TW201802268A - Fine metal mask for producing organic light-emitting diodes - Google Patents

Abstract

The embodiments described herein generally relate to the formation of low tension fine metal masks for electro-optic devices. The low tension fine metal mask has a frame. The frame has a plurality of apertures. The low tension fine metal mask has a plurality of mask units. Each mask unit has a having a plurality of openings. Each metal mask unit is coupled to the frame in a manner that maintains a tension across the mask unit of about less than about 0.4 kgf/cm.

Description

Fine metal mask for the production of organic light-emitting diodes

The embodiments disclosed herein generally relate to the production of electro-optic devices. More specifically, the embodiments disclosed herein generally relate to forming a fine metal reticle.

Electro-optical devices utilizing organic materials are becoming more and more desirable for a variety of reasons. Many of the materials used to make such devices are relatively inexpensive, and thus organic electro-optic devices have the potential to exceed the cost advantages of inorganic devices. As such, the inherent properties of organic materials, such as their flexibility, may be advantageous for particular applications, such as for deposition or formation on flexible substrates. Examples of the organic electro-optical device include an organic light-emitting device (OLED), an organic photoelectric crystal, an organic photovoltaic cell, and an organic photodetector.

For OLEDs, organic materials are considered to have performance advantages over traditional materials. For example, the wavelength at which the organic light-emitting layer emits light can generally be easily tuned with a suitable dopant. When a voltage is applied to the device, the OLED utilizes a thin organic film that emits light. OLEDs are becoming an increasingly interesting technology for applications such as flat panel displays, lighting and backlighting.

A fine metal mask (FMM) is used to define the deposition area on the substrate before and during evaporation deposition of the OLED material. Mask manufacturing issues, mask materials, small differences from batch to batch, and temperature variations during deposition can cause FFM misalignment on the substrate. So far, these small temperature changes and variations during processing have limited the use of FMM for evaporation patterning to relatively small substrates and relatively large defined features.

One solution is to achieve very precise alignment of the reticle with the substrate, keep the deposition temperature as low and constant as possible during processing, use a reticle material with a low coefficient of thermal expansion, and place the reticle under tension. This deposition technique has been carried out for many years and has reached its limits in terms of feature density (i.e., the number of features that can be formed in the region).

Another possible solution is small mask scanning (SMS). SMS involves the use of a reticle that is smaller than the entire substrate or display and scanned relative to the substrate, whereby the reticle is used to deposit stripes of red, green, and blue (RGB) material. This technique has a number of problems because a gap must be maintained between the substrate and the reticle during deposition, which results in cross-contamination between the emitted RGB materials. In addition, SMS may create defects due to scratching, as it is desirable to maintain as small a gap as possible during scanning to avoid cross-contamination as described above.

Accordingly, there is a continuing need for improved reticle and reticle technology for forming electro-optical devices.

Embodiments described herein generally relate to forming a low tension fine metal reticle for an electro-optical device. The low tension fine metal reticle has a frame. The frame has a plurality of holes. The low tension fine metal reticle has a plurality of reticle units. Each reticle unit has a plurality of openings. Each metal reticle unit is coupled to the frame in a manner that maintains a tension of less than about 0.4 kgf/cm (such as 0.1 kgf/cm) across the reticle unit.

In another embodiment, a reticle assembly is disclosed. The photomask assembly has a body. The body has a frame and a plurality of supports forming a hole in at least one side of the frame. The reticle unit is sized to fit the aperture and engage the aperture. The reticle unit has a fine metal reticle with a plurality of openings. The fine metal reticle is placed inside the frame and at low tension.

In yet another embodiment, a method for forming a fine metal reticle assembly is disclosed. The method begins by preparing a substrate formed of a ruthenium-metal hybrid material. A through hole is formed in the void of the metal layer by the tantalum layer of the tantalum-metal mixed material. The through hole has a side wall formed at a first angle. A second angle is formed on the sidewall of the metal layer. The substrate is cut to a shape suitable to form a reticle unit. The reticle unit is then coupled into the fine metal reticle assembly wherein the tension across the reticle unit is less than about 0.4 kgf/cm.

