Improved film encapsulation

Abstract

A method for encapsulating an organic light emitting diode (OLED) is provided. The method includes generating a first plasma in a process chamber, the first plasma having an electron density of at least 10<supgt;11< / supgt> cm<supgt;‑3< / supgt> when the OLED device is positioned in the process chamber. The OLED device includes a substrate and an OLED formed on the substrate. The method further includes: pretreating one or more surfaces of the OLED and the substrate with the first plasma; depositing a first barrier layer including silicon and nitrogen over the OLED by generating a second plasma including silicon and nitrogen in the process chamber, the second plasma having an electron density of at least 10<supgt;11< / supgt> cm<supgt;‑3< / supgt>; depositing a buffer layer over the first barrier layer; and depositing a second barrier layer including silicon and nitrogen over the buffer layer by generating a third plasma including silicon and nitrogen in the process chamber.

Description

[0001] This application is a divisional application of the patent application for "Improved Thin-Film Encapsulation" with the application date of July 3, 2018, application number 201880041661.5. Technical Field

[0002] Embodiments described herein generally relate to a thin-film encapsulation (TFE) structure formed over a device on a substrate and a method of forming the same. Background Art

[0003] Compared to traditional liquid crystal displays (LCDs) or plasma displays, organic light emitting diode displays (OLED displays) have recently received much attention in display applications due to faster response times, larger viewing angles, higher contrast ratios, lighter weights, lower power consumption, and suitability for being formed on flexible substrates. In addition to the organic materials used in OLED devices, many polymeric materials have been used to develop small molecule, flexible organic light emitting diode (FOLED) and polymer light emitting diode (PLED) displays. Many of these organic and polymeric materials are suitable for the fabrication of complex multi-layer devices on some substrates, making the complex multi-layer devices ideal for various transparent multi-color display applications such as flat panel displays (FPDs), electrically pumped organic lasers, and organic optical amplifiers.

[0004] OLED devices may have a limited lifespan, characterized by a decrease in electroluminescence efficiency and an increase in their driving voltage. A known cause of the deterioration of these OLED device performances is the formation of non-emissive dark spots or regions within the OLED display due to the ingress of moisture and / or oxygen into the organic layers of the OLED device. To this end, OLED devices typically use thin films comprising one or more moisture-transport limiting, transparent materials to encapsulate. The moisture and oxygen blocking properties of these thin-film encapsulants are generally directly related to the thickness of the thin-film encapsulants. Due to the moisture and / or oxygen penetration during the service life of the OLED device, current thin-film encapsulants (including barrier layers and buffer layers) generally have a thickness of about to about to prevent the OLED device from degrading. Although to about are relatively thin, when the OLED device is subjected to bending, folding, rolling or similar stresses, these thicknesses reduce the flexibility of the OLED device and may cause cracking.

[0005] Accordingly, there is a need for an improved thin-film encapsulant that has the moisture and oxygen blocking properties of current thin-film encapsulants while avoiding the above problems. SUMMARY OF THE INVENTION

[0006] Embodiments of the present disclosure generally relate to improved methods of encapsulating organic light-emitting diodes and related devices. In one embodiment, a method of encapsulating an organic light-emitting diode (OLED) is provided. The method includes: generating a first plasma in a process chamber, the first plasma having an electron density of at least 10 11 cm -3 wherein the OLED device is positioned within the process chamber, the OLED device comprising a substrate and an organic light-emitting diode formed on the substrate; pretreating one or more surfaces of the organic light-emitting diode and the substrate using the first plasma, and depositing a first barrier layer comprising silicon and nitrogen over the organic light-emitting diode by generating a second plasma comprising silicon and nitrogen in the process chamber, the second plasma having an electron density of at least 1011 cm -3 The electron density of -3 , the second plasma is generated after the first plasma; a buffer layer is deposited over the first barrier layer; and a second barrier layer including silicon and nitrogen is deposited over the buffer layer by generating a third plasma including silicon and nitrogen in the process chamber, the third plasma being generated after the deposition of the buffer layer.

