USP_20010020443 (1063353), страница 3
Текст из файла (страница 3)
In other embodiments, the barrier 140can have other shapes and con?gurations that separate theexternal air volume 150 from the internal air volume 160 andalloW excess liquid to drain aWay from the substrate 112.removed from the internal air volume 160 as the substrate122 can be open continuously or periodically to WithdraWgaseous or gas-borne constituents from Within the barrier[0024] In one embodiment, the noZZle aperture 124, thesubstrate 112, and the drive shaft 132 are each aligned Withthat alloW some ?uid communication betWeen the internalair volume 160 and the external air volume 150.
Forexample, gas can pass out of the internal air volume 160the axis 136 so that the substrate 112 spins about its centerand the noZZle aperture 124 dispenses the liquid to the centerof the substrate upper surface 113. In one embodiment, theliquid supply conduit 123 can be coupled to a source ofliquid (not shoWn) that includes a photoresist material for112 and the barrier 140 rotate. For example, the exhaust port140. Accordingly, the barrier 140 and/or the barrier support134 can have vents 148 (in addition to the drain holes 146)through the drain holes 146 and into the internal air volume160 through the vents 148. Alternatively, the barrier 140 canbe periodically lifted from the barrier support to alloW gas toescape from Within the barrier 140.etching the substrate 112 generally as discussed above.[0029]Alternatively, the liquid supply conduit 123 can be coupledence to FIG.
3, rotating the internal air volume 160 canreduce the likelihood for the liquid to form Waves or othernon-uniformities on the upper surface 113 of the substrateto sources of other liquids.[0025] The apparatus 10 can further include a collectionvessel 120 ?xed relative to the motor 130 and disposedcoaxially around the drive shaft 132 and the substrate 112 tocollect excess liquid ?oWing from the substrate 112. Thecollection vessel 120 can include a base 126 extendingoutWardly from the driveshaft 132 beneath the substrate 112,and Walls 125 extending upWardly around the substrate 112.Accordingly, the collection vessel 120 can collect liquid thatspills over the edge 115 of the substrate 112 as the substrate112 spins.
A seal 127 betWeen the drive shaft 132 and thebase 126 prevents the liquid collected in the collectionvessel 120 from leaking around the drive shaft 132. A drain121 beloW the base 126 conducts the collected liquid aWayfrom the collection vessel 120 via a drain tube 127. Thecollection vessel 120 can also include an exhaust port 122having an adjustable ?oW area to control a How of air pastthe substrate 112 and out of the collection vessel 125.In any of the methods discussed above With refer112, particularly toWard the outer edge of the substrate 112.Rotating the internal air volume 160 can also reduce the rateof convective heat transfer from the substrate 112.
Accordingly, the liquid can be deposited to a more uniform thickness over the entire upper surface 113. For example, in oneembodiment, the liquid can be deposited to a thickness thatvaries from about ten Angstroms to about thirty Angstromsacross the surface of a substrate 112 having a diameter ofgreater than eight inches (up to and exceeding tWelveinches).
In another embodiment, the liquid can be depositedto a thickness that varies by no greater than about tenAngstroms across the surface of the substrate 112, or theliquid can be deposited to thicknesses With other thicknessvariations on substrates 112 having other diameters.[0030] Furthermore, a liquid having a single viscosity canbe used to produce layers on the substrate 112 having aSep. 13, 2001US 2001/0020443 A1greater range of thicknesses than is possible Without thebarrier 140.
For example, in one embodiment, a ?uid havinga single viscosity value of betWeen about ?ve centipoise andabout tWenty centipoise can be deposited on a substrate 112(having a diameter of greater than eight inches, up to andexceeding tWelve inches) to a selected uniform thicknessWithin a range of approximately 3,000 Angstroms.
In oneembodiment, a liquid having a viscosity of from about ?vecentipoise to about ten centipoise can be deposited on thesubstrate 112 to a thickness of from approximately 5,000Angstroms to approximately 8,000 Angstroms by rotatingthe substrate 112 at a speed of from about 2,000 rpm to about4,000 rpm. The particular viscosity value and rotation rateselected to produce the desired thickness can be selectedbased on such factors as evaporation rate of the liquid. Inanother embodiment, the thickness can range from approximately 7,000 Angstroms to approximately 10,000 Angstroms by depositing on the substrate 112 a liquid having aviscosity of from about ten centipoise to about tWentycentipoise and spinning the substrate at from about 2,000rpm to about 4,000 rpm.
