TW508652B - Device and method for wafer drying - Google Patents

Abstract

A wafer drying device, which comprises a microwave drying room, a top cover, a wafer accommodation tank, a gas input, a gas output, a liquid output and a supersonic spray, and the assembly of the supersonic spray comprises a solution pipe, a supersonic agitator, and a spray head. The solution is agitated by the supersonic agitator, and the spray head is to nebulize the solution and spray onto the wafer surface, so as to dissolve the solution in the water on the wafer surface. After being heated by microwave, the solution is nebulized and vaporized, and the dried inert gas is sent from the gas output and diluted, and exhausted from the gas output, so as to get a clear and dry wafer surface.

Description

508652 V. Description of the invention (1) Field of the invention: The present invention relates to a wafer drying device and method, especially a device and method for achieving wafer drying using solution spraying and microwave heating. BACKGROUND OF THE INVENTION: Semiconductor technology has made considerable progress in integrated circuit manufacturing technology. The design of semiconductor components and circuits is continually moving towards saving component space and increasing packing density. For example, early dynamic random access memory cells (DRAM memory cells) required six transistors, and now dynamic random access memory cells Only one transistor and one capacitor are needed. Semiconductor manufacturing processes including processes such as oxidation, diffusion, chemical vapor deposition, and heat treatment are all performed in furnace tubes or chambers. u In the LS I process, silicon wafers enter the high temperature furnace tube for diffusion or oxygen heat treatment. For example, before chemical vapor phase and thin film deposition or after etching, the wafers need to be chemically cleaned and high-purity deionized pure water. (Deionize water and wash and finally dehumidify and dry the wafer to make it clean. 2. It mainly removes pollutants on the wafer surface; especially the degree, which is below 100 angstroms, and the thickness of fate oxide is still required. Roughness and removal of natural oxides: η said that the surface of the round surface is micro-built to + V body ultra-thin gate

508652 V. Description of the invention (2) Electrical parameters and characteristics of the oxide layer, and achieve the quality and reliability of the element Silicon wafers are washed with a series of chemical tanks and DI ultrapure water. Water-wet silicon wafers, desiccated and dried. Isopropyl alcohol (IPA) vapor drying method is used. This drying technology is a quasi-quiet and forceful drying technology. ) As a transport gas (Carrie = α gas) '' In Luoqi dry without passing through the heater at the bottom, ιpa is heated to evaporate into steam, wet wafers are placed in the IPA steam drying chamber, immersed in IPA steam, Next, the exhaust pressure was adjusted to achieve & stable parallel flow in the steam chamber. The high volatility of IPA dehydrated and dried the water on the wafer surface, and removed water marks, particles and metal impurities on the surface. During the entire dehydration and drying process, except for the robotic arm to transport wafers into and out of the I ρ Α steam room, there is no chance of other activities to generate particles to cause pollution. Therefore, the entire IPA steam drying chamber passes parallel clean air passing through ultra-low penetration air-filter (ULPA filter) to maintain an ultra-clean PA drying steam chamber. There are resistance testers (Resistivitymeter) to detect its purity and moisture content. The entire I PA steam drying chamber is made of high-grade stainless steel & 6 L material, the surface is mechanically The polishing and chemical treatment are completed into a dust-free ultra-clean I PA steam drying chamber. …, The side wall device of the Luo steam room has a heater, the temperature is set to 2000, and

Page 5 508652 V. Description of the invention (3) Avoid IPA and water vapor from condensing on the side wall. At the same time, the bottom heater must not overheat, avoid IP A boiling, too strong steam, and also contaminate the surface of the wafer. The upper end of the steam room is equipped with a cooler. After dehumidifying, dehydrating and drying, the I PA vapor containing moisture condenses into a liquid, and the liquid discharged into the lower end of the drying room is recovered and purified before reuse. There are three main factors affecting I PA steam drying, namely the purity and water content of I PA, the flow and velocity of IPA steam, and the cleanliness of the IPA steam chamber. Therefore, the ultra-clean IPA steam drying technology needs to be adjusted. In order to achieve the most perfect conditions, the surface of the wafer after dehydration and drying is free of contamination by particles, water marks and metal impurities. The I PA drying method is mainly due to the high volatility of I PA. The surface moisture is dehydrated and dried to achieve no water marks and no particulate pollution, and the flammable I PA should pay special attention to the safety of exhaust and fire prevention. When the above-mentioned gas enters the drying device towel, with the tp A steam drying method (a) it takes a long time to dry the wafer; (b) and a certain steam drying method requires the use of a large amount of ίΑΑ solution, that is High cost; (;;) must be carried out at high temperature, the IPA temperature is increased, and the grains are made 1; the IPA is set on fire. Therefore, how to make it easy to provide a wafer drying device and method, to reduce the problem of reduction, and to avoid IPA combustion, in order to reduce the process time, reduce the amount of IpA < loss, will be very important. Purpose and summary of the invention:

508652 V. Description of the invention (4) The main purpose of the present invention is to provide a drying device for removing moisture from the surface of a wafer. Another object of the present invention is to provide a drying method for removing moisture from the surface of a wafer. The wafer drying device of the present invention includes an eigenwave drying chamber and a top cover. The combination of the two can form a closed chamber for space for wafer storage and drying, and the microwave drying chamber can emit microwave energy. For drying wafers. The microwave drying chamber is also provided with a wafer receiving tank. A gas input end is provided at one end of the microwave drying chamber for inputting diluted microwave drying chamber gas; a gas exhaust end is provided at the other end of the microwave drying chamber for exhaust gas; another end of the microwave drying chamber of the wafer drying device is provided with a The liquid discharge end can drop the liquid. The liquid is discharged out of the microwave drying chamber. The wafer drying device is also provided with at least one ultrasonic sprayer. The composition of the ultrasonic sprayer includes a set of solution delivery tubes, an ultrasonic oscillator and a spray head. The operation of the ultrasonic sprayer and The operation is not limited to the microwave drying room, and can also be moved to the microwave drying room for operation. The solution transfer tube can transport the dried wafer solution. The solution is oscillated by the ultrasonic oscillator, and the spray head atomizes and sprays the solution onto the wafer surface. Detailed description of the invention:

508652 V. Description of the invention (5) Shi Xi wafers are washed with a series of chemical tanks and washed with DI water. The final process is to dehumidify and dry the silicon wafers that are moistened with water. Isopropyl alcohol (IPA, iSOpropyl alcohol) steam drying method is used to transfer the cleaned wet wafer to the I p A steam chamber. The high-purity nitrogen () is used as the carrier gas to introduce the cleaned wafer into the steam drying chamber. Through the heater at the bottom, the IPA is heated to evaporate into steam. The wet wafer is placed in the I PA steam drying chamber and immersed in it! In the pa steam, the volatility of pA dehydrates the water on the wafer surface and removes water marks, particles and metal impurities on the surface. The present invention discloses a new type of wafer drying device and method ', which are described in detail below. The preferred embodiment described is only described, and is not intended to limit the present invention. Figure 1 is a cross-sectional view of a wafer drying device according to the present invention. Figure 5 is a schematic view of the figure. The device includes a microwave drying chamber (Micrwave drying c ^ mber) 100 and a top cover (T〇pc〇ve). 〇1〇2, the two can be combined to form a closed space for wafer storage and drying space, and the microwave drying chamber = 0 can emit microwave energy for subsequent use to dry wafers. In this microwave ^ = Up to 100 and a wafer receiving slot 丨 〇4, which can be used to place or fix a circle 10 06. I am jealous in the microwave drying chamber of the wafer drying device and set up a gas' as Enter 100 micrometers of diluted microwave drying chamber, enter round body, such as nitrogen (N2), argon (red), etc .; and set a gas exhaust port at the other end of the wafer drying chamber 100 without microwave drying chamber

Page 8 508652 V. Description of the invention (6) 11 0 for exhausting the gas in the microwave drying chamber 丨 00; and the microwave drying chamber 100 and the other end of the wafer drying device is provided with a liquid discharge end 112, can be used for draining water (or solution). . The Japanese Yen has no device and is equipped with more than one Ultrasonic Nebulizer 144, the ultrasonic sprayer; [14 consists of a set of solution delivery tubes 1 1 6 and ultrasonic oscillators 1 1 8 and Spraying 丨 head 1 2 0, and the operation of the ultrasonic sprayer 丨 4 is not limited to the operation within the microwave drying chamber 100, it can also be moved to the microwave drying chamber 1000, as shown in Figure 2. Show. Solution transfer tube 丨 6 can transport wafer 106 dried solutions, such as IPA and deionized water; during the solution transfer, the solution is oscillated through the spray head 120 and the ultrasonic oscillator 1 1 8 to atomize the solution And sprayed onto the wafer surface. May. Please refer to Fig. 2 'and Fig. 3 for a schematic diagram of the spraying process of wafer drying according to the present invention. The wafer 106 is placed on the wafer accommodating tank 104, and the valves of the gas input terminal 108 and the gas discharge terminal 110 are closed to prevent external gas interference and prevent the IPA spray from being discharged at this time. Then start to start the ultrasonic sprayer 1 1 *, input the I p A solution from the solution delivery pipe 1 1 6 of the ultrasonic sprayer 11 4, the input solution is not limited to I PA, and deionization can be added to PA The mixed solution of water, etc. Then the solution was oscillated through the ultrasonic oscillator 118, and the A-label liquid mist was also applied to produce ^ ΙΡΑ solution spray 122, and sprayed on the surface of the wafer 106 to make the microwave drying chamber 100 Fill the mouth spray 122 of the IPA solution. The spraying time is about 30 seconds to 300 seconds, and the preferred embodiment is 60 seconds. The ultrasonic oscillation frequency ranges from about 1.0 MHz to 5.0 MHz, and the preferred embodiment is 16302.