Embodiments disclosed herein generally relate to fine metal reticle. A fine metal reticle refers to a reticle that can be used during deposition of material onto a substrate. A fine metal reticle can be used to form features having a pattern resolution that is less than the entire active (light emitting) region of the substrate. Typically, a fine metal reticle has a size that is the size of the size of a portion of a sub-pixel (usually a color) to be disposed on a substrate. Thus, fine metal reticle is typically used to deposit an emissive layer of an organic device, wherein the different colors of the display are each deposited separately by a fine metal reticle and designed to allow deposition only on a portion of the active OLED present in the display ( For example, a fine metal mask that deposits only a red emitting layer, another fine metal mask that deposits only a green emitting layer, and the like).

The fine metal reticle can be formed from a bismuth-metal hybrid material using micromachining (microelectromechanical systems) or plasma processing to achieve a reticle pattern having an accuracy of about 1 micron. In addition, both the substrate and the fine metal mask can be heated during the deposition process, and thus both the substrate and the fine metal mask are expanded to some extent. When the substrate and the fine metal mask are inflated, the alignment of the fine metal mask with respect to the substrate must be maintained to achieve high accuracy and high resolution. For example, a fine metal reticle can achieve a pixel per inch (PPI) resolution of greater than 600 PPI, such as between about 800 PPI and about 1200 PPI on next generation and large substrates. By positioning the fine metal reticle in the rigid frame without tensioning the fine metal reticle, the fine metal reticle can be aligned with the substrate without offset or deformation during the processing process. The embodiments disclosed herein are more clearly described below with reference to the drawings.

FIG. 1 depicts a schematic diagram of a portion of a processing chamber 100 having a fine metal mask assembly 130. Processing chamber 100 can be a processing chamber suitable for use with the embodiments described below. In one embodiment, the processing chamber 100 can be a chamber available from AKT America, a subsidiary of Applied Materials, Inc. of Santa Clara, California. It should be understood that the embodiments discussed herein may be implemented in other chambers (including those sold by other manufacturers).

The substrate 102 can be positioned in the processing chamber 100 in relation to an electrostatic chuck (not shown). The substrate 102 may be a substrate suitable for forming an organic light emitting diode (OLED) thereon. Additionally, the substrate 102 can be a flexible material. The OLED may be composed of an organic material layer between the two electrodes (anode and cathode), all deposited on the substrate 102. In one embodiment, the substrate 102 consists essentially of glass. The substrate can have a wide range of sizes (eg, length, width, shape, thickness, etc.). In one embodiment, the substrate 102 is about 1 meter long and 1 meter wide. In this embodiment, the substrate 102 is depicted as having a cathode 104 formed over the lower surface 103. Cathode 104 can comprise indium tin oxide (ITO). In other embodiments, the cathode 104 is discontinuous and formed on the substrate 102 in combination with the formation of an OLED layer (not shown).

Source 108 is positioned adjacent to substrate 102 and cathode 104. Generally, source 108 can be a source boat or other container or reservoir capable of producing vapor of organic material 110. The vapor of organic material 110 can be configured to deposit a further layer, such as an emissive layer, a hole transport layer, a color change layer, or a further layer (not shown) needed or desired to form the OLED structure, over cathode 104. In one embodiment, source 108 produces vapor of organic material 110 to form a white emissive layer (not shown) over cathode 104 and form a color changing layer over the white emissive layer. In another embodiment, source 108 produces a vapor of organic material 110 to form a colored emissive layer (not shown) over cathode 104. One or more additional layers, such as an electron transport layer (not shown), may be formed over the cathode 104.

A fine metal mask assembly 130 is located between the substrate 102 and the source 108. It should be understood that the fine metal reticle assembly 130 is not drawn to scale and may be smaller or larger in length, width or height than shown, as compared to related structures. The fine metal reticle assembly 130 includes a fine metal reticle 106 and a frame 112. The fine metal reticle 106 can be positioned in the frame 112. The fine metal mask 106 can be at least partially constructed from one or more magnetic or non-magnetic metals. For example, a fine metal reticle can be formed from a bismuth-metal hybrid material. Suitable materials for the fine metal reticle 106 or components thereof include, but are not limited to, bismuth-nickel hybrid materials, INVAR (64FeNi), ASTM grade 5 titanium (Ti-6Al-4V), titanium, aluminum, molybdenum, copper, 440 Stainless steel, HASTELLOY® alloy C-276, nickel, chrome molybdenum steel, 304 stainless steel, other iron containing compositions, or combinations thereof. The frame 112 may be constructed of a material similar to that of the fine metal reticle 106. In one embodiment, the frame 112 is comprised of INVAR.

