System for drying patterned organic light-emitting diode formulations

Abstract

To prevent pixels and picture quality from varying by precisely and uniformly removing a carrier liquid from an organic light-emitting diode material deposited by the use of ink jet technique.SOLUTION: There is provided a drying chamber for drying a substrate patterned with display areas wetted by organic light-emitting diode materials dissolved or suspended in a volatile carrier liquid and separated from one another by dry boundary regions. A mask adjusts drying rate of the carrier liquid during vacuum extraction using vapor-transmissive areas opposite the wet areas and vapor-barrier regions opposite the dry boundary regions, or by confining the wet areas collectively in a chamber with a volume small enough to quickly saturate with the carrier liquid before vacuum extraction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 702,270, filed July 23, 2018, and U.S. Provisional Patent Application No. 62 / 812,143, filed February 28, 2019, which applications are incorporated herein by reference. [Background technology]

[0002] An organic light-emitting diode (OLED) is a light-emitting diode (LED) whose light-emitting component comprises a layer or film of organic material. Increasingly, displays in televisions, computers, and mobile phones contain arrays of tiny, individually controlled organic LEDs as pixels.

[0003] Inkjet technology can be used to deposit organic LED materials dissolved or suspended in a carrier liquid onto a substrate. In a process similar to printing characters on paper, organic LED pixels are "printed" onto a suitable substrate by precisely arranging droplets of the organic LED formulation in the desired pattern. A subsequent drying process removes the carrier liquid from the deposited solution, leaving behind the organic LED material.

[0004] During the drying process, the temperature, flow rate, and pressure are precisely controlled to remove the carrier liquid without causing physical distortion of the pixel and thus adversely affecting image quality. However, precise control of pressure and temperature is difficult at the pixel scale, which can result in variations in pixel and image quality across the entire display area. Therefore, there is a need for an apparatus and method that provides precise and uniform control for removing the carrier liquid from deposited organic LED materials. Summary of the Invention

[0005] In embodiments described herein, a drying chamber is provided that includes a substrate support disposed within a container and having a support surface; a mask having a plurality of vapor-permeable regions and a plurality of vapor barrier regions disposed across the support surface of the substrate support within the container, the mask having an adjustable distance from the support surface; a gas source coupled to the container; and a vacuum source coupled to the container.

[0006] In another embodiment described herein, a method is provided for drying a substrate having multiple wetted regions separated by multiple dry boundary regions and wetted with a carrier liquid, the method comprising: positioning a mask having multiple vapor-permeable regions and multiple vapor barrier regions against the substrate; and aspirating carrier liquid from the multiple wetted regions of the substrate through the multiple vapor-permeable regions of the mask.

[0007] In another embodiment described herein, a drying chamber is provided that includes a substrate support for supporting a substrate having a plurality of wet regions separated by a plurality of dry boundary regions, the plurality of wet regions containing a volatile carrier liquid that exhibits a carrier liquid vapor pressure; a gas distribution mechanism that defines a processing space above the substrate having a volume that approaches saturation with volatile carrier liquid vapor within five minutes; and a vacuum source that draws the volatile carrier liquid vapor from the processing space. [Brief explanation of the drawings]

[0008] The detailed description is illustrated by way of example and not by way of limitation in the accompanying drawings, in which like reference symbols refer to similar elements and in which:

[0009] [Figure 1] 1 shows a drying chamber 100 for drying a substrate 105 patterned to include multiple display areas 110 separated by border areas 115. FIG.

[0010] [Figure 2] 2 is a detailed view of a portion of the substrate 105 and mask 125 shown in FIG. 1. FIG.

[0011] [Figure 3] 1 is a plan view of a substrate 105 and a mask 125. FIG.

[0012] [Figure 4] FIG. 10 is a detailed view of a drying chamber 400 according to another embodiment.

[0013] [Figure 5] FIG. 1 is a plan view of a mask according to an embodiment.

[0014] [Figure 6] FIG. 10 is a plan view of a mask according to another embodiment.

