TW522446B - Method and apparatus for removing thick dry film photoresist on wafer - Google Patents

Abstract

This invention provides a method and an apparatus for removing thick dry film photoresist on wafer. The method is characterized that a smooth-surface support rod is provided, which has a cross-section of elliptic shape. A cassette carrying wafers is placed on the support rod in a fashion that the edge of the bottom of the wafer is in contact with the support rod. The support rod is then rotated to drive the wafer in an up-and-down motion and also rotate the wafer. This facilitates removal of thick dry film photoresist in a photoresist removal tank containing photoresist removal liquid.

Description

522446 V. Description of the invention (1) The present invention relates to a wet etching method for removing photoresist, and particularly relates to removing thick dry film photoresist (thick dry film ph〇t〇) in a metal bumping process. resist) method and the device used by it. [Known technical description] In the semiconductor manufacturing process, when various semiconductor elements have been prepared, f] will cover the surface of the wafer with a protective layer to prevent the semiconductor elements from being affected by pollution, scratches, and moisture. . Subsequently, an opening is defined and formed on the protective layer by using a lithography and etching process, so that the surface of the metal layer provided at the bottom of the protective layer is exposed and used as a bonding pad to enable the semiconductor device to communicate with The external substrate forms an electrical connection. At present, most of the electrical connection methods adopt f-chip technology. In a broad sense, the flip-chip technology refers to the fact that after a wafer is flipped, it is bonded to an external substrate through a metal conductor in a face-down direction. Generally speaking, metal conductors include metal bumps, tape_ aut⑽ated bonding, anisotropic conductive adhesives, polymer bumps, and polymer bumps. , Stud bump, etc. Among them, metal bump technology is the most mature, and it is also widely used in mass-produced products. There are many methods for forming metal bumps. Common ones include evaporation, sputtering, electroplating, printing, wire forming, and he injection molding #, and the material of metal bumps is tin fault, low temperature tin fault, gold, recording, etc. according to different needs. Flip chip, copper, etc., of which ^ bumps are most commonly used in the construction of LCD products, communications products. , U; Please refer to FIGS. 1A to 1E, which show the method of manufacturing the conventional bump 26.

0503-6634TWF; TSMC2001 -0579; Jacky.ptd Page 5 522446 Description of the invention (2) Schematic. As shown in FIG. 1A, a wafer 10 is provided, which includes prepared semiconductor elements (not shown). A connection pad 12 is disposed on the surface of the wafer, and a passivation layer 14 is provided. All the semiconductor elements covering the surface of the wafer 10, and a first opening 6 are defined on the protective layer 14 'so that the surface of the connection pad 12 is exposed. Among them, the material of the connection 塾 12 is made of metal aluminum, and the material of the protective layer 丨 4 can be made of silicon nitride (“Λ) or phosphosilicate glass (PSG). Second, as shown in FIG. A barrier layer 18 and a metal layer are sequentially formed on the surface of the wafer 10, wherein the barrier layer 18 is composed of Ti / TiW to block the diffusion of the metal ', and the metal layer 20 is a bump that is helpful for subsequent The metal layer 20 is, for example, Cu. Next, as shown in FIG. 1C, a thick dry film photoresist layer 22 is formed on the surface of the wafer 10, which includes a second opening 24 for defining The pattern of the bumps. Afterwards, Yudi opened a metal bump in the opening 24. The metal bump 26 includes a copper layer 28, a nickel layer 30, and a solder layer 32, and is used as a bump for the electrical connection bridge. When the thickness of the plated metal bump 26 exceeds the thick dry film photoresist layer 22, a mushroom-shaped metal bump will be formed, as shown in FIG. 1D. 'Photoresist removal will be added in the subsequent photoresist stripping process. Difficulty, which makes it difficult to improve productivity and yield. Especially in the metal bump process, thick dry film is often used Generally, it is negative photoresistor (above 100mm), and the characteristic of negative photoresistor when it is removed is that it peels off piece by piece, so the thick dry film photoresist that is peeled off can easily get stuck in a mushroom shape ( The lower side of the metal bump of the mushroom head) is more likely to get stuck in the gap (slot) between the wafer and the cassette / boat, causing a part of the thick dry film photoresist layer to remain around the wafer and affect it. Follow-up process.