The fine metal reticle 106 can have a size and shape that allows for covering at least a portion of the substrate. In one embodiment, the fine metal reticle 106 has a length of from 1 meter and 1.5 meters and a height of from 750 mm to 925 mm. The fine metal reticle 106 can have a thickness of less than 80 microns, such as about 40 microns or about 20 microns. In one embodiment, the fine metal reticle 106 has a thickness of less than 40 microns.

The fine metal reticle 106 is positioned in the processing chamber 100. The processing chamber is evacuated with a temperature stable and ready to receive the substrate 102. The substrate 102 can then be brought into the processing chamber 100 and the alignment marks on the fine metal mask 106 aligned with corresponding features on the substrate 102.

To better understand and appreciate the fine metal reticle 106, the fine metal reticle assembly 130 will first be discussed with respect to a conventional fine metal reticle 206. 2 depicts a top view of a conventional fine metal reticle 206 disposed in a fine metal reticle assembly 130 suitable for use in the processing chamber 100 of FIG. A conventional fine metal reticle 206 is attached to the frame 112. In one example, a conventional fine metal reticle 206 uses a microactuator 214 to attach to the frame 112. In another example, a conventional fine metal reticle 206 is stretched and welded to the frame 112.

The conventional fine metal reticle 206 is stretched, or an alternative microactuator 214 applies a force that aligns and/or stretches the conventional fine metal reticle 206. The reticle opening 216 and the frame opening 218 are depicted as apertures in the conventional fine metal reticle 206 and frame 112, respectively. However, other connections may be used, such as hooks or bolts to which the microactuator 214 is attached, or the microactuator 214 to the frame 112, the conventional fine metal mask 206, or both. In operation, the conventional fine metal reticle 206 is tensioned to bring the conventional fine metal reticle 206 and pattern defining features 220 to the final desired size and position relative to the substrate 102. For example, the fine metal reticle 206 can be tensioned typically in the range of from about 0.7 to about 0.9 kgf/cm. The fine metal mask assembly 130 will then be loaded into the processing chamber 100.

Conventional fine metal reticle 206 can include a size of about 750 mm x 650 mm that is tensioned to more than 0.8 kgf/cm in one or more dimensions. The larger dimensions for the conventional fine metal reticle 206 include about 920 mm x about 730 mm, GEN 6 half cut (about 1500 mm x about 900 mm).

A conventional fine metal reticle 206 is formed from a sheet of low thermal expansion metal that is stretched and then attached to the heavy frame in a stretched state. Heavy frames are often required to maintain the high stretch of the fine metal mask, i.e., tension, and can be on the order of thousands of pounds. For example, a conventional fine metal reticle 206 having 16 actuators can be formed from INVAR having a coefficient of thermal expansion (CTE) of 1.3 μm/m ° C, a drop strength of 70 ksi, and a Young's modulus of 21500 ksi. When the temperature was raised to 50 ° C, the thermal expansion was 162.5 μm. The strain and stress that need to be corrected for expansion are 0.0065%, requiring each of the 16 actuators to use 27.1 pounds of force. Similarly, a fine metal mask (FMM) can be formed by Ti-6Al-4V, which requires 137.5 pounds per actuator; titanium, 144.8 pounds per actuator; Al, per consistent The force required is 222.8 lbs; molybdenum and titanium, 248.3 lbs per actuator; copper, 254.2 lbs per actuator; stainless steel, 286.6 lbs per actuator; HASTELLOY® The force required for each actuator is 322.2 lbs; for nickel, the force required for each actuator is 347.3 lbs; and for chrome molybdenum steel, the force required for each actuator is 351.7 lbs. However, the tension applied to the conventional fine metal reticle 206 limits the resolution and causes the reticle to deflect and deflect at high temperatures. Therefore, conventional fine metal masks provide poor guidance for high resolution and larger size scalability.