[0015] [Figure 7A] FIG. 7A is a cross-sectional view of a portion of a mask according to a different embodiment. [Figure 7B] FIG. 7B is a cross-sectional view of a portion of a mask according to a different embodiment. [Figure 7C] FIG. 7C is a cross-sectional view of a portion of a mask according to a different embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 1 illustrates a drying chamber 100 for drying a substrate 105 patterned to include multiple display regions 110 separated by boundary regions 115. The substrate 105 may be, for example, a large piece of “mother glass” onto which a pixel array for a large number of organic LED displays has been deposited. The boundary regions 115 may contain, for example, drive electronics, but not pixels. The substrate 105 is placed on a temperature-controlled support 120 within a vessel 102 of the drying chamber 100 and allowed to dry, resulting in the display regions 110 being patterned with organic LED material dissolved or suspended in a volatile carrier liquid. The boundary regions 115 do not contain pixels, and therefore no carrier liquid. Therefore, the vapor concentration of the carrier liquid may be relatively low above the boundary regions 115. This non-uniform concentration across the surface of the substrate 105 can cause pixels adjacent to the boundary regions 115 to dry faster than pixels within the display regions 110. This non-uniform drying can result in non-uniform pixel formation, which in turn can lead to poor image quality. Although it is desirable for the ink layer defining a pixel to be flat, for example, non-ideal drying conditions can result in raised or depressed layers, and thus variations in drying conditions across the wet pixel array can result in undesirable visible variations in pixel appearance.

[0017] A hard mask 125 above the substrate 105 is patterned to include a vapor-permeable region facing the wet-display region 110 and a vapor-barrier region facing the dry region 115. The mask is a covering member that covers at least a portion of the substrate support 120 and is generally parallel to a support surface 121 of the substrate support 120. In this embodiment, the support surface 121 and the mask 125 are generally planar. The mask 125 has a proximal surface 122 that faces the support surface 121 and a distal surface 123 that faces the opposite side from the support surface 121. In this embodiment, both the proximal surface 122 and the distal surface 123 are parallel to the support surface 121 (here, both are planar), although the distal surface 123 may have any convenient shape. The proximal surface 122 may be shaped to manage gas flow and gas evolution from the wet region. Therefore, in some cases, the proximal surface 122 may be non-parallel to the support surface 121 to achieve specific gas flow or vaporization characteristics (e.g., solvent fugitive power, vapor flow, or vapor space adjustment for vapor removal, etc.).

[0018] The size and spacing of the vapor barrier regions relative to the drying region 115 are selected to reduce the diffusion rate above the edge pixels during the drying process. In the example of FIG. 1 , the vapor permeable regions of the mask 125 are located above and slightly smaller than the centers of the corresponding wetting regions. The resulting overlap of the mask 125 reduces the diffusion rate of the carrier liquid near the edges of the wetting regions. This allows the drying rate at the edges of the wetting regions to be the same as the drying rate near the centers of the wetting regions. The size and spacing of the vapor permeable regions relative to the substrate 105 are selected to equalize the drying times between the edge pixels and the interior pixels. By adjusting the spacing between the mask 125 and the substrate 105, the diffusion rate of the carrier liquid at the edge pixels can be increased or decreased, thereby adjusting the drying time of the edge pixels.

[0019] In this embodiment, the vapor-permeable region is shown as a large opening in the mask 125 juxtaposed to the display region 110. In this embodiment, the opening has a shape related to the shape of the display region 110. The dimensions of the coated edge of the display region 110 relate to the desired difference in drying rate between the coated and uncoated portions of the display region 110. The width of one edge of the coated display region 110 along the width axis of the edge may be 1-10% of the overall width of the display region 110. This percentage depends on the edge width expected to be affected by accelerated drying at the edge. Note that the spacing between adjacent display regions 110 may be narrow enough that the difference in air composition between the wet and dry zones is not significant enough to cause accelerated drying at the edge. In this case, the edges adjacent to such narrow dry regions do not need to be coated to adjust the drying rate. Depending on the composition of the material of the display areas 110 being dried, the dimensions of the drying zone between the display areas 110 along the width axis may be less than 1% of the dimensions of the display areas 110, small enough that adjustments to the edge drying rate for the edges adjacent to the drying zone are not necessary. In this case, the opening may span multiple display areas 110, as described below.