[0007] In another embodiment, a method of encapsulating an organic light emitting diode (OLED) device is provided. The method includes: generating a first plasma including silicon and nitrogen; using the first plasma to deposit a first portion of a first barrier layer including silicon and nitrogen over the organic light emitting diode; generating a second plasma including silicon and nitrogen; and using the second plasma to deposit a second portion of the first barrier layer including silicon and nitrogen over the first portion of the first barrier layer, wherein the density of the first plasma and the second plasma differ by at least 100 times.

[0008] In another embodiment, a method of encapsulating an organic light emitting diode (OLED) device is provided. The method includes: generating a first plasma including silicon and nitrogen in a first process chamber; using the first plasma to deposit a first portion of a first barrier layer including silicon and nitrogen over the organic light emitting diode; generating a second plasma including silicon and nitrogen in a second process chamber; using the second plasma to deposit a second portion of the first barrier layer including silicon and nitrogen over the first portion of the first barrier layer, wherein the density of the first plasma and the second plasma differ by at least 100 times; depositing a buffer layer over the first barrier layer in a third process chamber; and depositing a second barrier layer over the buffer layer in a fourth process chamber, wherein the first process chamber, the second process chamber, the third process chamber and the fourth process chamber are arranged surrounding a single transfer chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Thus, it can be understood in detail the manner of the features of the present disclosure above. A more detailed description of the present disclosure (as outlined above) can refer to the embodiments, and certain embodiments are illustrated in the drawings. It should be noted, however, that these drawings only illustrate the representative embodiments of the present disclosure and thus are not intended to limit the scope of the present disclosure, and the present disclosure may permit other equally effective embodiments.

[0010] Figure 1 is a side cross-sectional view of an OLED device including an organic light emitting diode and an encapsulant layer formed over the organic light emitting diode according to the embodiments described herein.

[0011] Figure 2ASchematic cross-sectional view of an exemplary process chamber according to one embodiment.

[0012] Figure 2B Illustrates according to one embodiment Figure 2A Plan view of partial features of the illustrated process chamber.

[0013] Figure 2C Is according to one embodiment Figure 2B Cross-sectional view of one of a plurality of antennas illustrated.

[0014] Figure 2D Is according to one embodiment using Figure 1 Process flow diagram of a method of encapsulating an organic light-emitting diode (OLED) using an encapsulant.

[0015] Figure 3A Is according to another embodiment including Figure 1 Side cross-sectional view of an OLED device including an organic light-emitting diode and an encapsulant formed over the organic light-emitting diode.

[0016] Figure 3B Is according to one embodiment of a cluster tool usable to form an encapsulant over Figure 3A An organic light-emitting diode of an OLED device.

[0017] Figure 3C Is according to one embodiment using Figure 3B Of a cluster tool and using Figure 3A Process flow diagram of a method of encapsulating an organic light-emitting diode using an encapsulant.

[0018] Figures 4A - 4I Shows comparative measurements of the barrier properties and other properties of a silicon nitride layer deposited using a high-density plasma chemical vapor deposition (HDP-CVD) process according to embodiments described herein and a silicon nitride thin film deposited using a conventional capacitive coupled plasma (CCP) plasma enhanced chemical vapor deposition (PECVD).

[0019] Figures 5A - 5F Illustrates that applying a bias to a substrate support can affect the properties of a silicon nitride layer deposited using a high-density plasma chemical vapor deposition process.

[0020] For ease of understanding, wherever possible, the same reference numerals are used to denote the same elements that occur in the figures. It is contemplated that elements disclosed in one embodiment can be advantageously utilized in other embodiments without further elaboration. Unless otherwise specified, the figures referred to herein should not be construed as being drawn to scale. Moreover, the figures are often simplified and some details or components are omitted for clarity of presentation and explanation. The figures and the discussion are used to explain the principles discussed below, and like reference numerals denote like elements. Detailed Description

[0021] Embodiments of the present disclosure include a method and related apparatus for forming an encapsulant for an improved organic light emitting diode (OLED) device. Compared to conventional OLED encapsulants, the encapsulants described below have a reduced thickness yet still effectively block the ingress of moisture and oxygen to prevent damage to the formed OLED device. During manufacturing, this reduced thickness increases yield and also makes the OLED device more flexible and durable compared to OLED devices having thicker encapsulants or encapsulant structures.