FIG. 3 shows a top view of a fine metal reticle 106 disposed in a fine metal reticle assembly 130 suitable for use in the processing chamber of FIG. 1 in accordance with one embodiment. The fine metal reticle 106 is not subjected to the tension used in the conventional fine metal reticle 206 discussed above with respect to FIG. The fine metal reticle 106 can comprise a size of about 750 mm x 650 mm that is tensioned to less than about 0.4 kgf/cm, such as 0.1 kgf/cm or less, in one or more dimensions. The larger dimensions of the fine metal reticle 106 include about 920 mm x about 730 mm, GEN 6 half cut (about 1500 mm x about 900 mm), and extend to even larger sizes, such as GEN 6 (about 1500 mm x about 1800 mm), GEN 8.5 ( About 2200 mm x about 2500 mm) and GEN 10 (about 2800 mm x about 3200 mm).

The frame 112 of the fine metal reticle assembly 130 has a body 352. The main body 352 can be made of INVAR (64FeNi), ASTM grade 5 titanium (Ti-6Al-4V), titanium, aluminum, molybdenum, copper, 440 stainless steel, HASTELLOY® alloy C-276, nickel, chrome molybdenum steel, 304 stainless steel, other iron-containing The composition, or a combination thereof, is formed. The body 352 has a housing 354. The housing 354 can be shaped as a strip having an inner portion 342 and an outer perimeter 344. Examples of the strip shape for the housing 354 may include a toroidal shape, an elliptical ring shape, a rectangular ring shape, or other suitable polynomial strip/ring shape having a central hollow region.

The body 352 can additionally have one or more supports 336. The body 352 can also have a plurality of auxiliary supports 334. The supports 336, 334 divide the inner portion 342 of the housing 354 into a plurality of apertures 332. The supports 336, 334 can be integral with the housing 354. For example, the apertures 332 and the supports 336, 334 may be formed by removing material from the housing 354 or by an additional manufacturing process similar to 3D printing during manufacture of the housing 354 such that the housing 354 and the support 336, 334 is formed from a sheet of solid, uniform material. Alternatively, the supports 336, 334 can be a single unit or separate member that is attached to the housing 354 when the body 352 is formed. For example, the supports 336, 334 can be welded, glued, fastened, or attached to the housing 354 by other techniques, with or without tension. In one embodiment, the frame 112 has ten (10) holes 332. The apertures 332 can be shaped as rectangles, squares, circles, triangles, pies or other suitable shapes. For example, ten holes 332 can have a substantially rectangular shape.

The reticle unit 306 is configured to be disposed in the aperture 332. The reticle unit 306 can have an outer support 308. The fine metal reticle 106 can be formed in or supported by the outer support 308 to form the reticle unit 306. Alternatively, the reticle unit 306 may be formed only of the fine metal reticle 106. The reticle unit 306 can be shaped to be held by a combination of the supports 336, 334 and the housing 354. The outer support 308 can be substantially or partially aligned with one or more of the supports 336, 334 and the housing 354 that form the aperture 332. One or more reticle units 306 can be configured to cover one of the apertures 332. In one embodiment, each aperture 332 has an individual reticle unit 306. In another embodiment, each aperture 332 has two or more reticle units 306. In yet another embodiment, the aperture 332 can include a plurality of reticle units 306 disposed therein.

A fine metal mask 106 is disposed in each of the reticle units 306. Suitable materials for the fine metal reticle 106 or components thereof include, without limitation, bismuth-metal mixtures such as bismuth-nickel, INVAR 36 (64FeNi), ASTM grade 5 titanium (Ti-6Al-4V), titanium, aluminum, Molybdenum, copper, 440 stainless steel, HASTELLOY® alloy C-276, nickel, chrome molybdenum steel, 304 stainless steel, other iron containing compositions, or combinations thereof.