[0020] Instead of openings, the vapor-permeable region can also be formed using a mesh, screen, or porous material. A combination of mesh, screen, porous, and openings can be used to create a specific flow pattern through the mask 125. Additionally or alternatively, the vapor-permeable region can utilize a large number of holes. In all of these cases, the vapor-permeable region generally includes a material having some number of openings formed therethrough. This material extends from one end of the vapor-permeable region to the other end of the mask 125, connecting it to the boundary region of the mask 125. The thickness of the material in the vapor-permeable region can be the same as or different from the thickness of the boundary region. For example, the material in the vapor-permeable region can have openings and / or passages formed therethrough, and the thickness of this region can be thinner than the thickness of the boundary region. In other words, the vapor-permeable region can be a recess in the mask having some number of openings or passages formed therethrough.

[0021] The drying chamber 100 includes lift pins 130 to facilitate substrate loading and removal. The substrate support 120 is vertically movable to adjust the spacing between the substrate 105 and the mask 125. The mask 125 is similarly movable via a mask support 135. Actuators (not shown) for operating these adjustable elements may be provided outside the interior space 140 of the drying chamber 100. The mask supports 135 may be positioned along both sides of the mask 125 or may be attached to a frame (see FIG. 5 ) that can be used to support the mask 125. By positioning the supports 135 along both sides of the mask 125, a substrate can be loaded onto or removed from the substrate support 120 between the substrate support 120 and the mask 125. The mask supports 135 extend through a floor 136 of the vessel 102 to a position outside the vessel 102, where they may be driven, for example, by a linear actuator (not shown).

[0022] During the drying process, an inert gas is introduced from an external gas source 142 under closed-loop control, using a vacuum source 170 to maintain a desired pressure profile in the interior space 140. The vacuum source 170 is coupled to the interior of the vessel by a vacuum port 103, and the external gas source is coupled to the interior of the vessel by a gas port 104. These ports are shown on opposite walls of the vessel 102 but can be located in any convenient location. Other gases, such as dry, clean air, optionally treated with ozone removal, may also be used. The temperatures of the interior space 140, the support 120, and other elements of the drying chamber 100 may be heated, cooled, or both, using closed-loop control. Thus, the carrier liquid evaporates from the wet region 110 in response to both pressure and temperature. Mechanisms for controlling temperature and pressure are well known to those skilled in the art, and therefore, detailed procedures will not be discussed. If interested, please refer to U.S. Patent Publication No. 2017 / 0141310, which is incorporated herein by reference.

[0023] A movable or fixed gas distribution element 145 may optionally be provided to evenly direct the flow of vapor 160 from the wetting region 110. The gas distribution element 145 has holes 150 and a region-selective peripheral vapor barrier 155. The vapor barrier 155 surrounds the gap between the mask 125 and the gas distribution element 145. The vapor barrier 155 serves to minimize diffusion of vapor from the region 165 above the substrate 105 and also to reduce the influx of gases that may disrupt the flow or distribution of the vapor 160. During the drying process, a vacuum source 170 draws the carrier liquid vapor 160 from the wetting region 110 through the vapor-permeable region of the mask. While not shown, in some embodiments, a temperature-controlled or passive condenser plate, for example, is provided to collect the vapor 160 above the gas distribution element 145. 1, the gas source 142 generally provides a flow of gas around and outside the vapor barrier 155 within the vessel 102. However, the gas source 142 may be located in any convenient location, such as along the floor of the vessel 102 or within the sidewall of the vessel 102.

[0024] The size and spacing of the holes in the gas distribution element 145 may be uniform or non-uniform. For example, the holes may be smaller and / or more widely spaced closer to the edge, thereby gradually increasing the gas pressure near the edges of the gas distribution element 145 (and mask 125) and gradually affecting the drying conditions at the edges of the mask 125. A mesh or screen may also be used in the gas distribution element 145 rather than holes.

[0025] Alternatively, for convenience in locating one or more actuators for moving the mask support 135, the mask support 135 can be provided to penetrate the ceiling 138 or sidewall 139 of the vessel 102. If desired, the mask support 135 can be disposed to penetrate the gas distribution element 145 and ceiling 138, or can be provided to surround the gas distribution element 145.