[0022] According to embodiments described herein, Figure 1 is a side cross-sectional view of an OLED device 100 including an organic light emitting diode 102 and an encapsulant 111 formed over the organic light emitting diode 102. The OLED device 100 includes a substrate 106 and an organic light emitting diode 102 formed over the substrate 106. The organic light emitting diode 102 can be formed by a series of depositions using masks. Typically, the substrate 106 can be formed of glass, metal (such as copper or stainless steel), or a polymer material. For example, in some embodiments, the polymer substrate is composed of a thin, flexible polymer sheet, such as a polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN) sheet. The OLED device 100 may further include a contact layer 108 disposed between the organic light emitting diode 102 and the substrate 106. The contact layer 108 includes a transparent conductive oxide, such as indium tin oxide, indium zinc oxide, zinc oxide, or tin oxide.

[0023] During the normal use period of the formed OLED device, the encapsulant 111 is a Thin-film Encapsulant (TFE) formed over the organic light-emitting diode 102 to protect the OLED device 100 from performance degradation caused by the exposure of the organic light-emitting diode 102 to moisture and / or oxygen. The encapsulant 111 may include a first barrier layer 110, a buffer layer 112, and a second barrier layer 114. In other embodiments, the encapsulant 111 may include multiple buffer layers and more than two barrier layers, where each buffer layer is disposed between two barrier layers, for example, the buffer layer 112 is disposed between the barrier layers 110 and 114. In some embodiments, at least one of the barrier layers 110, 114 is formed using high-density plasma (i.e., plasma having an electron density of at least 10 11 cm -3 ), which will be described in more detail below. In still other embodiments, one or more of the barrier layers 110, 114 may include two or more portions, where each portion is formed using plasma having a different density (e.g., the first portion is formed using high-density plasma having an electron density of at least 10 11 cm -3 , and the second portion is formed using lower-density plasma, such as plasma having an electron density of about 10 9 cm -3 ), which will be described in more detail below. At least a portion of at least one of the barrier layers 110, 114 formed using high-density plasma improves the moisture and oxygen barrier properties as compared to a similar thickness portion formed using lower-density plasma.

[0024] The first barrier layer 110 may include a dielectric film, such as silicon nitride (SiN), silicon oxynitride (SiON), silicon dioxide (SiO2), aluminum oxide (Al2O3), aluminum nitride (AlN), titanium oxide (TiO2), zirconium(IV)oxide (ZrO2), or a combination thereof. The buffer layer 112 may be an organic layer, such as a hexamethyldisiloxane (HMDSO) layer, such as plasma-polymerized HMDSO (pp-HMDSO:F) and / or a polymeric material including hydrogen, carbon, and oxygen, where the polymeric material has the chemical formula Cx H y O z where x, y, and z are integers. In other embodiments, the buffer layer material is selected from the group consisting of polyacrylate, parylene, polyimide, polytetrafluoroethylene, a copolymer of fluorinated ethylene propylene, a perfluoroalkoxycopolymer resin, a copolymer of ethylene and tetrafluoroethylene, parylene, and combinations thereof.

[0025] At least one of the barrier layers 110, 114 can be a barrier layer (e.g., a silicon nitride layer) deposited using a high-density plasma (i.e., a plasma having an electron density of at least 10 11 cm -3 ), which will be described in more detail below. The barrier layers 110, 114 are separated in the Z direction (the first direction) above the organic light-emitting diode 102 (i.e., not on the side of the organic light-emitting diode 102). The barrier layer deposited using a high-density plasma can have a thickness of about to about , for example, a thickness of about to about in the Z direction above the organic light-emitting diode 102. The barrier layer in the thin film encapsulation is generally formed using a technique such as a capacitively coupled plasma (CCP) process, and a plasma with a lower density (i.e., a plasma having an electron density of about 10 9 cm -3 ) is used. The lower-density plasma formed during the capacitively coupled plasma process is generally used to achieve the desired deposition film (e.g., uniformity, stress, etc.) and plasma characteristics (e.g., uniformity, reduced arcing, etc.). In some embodiments, the density of the high-density plasma used to form at least one barrier layer (e.g., an electron density of about 10 11 cm -3 ) is at least 100 times greater than the density of the lower-density plasma used to form another barrier layer in the encapsulation 111 (e.g., an electron density of about 10 9 cm -3 ).

