TW588434B - Method and apparatus of wafer dryer - Google Patents

Abstract

The present invention disclosed a method and apparatus for drying wafer, to remove a wafer with solder bumps of Tin-Lead alloy, comprising: a wet etch bench, for removing the photo resist; a DI water over flow bench, for rinsing the etching chemical solution; an organic solvent bench, using high volatile and dissolve solvent to replace the water on the wafer; multiple of vibrator or nitrogen bubble generator, placing on the bottom or the side-wall of the bench to increase the replacing rate of water; a drying chamber, for drying the organic solvent quickly.

Description

588434 V. Description of the invention (l) 1. Technical field to which the invention belongs The present invention relates to a wafer moisture removal device for a semiconductor device, and particularly to a pillar solder bump with high density and low pitch of lead-tin alloy or gold ( solder bump) of the wafer surface moisture removal device. 2. The prior art overlying the day (flip chip) to engage the engaging paracytic formula (area array), suitable for high density wiring configuration package, wherein the package as a ball format (ball gri (1 array, BGA) type wafer and configuration means (chip Si ze package, csp), direct wafer package (direct chip array, DC A) are best suited for use flip chip bonding. the flip-chip bonded to the first step, solder bumps (solder bump on a wafer Shu c ), Whose material is 95% total, 5% tin or 98% wrong, 2% tin. When high reliability is required, gold can also be used as solder bumps. Figure 1 is formed on a wafer A cross-sectional view of a solder bump on each wafer (^ 丨 port). As shown in FIG. 1 (A), on the wiring pad 104 on the wafer 102, the opening 106 of the protective layer 106 It is exposed for wiring, here is used to make solder bumps on it. Then coated with a multilayer metal film (Under BUmp Metallurgy, UBM) 108 to 110 as a conductive layer for electroplating or as adhesion during evaporation And the metallization conditions required to provide solder wetting = photoresist patterns (openings) 11 required to form solder bumps on the substrate 10 2, and then electroplated lead-tin alloy to form dense solder on the wafer

Page 6 588434 V. Description of the invention (2)

Tin bumps 114. As shown in FIG. 1 (A) of FIG, after the photoresist 112 is removed, etching solution to multiple metal layers 108 to 110 are formed solder bump 114. This is shown in Figures 1 (B) and 1 (c). The pattern on the water to be removed after the etching is completed. The general wafer etching and drying method is as shown in the prior art in FIG. 2. After the multilayer metal is etched in the etching treatment tank 202, it is moved to a pure water overflow tank 204 and the etching solution is washed with pure water until the etching solution has been replaced by pure water. removed. Generally, there are two methods for removing moisture: spin-drying method 206 and Maragoni Effect 20 8. The spin-drying method uses high-speed centrifugal force and nitrogen blow-drying method, and the fragmentation rate is high, which is prone to produce water marks. The Marenconi effect method uses surface tensioning method to destroy the surface tension of water and remove the water from the wafer surface. Because the density of solder bumps on the wafer is very high, it takes a long time for the water to adhere to the surface of the wafer with columnar known solder bumps ‘not easy to remove’ due to adhesion and tension. However, devices generally used for removing moisture from the surface of wafers with tin alloy solder balls, because the removal of moisture needs to be completed within a short time, otherwise the tin-lead alloy exposed to water molecules is liable to form stray particles. As the distance between the columnar structures is getting smaller and smaller (approximately = 2 and the density is getting higher (> 30 pieces / 5 mm), spin-drying

1 Ma Shang Cornelius steal mode and effect solvent substitution method of drying equipment, has gradually ",, 'competent and have the phenomenon of metal particle contamination of the precipitate. ^ A of this present invention addresses the disadvantages of the prior art design and process requirements clock An apparatus and method for removing the knife 7, the moisture is removed more economical and more