The fine metal mask 106 can be formed by electroforming process or MEMS technology, such as molding and plating, wet etching, dry etching, electrical discharge machining (EDM), thinning of the germanium wafer by grinding, and suitable for fabrication. Other techniques for small devices. The fine metal reticle 106 can have a plurality of small openings 310. The small opening 310 is adapted to form features such as devices or pixels on the surface of the substrate that is exposed to the fine metal reticle 106. The opening 310 can have an area between about 1 micron and about 100 microns (i.e., about 0.001 mm to about 0.1 mm), such as about 25 microns. The small opening 310 in the fine metal reticle may be adapted to form features at 300 features per inch or greater, such as 800 features per inch or 1000 features per inch. For example, the fine metal reticle 106 can have a small opening 310 configured to produce between about 250 pixels per inch (PPI) and about 1200 PPI, such as between about 600 PPI and 900 PPI, such as about 800 PPI. The small opening 310 can have a dimensional change of less than about 1 micron (such as about 0.2 microns) and a pitch of less than about +/- 3 [mu]m / 160 mm (i.e., a center-to-center distance between the small openings 310).

A plurality of reticle units 306 can be bonded to the body 352 when the fine metal reticle assembly 130 is formed. Engagement with the body 352 can be performed by welding (such as laser welding), gluing, such as by epoxy or acrylic, integrally with the body 352 or by other suitable means. Engagement of the fine metal reticle 106 with the outer support 308 or directly onto either of the bodies 352 of the fine metal reticle assembly 130 such that the fine metal reticle 106 is at low tension, such as at about zero kg/cm and about 0.1 kg Tension between /cm. The low tension of the reticle unit 306 is formed without any substantial sag and has a flatness between 2 microns and about 5 microns. Deformation of the fine metal mask 106 due to temperature changes can be prevented by bonding the fine metal mask 106 at a low temperature, such as by epoxy. In one embodiment, the reticle unit 306 is bonded to the body 352 of the fine metal reticle assembly 130 with epoxy to form pixels at an area greater than about 800 PPI over an area of from about 900 mm to about 1500 mm. The reticle unit 306 can have an alignment accuracy of about 1 micron to about 5 microns, that is, the actual position (compared to the design position) of the reticle unit 306, the opening 310, the alignment mark (not shown), and the like. Within about 1 micron.

Advantageously, the fine metal mask assembly 130 described above can be positioned in the processing chamber in relation to the substrate. The fine metal mask assembly 130 can be aligned and positioned in conjunction with the substrate for deposition. The low tension of the fine metal mask 106 significantly prevents offset or deformation in the alignment of the fine metal mask assembly 130 with the substrate at high temperatures. Thus, the low tension of the fine metal mask 106 in the fine metal mask assembly 130 can have a higher resolution and operate at a higher temperature than conventional metal masks such as those shown and described in FIG.

An additional advantage is that the reticle unit 306 can be easily replaced by disengaging or unjoining the reticle unit 306 from the body 352 of the fine metal reticle assembly 130. When the reticle unit 306 becomes clogged, dirty, damaged, or worn, the individual reticle units 306 can be replaced or repaired, thereby minimizing cost and operational downtime.

Figures 4A and 4B depict cross-sectional views for forming a low tension fine metal reticle. The figure shows an opening 310. However, it should be understood that the fine metal reticle 106 has a plurality of openings and may have more than 250 openings per square inch or more.

The layer 402 has a top surface 472. Silicon wafer 402 can have a thickness between about 700 microns and about 40 microns, such as about 65 microns. A seed layer 404 can be disposed on the ruthenium layer 402. Seed layer 404 can be titanium (Ti), copper (Cu), or other suitable material. Metal layer 432 can be disposed on seed layer 404. Metal layer 432 may be formed of nickel (Ni) or a nickel alloy, such as nickel-cobalt (NiCo) or other suitable materials.

The germanium layer 402 can be thin, such as by etching in and around the opening 310 such that the germanium layer 402 is about 30 microns thick. For example, thinning can be performed by chemical etching or grinding the bottom of the layer 402 prior to etching the top surface 472. Alternatively, the germanium layer 402 may be subjected to bi-directional chemical etching in a single step to perform etching.