[0026] Encapsulations (including individual barrier layers and buffer layers) using barrier layers formed only with traditional lower-density plasmas generally require a thickness greater than to obtain the moisture barrier and / or oxygen barrier properties of the barrier layer, e.g., less than 1x10 -4 g / m2 The water vapor transmission rate (WVTR) of the "day". However, for example, an encapsulation using a silicon nitride barrier layer deposited using high density plasma may have less than 1x10 - 4 g / m 2 WVTR of "day" and less than Total encapsulation thickness. In addition, compared to a barrier layer formed by a lower density plasma having a thickness of at least Individual silicon nitride barrier layers in these encapsulations can be formed by high density plasma and can have a thickness of about To about For example, it is about To about Thickness, resulting in an OLED device with higher flexibility. Compared to an OLED device containing a barrier layer formed by a lower density plasma, an OLED device including these thinner barrier layers is also less likely to break, improving the function and durability of the OLED device ultimately produced using a barrier layer formed by high density plasma.

[0027] According to one embodiment, Figure 2A Is a side cross-sectional schematic view of the exemplary process chamber 200. Referring to Figure 1 And 2A The process chamber 200 will be described. The process chamber 200 can be used to perform Figure 1 Deposition of one or more layers included in the encapsulation 111 of. In some embodiments, the process chamber 200 can be further used to pre-treat the OLED device 100 before the encapsulation 111 is formed over the organic light emitting diode 102. In one embodiment, the process chamber 200 can be used to form one or more barrier layers 110, 114 of the encapsulation 111. One or more barrier layers 110, 114 can be silicon nitride layers deposited according to the methods described herein.

[0028] The process chamber 200 is configured to process large area substrates, such as substrates having a surface area greater than about 0.1 m 2 For example, greater than about 2 m 2 . The process chamber 200 is configured to process substrates oriented in a horizontal position. In other embodiments, the methods described herein are used in a process chamber that processes substrates oriented in a vertical or substantially vertical position.

[0029] The process chamber 200 is characterized by one or more sidewalls 204, a lid 208, and a bottom 206, defining a processing volume 299. The processing volume 299 is fluidly coupled to a vacuum 209, such as one or more dedicated vacuum pumps. The process chamber 200 further includes a substrate support 210 disposed therein. The substrate support 210 includes a shaft 214 extending through the chamber bottom 206 to raise and lower the substrate support 210 to facilitate the transfer of the substrate 106 into and out of the process chamber 200.

[0030] The substrate 106 is loaded into the processing volume 299 through an opening 212 in one of the sidewalls 204, which is conventionally sealed during deposition or other processes using a door or a slit valve (not shown). A plurality of lift pins 216 are movably disposed through the substrate support 210 to transfer the substrate 106 towards or away from the substrate support 210. When the substrate support 210 is in a lower position, the plurality of lift pins 216 extend above the surface of the substrate support 210 to lift the substrate 106 for access by a robot handler (not shown). When the substrate support 210 is in a raised position, the plurality of lift pins 216 are in the same plane or below the surface of the substrate support 210, and the substrate 106 is directly placed on the substrate support 210 for processing. The lift pins 216 can be moved by contacting their lower ends with a fixed or movable pin plate (not shown). The substrate support 210 may further include a resistive heater 298, coupled to a controller 280 and cooling fluid conduits 296, and the controller 280 and the cooling fluid conduits 296 cooperate to control the temperature of the substrate 106 disposed on the substrate support 210 during deposition.

[0031] In some embodiments, during processing, for example during deposition, an electrical bias may be provided to the substrate support 210. The substrate support 210 may include a bias electrode 250 disposed on or within the substrate support 210. The bias electrode 250 is coupled to a bias power supply 255 that provides DC power, pulsed DC power, AC power, pulsed AC power, RF power, pulsed RF power, or a combination thereof. In one embodiment, during deposition, the substrate support 210 is subjected to an electrical bias by charging the bias electrode 250 to create a negative bias on the substrate support 210 and / or the substrate 106. In some embodiments, the substrate support 210 further includes an electrostatic chuck electrode (not shown) disposed on or within the substrate support 210. Typically, the electrostatic chuck electrode is coupled to DC power to hold the substrate 106 on the surface of the electrostatic chuck electrode.

