CN1841669A

CN1841669A - Wafer drying method

Info

Publication number: CN1841669A
Application number: CN 200510059720
Authority: CN
Inventors: 黎源欣; 吴志鸿; 许扬诗; 黄汉民
Original assignee: HONGSU TECH Co Ltd
Current assignee: HONGSU TECH Co Ltd
Priority date: 2005-03-29
Filing date: 2005-03-29
Publication date: 2006-10-04

Abstract

The invention discloses a method for drying a crystal plate which uses liquid volatile solvent (such as alcohol isopropylicum, IPA) to displace the cleaning liquid to dry the crystal plate. It at least comprises the following steps: a) putting the crystal plate in the wash tank; b) adjusting the flow of the flow controller at the water inlet to wash the crystal plate; c) using cleaning liquid to wash the crystal plate, using overflow to wash the particle and relict chemical; d) closing the water inlet, opening the water outlet, controlling the water outlet flow to let the liquid level upper than the crystal plate, adding some liquid volatile solvent to form two liquid phase layer; e) doing water outlet until the liquid level of the volatile solvent is lower than the min level; f) disposing the resident liquid of the tank; g) getting through the normal temperature N2 and higher temperature N2 to the tank to dry the solvent of the crystal plate.

Description

Wafer drying method

Technical field

The present invention is relevant for a kind of semiconductor manufacturing process, and particularly relevant wafer cleans and dry method.Especially from the flow field control of the open rinse bath of below feedwater with the control that produces flow-disturbing and utilize lifting rate with accurate and continuous cleaning and discharge opeing, and drying means to be the mode of utilizing liquid isopropyl alcohol (IPA) to replace the moisture content of wafer surface make wafer can be fast and is cleanly dry.

Background technology

In making semi-conductive manufacturing process, having many wet type manufacturing process such as cleaning, wet etching, photoresistance to remove and gasify to spread to handle before needs chemical liquids and wafer surface contact, to remove film or photoresistance, again with the clean drying that reaches of pure water.This kind system has open and closed two kinds traditionally, closed have the chemicals of preventing volatilization and keep isolation and anti-particle contamination, as people's such as MeComnell United States Patent (USP) case " Process and Apparatus For Treating waters with ProcessFluids " case number is 4,778,532, the application people is CFM Technologies Limited.Its rinse bath and dry slot are all closed, waste a large amount of chemicals and pure water, and the isopropyl alcohol of dry slot (IPA) add the thermosetting steam, import dry slot upper end again and contact with water and be condensed into liquid state.Reach dry purpose to replace the water on the wafer.But because of the high pressure-temperature of isopropyl alcohol needs expensive Sealing Arrangement, and difficult management.The European patent case WO99136944 case of another prior art such as the application of Steag AG company, another way for the wafer drying, utilize semi-enclosed dry slot, mainly be to utilize nitrogen (N2) isopropyl alcohol by liquid state under constant temperature, methanol vapor is brought in the dry slot, be dissolved in the moisture of wafer surface, but the concentration of the methanol vapor of this method gained is very low, major part still is a nitrogen, that is the steam of isopropyl alcohol is a low concentration under poised state, remove moisture on the wafer with the concentration gradient variation pattern, be spin-dried for mode though be better than nitrogen, drying effect has the restriction on the concentration.This technology is called Marargoni Dryer again.

The tenesmus laminar flow of prior art is spin-dried for technology as shown in Figure 1, cardinal principle is to insert in the swivelling chute 104 of a spinner cleaning the moist wafer 102 in back, utilize motor 112 to quicken the centrifugal force that rotation produces down at a high speed, and gas dynamical bernoulli principle (Bernoulli ' s theorem), after screen pack (ULPA) 108 on the top cover 106 of swivelling chute filters air 110, air is imported the formation air-flow, the globule on the wafer, water droplet are spin-dried for dehydration, and aqueous vapor evaporated mummification, and there is not particulate and washmarking (Water Marks) stays.But spinner is under high speed rotating, produce vibration, make wafer produce Si powder, and the easily change and form flow-disturbing or exhaust is poured in down a chimney of the size of exhaust pressure (Exhaust Pressure), cabin in spinner (Chamber) easily makes Si powder in the cabin and chemical powder kick up and forms source of particulate contamination when unholiness.Rotation should be avoided resonance point (resonance) again, otherwise because of vibrations produce particulate, but because of number of wafers not for the moment, the unavoidable resonance that produces.Therefore the laminar flow that drops is spin-dried for technology and very easily in the end is spin-dried in the process wafer of cleaning contaminated again.