V. Description of the invention (3) After 'K removes the outer layer = the layer 22 is stripped and removed' until the exposure is exposed. Second: The metal layer 20 and the barrier layer 18 are etched to flow to form a spherical gold :: block surface 'and then heat the metal. The bump 26 makes it re-groove i ί t ί ί 上: up; f dry film photoresist stripping if used to remove light with residual problems, right: 廄: Shimei "gross time-consuming and easy to have thick dry film The photoresist layer method has a lot of trouble in removing photoresistive grooves. It is known; the effect is not good, and it is necessary to wash it with deionized water.

Big 1 king and easy to be bad bad metal bumps. F ^ K, in order to solve the difficulty of removing the thick dry film photoresist in the photoresist stripping, P φ i ^, and make it difficult to improve the yield and yield. &Amp; Urgently seek to address the above problems [Inventory Summary] Engraved recipe :: is to provide a way to remove the photoresist _ make the wafer-up and down: install-support rod and rotate it, to remove the effect, and increase the wafer The yield and yield of the membranes per hour (wph) were improved. To achieve the above objective, the present invention proposes a method around a wafer, which is suitable for placing at least one table: resistance remaining in: f; assette / bt) ^ f, marking the photoresist. The method includes the following steps. Promote in the middle 1. Support with smooth surface 0503 -6634TWF; TSMC2001 -0579; J a cky.ptd 522446

The photoresist removing groove is an ellipse $ 'and the support rod is moved to the bottom to move the wafer' and the wafer is rotated. In addition to == Ming proposed-a device for removing thick dry film photoresist, which is suitable for removing thick dry film photoresist, the device includes:-photoresist removal tank κ is used to remove photoresist to remove households on the wafer It is located at Xunyangyangzi c, first resistance, a wafer is loaded to go to the well = Medium 1 to carry the wafer;-a swing rod is located in the first resistance groove, the cross section of the support rod is almost an elliptical edge Contacting; and a driving device for making it. = Instead, move the wafer up and down and rotate the wafer. In order to make the above-mentioned objects, features, and advantages of the present invention more obvious and easy to understand; a special embodiment of the present invention is described in detail with reference to the accompanying drawings. [Simplified description of the drawings] Figures 1 A to 1 E Know the cross-sectional schematic diagram of the process of metal bumps. Figures 2A to 2F are schematic cross-sectional views of a process for removing a thick dry film photoresist according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing a surface of a thick dry film photoresist removing device according to an embodiment of the present invention. [Symbol description] 10, 60 ~ wafer; 12, 62 ~ connecting pad; 14, 64 ~ protective layer; 16, 24, 66 ~ opening;

522446 V. Description of the invention (5) m wall layer; 20, 7. ~ Metal layer; ΓΓ2 臈 photoresist layer; 26, 76 ~ metal bump; 28 8 ~ copper layer; 30, 80 ~ nickel layer; 32, 82 ~ solder layer; nn t, 100 ~ photoresist removal groove; 1 0 4 to wafer carrier (crystal boat); 106 to support rods (the cross section is mostly oval); 107 to connecting rods; 108 to drive devices. Embodiments Please refer to Figs. 2A to 2F, which show cross-sectional views of a process of an embodiment of the present invention. It should be emphasized here that although this embodiment removes the thick dry film photoresist as an example for illustration, it does not first refer to FIG. 2A to provide a wafer 60, which includes the completed semiconductor device (not shown). (Shown), a connection pad 62 is provided on the surface of the wafer 60, a protective layer 64 covers all semiconductor elements on the surface of the wafer 60, and a first opening 66 is defined on the protective layer 64. So that the surface of the connection pad 62 is exposed. Among them, the material of the connection pad 62 is made of metal aluminum, and the material of the protective layer 64 may be made of silicon nitride (Si3N4) or phosphosilicate glass (PSG) to protect the semiconductor device from being polluted. Referring to FIG. 2B, a wall layer 68 and a metal layer 70 are sequentially formed on the surface of the wafer 60, wherein the barrier layer 68 can be blocked by titanium / a barrier, and the metal layer 70 can be composed of copper, "Cheng Cheng" uses the adhesion of subsequent bumps. < Contribute Next, referring to FIG. 2C, the step of forming the metal layer 7

