USP_6261635 (1063343), страница 2
Текст из файла (страница 2)
The microelectronic substrate can havea ?rst surface that receives the liquid and a second surfacefacing opposite the ?rst surface With the engaging portioncon?gured to engage less than the entire second surface. Arotating barrier proximate to the support rotates at a secondrate approximately equal to the ?rst rate to separate a ?rst15portion of gas adjacent the microelectronic substrate androtating With the microelectronic substrate from a secondportion of gas spaced apart from the microelectronic substrate and generally stationary relative to the microelectronicsubstrate.In a method in accordance With an aspect of the invention,a liquid having a single viscosity can be distributed over the?rst surface of the substrate to a generally uniform thicknessranging from a ?rst value to a second value approximately202530from about 7,000 Angstroms to about 10,000 Angstroms.The viscosity can be selected to be from about six centipoiseto about tWenty centipoise and the liquid can be distributedto a thickness that varies by less than tWenty Angstroms.35BRIEF DESCRIPTION OF THE DRAWINGSgenerally parallel to the upper surface 113 of the substrateelevation vieW of an apparatus in accordance With the prior40FIG.
2 is a partially schematic, partially cutaWay sideelevation vieW of an apparatus in accordance With ansubstrate 112 by relatively small distances (exaggerated in45embodiment of the invention.FIG. 4 is a partially schematic, partially cutaWay sideelevation vieW of an apparatus in accordance With anotherembodiment of the invention.elevation vieW of an apparatus 110 that spins a substrate 112and a barrier 140 at approximately the same rate to distributea liquid over the substrate 112 in accordance With anFIG. 3 for purposes of illustration) to keep the volume of theinternal air volume 160 relatively small.
For example, theupper Wall 145 can be separated from the upper surface 113of the substrate 112 by a distance of at least approximatelyone millimeter to approximately ten millimeters, or some50DETAILED DESCRIPTION OF THEINVENTIONThe present invention is directed toWard methods andapparatuses for distributing liquid over the surfaces ofmicroelectronic substrates and/or substrate assemblies.Many speci?c details of certain embodiments of the invention are set forth in the folloWing description and in FIGS.3 and 4 to provide a thorough understanding of suchembodiments.
One skilled in the art, hoWever, Will understand that the present invention may have additionalembodiments, or that the invention may be practiced Withoutseveral of the details described in the folloWing description.FIG. 3 is a partially schematic, partially cutaWay side112. The barrier 140 can also include sideWalls 144 extending doWnWardly from the upper Wall 145 to the barriersupport 134. In one aspect of this embodiment, the upperWall 145 and the sideWalls 144 can be spaced apart from theelevation vieW of another apparatus in accordance With theprior art.FIG.
3 is a partially schematic, partially cutaWay sidesubstrate support 133 and the substrate 112 to support androtate the barrier 140 as the support assembly 131 rotates.The barrier support 134 can include a plurality of spacedapart stanchions 135 to restrict radial motion of the barrier140 relative to the barrier support 134. Alternatively, thebarrier 140 can rotate independently of the substrate 112, asWill be discussed in greater detail beloW With reference toFIG. 4.In one embodiment, the barrier 140 has a generallycircular platform shape and extends around and over thesubstrate 112 to separate a stationary, external air volume150 outside the barrier 140 from a rotating, internal airvolume 160 inside the barrier 140. Accordingly, the barrier140 can be coupled to the drive shaft 132 via the barriersupport 134 to spin at the same rate as the substrate 112. Thebarrier 140 can include an upper Wall 145 facing andFIG.
1 is a partially schematic, partially cutaWay sideart.The support assembly 131 can include a substrate support133 that supports the substrate 112 such that an uppersurface 113 and an outer portion of a loWer surface 114 ofthe substrate 112 are exposed. Accordingly, the substratesupport 133 can have a lateral extent perpendicular to theaxis 136 that is less than the lateral extent of the substrate112 in the same direction, ie., the substrate 112 can overhangthe substrate support 133.The support assembly 131 can further include a barriersupport 134 that extends radially outWardly beyond the3,000 Angstroms greater than the ?rst value by positioninga barrier to separate a rotating ?rst volume of gas adjacentthe ?rst surface from a generally stationary second volumeof gas.
For example, the 3,000 Angstrom range can extendfrom about 5,000 Angstroms to about 8,000 Angstroms, orThe apparatus 110 can include a motor 130 coupled Witha drive shaft 132 to a support assembly 131 to rotate thesupport assembly about an axis 136 as indicated by arroW A.other spacing. The sideWalls 144 can be separated from anouter edge 115 of the substrate 112 by a distance of fromapproximately ?ve millimeters to approximately ten millimeters or some other distance.