In FIG. 6A, a via 422 is formed in the germanium layer 402 as part of forming the opening 464. The via 422 can have a sidewall 415 that extends from the bottom surface 411 of the layer 402 to the surface. Via 422 can be formed by an anisotropic chemical etch such as potassium hydroxide (KOH) etching or other suitable technique in germanium layer 402. The etch rate can be controlled such that the width of the via 422, such as the bottom width 408, narrows as the depth 482 of the via 422 increases from the top surface 472 of the germanium layer 402. The sidewall 415 of the via 422 extends at an angle 406 such that the opening of the via 422 is larger than the opening of the bottom surface 611 (ie, the bottom width 608) at the top surface 472. Angle 406 can be between about 40 degrees and about 60 degrees, such as about 54.7 degrees. The angle 406 can be precisely controlled by an anisotropic etch, allowing the bottom width 408 to be maintained with an accuracy of about 1 micron, and the angle 406 of the sidewall 415 remaining about 54.7 degrees. The bottom width 408 of the via 422 can be about 38 microns. The width of the via 422 at the top surface can be about 94 microns. Accordingly, the corresponding portion 409 of the bottom surface 411 adjacent the bottom width 408 of the opening 310 can be about 28 microns.

In Figure 4B, the metal layer 432 is circular. Metal layer 432 can be rounded by grinding, etching, or other suitable technique. For example, ferric chloride (FeCl ₃ ) etching can be used to round the nickel material of metal layer 432. The sidewall 425 of the metal layer 432 can similarly be aligned with the sidewall 415 of the germanium wafer. That is, sidewall 425 can be angled between about 40 degrees and about 50 degrees, such as about 54.7 degrees, to match angle 406 of sidewall 415 of layer 401. Each opening for the via 422 corresponds to a small opening 310 in the finished low tension fine metal mask (as shown in Figure 3). Thus, the vias 422 can be formed with a suitable density to form a plurality of features in a substrate having a low tensile fine metal mask. The ruthenium layer 402 can now be cut to fit in each reticle unit 306 to form a low tension fine metal reticle 106. The tension across the low tension fine metal reticle 106 is less than about 0.4 kgf/cm. The low tension fine metal reticle 106 can be joined and unbonded to the reticle assembly for use and replacement of the unit. For example, the low tension fine metal mask 106 can be joined by epoxy at a temperature of about 25 degrees Celsius or room temperature.

Advantageously, the sidewalls 415, 425 of the via 422 are angled to minimize shadowing and promote evaporation performance. The 张力-metal hybrid material of the low tension fine metal reticle can be biased onto the substrate by magnetic force for more stringent process control. The bismuth-metal hybrid material also enhances the durability of low tension fine metal reticle. Materials and methods of manufacture for low tension fine metal reticles allow higher density openings to be coupled with alignment accuracy of less than about 1 micron to form a feature density on a substrate with minimal deflection.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be

100‧‧‧Processing chamber
102‧‧‧Substrate
103‧‧‧ lower surface
104‧‧‧ cathode
106‧‧‧Fine metal mask
108‧‧‧ source
110‧‧‧Organic materials
112‧‧‧Frame
130‧‧‧Fine metal mask assembly
206‧‧‧Fine metal mask
214‧‧‧Microactuator
216‧‧‧mask opening
218‧‧‧Frame opening
220‧‧‧ pattern definition features
306‧‧‧Photomask unit
308‧‧‧External support
310‧‧‧ openings
332‧‧‧ hole
334‧‧‧Support
336‧‧‧Support
342‧‧‧ internal part
344‧‧‧outer perimeter
352‧‧‧ Subject
354‧‧‧Shell
401‧‧‧矽
402‧‧‧矽/矽 wafer
404‧‧‧ seed layer
406‧‧‧ angle
408‧‧‧ bottom width
Section 409‧‧‧
411‧‧‧ bottom surface
415‧‧‧ side wall
422‧‧‧through hole
425‧‧‧ side wall
432‧‧‧metal layer
464‧‧‧ openings
472‧‧‧ top surface
482‧‧ depth
608‧‧‧ bottom width
611‧‧‧ bottom surface

Thus, the manner of the above-described features of the present invention can be understood in detail, and a more specific description of the invention briefly summarized above can be obtained by reference to the embodiments (some embodiments are shown in the accompanying drawings). . However, it is to be noted that the appended drawings are merely illustrative of the exemplary embodiments of the invention and are not to be construed as limiting

Figure 1 depicts a schematic of a portion of a processing chamber having a reticle assembly.

