Deposition mask and method of fabricating the same

A deposition mask comprises a mask body comprising a plurality of through holes; and a deposition layer formed on external surfaces of the mask body. A method of manufacturing a deposition mask comprises: installing a deposition mask body in a chamber; forming a magnetic field between a plurality of magnet units within the chamber, wherein the deposition mask body is disposed between the magnet units; and applying voltages to first and second sputtering targets comprising a material to generate electric discharge such that particles of the material are sputtered from the first and second sputtering targets and deposited on the deposition mask body, thereby making a deposition mask with a layer of the material. The voltages having different magnitudes are applied to the first and second sputtering targets.

RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2014-0164423, filed on Nov. 24, 2014, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more embodiments relate to a deposition mask and a method of fabricating the deposition mask.

2. Description of the Related Art

Generally, an organic light-emitting display apparatus may be used as a display apparatus in mobile devices such as smart phones, tablets, personal computers (PCs), laptop computers, digital cameras, camcorders, and mobile information terminals, or electronic devices such as an ultra-thin televisions, and advertisement panel.

The organic light-emitting display apparatus includes an organic light emissive layer interposed between an anode and a cathode. The organic light-emitting display apparatus includes thin film encapsulation (TFE) for protecting the organic light emissive layer.

The TFE may be formed through a thin film deposition process. The thin film deposition process includes chemical vapor deposition (CVD) or physical vapor deposition (PVD).

A deposition mask may be used to perform the CVD. The deposition mask may be recycled through a cleansing process after depositing a plurality of thin films on a substrate.

SUMMARY

One or more embodiments include a deposition mask and a method of fabricating the deposition mask.

One aspect provides a method of manufacturing a deposition mask, the method comprising: installing a deposition mask body in a chamber; forming a magnetic field between a plurality of magnet units within the chamber, wherein the deposition mask body is disposed between the magnet units; and applying voltages to first and second sputtering targets comprising a material to generate electric discharge such that particles of the material are sputtered from the first and second sputtering targets and deposited on the deposition mask body, thereby making a deposition mask with a layer of the material, wherein voltages having different magnitudes are applied to the first and second sputtering targets.

In the foregoing method, pulsed direct current (DC) voltages may be applied to the first and second sputtering targets. The pulsed DC voltages may be simultaneously applied to the first and second sputtering targets. The pulsed DC voltages may be within a range from about 300 V to about 500 V. The temperature of the chamber may be lower than about 150° C. The layer of the deposition mask may be formed of a metallic material selected from the group consisting of aluminum, aluminum oxide, tungsten and tungsten oxide. The layer of the deposition mask may comprise a first sub-layer formed on and contacting the deposition mask body and a second sub-layer formed on and contacting the first sub-layer, wherein the first sub-layer may be formed of a metal, and the second sub-layer is formed of oxide of the metal, wherein the metal is aluminum or tungsten.

Still in the foregoing method, the deposition layer may be deposited in a range from about 0.1 μm to about 100 μm. The layer may be formed to cover on external surfaces of the deposition mask body comprising a plurality of through holes, the external surfaces comprises a first surface, a second surface facing away from the first surface and an inner sidewall surface of one of the plurality of through holes connecting the first and second surfaces, wherein the layer continuously extends on the first and second surfaces and the inner sidewall surface.

Another aspect provides a deposition mask device comprising: a mask body comprising a plurality of through holes; and a deposition layer formed on external surfaces of the mask body.

In the foregoing device, the external surfaces comprises: a first surface; a second surface facing away from the first surface; and an inner sidewall surface of one of the plurality of through holes connecting the first and second surfaces, wherein the deposition layer continuously extends on the first and second surfaces and the inner sidewall surface. The deposition layer may be formed of a material different from that of the mask body. The external surfaces may comprise an inner circumferential wall surface of each of the plurality of through holes, wherein the deposition layer is formed on the inner circumferential wall surface.