An advantage of this featureis that it can reduce the time required to spin the internal air55volume 160 up to the same speed as the substrate 112.The upper Wall 145 of the barrier 140 can include anaperture 141 aligned With a noZZle aperture 124 of a liquidsupply conduit 123 to alloW liquid to descend from thenoZZle aperture 124 to the upper surface 113 of the substrate60112. The upper surface 145 can also include an engagementportion 147 for positioning the barrier 140. For example, theapparatus 110 can include a control arm 142 having a65positioning head 143 for releasably engaging With theengagement portion 147 of the barrier 140.
Once the positioning head 143 is engaged With the barrier 140, the controlarm 142 can move the barrier 140 toWard and aWay from thebarrier support 134, for example during installation orUS 6,261,635 B156removal of the substrate 112 from the substrate support 133.In one aspect of this embodiment, the positioning head 143can be coupled to a vacuum source (not shoWn) to grip theexample, approximately 1,000 rpm). The control arm 142barrier 140 With a suction force and the control arm 142 cancan then loWer the barrier 140 into place on the spinningbarrier support 134 and release the barrier 140. The rotationrate of the substrate 112 and the barrier 140 can be graduallybe remotely actuated to move the barrier 140 toWard andaWay from the barrier support 134.
In other embodiments thecontrol arm 142 and the positioning head 143 can have othercausing the liquid to spread out over the upper surface 113While at the same time spinning the internal air volume 160increased to a higher rpm (for example up to 4,000 rpm),up to the same rotation rate of the substrate 112 and thearrangements for positioning the barrier 140.The sideWalls 144 of the barrier 140 can be sloped tode?ne a rustum of a cone, or alternatively, the sideWalls 144 10can be vertical to de?ne a cylindrical section or have someother con?guration. The sideWalls 144 can include drainholes 146 adjacent to the barrier support 134 positioned suchthat liquid ?oWing off the substrate 112 can ?oW through thedrain holes 146 and through the spaces betWeen the stan15barrier 140.In still another method, gas can be selectively removedfrom the internal air volume 160 as the substrate 112 and thebarrier 140 rotate.
For example, the exhaust port 122 can beopen continuously or periodically to WithdraW gaseous orgas-borne constituents from Within the barrier 140.Accordingly, the barrier 140 and/or the barrier support 134can have vents 148 (in addition to the drain holes 146) thatchions 135. In other embodiments, the barrier 140 can havealloW some ?uid communication betWeen the internal airother shapes and con?gurations that separate the external airvolume 160 and the external air volume 150. For example,gas can pass out of the internal air volume 160 through thedrain holes 146 and into the internal air volume 160 throughthe vents 148.
Alternatively, the barrier 140 can be periodically lifted from the barrier support to alloW gas to escapefrom Within the barrier 140.In any of the methods discussed above With reference toFIG. 3, rotating the internal air volume 160 can reduce thevolume 150 from the internal air volume 160 and alloWexcess liquid to drain aWay from the substrate 112.In one embodiment, the noZZle aperture 124, the substrate112, and the drive shaft 132 are each aligned With the axis136 so that the substrate 112 spins about its center and thenoZZle aperture 124 dispenses the liquid to the center of thesubstrate upper surface 113. In one embodiment, the liquidsupply conduit 123 can be coupled to a source of liquid (not20likelihood for the liquid to form Waves or other nonuniformities on the upper surface 113 of the substrate 112,shoWn) that includes a photoresist material for etching thesubstrate 112 generally as discussed above.
Alternatively,the liquid supply conduit 123 can be coupled to sources ofother liquids.The apparatus 10 can further include a collection vessel120 ?xed relative to the motor 130 and disposed coaxiallyaround the drive shaft 132 and the substrate 112 to collectexcess liquid ?oWing from the substrate 112.
The collectionvessel 120 can include a base. 126 extending outWardly fromthe driveshaft 132 beneath the substrate 112. and Walls 125particularly toWard the outer edge of the substrate 112.30that varies from about ten Angstroms to about thirty Angstroms across the surface of a substrate 112 having a35extending upWardly around the substrate 112. Accordingly,the collection vessel 120 can collect liquid that spills overthe edge 115 of the substrate 112 as the substrate 112 spins.A seal 127 betWeen the drive shaft 132 and the base 126prevents the liquid collected in the collection vessel 120from leaking around the drive shaft 132. A drain 121 beloWthe base 126 conducts the collected liquid aWay from theRotating 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 uniformthickness over the entire upper surface 113.
![](https://s.studizba.com/z.php?f=/templates/si/i/noavatar.png&w=100&h=100&t=1"){kind=avatar}