[0026] The mask 125 is made of a low-outgassing material that is sufficiently rigid to maintain a uniform gap, e.g., several millimeters, above the substrate 105 without contacting it. Non-limiting examples include stainless steel, aluminum, or titanium. A rigid plastic material can also be used. The gas source 142 provides a controlled flow of, e.g., nitrogen, argon, or purified air and can be controlled to maintain a predetermined maximum concentration of these or other gases. The drying of the wetted area 110 during the drying cycle is controlled by, for example, adjusting the temperature of the support 120 using a heating / cooling element 131 located within the support 120 to control the temperature of the substrate 105, the pressure and gas composition of the drying chamber interior space 140, and the gap between the mask 125 and the substrate 105. The heating / cooling element 131 can be a resistor or an electrical conductor, e.g., a heating coil, or tubing carrying a heating or cooling fluid. Those skilled in the art will be able to empirically derive a preferred combination of these process parameters. Any or all of these parameters could be varied during the drying cycle for a given substrate. Although not shown, as noted above, the substrate support 120 or the like may include temperature control elements for heating and cooling the substrate 105 and maintaining the substrate 105 at a constant temperature or a desired temperature profile.

[0027] FIG. 2 is a detailed view of a portion of the substrate 105 and mask 125 shown in FIG. 1. The wetting region 110 is divided into a central region 110A and an edge region 110B. Each region contains a pixel of wetted organic LED formulation, i.e., "ink" 200, contained in ink channels 205. The depicted portion of the mask 125 overlaps the edge region 110B so that the vapor concentration above the edge pixels is maintained at or near the vapor concentration above the central region 110A. The edge region 110B may extend beyond the area required for the fabricated device to function. In this case, the extended outer edge pixels act as a vapor source to improve the function of their inner neighboring pixels. These sacrificial, or "dummy," pixels are inactive in generating an image on the display.

[0028] Figure 3 is a plan view of the substrate 105 and mask 125 of Figures 1 and 2. The openings 125A and wetting areas 110 in the mask 125 are geometrically similar in this example, and the mask 125 is otherwise tailored for the substrate 105. The mask 125 is easily removable from the drying chamber 100 and can be replaced with a mask dedicated to a different patterned substrate. Dedicated and interchangeable masks for each substrate are simpler and less expensive than the extensive modifications required to improve drying uniformity across a variety of substrates.

[0029] Figure 4 is a detailed view of another embodiment of a drying chamber 400. The drying chamber 400 is similar in some respects to the drying chamber 100 of Figure 1, with like numbers identifying like elements.

[0030] In the drying chamber 400, the substrate 105 is sealed within a processing space 405 defined by a substrate support 410 and a gas distribution mechanism 415. The gas distribution mechanism 415 is shaped like an inverted showerhead and incorporates a channel 420 and a peripheral boundary 425. One or both of the support 410 and mechanism 415 move vertically, facilitating the loading and unloading of the substrate. The second processing space 430 can be filled with, for example, an inert gas or dry, clean air. A sealing member 432 (e.g., an O-ring) can prevent the gas from reaching the contents of the processing space 405 during the drying process. In other embodiments, the processing space 405 can be accessible, for example, by providing a door or opening in the side.

[0031] The drying chamber 400 improves drying uniformity by allowing the vapor concentration of the carrier liquid to equilibrate throughout the substrate 105. The volume of the space 405 is designed to allow the evaporating carrier liquid (shown herein as vapor 160) to reach saturation in less than five minutes. The near-saturated vapor concentration equilibrates throughout the wet and dry regions 110 and 115. This reduces the difference in drying of edge pixels relative to drying of center pixels. The volume of the space 405 is determined by the vapor concentration of the carrier liquid, which varies with solvent, pressure, and temperature. The cross-section in FIG. 4 is not to scale. For example, in an embodiment where the substrate 105 is 9 square meters, the perforated underside of the feature 415 can be located within a few millimeters above the substrate.

[0032] The drying process is accomplished by allowing the vapor concentration within the volume 405 to approach equilibrium before a low pressure is applied by the vacuum source 170 to evacuate the volume 405. In one embodiment, process variables are set so that the volatile carrier liquid within the process volume 405 is within 90% saturation before vapor evacuation begins. The low volume of the volume 405 allows the vapor 160 to be drawn quickly. Rapid evacuation reduces the impact on drying times between neighboring pixels and reduces edge pixel defects. In other embodiments, a vapor mask of the type detailed above may be included within the volume 405. The hole pattern of the gas distribution mechanism 415 may also be modified to preferentially draw vapor away from the wetting region 110.