[0032] The process chamber 200 further includes a plurality of tubular gas distribution conduits 221 and a plurality of antennas 233, each disposed above the substrate support 210 within the process chamber 200. The plurality of gas distribution conduits 221 are configured to distribute process gases from gas inlets 222A, 222B into the processing space 299. The plurality of gas distribution conduits 221 are located between the substrate 106 disposed on the substrate support 210 and the plane in which the plurality of antennas 233 are located. In one embodiment, each of the gas distribution conduits 221 may be spaced apart from the surface of the substrate 106 by a substantially identical spacing distance, such as a vertical spacing between about 3000 mil and about 10000 mil. A plurality of holes 223 disposed in the gas distribution conduits 221 face the substrate 106 and provide a substantially uniform gas flow above the surface of the substrate 106.

[0033] In some embodiments, for example, forming a silicon nitride barrier layer (such as Figure 1In an embodiment of the barrier layer 110), when in use, a silicon precursor, one or more nitrogen precursors, and a carrier gas are mixed to flow together through the same gas distribution conduit 221. Each end of the gas distribution conduit 221 is coupled to an individual gas inlet 222A or 222B to provide a more uniform pressure along the length of the gas distribution conduit 221, and thus a more uniform gas flow exits through the plurality of holes 223 disposed in the gas distribution conduit 221. In other embodiments, each of the precursor gases flows through a respective gas distribution conduit 221 before reaching the surface of the substrate 106 to prevent the precursor gases from reacting with each other.

[0034] The process chamber 200 uses a plurality of antennas 233 disposed within and extending through the processing space 299 to enable a high-density plasma assisted chemical vapor deposition process. In this embodiment, the high-density plasma source is a linear microwave plasma source (LPS) (also referred to as the antenna 233). However, the methods described herein can be used with any suitable high-density plasma source, such as an electron cyclotron resonance (ECR) plasma source or an inductively coupled plasma (ICP) source. Importantly, when attempting to achieve similar deposition rates in a capacitively coupled plasma chamber, these high-density plasma deposition techniques can achieve high deposition rates (e.g., / min) without any significant risk of arc generation, which can occur in a capacitively coupled plasma chamber or elsewhere in the radio frequency (RF) circuit. During plasma deposition, the occurrence of arcs is known to result in unstable plasmas and non-uniform process results, and can even damage the device being fabricated. Here, the plurality of antennas 233 extend through a dielectric tube 237 (see Figure 2C) extends through the process chamber 200 to provide an interior volume across the process chamber 200, which interior volume is isolated from the processing space 299 of the process chamber 200. Each antenna 233 is located in an antenna plane between the chamber lid 208 and a planar arrangement of a plurality of gas distribution ducts 221. One or more microwave generators 230, each coupled to a power source 232, are coupled to one or both ends of each antenna 233. A cooling gas flow is provided from a cooling gas inlet 243 to each antenna 233, the cooling gas inlet 243 being coupled to a first end of each dielectric tube 237, and a cooling gas exhaust 245 is coupled to a second end of each dielectric tube 237. Typical cooling gases include clean dry air (CDA) and nitrogen (N2).

[0035] According to one embodiment, Figure 2C is Figure 2B A cross-sectional view of one of the plurality of antennas 233 shown. The antenna 233 generally includes a conductive stub 235 for radiating microwave energy into the processing space 299, and the conductive stub 235 is surrounded by a dielectric tube 237 substantially coaxial with the conductive stub 235, such as a quartz tube. Electromagnetic waves from the stub 235 are radiated into the processing space 299 through the dielectric tube 237, where a plasma of the processing gas introduced from the plurality of gas distribution ducts 221 is formed.

[0036] According to one embodiment, Figure 2B illustrates Figure 2A A plan view of some features of the process chamber 200 shown. A plurality of gas distribution ducts 221 are above the substrate 106 on the substrate support 210 and are spaced apart from each other in a parallel arrangement (see Figure 2A of the substrate support 210). Each gas distribution duct 221 is located between two parallel antennas 233 of the plurality of antennas 233, and the plurality of antennas 233 are also spaced apart from each other in a parallel arrangement above the substrate support 210( Figure 2A ).