508652, Description of the invention (7) The I PA steam drying method of the conventional technique needs to heat I pa to 2000 ° C, and the temperature of the entire drying chamber is more than 80, and the ρρ of the present invention is not%. Heating 'can keep the temperature of the microwave drying chamber 1 Q 〇 at 10 ℃ all the time. 〇 to 6 〇 c ', to avoid I ρ A fire. ί Α spray A 2 2 condenses into particles, and the solution on the particles or wafer flows into the liquid discharge end 11 2 at the lower end of the microwave drying chamber. . Please refer to Figure 4, which is a microwave heating method for drying wafers according to the present invention. Next, stop spraying 1 2 2 and open the valve of the gas input terminal 108 and the gas discharge terminal 110. Nitrogen (^) is continuously introduced from the gas input terminal 108 to serve as a gas for diluting the microwave drying chamber. Then, it is discharged from the gas discharge end 110, and then the wafer 10 is heated by microwave heating 124, and the temperature 5 of the microwave heating 124 is about 2 ° to 90 °. . The microwave heating time is about 30 seconds to 300 seconds. The best example is β 0 seconds. The microwave heating frequency range is about 2.4 GHz. The microwave heating power range is about 100W. To 2 0 0 0W, the best embodiment is 1 0 0 0 w.

—The above procedure is only for the description of a preferred embodiment. It is not necessary to use 1 book, but also to carry out ultrasonic atomization wafer and microwave heating at the same time. The valve at the discharge end 11 〇 is continuously introduced from the body input end 108 > corpse ", ^, and the lice gas (N2) is introduced as the gas for diluting the microwave drying chamber 1 0 1 1/1 and discharged from the gas discharge end 1 1 〇 discharge, start the ultrasonic spray | 114, the IPA solution is input from the solution delivery pipe 116 of the ultrasonic sprayer 114

4 508652 V. Description of the invention (8) = Ultrasonic oscillator oscillates the IPA solution, and the spray head 120 uses gas to atomize the corpse a solution to generate an IPA solution spray 122 and spray it onto the surface of the wafer ι〇6 ' The microwave drying chamber 100 is filled with the IPA solution spray 122, and the Lin Linbei interval is about 3 seconds to _ seconds. The best embodiment is two. The super-frequency dry range is about 1.0 MHz to 5.0 MHz, and the best is The example is ^ 63MΗζ. . . At the same time, microwave heating 124 wafer 1 (? 6, microwave heating 124 degrees, at 50 ° C to 90 t, microwave heating 124 time is about 30 seconds to 300 seconds, the best embodiment is 60 seconds, The microwave heating 124 frequency range is about Φ # 2.45GHz 'The microwave heating power range is about 10% to 2000%, and the best embodiment is 100W. The rabbit is a brand new crystal The circular drying device and method are different from the defects derived from the conventional technology. The present invention has the following advantages: (a) it can shorten the process time of wafer drying; (b) it can save the amount of IPA; (c) it can be used in It is carried out at a low temperature to prevent IPA from burning. The present invention is described above with reference to the preferred embodiments, and those skilled in the art can make some changes without departing from the spirit of the present invention.

The scope of its patent protection depends on the scope of the attached patent application and its equivalent fields.

Page 11 508652 Brief description of drawings Figure 1 shows the first example of the device of the present invention. Figure 2 is a second example of the device of the present invention. FIG. 3 is a schematic diagram of a spraying process for wafer drying according to the present invention. FIG. 4 is a schematic diagram of a microwave heating procedure for wafer drying according to the present invention. Description of drawings and figures: Microwave drying chamber 1 0 0 Top cover 1 0 2 Wafer receiving tank 1 0 4 Wafer 1 0 6 Gas input 1 0 8 Gas exhaust 11 1 Liquid exhaust. Out 112 Ultrasonic spray Nebulizer 1 1 4 Solution delivery tube 11 6 Ultrasonic oscillator 11 8 Spray head 1 2 0 Spray 122 Microwave heating 1 2 4

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Claims (1)