Still in the foregoing device, the deposition layer may be formed as a single layer of a metallic material. The metallic material may be one selected from the group consisting of aluminum, aluminum oxide, tungsten and tungsten oxide. The thickness of the deposition layer may be in a range from about 0.1 μm to about 100 μm. The deposition layer may comprise a first sub-layer formed on and contacting the main body and a second sub-layer formed on and contacting the first sub-layer. The first sub-layer may be formed of a metal, and the second sub-layer is formed of oxide of the metal, wherein the first sub-layer has a thickness greater than that of the second sub-layer.

A further aspect provides a method of manufacturing a display panel, the method comprising: placing the foregoing deposition mask and a substrate such that the deposition mask is placed between the substrate and a deposition material source; and transferring the deposition material from the deposition source to the substrate through the plurality of through holes of the deposition mask thereby depositing the deposition material over the substrate to make a display panel. In the foregoing method, the method may further comprise, subsequently to the depositing, cleaning the deposition mask with nitrogen trifluoride (NF3) gas.

According to one or more embodiments, a method of manufacturing a deposition mask includes installing the deposition mask in a chamber; inducing discharge by applying power to a sputtering target including a deposition material; and forming a magnetic field between a plurality of magnet units and depositing particles sputtered in the sputtering target on the deposition mask, wherein voltages having different magnitudes are applied to the sputtering target.

A plurality of the sputtering targets may be arranged, and wherein pulsed direct current (DC) voltages having different magnitudes are applied to each of the plurality of sputtering targets.

The pulsed DC voltages may be simultaneously applied to each of the plurality of sputtering targets.

The pulsed DC voltages may be in a range from about 300 V to about 500 V.

A temperature of the chamber may be lower than 150° C.

A deposition layer including at least one layer may be formed on the deposition mask.

The deposition layer may include one selected from the group consisting of an aluminum layer deposited on the deposition mask, an aluminum layer and an aluminum oxide layer having a stack structure, a tungsten layer, and a tungsten layer and a tungsten oxide layer having a stack structure.

The deposition layer may be deposited in a range from about 0.1 μm to about 100 μm.

The deposition layer may be formed to cover a first surface of the deposition mask and a second surface of the deposition mask opposite to the first surface.

According to one or more embodiments, a deposition mask includes a mask body in which a plurality of through holes are formed; and a deposition layer formed on an external surface of the mask body and including at least one layer.

The deposition layer may be formed on a first surface of the mask body and a second surface opposite to the first surface.

A material of the deposition layer may be different from a material of the mask body.

The deposition layer may be further formed on an inner circumferential wall of the mask body in which the plurality of through holes are formed.

The deposition layer may include a metal layer of at least one layer.

The deposition layer may include one selected from the group consisting of an aluminum layer deposited on the deposition mask, an aluminum layer and an aluminum oxide layer having a stack structure, a tungsten layer, and a tungsten layer and a tungsten oxide layer having a stack structure.

A thickness of the deposition layer may be in a range from about 0.1 μm to about 100 μm.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. In drawings, like reference numerals refer to like elements throughout and overlapping descriptions shall not be repeated.

It will be understood that although the terms “first”, “second”, etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components. It will be understood that when a layer, area, or component is referred to as being “formed on,” another layer, area, or component, it can be directly or indirectly formed on the other layer, area, or component. That is, for example, intervening layers, areas, or components may be present.

FIG. 1is a perspective view of a flexible display apparatus100that is unfolded according to an embodiment.FIG. 2is a perspective view of the flexible display apparatus100ofFIG. 1that is bent.

Referring toFIGS. 1 and 2, the flexible display apparatus100includes a flexible display panel110displaying an image and a flexible case120accommodating the flexible display panel110. The flexible display panel110includes not only a device for implementing a screen but also various films such as a touch screen, a polarizing plate, a window cover, etc. The flexible display apparatus100may see the image at various angles in an unfolded state or in a bent state.

In the present embodiment, although the flexible display apparatus100is described, for example, as a flexible organic light emitting display apparatus, the flexible display apparatus100may be one of a liquid crystal display, a field emission display, an electronic paper display, etc.

FIG. 3is a cross-sectional view of a pixel of a flexible display apparatus300according to an embodiment.