Page five 7,588,434, described invention (3) ---- 3. SUMMARY OF THE INVENTION The present invention master i ^ ~ object to provide moisture removing means and the A wafer 1 side = back Shu enough energy to break through the water formation of capillarity and adhesion force 'water miscible solvent and water substitution position. The purpose of the present invention is to provide a wafer moisture removal device and method to quickly remove moisture from the wafer surface, & reduce the amount of lead precipitation and reduce wafer contamination. Further object of the present invention is to provide a moisture of A wafer removal apparatus and method to reduce the operation time. In order to achieve the above object, the present invention proposes a wafer moisture removing device 'for removing the moisture on the wafer surface of a tin tin alloy or gold solder bump, which at least includes: an etching treatment tank for removing the etching resist film; a water overflow tank for rinsing the chemical etching solution; a solvent tank to the high volatility of the water-soluble organic solvent San substituted water; a plurality of vibrators, arranged in the solvent tank and around the bottom, to enhance the speed of water solvent substitution; a drying tank, the solvent is evaporated into the wafer arrest and fast drying. Another aspect of the present invention is to replace the vibrator with a nitrogen bubble generator to generate nitrogen bubbles and increase the rate of solvent displacement of water.邡 8434 V. Description of the invention (4) 4 · Embodiment Figure 3 is a block diagram of wafer moisture removal according to a preferred embodiment of the present invention. Etching grooves 3 〇2 system is generally of a wet etching grooves, the resist film is removed for more than engraved, may be a batch (batch type) or sheet rotary engraving device I, francium moment after, into pure water overflow (0 verf 1 0 w) The chemical solution for cleaning and etching is used in the tank 3 0 4. At this time, pure water is likely to precipitate lead to form particles and contaminate the wafer, so it should be dried quickly. Once the chemical etching solution is cleaned, the wafer is immediately transferred into the solvent tank 3 06. The solvent sword in the solvent tank is preferably a highly volatile and water-soluble organic solvent, so as to place the entire batch of wafers to be processed. So that the solvent replaces the moisture on the wafer surface. But it can also be a single-piece solvent tank. Because the density of solder bumps on the wafer is very high, water adheres to the surface of the wafer with columnar solder bumps due to adhesion and surface tension, which is not easy to be replaced by the solvent. Therefore, a vibrator is provided in the solvent tank in this case. Or nitrogen bubble generator 3 0 8 'Using vibration or nitrogen bubbles to destroy the adhesion between the water and the columnar solder bumps due to capillary phenomenon and the surface tension build up a large amount of water to make the solvent replace the water and mutually dissolve to accelerate the solvent to replace the water Speed to prevent lead from precipitating and forming particles to contaminate the wafer. The solvent in the solvent tank is, for example, isopropyl alcohol (IPA). If the vibrator uses a piezoelectric element (piez〇electric de ^ ice) to generate vibrations, the vibration frequency is IK z to 2 0,00. Audio, or ultrasonic frequencies from 20,000Ηζ to 100,000Ηζ. Set a plurality of piezoelectric elements (see Figures 4 and 5) at the bottom and surroundings of the solvent tank so that the vibrating solvent has enough energy to break the capillary phenomenon and surface tension of water and be replaced with a solvent.

Page 9 588434

5. Description of the invention (5) agent; a large amount of bubbles can also be formed in the solvent tank by using a nitrogen bubble generating device, and the capillary phenomenon and surface tension of water can be destroyed and replaced with the agent. Thus, the water was soon replaced by the solvent, precipitated greatly reduce the error. The wafer is then moved to a drying tank 3 10, which can be a low-temperature oven or a drying nitrogen flow tank, etc., to evaporate the solvent and quickly air dry or dry. Section 4 (A) The picture shows a top view of the vibration type solvent tank of FIG embodiment of the present invention according to one preferred embodiment, the 4 (B) A A graph-based cross-sectional view taken along line 4 (a) in FIG. Prepared as described in Section 4 (A) and 4 (B), FIG, tank 402 solvent-based material such as stainless steel with the corrosion, metal such as aluminum, a plurality of solvent tank bottom so that the piezoelectric element is set 4〇8 f side and the vibration can be uniformly transmitted to the crystal within the pod 4〇4 ^ 41〇 vibration agents, it has enough energy to break of the solder bumps ° capillary phenomenon and surface tension of 7 and quickly solvent replacement. The groove is a plan agent ί According to another preferred embodiment of the present invention the solution of Example bubble type ^ ([alpha]) and Gu. Section 5 (Β) system of FIG. 5 (A) a cross-sectional view taken along ΑΑ referred to FIG. The step Wa) and (b), FIG notches steel, Shao, broken glass, quartz prepared Γ "Surname material such solvent does not rot money generated by the discharge port 508, the bottom 51j 2 of the tank body disposed atmosphere f Nitrogen source is supplied via line 512 with nitrogen bubbles. ^ 1 · / 1 'The gas system is a pressure bubble not shown, which surrounds the columnar solder bumps to form a large amount of extremely fine gaseous gas. water; '^ of capillary phenomenon and surface tension rupture group, Ά of: Λ removing unit devices may each independently become - be combined or functions at a single slot cavity (cluster