[0037] According to one embodiment, Figure 2D is a process flow diagram of a method 1000 for encapsulating an organic light emitting diode 102 with an encapsulant 111 of Figure 1 . In this exemplary embodiment, the process chamber 200 of Figure 2A is used to perform the method 1000. The following will refer to Figure 1 and Figures 2A - 2DTo describe method 1000.

[0038] At block 1002, a first plasma is generated over an organic light emitting diode 102 formed on a substrate 106, where the substrate 106 is disposed in a processing space 299 of a process chamber 200. The first plasma can be a high density plasma having an electron density of at least 10 11 cm -3 . Generating the first plasma generally includes supplying a flow of a pretreatment process gas (e.g., a single gas molecule or atom) to the processing space 299 of the process chamber 200, and exciting the gas into a plasma to pretreat the organic light emitting diode 102 and the substrate 106. The first plasma pretreatment can improve the interface properties of the organic light emitting diode 102 and the substrate 106 to improve the adhesion when a first barrier layer 110 is formed over the organic light emitting diode 102 and the substrate 106. In some embodiments, the first plasma can be formed from a pretreatment process gas that includes a nitrogen and / or hydrogen containing gas stream (e.g., nitrogen (N2), hydrogen (H2), ammonia (NH3), or nitrous oxide (N2O)), while in other embodiments, the first plasma can be formed from an inert gas (e.g., helium or argon). In some embodiments, the plasma generated can depend on the type of substrate being used. For example, an argon (Ar) plasma can be suitable for increasing adhesion to a polyethylene terephthalate (PET) substrate or a polyethylene naphthalate (PEN) substrate, while a nitrogen (N2) plasma can be more suitable for increasing adhesion to a copper substrate. Additionally, an ammonia (NH3) plasma can be more suitable for promoting adhesion to a glass substrate.

[0039] The flow rate of the pre-treatment gas to the chamber depends on the size of the substrate and the process chamber. For example, for a chamber sized to process a 500 mm by 730 mm substrate, the total flow rate of the pre-treatment process gas, including nitrogen (N2), can be between about 150 sccm and about 3,000 sccm, such as between about 250 sccm and about 1,500 sccm, such as between about 300 sccm and about 900 sccm, such as about 480 sccm. The first plasma can be formed by a linear microwave plasma source (LPS) 233. The linear microwave plasma source 233 can have power supplied at both ends of the conductive stub 235, at a frequency between about 1 gigahertz (GHz) and about 10 GHz, such as about 2.45 GHz or about 5.8 GHz. The power used depends on the size of the chamber. For example, for a chamber sized to be used for a 500 mm by 730 mm substrate, the power can be set between about 500 W and about 8000 W, such as between about 500 W and about 5000 W, such as between about 1000 W and 4000 W. Appropriate scaling can be used for chambers sized to be used for other substrates, where the power is set between about 130 mW / cm 2 and about 2300 mW / cm 2 such as between about 130 mW / cm 2 and about 1400 mW / cm 2 such as between about 270 mW / cm 2 and about 1100 mW / cm 2 such as between about 130 mW / cm

[0040] In block 1004, for a period of time while maintaining a first plasma having an electron density of at least 10 11 cm -3 the one or more surfaces of the organic light emitting diode 102 and the substrate 106 are pre-treated using the first plasma.

[0041] In block 1006, a second plasma is generated in the processing space 299 of the process chamber 200. The second plasma can be a plasma having an electron density of at least 10 11 cm -3High-density plasma of electron density. The gas provided to form the second plasma may include a silicon precursor gas and a nitrogen precursor gas, and flows into the processing space 299 of the process chamber 200 through a plurality of linear gas distribution ducts 221. The silicon precursor gas is any suitable silicon-containing gas, such as silane (SiH4), disilane (Si2H6), trisilane (Si3H3), tetrasilane (Si4H 10 ), silicon tetrafluoride (SiF4), silicon tetrachloride (SiCl4), dichlorosilane (SiH2Cl2), or a mixture of the above. The nitrogen precursor gas is any suitable nitrogen-containing gas, such as nitrogen (N2), ammonia (NH3), diazene (N2H2), hydrazine (N2H4), or a mixture of the above. In some embodiments, a carrier gas is also provided, such as argon (Ar), hydrogen (H2), helium (He), its derivatives, or a mixture thereof. In one embodiment, silane (SiH4), ammonia (NH4), and nitrogen (N2) co-flow through a plurality of linear gas distribution ducts 221 and into the processing space 299. Here, the silicon precursor gas and the nitrogen precursor gas co-flow through the same linear gas distribution duct 221. In other embodiments, the precursor gases flow through individual gas distribution ducts 221 to prevent the precursor gases from reacting prematurely in the gas distribution ducts 221.