In this regard, pixels may include at least one thin film transistor (TFT) and an organic light emitting device or diode (OLED). The TFT does not necessarily have a structure ofFIG. 3and its number and structure may be modified in various ways.

Referring toFIG. 3, the flexible display apparatus300includes a flexible substrate311and a thin film encapsulation (TFE)340facing the flexible substrate311.

The flexible substrate311may be formed of a flexible insulating material.

The flexible substrate311may be a polymer substrate formed of polyimide (PI), polycarbonate (PC), polyethersulphone (PES), polyethylene terephthalate (PET), polyethylenenaphthalate (PEN), polyacrylate (PAR), fiber glass reinforced plastic (FRP), etc. According to an embodiment, the flexible substrate311may be a glass substrate having a thickness allowing the flexible substrate311to be bendable.

The flexible substrate311may be transparent, semitransparent, or opaque.

A barrier film312may be formed on the flexible substrate311. The barrier film312may entirely cover a top surface of the flexible substrate311.

The barrier film312may be formed of one selected from inorganic materials such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), etc. or organic materials such as acryl, polyimide, polyester, etc.

The barrier film312may be formed as a single film or a multilayer film.

The barrier film312prevents oxygen and moisture and flattens the top surface of the flexible substrate311.

The TFT may be formed on the barrier film312. In the present embodiment, although the TFT is described as a top gate transistor, a TFT having a different structure such as a bottom gate transistor may be provided.

A semiconductor active layer313may be formed on the barrier film312.

The semiconductor active layer313includes a source region314and a drain region315that are formed by being doped with N type impurity ions or P type impurity ions. A channel region316that is not doped with impurities is disposed between the source region314and the drain region315.

The semiconductor active layer313may be formed of amorphous silicon, an inorganic semiconductor such as poly silicon, or an organic semiconductor.

According to an embodiment, the semiconductor active layer313may be formed of an oxide semiconductor. For example, the oxide semiconductor includes an oxide of a metal selected from Groups 4, 12, 13, and 14 such as zinc (Zn), indium (In), gallium (Ga), tin (stannum; Sn), cadmium (Cd), germanium (Ge), and hafnium (Hf), and a combination thereof.

A gate insulating film317may be deposited on the semiconductor active layer313. The gate insulating film317may be formed as an inorganic film such as silicon oxide, silicon nitride, or metal oxide. The gate insulating film317may be a single layer film or a multilayer film.

A gate electrode318may be formed on the gate insulating film317. The gate electrode318includes a single film or a multilayer film such as Au, Ag, Cu, Ni, Pt, Pd, al, Mo, Cr, etc. According to an embodiment, the gate electrode318includes an alloy such as Al:Nd, Mo:W, etc.

An interlayer insulating film319may be formed on the gate electrode318. The interlayer insulating film319may be formed of an inorganic material such as silicon oxide, silicon nitride, etc. According to an embodiment, the interlayer insulating film319includes an organic material.

A source electrode320and a drain electrode321may be formed on the interlayer insulating film319. In more detail, a contact hole may be formed by selectively removing the gate insulating film317and the interlayer insulating film319so that the source electrode320may be electrically connected to the source region314and the drain electrode321may be electrically connected to the drain region315through the contact hole.

A passivation film322may be formed on the source electrode320and the drain electrode321. The passivation film322may be formed of an inorganic material such as silicon oxide, silicon nitride, or an organic material.

A planarizing film323may be formed on the passivation film322. The planarization film323includes an organic material such as acryl, polyimide, benzocyclobutene (BCB), etc.

One of the passivation film322and the planarization film323may be omitted.

The TFT may be electrically connected to the OLED.

The OLED may be formed on the planarization film323. The OLED includes a first electrode325, an intermediate layer326, and a second electrode327.

The first electrode325may function as an anode and may be formed of various conductive materials. The first electrode325includes a transparent electrode or a reflective electrode. For example, when the first electrode325is used as a transparent electrode, the first electrode325includes a transparent conductive film formed of ITO, IXO, ZnO, In2O3, etc. When the first electrode325is used as the reflective electrode, the first electrode325may be formed as a reflection film formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and a combination thereof. In this regard, a transparent conductive film formed of ITO, IZO, ZnO, In2O3, etc. may be formed on an upper portion of the reflection film.