Fifth, the invention is described in (6) t〇〇 1) square section 4 (A) according to one of the picture shows the preferred embodiment of the present invention is a method flowchart of the wafer ^ moisture removal. For the multi-layer metal etch resist and the metal bump, O process begins at step 602, the wafer is etched into the treatment tank 302, in # 604 'is etched. In step R η β β $ A, if step, the process begins at step 602, the wafer is etched into the treatment tank 3〇2 at '04 # for moment. At step 6 06, it is judged whether the remaining time is completed, and then return to step 6 0 4 and continue etching; if so, proceed to step 6 0 8 and crystallize to pure water overflow tank 3 04, and at step 61 0, Wash the wafer with pure water. Continued t step 612, it is determined whether or not clean, if not, returns to step 61〇, following washing; if yes, proceeds to step 614, to move the wafer solvent tank. In step disclosure, or nitrogen bubbles to vibrate to promote solvent exchange water. This step-based energy, the key steps. At this time, vibration or movement phenomenon of nitrogen bubbles increase the solvent to break the wafer 2 surface density of the pillar-shaped solder bumps is enhanced and the opposing capillary t ... Ϊ adhesion and surface tension of the solvent is rapidly replacing water position 618, U fraction, leaving volatile solvents, reducing lead precipitation. At step vibrate or open, Erzhi / change, is it finished * ’If $, go back to step 616 and continue the groove. Use 7 heat ^ 2 Ϊ, go to step 620, move the wafer to a dry and dry crystal circle: round, or use a low temperature oven to evaporate the solvent from the wafer. End the process. Sparkle continue to dry, the right piece goods, proceeds to step 624, although the present invention to remove Laid person will appreciate that this can keep I = the embodiments have been disclosed, well known in slightly modified form of embodiment of the art and the details of this embodiment Laid piece goods, in

Page 11 588434 V. Description of the invention (7) Modifications and changes made without departing from the spirit and concept of the present invention are all within the scope of the present invention, and the above-mentioned embodiments of the present invention are for illustrative purposes only, and are not intended to be limiting. the appended claims. Brief Description of the drawings 588 434 5. Brief Description of the drawings FIG 1, one based on a cross-sectional view fresh tin bumps formed each wafer (Chip) on the wafer (wafer). Fig. 2 Fig. 3 is a general method for processing and drying wafers. This is a block diagram of wafer moisture removal according to a preferred embodiment of the present invention. A top view of the vibration type embodiment of FIG solvent tank ', and catching rabbits section 4 (A) according to one of the picture shows the preferred embodiment of the present invention. β 9 Figure 4 (B) Figure 5 (A) is a sectional view taken along line AA of Figure 4 (A). A top view of a bubble type solvent tank according to another preferred embodiment of the present invention. Figure 5 (B) is a cross-sectional view taken along AA in Figure 5 (A). FIG. 6 is a flowchart of a method for removing moisture from a wafer according to a preferred embodiment of the present invention. Explanation of symbols: 102 wafers 104 wiring 塾 105 openings 1 106 protective layer 108, 110 multilayer metal film 112 photoresist pattern 114 fresh tin bump 202 Μ etched processing tank 204 pure water overflow tank 206 spin-dry type 208 Marengoni effect 210 solvent groove