508652 # JL · VI. Patent application scope 1. A device for drying wafers, at least including: a drying chamber, which is provided with an accommodating slot for accommodating the wafer, and an opening is formed on one side for the wafer Input / output; and more than one sprayer; characterized in that: the sprayer generates a solution nozzle mist 'mouth swings the wafer' and generates microwave heating by the dry chamber to make the wafer surface water volatilize, and obtain Clean wafer surface. 2. For the device in the scope of patent application, the drying chamber is provided with a microwave heating function device. 3. The device according to item 1 of the patent application scope, wherein one end of the drying chamber is provided with a gas input end. 4. For the device in the scope of patent application item 3, the gas may be an inert gas. 5. For the device in the scope of patent application, the gas can be nitrogen (N2). 6. The device according to item 3 of the scope of patent application, wherein the gas may be argon (Ar). in Page 13 508652 6. Scope of patent application-7. The device of scope 1 of the patent application, wherein the drying chamber is provided with a gas exhaust end. 8. The device according to item 1 of the patent application range, wherein the drying chamber is provided with a liquid discharge end. 9. The device according to item 1 of the scope of patent application, wherein the sprayer is an ultrasonic sprayer, which can generate an ultrasonic spray. 10. The device according to item 1 of the scope of patent application, wherein the sprayer further includes a solution delivery pipe, an ultrasonic oscillator, and a spray head. 1 1 · The device according to item 1 of the patent application range, wherein the solution is isopropyl alcohol (IPA), or a mixture of isopropyl alcohol and DI water. 1 2. A device for wafer drying, including at least: a microwave drying chamber, which is provided with an accommodating slot for accommodating the wafer, and an opening is formed on one side for wafer input / output; and More than one ultrasonic sprayer; Features: 〇 The ultrasonic sprayer generates a solution spray, sprays the wafer, and generates microwave heating from the microwave drying chamber to volatilize the water on the wafer surface to obtain Clean wafer surface. Page 14 508652 VI. Application scope of patent 1 3 · If the device of the scope of patent application No. 12 is applied, the microwave drying chamber is provided with a gas input port, which can input the gas used to dilute the microwave drying chamber gas. 1 4 · The device according to item 13 of the scope of patent application, wherein the gas may be an inert gas. 15 · The device according to item 13 of the patent application scope, wherein the gas may be nitrogen (N 2). 16 · The device according to item 13 of the patent application range, wherein the gas may be argon (Ar). 17 · The device according to item 12 of the scope of patent application, wherein the microwave drying chamber is provided with a gas exhaust end. 18. The device according to item 12 of the patent application range, wherein the microwave drying chamber is provided with a liquid discharge end, which can be used to recover the condensed solution. 19 · The device according to item 12 of the patent application scope, wherein the ultrasonic sprayer further comprises a solution delivery pipe, an ultrasonic oscillator and a spray head. 2 0. The device according to item 12 of the scope of patent application, wherein the solution is isopropyl alcohol (IPA), or a group of isopropyl alcohol mixed with deionized water (DI water) mm Page 15 508652 6. Scope of patent application * to make. 2 1 — A method of wafer drying, the method includes at least the following steps: providing a wafer; spraying an ultrasonic solution onto the surface of the wafer; microwave heating the wafer to obtain a clean and dry wafer surface . 2 2 · The method according to item 21 of the scope of patent application, wherein the solution is selected from the group consisting of isopropyl alcohol (IPA) or a mixture of isopropyl alcohol and DI water. 2 3 · The method according to item 21 of the patent application range, wherein the solution spray can be generated by an ultrasonic sprayer. 24. The method according to item 21 of the patent application range, wherein the spraying working temperature is 10 ° C to 60 ° C. 25. The method of claim 21, wherein the spraying time is about 30 seconds to 300 seconds. ® 26. The method according to item 25 of the patent application range, wherein the preferred embodiment of the spray time is 60 seconds. Page 16 508652 VI. Patent Application Range-27. The method of item 21 of the patent application range, wherein the microwave heating working temperature is about 50 ° C to 90 ° C. 28. The method of claim 21, wherein the microwave heating time is about 30 seconds to 300 seconds. 29. The method according to item 28 of the scope of patent application, wherein the microwave heating time is the best in the embodiment of 60 seconds. 3 (K as the method of the 21st scope of the patent application, wherein the ultrasonic vibration 4 oscillating frequency range is about 1.0MHz to 5.0MHz. 3 1. As the method of the 30th scope of the patent application, the ultrasound The embodiment with the best sonic oscillation frequency is 1. 63 MHz. 3 2. The method according to item 21 of the patent application range, wherein the embodiment with the microwave heating frequency is 2. 45 GHz. The method according to item 21, wherein the microwave heating power ranges from about 100 W to 2000 W. ❶ 3 4. The method according to item 33 of the patent application range, wherein the microwave heating power is the best embodiment 1 0 0 0 W 6 Page 17 508652 Page 18