A pixel defining film324partially covers the planarization film323and the first electrode325. The pixel defining film324defines an emission region of each pixel by surrounding an edge of the first electrode325. The first electrode325may be patterned for each pixel.

The pixel defining film324may be formed as an organic film or an inorganic film. For example, the pixel defining film324may be formed of an organic material such as polyimide, polyamide, BCB, acryl resin, phenol resin, etc. or an inorganic material such as silicon nitride, etc.

The pixel defining film324may be a single film or a multiple film.

The intermediate layer326may be formed on a region of the first electrode325exposed by etching a part of the pixel defining film324. In the present embodiment, the intermediate layer326may be formed through a deposition process.

The intermediate layer326may include an emissive layer. For example, the intermediate layer326may include the emissive layer and may further include at least one of a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL) but the present embodiment is not limited thereto. The intermediate layer325may include the emissive layer and may further include various other functional layers.

Holes and electrons that are injected into the first electrode325and the second electrode327may be combined with each other in the emissive layer to generate light of a desired color.

The second electrode327may be formed on the intermediate layer326.

The second electrode327may function as a cathode. The second electrode327includes a transparent electrode or a reflective type electrode. For example, when the second electrode327is used as the transparent electrode, the second electrode327may be formed by depositing a metal having a small work function such as Li, Ca, LiF/Ca, LiF/Al, Al, or Mg, and a combination of these on the intermediate layer326. In this regard, a transparent conductive film such as ITO, IZO, ZnO, In2O3, etc. may be formed on the metal and the combination. When the second electrode327is used as the reflective type electrode, the second electrode327may be formed of Li, Ca, LiF/Ca, LiF/Al, Al, Mg, and a combination of these.

In the present embodiment, the first electrode325may function as the anode, and the second electrode327may function as the cathode but the present invention is not limited thereto. For example, the first electrode325may function as the cathode, and the second electrode327may function as the anode.

According to an embodiment, a plurality of pixels may be formed on the flexible substrate311, and a red, green, blue, or a white color may be implemented for each pixel but the present embodiment is not limited thereto.

According to an embodiment, the intermediate layer326may be commonly formed on the first electrode325irrespective of a location of a pixel. In this regard, the emissive layer may be formed by vertically stacking layers including an emissive material that emits red, green, and blue light or by mixing emissive materials that emit the red, green, and blue light.

According to an embodiment, as long as white light may be emitted, a combination of other colors may be possible. A color conversion layer that converts the emitted white light into a predetermined color or a color filter may be further provided.

The TFE340may be formed to protect the OLED from external moisture or oxygen. According to an embodiment, the TFE340may be formed by alternately stacking an inorganic film341and an organic film342on the OLED.

For example, the TFE340may have a structure in which at least one inorganic film341and at least one organic film342are stacked. The inorganic film341includes a first inorganic film343, a second inorganic film344, and a third inorganic film345. The organic film342includes a first organic film346and a second organic film347.

The inorganic film341may be formed of one selected from the group consisting of SiO2, SiNx, aluminum oxide (Al2O3), titanium oxide (TiO2), zirconium oxide (ZrOx), or zinc oxide (ZnO). The organic film342may be formed of one selected from the group consisting of epoxy, polyimide, polyethylene terephthalate, polycarbonate, polyethylene, and polyacrylate.

The TFE340may be formed through plasma enhanced chemical vapor deposition (PECVD).

In more detail, a substrate is installed and deposited in a deposition chamber. PECVD may mount a deposition mask on the substrate. The deposition mask may be subject to a cleansing process for recycling after performing a deposition process several times. During the cleansing process, the deposition mask uses nitrogen trifluoride (NF3) gas. The deposition mask reacts with fluorine over time, which causes corrosion of surfaces and edges of the deposition mask.

In the present embodiment, a deposition layer may be formed on the deposition mask to improve an anti-corrosion property. The layer may be formed as a single layer or may include multiple sub-layers.