0503 -6634TWF; TSMC2001-0579; Jacky.ptd Page 9 522446 V. Description of the invention (6): :: 5 ί 2: Thick dry film photoresist layer 72. The thick dry film photoresist layer 72 is preferably p50m, ^: \ made by τοκ, and more preferably is made of τοκ's negative photoresist. Or a series of bumps 7Ι produced by TOK Company ’s P5012 ° series. A metal bump 76 is formed in the bump pattern. This metal is connected to a nickel layer 80 and a solder layer 82 for use as an electrical film. Photoacoustic 72 days When the thickness of the plated metal bumps 76 exceeds that of the metal bumps that are thick and dry, as shown in FIG. 2D, it is difficult to perform the photoresist removal of the present invention. Next, nf ,,,, and sigma v were suddenly installed in the photoresistive groove with a support rod (, ar to enhance the stripping effect of the thick dry film photoresist. U.slueZ Ϊ ^ ^ ^ ^ 60 ^ ^ ^ '1 ^ ^ a, # 60 is placed on the & door J Β of the boat, and the round carrier device 104 is usually placed in the gap (slot) of the sun-dial boat. Then put them together in a photoresist removing groove with a photoresist removing liquid inside it. Autumn,, 106, 哕 Φ-h…, a stupid support rod for smooth surface 1 0 6 W ^ ^ ZI The cross section is almost elliptical, and the support rod is in the photoresist groove 100. Then the Xizhou boat 104 with the circle 60 is placed on the support block 1nfiu order / day H60 on the day The sun support rod 106 is in contact. After that, the edge of the bottom of the back shovel wafer 60 and the support are moved up and down to turn the child support rod 106 and drive the wafer 60 — the force makes the circle βηίί the support rod 106 The contact with the wafer 60 is used to remove the thick dry film photoresist layer 72 on the wafer 6 °. The thick dry film around the wafer 60 is easily removed, and the support #rod 106 may be Made of TeflQn. And this example

522446 V. Description of the invention (7) The wafer carrier of the wafer / boat can be made by

Made of Teflon or quartz. The photoresist solution in the photoresist removal tank 100 may include tetramethylammonium hydroxide (Tetramethylammoniumhydroxide) 3%, Dimethyisulphoxide (DMSO) 96-99% And water < 3%. In addition, in order to enable the support rod 〇〇6 to rotate, a driving device 108 is also included. The drive device 108 is connected to the support rod 106 to rotate the support rod 106. The connecting rod 107 may be made of Tef 100n or stainless steel. It should be noted that the rotation speed of the support rod is less than or equal to 60 rpm. If the rotation speed is too fast, the wafer 60 and the wafer 4 are likely to be rubbed too much, which may cause damage and release particles. In addition, the photoresist removing groove 丨 〇〇 may further include a solution for filtering a solution (not shown) for filtering the thick film photoresist and particle impurities peeled from the wafer 60 or using The photoresist removal liquid in the photoresist removal tank is mixed uniformly. For subsequent manufacturing, the metal layer 70 and the barrier layer 68 outside the bump region can be etched and removed according to a conventional method until the surface of the protective layer 64 is exposed, and then the metal bump 76 is heated to flow again to form a spherical metal bump. Then, the production of the bump is completed, and the result is shown in FIG. 2F. The device for removing the thick dry film photoresist in the metal bump manufacturing process according to the present invention is not shown in FIG. 3. The device includes a photoresist removal tank 100 for containing a photoresist removal solution to remove thick dry film photoresist on a photoresist wafer. The photoresist removal tank 100 may contain tetrafluorene ammonium hydroxide ( Tetramethy lammoniumhydi'oxide) < 3%, Dimethyisulphoxide (DMSO) 9 6-99% and