[0042] The flow rate of the precursor gas flowing into the chamber depends on the size of the substrate and the process chamber. For example, for a chamber designed to process a substrate of 500 mm by 730 mm, the total flow rate of the silicon precursor gas including silane (SiH4) is between about 150 sccm and about 3,000 sccm, such as between about 250 sccm and about 1,500 sccm, such as between about 300 sccm and about 900 sccm, such as about 480 sccm. The flow rate of the nitrogen precursor gas including ammonia (NH3) flowing into the chamber is between about 1,200 sccm and about 5,000 sccm, such as between about 2,000 sccm and about 4,000 sccm, such as about 3,000 sccm. When in use, the flow rate of the carrier gas including argon (Ar) or nitrogen (N2) is between about 450 sccm and about 5,000 sccm, such as between about 500 sccm and about 3,500 sccm, such as about 2,500 sccm. Suitable scaling can be used for chambers designed for other substrates, where the gas flow ratio of silane to ammonia (SiH4:NH3) can be between about 1:2 and about 1:6, such as about 1:3. When argon is used, the gas flow ratio of silane to argon (SiH4:Ar) can be between about 1:1 and about 1:20, such as between about 1:5 and about 1:10. When argon is used, the gas flow ratio of ammonia to argon (NH3:Ar) can be between about 1:1 and about 1:10, such as between about 1:2 and about 1:5. The chamber pressure is maintained below 1 Torr, such as between about 50 mTorr and about 250 mTorr, such as below about 200 mTorr, such as below about 125 mTorr. The substrate 106 can be separated from the linear gas distribution conduit 221 by a spacing between about 3000 mil and about 10000 mil (for example, about 7000 mil).

[0043] Through the linear microwave plasma source 233, the electron density is greater than about 10 11 / cm 3The high-density plasma is formed using a carrier gas (during use), a silicon precursor gas, and a nitrogen precursor gas. At a frequency between about 1 GHz and about 10 GHz, such as about 2.45 GHz or about 5.8 GHz, the linear microwave plasma source 233 can have power supplied at both ends of the conductive stub 235. The power used depends on the size of the chamber. For example, for a chamber sized to accommodate a substrate of 500 mm by 730 mm, the power can be set between about 500 W and about 8000 W, such as between about 500 W and about 5000 W, such as between about 1000 W and about 4000 W. Appropriate scaling can be used for chambers sized for other substrates, where the power is set between about 130 mW / cm 2 and about 2300 mW / cm 2 such as between about 130 mW / cm 2 and about 1400 mW / cm 2 such as between about 270 mW / cm 2 and about 1100 mW / cm 2 In other embodiments, the high-density plasma can be formed by an inductively coupling a plasma source power (ICP) having a frequency between about 1 MHz and about 20 MHz, such as about 13.56 MHz.

[0044] At block 1008, a first barrier layer 110 including silicon and nitrogen is deposited over the organic light emitting diode 102 by maintaining a second plasma for a period of time. In one embodiment, the second plasma is maintained to form the first barrier layer 110 having a thickness of about to about such as about to about such as about or about As described above, compared to a barrier layer of the same thickness formed using a lower density plasma, forming the first barrier layer 110 using a high-density plasma can result in a given thickness (e.g., ) The barrier layer. It is believed that, compared to a plasma of lower density, at least a part of the improved water barrier property and oxygen barrier property of the barrier layer formed by a high-density plasma is due to a reduced amount of damage to the barrier layer formed by the high-density plasma, which has a lower rate of ion bombardment. A lower rate of ion bombardment results in fewer pin holes in the formed barrier layer compared to the barrier layer formed by a plasma of lower density, and the high-density plasma causes a denser layer to be formed, both of which result in the improved water barrier property and oxygen barrier property of the barrier layer.