Figure 2 is a prior art depicting a top view of a fine metal reticle disposed in a reticle assembly suitable for use in the processing chamber of Figure 1.

Figure 3 shows a top view of a low tension fine metal reticle in accordance with one embodiment, similarly disposed in a reticle assembly suitable for use in the processing chamber of Figure 1.

Figures 4A and 4B depict cross-sectional views for forming a low tension fine metal reticle.

For ease of understanding, the same element symbols are used to denote the same elements as commonly used in the drawings, where possible. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

Domestic deposit information (please note according to the order of the depository, date, number)

Foreign deposit information (please note in the order of country, organization, date, number)

(Please change the page separately) No

106‧‧‧Fine metal mask

112‧‧‧Frame

130‧‧‧Fine metal mask assembly

306‧‧‧Photomask unit

308‧‧‧External support

310‧‧‧ openings

332‧‧‧ hole

334‧‧‧Support

336‧‧‧Support

342‧‧‧ internal part

344‧‧‧outer perimeter

352‧‧‧ Subject

354‧‧‧Shell

Claims (19)

A low tension fine metal reticle comprising: a frame having a plurality of holes; and a plurality of fine metal reticle units, each of the fine metal reticle units being disposed in each of the holes, each fine metal light The cover unit has a plurality of openings, wherein each of the fine metal reticle units is coupled to the frame in a manner that maintains a force of less than about 0.4 kgf/cm across the reticle unit. A low tension fine metal reticle as claimed in claim 1 wherein the openings have a density of between about 250 per inch and 1200 per inch. A low tension fine metal reticle as claimed in claim 1 wherein the openings in the reticle unit have an alignment accuracy of about 1 micron from the substrate. The low tension fine metal reticle of claim 1 wherein the openings have a plurality of sidewalls angled between about 40 degrees and about 60 degrees. A low tension fine metal reticle as claimed in claim 1 wherein the tension across the reticle unit is about 0.1 kgf/cm. A reticle assembly comprising: a body having a frame and a plurality of supports, a plurality of holes formed in at least one side of the frame; and a plurality of reticle units sized to fit the holes, wherein The reticle unit comprises: a fine metal reticle having a plurality of openings, wherein each reticle unit is bonded to the respective apertures in a manner that maintains a force across the metal reticle having less than about 0.4 kgf/cm One. The reticle assembly of claim 6 wherein the openings have a density of from 600 to 900 per inch. The reticle assembly of claim 6 wherein the openings have a density of about 800 per inch. The reticle assembly of claim 6, wherein the fine metal reticle is bonded to the frame by epoxy. The reticle assembly of claim 6 wherein the plurality of openings have a plurality of sidewalls of about 54.7 degrees. The reticle assembly of claim 6, wherein the fine metal reticle is formed of a bismuth-nickel hybrid material. A method for forming a fine metal photomask assembly, comprising the steps of: preparing a substrate formed of a tantalum-metal hybrid material; a plurality of voids in a metal layer via a tantalum layer of the tantalum-metal hybrid material Forming a through hole, wherein the through hole has a plurality of sidewalls formed at a first angle; forming a second angle on a sidewall of the metal layer; and cutting the substrate into a suitable one to form a reticle unit Shaped; and coupling the reticle unit to the fine metal reticle assembly, wherein a force across the reticle unit is less than about 0.4 kgf/cm. The method of claim 12, wherein the metal layer is one of nickel (Ni), nickel cobalt alloy (NiCo), stainless steel or nickel-iron alloy. The method of claim 12, wherein the preparing the substrate further comprises the step of: anisotropically etching the base metal hybrid material to a thickness of about 30 microns, wherein the first of the sidewalls in the layer of germanium The angle is about 54.7 degrees. The method of claim 12, wherein the coupling is performed with an epoxy resin at a temperature of about 25 degrees Celsius. A low tension fine metal reticle as claimed in claim 1 wherein the openings have a density of from 600 to 900 per inch. A low tension fine metal reticle as claimed in claim 1 wherein the openings have a density of about 800 per inch. A low tension fine metal mask as claimed in claim 1 wherein the fine metal mask is bonded to the frame by epoxy. The low tension fine metal reticle of claim 1, wherein the fine metal reticle is formed of a bismuth-nickel hybrid material.