Page 13 588 434 300 Brief Description of the drawings wafer 212 Moisture removal device 302 of the drying vessel etching process water tank 304 overflow tank 306 or the solvent tank nitrogen bubble generation vibrator 308 310 402 groove 404 groove dried pod crystal 406 circular groove 408 of the piezoelectric element 502 of the wafer 504 cassette 506 508 510 nitrogen bubble generating ejection outlet 602--624 step

Page 14

Claims (1)

588434 VI. Patent application scope 1 · —A kind of wafer moisture removal device for removing the surface of wafers with lead solder or columnar solder bumps, including at least: 7 an etching treatment tank To remove the photoresist film by etching; a pure water overflow tank to wash the chemical liquid used for etching; a solvent tank to replace the organic solvent with a highly volatile and water-soluble organic solvent; a plurality of vibrators set in the solvent The bottom and the periphery of the tank to increase the rate of water replacement by the product agent; ^ Dry a drying tank, put the wafer into the solvent to evaporate the solvent and dry quickly 2. For example, the moisture removal device of the first patent application scope, wherein the corrosion treatment tank is Batch type etching tank. 3. The term of the patent scope of the moisture removal device 1, wherein the processing tank based rot than monolithic (s i ng 1 e waf er) I engraved rotating means. 4 · If the moisture removal device of item 1 of the patent application scope, the material of the solvent tank is non-recorded steel. 5 · If the moisture removal device of item 1 of the scope of patent application, the material of the solvent tank is the inscription. 6 • The water removal device as described in the first patent application, in which the solvent Page 15 588434 6. Scope of patent application The material of the tank is glass. 7. The moisture removal device of item 1 of the patent application scope, wherein the material of the solvent tank is quartz. 8. The moisture removal device according to item 1 of the patent application scope, wherein the plurality of vibrators may be replaced by a nitrogen bubble generator to generate nitrogen bubbles and increase the rate of solvent displacement of moisture. 9. The moisture removal device according to item 1 of the patent application scope, wherein the vibration actuator is a piezoelectric element. 10. The moisture removal device according to item 1 of the patent application range, wherein the vibration frequency of the vibrator is a sound wave of 1KHz to 20,000 Hz. 11. The moisture removal device according to item 1 of the patent application range, wherein the vibration frequency of the vibrator is an ultrasonic wave of 20,000 Hz to 100,000 Hz. 1 2. The moisture removal device according to item 1 of the patent application scope, wherein the dry φ canister is a low temperature oven. 1 3. The moisture removal device according to item 1 of the patent application scope, wherein the drying tank is a dry nitrogen gas flow tank. Page 16 588434 The water removal device, wherein the water 14. As in the scope of the patent application, each unit of the removal device becomes a set of water removal device, in which the water function is a single tank type. The moisture removal device, wherein the function much water cavity (cluster 1 5 · Patent application range as items 1 min each cell removing device 16 become the combined range-patent as items 1 min removing unit devices become the combined tool) square, 17 * - species wafer moisture removal method, the moisture wafer vibration in a solvent to enhance the solvent substitution under Xi, Optional * / wn aqueous speed, comprising at least the following steps: (a). Place the wafer to be processed into an etching process to remove the photoresist and exposed multilayer metal film; order the etching, main, and soil T. Move the Japanese yen to a pure water overflow (〇Ver f low) tank, and Water> Wash the wafer; (c) Move the wafer into the solvent tank, increase the solvent by vibration = can break the adhesion and surface tension increased by capillary phenomenon and quickly replace the water to reduce the precipitation of lead; (d) will The wafer is moved to a drying tank, and the wafer is blown dry with a stream of hot nitrogen. 18. If the method for removing moisture from item 17 of the scope of patent application, the vibration of the kinetic energy of the solvent can be replaced by nitrogen gas bubbles. Say 588,434 six, patent applications range 1 9. Item of patentable scope of moisture removal process 17, wherein the flow of hot nitrogen to dry the wafer may be replaced by low-temperature drying oven.