522446

^ 3 / °. The helium device includes a wafer carrying device 104 for carrying a name bearing device 104, such as a wafer boat (CaSSette / boat) made of Teflon or quartz. A support rod 106 is located in the photoresistance removing groove 1⑽. The cross-section of the support rod 106 is substantially elliptical and contacts the edges. The support rod 106 is made of, for example, TeflOn. The rod length of the supporting rod 106 is usually matched with the length of the wafer supporting device 104, so that all the wafers can be obtained by contacting the supporting rod 106. The device includes a driving device 108, which is connected to the supporting rod 106 to rotate the supporting rod 106 to move the wafer up and down, and to rotate the wafer. The connecting rod 107 can It is made of Teflon or stainless steel. In addition, the rotation speed of the support rod is less than or equal to 60 rpm. The device may further include a photoresist-removing circulating filter device (not shown) and a photoresist-removing heating device (not shown). The circulating filter device can filter the thickness of the peeled off wafer. Dry film photoresist, particles, and other impurities, and the heating device can heat the photoresist removal liquid to a temperature required for the manufacturing process. For example, in this embodiment, the working temperature of the photoresist liquid is about 60 °. For the convenience of description, the foregoing embodiment of the present invention is described by using a wafer as an example. However, the purpose of the present invention is to mass-produce batches, which can simultaneously remove multiple photoresist wafers, and is suitable for mass production in a factory. [Effects of the Invention] Through the method and device of the present invention described above, the wafer can not be kept still during the photoresist removal process, and the wafer can be driven up and down by a rotating support rod (ellipse in cross section). The ground shakes and the wafer rotates, which makes it easy to get stuck in the photoresistance around the wafer and where the wafer contacts.

W446

Claims (1)

J 厶 厶 呻 HO VI. Scope of Patent Application __ 1 · A method for removing thick dry film photoresist on a wafer: Wanfa, including the following steps: Place a wafer with a thick dry film photoresist on the surface (cassette / In the gap (slot) of the boat), the sun and the boat put the wafer and the wafer boat in a photoresistive tank; Fang Yongquan provided dry film photoresist liquid-a smooth surface support rod, Shaw is round, and the support rod is placed in the photoresistance removing groove; the J-plane is substantially elliptical; the wafer boat on which the wafer is placed is placed on the edge of the support bottom to contact the support rod; That is, the support rod is rotated to move the wafer up and down, and the wafer is rotated ... to remove the thick dry film photoresist located on the wafer. The method described in the item 1 of the scope further includes raising a driving device, and the driving device rotates with the supporting rod. * Using stool 4 3. The method as described in item 丨 of the patent application range, wherein the thick dry film photoresist is P50 1 0 0 manufactured by TOK Company, P5101 0 manufactured by τ〇κ Company or P50 manufactured by τ〇κ Company 1 of 20 series products. 4. The method according to item 丨 of the patent application scope, wherein the boat is composed of Teflon or quartz. 5. The method according to item 1 of the scope of patent application, wherein the support rod is composed of T e f 1 ο η. 6. The method as described in item 1 of the scope of patent application, wherein the photoresist removing bath further comprises tetramethylammonium hydroxide <3%, difluorenylsulfonate 96-99%, and 0503-6634TWF; TSMC2001 -0579; Jacky.p t d p. 14 6. Scope of patent application Water &lt; 30/0 〇 7. If the speed of the item 丨 of the scope of patent application is less than or equal to 60 rpm. The method described above, wherein the support rod 8 The groove as described in item 1 of the scope of patent application further includes providing a solution circulating filtration, the method, wherein the thick film photoresist peeled off by the photoresist removal or the "resistance groove" Medium = Transition from the wafer 9.-A kind of device for removing thick dry film photoresistors], ::: Mix evenly. Film photoresistors; ^ F, at night to remove the thick dry film on the wafer, a wafer carrier is located The light-removing circle; the Λ turbulence light-resisting groove is used to carry the crystal-selective rod located in the ellipse in the light-removing sample, and the circular hemp is :: The edge of the sundial at the bottom of d is in contact with each other; and-down 'is used to rotate the supporting rod to drive the wafer-upper dry film photoresist, and ii and rotate the crystal 1 to facilitate The thickness of the wafer is supported by the supporting rod, and the device carrier device described in item 9 of the scope of patent application includes a wafer boat (cassette / b〇at). The device described is composed of T ef 1 ο η. The photoresist removal 1 2 · The device described in item 9 of the scope of patent application ^ ~ Γ ″ The liquid further includes tetramethylammonium hydroxide &lt; 3%, dimethylsulfine 96-99%, and water &lt; 3% 〇1 3. The device as described in item 9 of the scope of patent application, Which the support rod 0503-6634TWF; TSMC2001-0579; Jacky.ptd Page 15 522446 6. The scope of patent application is higher than 0 to 60 rpm. 14. The device as described in item 9 of the scope of patent application, which further includes a circulating filter device for removing photoresist liquid. 1 5. The device according to item 9 of the scope of patent application, which further includes a heating device for removing the photoresist liquid. 0503-6634TWF; TSMC2001-0579; Jacky.ptd p. 16