The isopropyl alcohol dry technology is another kind of prior art, as shown in Figure 2.Be spin-dried for technology with respect to aforesaid tenesmus laminar flow, technology with the isopropyl alcohol drying belongs to " quasistatic ", the wafer of cleaning 202 is sent in the steam chamber (IPA vapor chamber) 204 of isopropyl alcohol (IPA), IPA makes transport gas (Carrier gas) by highly purified nitrogen (N2) 206 IPA208 is brought in the vapour seasoning chamber 210, heater 212 heating by the bottom, IPA is heated is evaporated to the steaming almost, utilize cold Qie's device 214 that IPA is liquefied again, moist wafer 202 is immersed in the IPA steam in IPA hothouse 210.Utilize the high volatile volatile of IPA, the moisture content dehydration and drying with wafer surface does not have washmarking and particle contamination.But the purity of IPA and water content need below 2000ppm, otherwise influence cleanliness factor, it is too low to steam the almost temperature again, easily make water and IPA condense in sidewall, it is vaporific that the dry steam chamber is formed, and make the vaporific pollution of wafer surface adularescent, the too high safety that influences again of temperature, and the IPA steam is also dangerous to operating personnel.

Summary of the invention

Purpose of the present invention is providing a kind of wafer drying method, utilizes the formula water intake mode of releasing, and the liquid phase that makes solvent and water form two liquid phases of not dissolving each other or the high concentration graded of dissolving each other is removed to carry out moisture content again.

For reaching above-mentioned purpose and other purpose, the present invention proposes a kind of drying means of wafer, the baffler that utilization has inclination is guided to a barrel structure liquid level with liquid solvent, with the solvent layer that forms two liquid phase separation or the solution phase of high concentration graded, again with the slow liquid level that descends, the moisture content that utilizes liquid volatile solvent replacement wafer surface comprises the following step: (a) wafer is inserted rinse bath at least with drying crystal wafer; (b) flow of the flow controller of adjustment water inlet is with clean wafers; (c) with cleaning fluid (for example pure water) clean wafers, particulate and the residual chemical utilizing overfall to discharge fast to clean out; (d) close water inlet, open discharge outlet, the control drain discharge drains into the wafer top with liquid level, injects a certain amount of liquid volatile solvent, to form two liquid phase layers; (e) continue draining, be lower than to the volatile solvent liquid level till the lowest order of brilliant boat; (f) surplus liquid in the drain tank; (g) the interim nitrogen (N that feeds room temperature ₂) and the nitrogen (N that heats ₂) in groove, the solvent on the drying crystal wafer.

Description of drawings

Fig. 1 (prior art) is spin-dried for the drying device of technology for the tenesmus laminar flow of prior art.

Fig. 2 (prior art) is the drying device of the isopropyl alcohol dry technology of prior art.

Fig. 3 is the profile when using according to the wafer drying device of one embodiment of the invention.

Fig. 4 is the flow chart that utilizes device cleaning of the present invention and drying crystal wafer.

The primary clustering symbol description

102 wafers, 104 swivelling chutes

106 top covers, 108 screen packs (ULPA)

110 air, 112 motors

The steam chamber of 202 wafers, 204 isopropyl alcohols (IPA)

206 highly purified nitrogen 208IPA

210IPA hothouse 212 heaters

302 wafer drying devices, 304 water inlet pipes

306 water inlet pipes, 310 wafer case

312 wafers, 313 pipelines

314 horizontal planes, 316 isopropyl alcohols

318 isopropyl alcohol liquid levels, 320 drainage pipes

The 402-414 step

Embodiment

Content of the present invention can be given open via the elaboration of following preferred embodiment and its relevant icon.The present invention is not illustrated the cleaning-drying groove that whole cleaning and drying system are just only done to describe wherein.In each figure, identical assembly is represented with same code name.