FIG. 4is a cross-sectional view of a deposition mask400according to an embodiment.

Referring toFIG. 4, the deposition mask400includes a mask body401and a deposition layer402.

The mask body401includes a first surface403facing a substrate that is to be deposited and a second surface404opposite to the first surface403. A plurality of through holes405may be formed in the mask body401. Shapes of the through holes405may be the same as those of thin film portions formed on a display apparatus.

For convenience of manufacturing, a mother substrate may be used to form devices, elements, or features of a plurality of display apparatuses thereon, thereby simultaneously manufacturing the plurality of display apparatuses. According to an embodiment, shapes of the through holes405may be the same as those of the inorganic film portions341of a plurality of TFEs (340ofFIG. 3) formed on the mother substrate.

The mask body401may be formed as a metal plate having high durability and strength. The mask body401may be a magnetic body. In the present embodiment, the mask body401may be a variety of metals such as stainless steel (for example, SUS defined in the Japanese Industrial Standard), invar, or a nickel alloy.

The deposition layer402may be formed on an external surface of the mask body401.

In more detail, the deposition layer402includes a first portion406deposited on a first surface403of the mask body401and a second portion407formed on the second surface404of the mask body401. A third portion408may be further formed on an inner circumferential surface409of the mask body401in which the through holes405are formed. The first portion406, the second portion407, and the third portion408may be integrally formed.

The deposition layer402may be formed on external surfaces of the mask body401. In the present embodiment, the deposition layer402may be formed through high speed and high density magnetron sputtering. High speed and high density magnetron sputtering may improve an adhesive property between the mask body401and the deposition layer402and easily control stress generated from the deposition layer402.

A material of the deposition layer402may be different from that of the mask body401. The deposition layer402includes a metal layer. According to an embodiment, the deposition layer402includes an aluminum layer or a tungsten layer.

A thickness of the deposition layer402may be in the range from about 0.1 μm to about 100 μm. The deposition layer402having a thickness in the foregoing range may increase a lifespan of the deposition mask400while avoiding negative effects to the precision of the deposition mask400.

The deposition mask400may have a structure of two or more layers.

Referring toFIG. 5, a deposition mask500includes a mask body501and a deposition layer502.

A plurality of through holes505may be formed in the mask body501.

The deposition layer502includes a first deposition layer506and a second deposition layer507formed on the first deposition layer506. The first deposition layer506may be directly coated on a first surface503of the mask body501, a second surface505opposite to the first surface503, and an inner circumferential wall509of each of the through holes505. The second deposition layer507may be deposited on external surfaces of the first deposition layer506. In embodiments, the second deposition layer507may be formed on an inner circumferential wall surface of each hole. In other embodiments, the second deposition layer507is not formed on an inner circumferential wall surface of each hole.

According to an embodiment, the first deposition layer506includes an aluminum layer or a tungsten layer. The second deposition layer507includes an aluminum oxide layer such as aluminum oxide (Al2O3) or a tungsten oxide layer such as tungsten oxide (WOx).

A thickness of the deposition layer502may be in the range from about 0.1 μm to about 100 μm.

The deposition layer502may be deposited on a mask by using a sputtering apparatus.

FIG. 6is a diagram of a sputtering apparatus600according to an embodiment.

Referring toFIG. 6, a chamber601providing a deposition space is provided in the sputtering apparatus600. The chamber601may be a vacuum chamber for a stable deposition of a material that is to be deposited.

A plurality of sputtering targets602and603may be installed in the chamber601. The sputtering targets602and603include a first sputtering target602and a second sputtering target603disposed to face the first sputtering target602. In the present embodiment, a plurality of the first sputtering targets602and a plurality of the second sputtering targets603may be installed.

The first sputtering target602and the second sputtering target603may have cylindrical shapes. The first sputtering target602and the second sputtering target603may have rectangular shapes.

The first sputtering target602and the second sputtering target603include a deposition layer material that is to be deposited on a mask606.