[0033] 5 is a plan view of a mask 500 according to one embodiment. The mask 500 can be used to tailor the drying profile of a substrate having wetting regions to be dried in a drying apparatus, such as the apparatus 100 of FIG. 1. The mask 500 has a plurality of first openings 502, a plurality of second openings 504, and a single third opening 506. The plurality of first openings 502 are for masking a plurality of first wetting regions 508 (represented herein by dashed lines) on the substrate. The plurality of second openings 504 are similarly for masking a plurality of second wetting regions 510. The third opening 506 is similarly for masking a plurality of third wetting regions 512.

[0034] The plurality of first openings 502 have a first size and a first shape. The plurality of second openings 504 have a second size and a second shape. The third opening 506 has a third size and a third shape. In this embodiment, the first, second, and third sizes are different from one another, and the first, second, and third shapes are different from one another. Each shape is generally rectangular, but the first and second shapes have rounded corners, while the third shape has regular right-angled corners. In this embodiment, the second size is larger than the first size. The first shape has rounded corners with a first radius of curvature. Meanwhile, the second shape has rounded corners with a second radius of curvature that is smaller than the first radius of curvature.

[0035] The first plurality of openings 502 are spaced apart by a first spacing, and the second plurality of openings 504 are spaced apart by a second spacing different from the first spacing. The spacing between the openings is generally determined by the spacing between the wetting regions and the edge coverage of the openings. As described elsewhere, the edge coverage of the openings is determined based on the drying adjustment of the edge regions relative to the central region. In this embodiment, as shown in FIG. 5 , the outer edge of each of the first and second openings is completely within and concentric with the corresponding wetting region to be dried when projected onto a substrate properly aligned below the mask 500. Thus, the edge coverage is symmetrical on all four sides of each wetting region. Note that while the shapes shown in the drawings herein are generally rectangular, the same concepts can be applied to other shapes, such as generally polygonal, generally elliptical, and generally circular, as well as irregular shapes.

[0036] The third opening 506 masks the edges of multiple wetted areas on the substrate that are separated from each other by drying zones that are small enough that masking to adjust the drying rate is not necessary. Thus, the third opening 506 masks the edges of wetted areas that are adjacent to larger drying zones. Thus, multiple wetted areas are masked by a single opening.

[0037] The aperture sizes, shapes, and placements shown in Figure 5 are intended to illustrate concepts of dry mask construction and can be used in any combination in a single mask. Multiple apertures in a single mask can have the same shape or all different shapes. The shapes can be generally rectangular or a mixture of shapes. Similarly, the aperture sizes and spacing can be all the same or all different in any combination.

[0038] The mask 500 shown in Figure 5 is coupled to a frame 514 that supports the mask 500 and allows manipulation of the mask 500. The frame is supported by supports 516. The supports 516 are shown in dashed lines because they are below the frame 514 and are not directly visible in the plan view of Figure 5. The supports 516 are generally similar to the mask supports 135 described in connection with Figure 1. The supports 516 are provided on both sides of the mask 500, thereby facilitating the loading and unloading of a substrate from one end of the mask 500 between the two sides coupled to the frame 514.

[0039] FIG. 6 is a plan view of a mask 600 according to another embodiment. The mask 600 has multiple holes to adjust the drying of a certain wet area. Specifically, the mask 600 has multiple holes that form vapor-permeable areas corresponding to the multiple first wet areas 508. The mask 600 has multiple vapor-permeable areas 602 that mask the multiple first wet areas 508. The holes in each vapor-permeable area 602 have different sizes, and the sizes generally increase toward the center of the vapor-permeable area 602 so that the drying rate from the edge to the center of the wet area 508 is uniform. The spacing between the holes is irregular, but the cross-section of the flow through the mask generally tends to increase from the edge to the center. In this embodiment, the vapor-permeable area 602 has smaller holes near the edge and larger holes near the center. The size of the holes generally increases monotonically (or linearly) from the edge to the center of the vapor-permeable area 602. In this embodiment, the pores near the corners of the vapor permeable region 602 are the smallest because the areas of the wetted region 508 near the corners are surrounded by the driest areas and are therefore subject to the fastest drying conditions.