Fig. 3 is the profile of the wafer drying device 302 according to one embodiment of the invention when using.At first, wafer 312 in the wafer case 310 promptly stops to flow into from water inlet pipe 304,306 after cleaning finishes, change into from drainage pipe 320 drainings, because of drainage pipe 320 is connected to flow controller, be subjected to program control and maintenance certain flow, draining reposefully, meanwhile, pipeline 313 on the self-cleaning groove begins to inject a certain amount of isopropyl alcohol (IPA) with the solution of the solvent layer that forms two liquid phase separation or high concentration graded mutually 316, but also can be other volatile solvent, for example methyl alcohol, ethanol etc.Horizontal plane 314 descends, and the liquid level 318 of isopropyl alcohol 316, is about to nitrogen (N2) and feeds dry slot after horizontal plane 314 leaves wafer 312 also in company with descending, and for example improving temperature with the isopropyl alcohol volatilization, or dries up with the clean nitrogen of earning.Should discharge pure water and isopropyl alcohol fully this moment.Refill pure water again, clean another batch wafer.

Fig. 4 is the flow chart that utilizes device cleaning of the present invention and drying crystal wafer.At first, in step 802, wafer etching is intact and that remove behind the photoresistance is inserted rinse bath 202 (see figure 3)s; In step 404, with cleaning fluid pure water clean wafers for example; In step 406, close water inlet earlier, open discharge outlet, as shown in Figure 3, the control drain discharge steadily descends liquid level 306; In step 408, inject a certain amount of volatile solvent (as isopropyl alcohol); Then in step 410, continue draining, liquid level is descended, volatile solvent replaces the cleaning fluid on the wafer, be lower than the lowest order of brilliant boat to liquid level 306 after, surplus liquid in the groove is discharged.In step 414, volatile solvent (as isopropyl alcohol) is removed with drying crystal wafer at last in modes such as nitrogen or heated nitrogens.Promptly finish the cleaning and the drying of wafer.

Though it is open that the present invention has given with certain embodiments; the personage who knows this technology will understand and can the form and the details of this specific embodiment be changed slightly; be all scope of the present invention not breaking away from modification and the change that spirit of the present invention and theory do; the above embodiment that is narrated of the present invention only makes illustrative purpose, rather than in order to limit the scope that claims are protected.

Claims

1. the cleaning of a wafer and drying means utilize overflow with the rinse bath of cleaning fluid overflow with acceleration discharge particulate and chemical liquids, and import rinse bath with drying crystal wafer with liquid volatile solvent, comprise the following step at least:

(a) wafer is inserted rinse bath;

(b) flow of the flow controller of adjustment water inlet with clean wafers, and is adjusted the flow field to assist clean wafers;

(c), utilize overfall to discharge particulate and residual chemical with the cleaning fluid clean wafers;

(d) close water inlet, open discharge outlet, the control drain discharge drains into wafer top with cleaning fluid, injects a certain amount of liquid volatile solvent, with the solvent layer that forms two liquid phase separation or the solution phase of high concentration graded;

(e) continue draining, be lower than to the volatile solvent liquid level till the lowest order of brilliant boat;

(f) surplus liquid in the drain tank;

(g) feed nitrogen in dry slot, the solvent on the drying crystal wafer.

2. the method for claim 1 is characterized in that, this cleaning fluid is a pure water.

3. the method for claim 1 is characterized in that, this liquid state volatile solvent is an isopropyl alcohol.

4. the method for claim 1 is characterized in that, this liquid state volatile solvent is a methyl alcohol.

5. the method for claim 1 is characterized in that, this liquid state volatile solvent is an ethanol.

6. the method for claim 1 is characterized in that, this rinse bath is cylindrical.

7. the method for claim 1 is characterized in that, this rinse bath is square.

8. the method for claim 1 is characterized in that, this rinse bath is a rectangle.

9. the method for claim 1 is characterized in that, this rinse bath is with the made of acid and alkali resistance and solvent.