This is unlike some conventionaldevices, Which may require coupling the liquid supplyconduit 123 to a plurality of liquid sources (each having adifferent viscosity) to deposit liquid layers of differentthicknesses on different substrates 112.[0031] Another feature of the apparatus and methodsdiscussed above With reference to FIG. 3 is that the substrate112 can be supported in a manner that does not trap the ?uidagainst the loWer surface 114 of the substrate 112, While atthe same time eliminating the need for rotating the collectionvessel 120, unlike some conventional apparatuses.
Accordingly, the loWer surface 114 of the substrate 112 can remainrelatively free of contaminants While the liquid is disposedvolume 250 remains approximately stationary, in a mannergenerally similar to that discussed above With reference toFIG. 3.[0034] In one embodiment, a ?ange 237 can be connectedto the drive shaft 232 and can extend radially outWardlybeneath the substrate support 233. The barrier 240 extendsabove and around the substrate 112 and is spaced apart fromthe ?ange 237 to de?ne an annular gap 238 betWeen the?ange and the barrier 240.
In one embodiment, a plurality ofnoZZles 270 can be positioned in the gap 238 and can becoupled to a source of cleaning ?uid 271. Accordingly, thenoZZles 270 can direct the cleaning ?uid toWard the loWersurface 114 of the substrate 112 to remove contaminantsfrom the loWer surface. In one embodiment, the source 271can be coupled to a temperature controller 272 to control thetemperature of the substrate 112 and the evaporation rate ofthe liquid disposed on the upper surface 113 of the substrate112.[0035] In a further aspect of the embodiment shoWn inFIG. 4, the gap 238 betWeen the barrier 240 and the ?ange237 can extend outWardly beyond an outer edge 115 of thesubstrate 112 so that the barrier 240 can be lifted upWardlyto access the substrate 112, for example to remove thesubstrate 112 after the liquid is disposed on the substrate112.
In a further aspect of this embodiment, the barrier 240can be lifted With a control arm 242 having a positioninghead 243, in a manner generally similar to that discussedabove With reference to FIG. 3. Alternatively, the barriershaft 247 can be directly coupled to an axial actuator 225 tomove the barrier 240 upWardly and doWnWardly.[0036] A feature of the apparatus shoWn in FIG. 4 is thatthe barrier 240 can be rotated independently of the substrate112, While still alloWing the barrier 240 to rotate at the sameon the upper surface 113. Furthermore, the apparatus 110can be simpler to manufacture and operate because thecollection vessel 120 is ?xed relative to the motor 130,rate as the substrate 112.
Conversely, a feature of theeliminating the need for rotating seals betWeen the drain 121and the drain line 127.substrate 112 When the barrier 140 is supported by thebarrier support 134, ensuring that the internal air volume 160[0032] FIG. 4 is a partially schematic, partially cutaWayWill spin at the same rate as the substrate 112.side elevation vieW of an apparatus 210 having a barrier 240that rotates independently of the substrate 112 in accordanceWith another embodiment of the invention. The apparatus[0037] From the foregoing, it Will be appreciated that,although speci?c embodiments of the invention have been210 can include a motor 230 having a drive shaft 232coupled to a substrate support 233 that supports the substrate112.
The drive shaft is rotatable about an axis 236, asindicated by arroW A in a manner generally similar to thatapparatus 110 discussed above With reference to FIG. 3 isthat the barrier 140 Will alWays rotate at the same rate as thedescribed herein for purposes of illustration, various modi?cations may be made Without deviating from the spirit andscope of the invention. For example, Where the environmentadjacent the substrate includes gases other than air, thebarriers discussed above With reference to FIGS. 3 and 4discussed above With reference to FIG. 3.
![](https://s.studizba.com/z.php?f=/templates/si/i/noavatar.png&w=100&h=100&t=1"){kind=avatar}