A first magnet unit604may be installed in the first sputtering target602. A second magnet unit605may be installed in the second sputtering target603. According to an embodiment, the first magnet unit604and the second magnet unit605may be respectively installed behind the first sputtering target602and the second sputtering target603. In the illustrated embodiment, at least a portion of the sputtering target602is placed between the magnet unit604and the mask606, and at least a portion of the sputtering target603is placed between the magnet unit605and the mask606.

The first magnet unit604and the second magnet unit605may be permanent magnets or electromagnets.

In embodiments, the first sputtering target602and the second sputtering target603may rotate in opposite directions by a target rotation apparatus coupled to a target holder. For example, when the first sputtering target602rotates in a clockwise direction, the second sputtering target603may rotate in a counterclockwise direction. Rotation directions of the first sputtering target602and the second sputtering target603are not necessarily limited thereto.

According to an embodiment, various apparatuses may be combined in the first sputtering target602and the second sputtering target603like an angle adjusting apparatus for rotating the first magnet unit604and the second magnet unit605at a predetermined angle or a yolk for concentrating magnetic fields of the first magnet unit604and the second magnet unit605.

A power source unit607providing a power supply may be connected to the first sputtering target602and the second sputtering target603. A pulsed direct current (DC) may be applied to the power source unit607. For example, a positive electrode may be connected to the chamber601, and a negative electrode may be connected to the first sputtering target602and the second sputtering target603.

A single power source unit607may be provided to distribute and supply a discharge electrode to the first sputtering target602and the second sputtering target603or a plurality of power source units607may be provided to supply a discharge electrode to each of the first sputtering target602and the second sputtering target603.

A mask606on which particles sputtered from the first sputtering target602and the second sputtering target603are deposited may be disposed in the chamber601. The mask606may be disposed between the first sputtering target602and the second sputtering target603. The mask606may be disposed in a direction perpendicular to a direction in which the first sputtering target602and the second sputtering target603are aligned. In the illustrated embodiment, the targets602and603are aligned in a horizontal direction and the mask604is upright in a vertical direction.

In the present embodiment, the mask606may be disposed between the first sputtering target602and the second sputtering target603but is not limited thereto. The mask606may be disposed on upper or lower portions of the first sputtering target602and the second sputtering target603.

The mask606may be mounted on a mask holder608. The mask606may be detached from the mask holder608. The mask holder608on which the mask606is mounted may move right and left by a driving force of a driving motor609.

Meanwhile, a vacuum pump610for forming the chamber601in a vacuum manner and a gas supply unit611for supplying gas into the chamber601may be connected to one side of the chamber601. Sputtering gas such as argon (Ar) or reactivity gas such as oxygen (O2) may be supplied through the gas supply unit611.

A film forming process using the sputtering apparatus600having the structure described above will now be described.

The mask606is installed in the chamber601. The mask606is mounted on the mask holder608. The mask holder608may move right and left by the driving force of the driving motor609. The chamber601may be in a vacuum state by using the vacuum pump610.

Discharge is induced by applying power to the first sputtering target602and the second sputtering target603that include a deposition material. The deposition material may be aluminum.

In more detail, the first sputtering target602and the second sputtering target603rotate. The first sputtering target602rotates in the clockwise direction. The second sputtering target603rotates in the counterclockwise direction. Gas is supplied into the chamber601through the gas supply unit611while rotating the first sputtering target602and the second sputtering target603. The gas may be argon (Ar) that is inert gas.

Thereafter, a glow discharge of the sputtering gas is induced by applying a negative voltage to the first sputtering target602and the second sputtering target603through the power source unit607.

Voltages having different magnitudes may be applied to the first sputtering target602and the second sputtering target603. A plurality of first sputtering targets602and a plurality of second sputtering targets603are installed. Pulsed DC voltages having different magnitudes are applied to the first sputtering target602and the second sputtering target603. The pulsed DC voltages may be simultaneously applied to the first sputtering target602and the second sputtering target603. The applied pulsed DC voltage may be in the range from about 300 V to about 500 V. For example, 380 V may be applied to a pair of the first sputtering target602and the second sputtering target603, and 420 V may be applied to another pair of the first sputtering target602and the second sputtering target603. To avoid negative effects of too high or too low voltage, the pulsed DC voltage may be within an appropriate range, for example, from 300 V to 500 V.