[0040] Mask 600 illustrates an embodiment with different types of vapor-permeable features. This embodiment includes vapor-permeable regions with multiple holes and vapor-permeable regions with a single opening. Additionally, it includes a vapor-permeable region with a single opening over a single wetting region and a single vapor-permeable region over multiple wetting regions. Different types of vapor-permeable regions can also be included within a single mask. In addition to those shown in FIG. 6, types of vapor-permeable regions include porous materials, grooved materials, solid materials with etched tortuous paths, sintered materials, and other permeable materials.

[0041] FIG. 7A is a cross-sectional view of a portion of a mask 700 usable in any of the devices described herein. This view illustrates a portion of the mask 700 at the edge of an opening that forms at least a portion of the vapor-permeable region of the mask 700. The mask 700 has a boundary region 702 disposed generally above the dry zone of the underlying substrate and a vapor-permeable region 704 recessed in the distal surface 706 of the mask 700. Thus, the vapor-permeable region 704 connects with the boundary region 702 at an outer wall 707. Alternatively, the vapor-permeable region 704 can be recessed in the proximal surface 708 of the mask 700 opposite the distal surface 706. The vapor-permeable region 704 has at least one opening 710. In this case, the edge 712 of the opening is tapered to achieve a desired evaporation profile in the portion of the substrate covered by the vapor-permeable region 704. This tapered shape terminates in a thin, flat wall 714 that surrounds the opening 710. In this embodiment, the taper is linear (e.g., sloped), and the dimensions of the tapered region are smaller than the dimensions of the vapor-permeable region 704 from the outer wall 707 to the wall 714 of the opening 710. The tapered region can also be curved and can extend any desired distance from the wall 714 away from the opening 710. In some cases, the tapered region can extend beyond the outer wall 707 to a position below the boundary region 702. In this embodiment, the proximal surface 708 of the mask 700 is tapered. However, alternatively or additionally, the distal surface 706 of the mask 700 can be tapered. FIG. 7B is a cross-sectional view of a portion of a mask 720 according to another embodiment. In this embodiment, the vapor-permeable region 722 has an opening 724. The opening 724 has a curved edge 726 that forms a wall surrounding the opening 724. The curved edge 726 is elliptical in this embodiment, but can be any desired shape (such as parabolic or hyperbolic) that affects gas flow at the edge. Figures 7A and 7B are examples showing that the openings in the vapor permeable regions of the various masks described herein can have different edge effects. If desired, each opening in a single vapor permeable region can have a different edge effect than all other openings. A single opening can also have varying edge effects along the entire perimeter of the opening.For example, the edge of an opening in one of the vapor-permeable regions of any of the masks described herein can be tapered, with the angle or shape of the taper varying continuously or discontinuously along the outer edge of the opening. In such an opening, only a portion of the opening can have an edge effect, with the remaining edge simply being a vertical, flat wall. An edge effect can also be used in the vapor-permeable region of a mesh or porous member (where the mesh or porous member meets the boundary region of the mask).

[0042] 7C is a cross-sectional view of a portion of a mask 740 according to another embodiment. In this embodiment, a vapor-permeable region 742 is surrounded by a boundary region 744, and a wall 746 protrudes from a proximal surface 748 of the mask 740 toward the support surface of the substrate support. The wall 746 has a flat end 750. The flat end 750 of the wall 746 faces the support surface, forming a gap between the flat end 750 and the support surface that reduces the cross section of gas flow along the flat end 750. The wall may protrude from the proximal surface 748 of the vapor-permeable region 742 or boundary region 744, or may overlap the region from the vapor-permeable region 742 to the boundary region 744. The wall 746 may extend around the entire outer edge of the opening in the vapor-permeable region 742 to partially seal the perimeter of the wetting region of the substrate. The wall may also extend around the entire outer edge of the vapor-permeable region 742. The wall may also extend around a portion of the opening or the entire perimeter of the vapor-permeable region. Partial sealing reduces the likelihood of solvent-laden gases being removed along the edges of the wetted region and accelerating evaporation, thereby reducing the drying-out effect from the dry zone adjacent to the wetted region. Note that wall 746 can also have curved edges rather than flat edges 750.

