it has been modified to be water-soluble and removes the protective film from the wafer. A dicing device equipped with the following features.

2. The dicing apparatus according to claim 1, wherein the ultraviolet irradiation unit is configured to move to a position opposite the cleaning stage of the cleaning unit and to irradiate the surface of the wafer that has been transported to the cleaning unit with ultraviolet light.

3. A first transport mechanism for transporting the wafer to the dicing section, A second transport mechanism for transporting the wafer from the dicing section to the cleaning section, A dicing apparatus according to claim 1, comprising:

4. The dicing apparatus according to claim 3, wherein the ultraviolet irradiation unit is mounted on the second transport mechanism.

5. The steps include: applying a water-insoluble protective film to the surface of the wafer, The steps include: dicing the wafer to which the protective film has been applied; The steps include: irradiating the protective film with ultraviolet light to modify the protective film to be water-soluble; The steps include: washing the protective film after it has been modified to be water-soluble to remove the protective film from the wafer; A wafer processing method comprising [the following].

6. The processing method according to claim 5, further comprising the step of cleaning the wafer to remove cutting debris between the dicing and the irradiation of ultraviolet light.

7. The processing method according to claim 5 or 6, wherein the irradiation of the protective film with ultraviolet light is performed on the surface of the wafer that has been transported to the cleaning unit, by moving the ultraviolet irradiation unit to a position opposite the cleaning stage of the cleaning unit.

8. The wafer is transported to the dicing section where the dicing is performed by a first transport arm. The processing method according to claim 5 or 6, wherein the wafer is transported from the dicing section to the cleaning section by a second transport arm.

Images