Plasma generated by the glow discharge is concentrated between the first sputtering target602and the second sputtering target603by the magnetic field formed by the first magnet unit604and the second magnet unit605.

When the positively-ionized argon gas collides with the first sputtering target602and the second sputtering target603that are negatively charged, target atoms or atom clusters are sputtered from the first sputtering target602and the second sputtering target603. The particles sputtered from the first sputtering target602and the second sputtering target603are discharged to a vapor phase. The particles may be confined in a space between the first sputtering target602and the second sputtering target603and may be deposited on the mask606.

Meanwhile, a temperature of the chamber601may be lower than about 150° C. to avoid deflection of the mask606.

The deposition layer612may be formed on the external surface of the mask606through the sputtering process described above.

As described above, if the pulsed DC having different intensities is applied to a pair of the first sputtering target602and the second sputtering target603and another pair of the first sputtering target602and the second sputtering target603that are adjacent to each other, a plasma condition may differ due to a voltage difference. Thus, a complex combination of compression remaining stress and tensile remaining stress may minimize a compression remaining stress value, and result in deposition of the deposition layer612on the mask606. Therefore, no peeling or cracking occurs in the deposition layer612with respect to the mask606.

FIGS. 7A through 7Dare pictures showing a surface change of a deposition mask according to an embodiment.

The mask ofFIG. 7Ais a mask on which no deposition layer is formed according to a comparative example. The mask is formed of stainless steel.

The mask ofFIG. 7Bis a mask on which a deposition layer is formed according to an embodiment. The mask is formed of stainless steel. The deposition layer is formed on the mask through high speed and high density magnetron sputtering. The deposition layer includes an aluminum layer and is deposited at a thickness of about 5 μm.

The masks ofFIGS. 7A and 7Bare in a state before being exposed to nitrogen trifluoride (NF3) gas during a cleansing process. No surface corrosion occurs in both the masks ofFIGS. 7A and 7B.

The mask ofFIG. 7Cis in a state before the mask is exposed to the nitrogen trifluoride (NF3) gas for 25 hours during the cleansing process of the mask ofFIG. 7A. The mask ofFIG. 7Dis in a state before the mask is exposed to the nitrogen trifluoride (NF3) gas for 25 hours during the cleansing process of the mask ofFIG. 7B.

If the mask ofFIG. 7Cis exposed to the nitrogen trifluoride (NF3) gas, a surface corrosion occurs over time, whereas, even though the mask ofFIG. 7Dis exposed to the nitrogen trifluoride (NF3) gas for a long period of time, no surface corrosion occurs.

As described above, a deposition layer is deposited on the mask through sputtering. Thus, a lifespan of the mask increases by at least 5 times.

FIGS. 8A and 8Bare pictures showing a surface change of a deposition mask according to another embodiment.

The mask ofFIG. 8Ais a mask on which a deposition layer is formed according to an embodiment and is in a state before the mask is exposed to nitrogen trifluoride (NF3) gas during a cleansing process. The mask ofFIG. 8Bis in a state before the mask is exposed to the nitrogen trifluoride (NF3) gas for 25 hours during the cleansing process of the mask ofFIG. 8A.

The masks ofFIGS. 8A and 8Bare formed of stainless steel. The deposition layer is formed on the masks through high speed and high density magnetron sputtering. The deposition layer has a two layer structure including an aluminum layer and an aluminum oxide layer stacked with the aluminum layer. In one embodiment, the aluminum layer has a thickness of about 1 μm, the aluminum oxide layer has a thickness of about 0.5 μm.

As shown inFIGS. 8A and 8B, if the deposition layer is formed on an external surface of the masks through sputtering, no damage occurs on the masks even though time has elapsed. Thus, a lifespan of a mask may increase.

As described above, according to one or more embodiments, a deposition mask and a method of manufacturing the deposition mask according to embodiments of the present invention may increase a lifespan of the deposition mask.