[0043] Although the subject matter has been described in connection with specific embodiments, other embodiments are contemplated. For example, while the mask 125 of FIG. 1 includes a single aperture per wetting area 110, other embodiments may use different numbers, shapes, and patterns of apertures to maintain a relatively uniform vapor concentration. Accordingly, the spirit and scope of the appended claims are not intended to be limited to the foregoing description. Only claims that recite "means for" or "step for" should be construed as satisfying the requirements of 35 U.S.C. 112, sixth paragraph.

Claims

1. A drying chamber, the drying chamber comprising: a substrate support disposed within the vessel and having a support surface; a gas source coupled to the vessel; a vacuum source coupled to the vessel; a mask disposed within the container, the mask having a rigid body patterned to include a plurality of vapor-permeable regions and a plurality of vapor-barrier regions so as to cover at least a portion of the support surface of the substrate support and generally parallel to the support surface, the mask having a generally planar proximal surface facing the support surface and movable so as to adjust the distance between the mask and the support surface; a gas distribution element disposed between the mask and the vacuum source, the gas distribution element having at least one hole and a vapor barrier surrounding a gap between the mask and the gas distribution element.

2. The drying chamber of claim 1 , wherein the mask has a mask support that extends through the container.

3. 10. The drying chamber of claim 1, wherein the mask extends through the container and has a plurality of mask supports disposed on opposite sides of the mask.

4. 10. The drying chamber of claim 1, wherein the gas source is coupled to the vessel at a location that provides a gas flow outside the vapor barrier.

5. The drying chamber of claim 1 , wherein the mask comprises a wall extending from the proximal surface of the mask toward the support surface.

6. The drying chamber of claim 1 , wherein the substrate support comprises a temperature control element.

7. The drying chamber of claim 1 , wherein each of the plurality of vapor-permeable regions has a single opening, a plurality of openings, a mesh member, a screen member, or a porous member.

8. The drying chamber of claim 1 , wherein the proximal surface of the mask is configured to direct gas flow from a substrate disposed on the support surface.

9. The drying chamber of claim 1 , wherein the gap is adjustable.

10. A drying chamber, the drying chamber comprising: a substrate support disposed within the vessel and having a support surface; a vacuum source coupled to the vessel; a gas source coupled to the vessel; a mask including a rigid body having a plurality of vapor permeable regions and a plurality of vapor barrier regions disposed away from the support surface of the substrate support within the container, wherein each of the plurality of vapor permeable regions has a single opening, a plurality of openings, a mesh member, a screen member, or a porous member, and a thickness of each of the plurality of vapor permeable regions is less than a thickness of a boundary region of the mask; a gas distribution element disposed between the mask and the vacuum source, the gas distribution element having at least one hole and further having a vapor barrier surrounding an adjustable gap between the mask and the gas distribution element.

11. 11. The drying chamber of claim 10, wherein the mask has a mask support that extends through the container.

12. 11. The drying chamber of claim 10, wherein the mask extends through the container and has a plurality of mask supports disposed on opposite sides of the mask.

13. The drying chamber of claim 10, wherein the mask includes a wall extending from a proximal surface of the mask toward the support surface.

14. The drying chamber of claim 10 , wherein the substrate support comprises a temperature control element.

15. A dryer, the dryer comprising: a substrate support disposed within the vessel and having a support surface; a gas source and a vacuum source coupled to the vessel; a mask having a plurality of vapor-permeable regions and a plurality of vapor barrier regions disposed away from the support surface of the substrate support within the vessel, the mask being a mask using a rigid body that is movable so as to adjust the distance between the mask and the support surface, and the vapor-permeable regions being sized and positioned based on characteristics of the substrate to be processed in the drying chamber; a gas distribution element disposed between the mask and the vacuum source, the gas distribution element having at least one hole and further having a vapor barrier, the gas distribution element and the mask enclosing an upper region of the substrate support surrounded by the vapor barrier.

16. The drying chamber of claim 15 , wherein the substrate support comprises a temperature control element.

17. 16. The drying chamber of claim 15, wherein the mask comprises mask supports positioned on either side of the substrate support and extending through the vessel.

18. 16. The drying chamber of claim 15, wherein each of the plurality of vapor-permeable regions has a single opening, a plurality of openings, a mesh member, a screen member, or a porous member.

19. The drying chamber of claim 15 , wherein the gap is adjustable to increase or decrease the drying time of a substrate disposed on the substrate support.

Images