[0045] In block 1010, a buffer layer 112 is formed (e.g., deposited) on top of the first barrier layer 110. In one embodiment, the buffer layer 112 is formed by a layer of hexamethyldisiloxane (HMDSO). In some embodiments, the buffer layer is formed in the process chamber 200, while in other embodiments, the buffer layer 112 can be formed in another process chamber.

[0046] In block 1012, a third plasma is generated in the processing space 299 of the process chamber 200. The third plasma can be a high-density plasma having an electron density of at least 10 11 cm -3 . In some embodiments, the same or a similar method as described above is used to generate the third plasma with reference to generating the second plasma (i.e., the same gas, gas flow rate, power and frequency supplied from a linear microwave plasma source (LPS), pressure, temperature, etc.).

[0047] In block 1014, a second barrier layer 114 including silicon and nitrogen is deposited on the organic light-emitting diode 102 by maintaining the third plasma for a period of time. In one embodiment, the third plasma is maintained to form a second barrier layer 114 having a thickness of about to about , for example about to about For example about or about

[0048] Although the second plasma and the third plasma used to form the respective barrier layers 110, 114 are described as high-density plasmas, in some embodiments, at least one of the barrier layers 110, 114 can be formed by a plasma of lower density, such as having an electron density of about 10 9 cm -3A plasma with an electron density, for example, using capacitively coupled plasma. In some of these embodiments, a barrier layer formed by a lower density plasma can help reduce the stress mismatch between the barrier layer and the buffer layer among multiple barrier layers. When the OLED device is subjected to external stress, such as bending, this reduced stress mismatch can assist in preventing the encapsulation from cracking.

[0049] According to another embodiment, Figure 3A is a side cross-sectional view of an OLED device 300 including an organic light-emitting diode 102 and an encapsulation 311 formed on the organic light-emitting diode 102. Except that the OLED device 300 includes an encapsulation 311 to replace the above-mentioned encapsulation 111, the OLED device 300 is similar to the OLED device 100. Except that the barrier layers 110, 114 from the encapsulation 111 are replaced with barrier layers 310, 314, the encapsulation 311 is similar to the above-mentioned encapsulation 111. In addition, the encapsulation 311 additionally includes a second buffer layer 316 and a third barrier layer 318.

[0050] In some embodiments, the barrier layers 310, 314 can be the same as the above-mentioned barrier layers 110, 114. In other embodiments, one or more barrier layers can be formed by two parts including a part formed using a high-density plasma and a second part using a lower density plasma. For example, in Figure 3A the lower right side of, a closeup of the barrier layer 310 shows including a first part 310A and a second part 310B. In one embodiment, the first part 310A can use a high-density plasma (i.e., a plasma having an electron density greater than about 10 11 cm -3 to form, and the second part 310B can use a lower density plasma (i.e., a plasma having an electron density of about 10 9 cm -3 for example, about 5×10 7 cm -3 to about 5×10 9 cm -3 of electron density) to form.

[0051] Referring to Figure 1 the barrier layer 110, any part formed using a high-density plasma can be formed using the above method. The first part 310A can have a thickness of about to about , for example, about to about The first portion 310A and the second portion 310B can be formed of the same material (e.g., silicon nitride), but forming portions 310A, 310B with plasmas having significantly different densities (e.g., a difference of 100 times or more) can change many properties of the resulting portions 310A, 310B of the barrier layer. For example, in one embodiment, the first portion 310A can be deposited using a high-density plasma to form a barrier layer portion having tensile stress and improved water vapor transmission rate (i.e., lower water vapor transmission rate) compared to a portion of the same thickness formed with a lower-density plasma, while the second portion 310B can be deposited using a lower-density plasma to form a barrier layer portion having compressive stress. The second portion 310B having compressive stress can form an improved interface with the buffer layer 112 deposited over the first barrier layer 310 compared to the barrier layer portion having tensile stress. Thus, the resulting barrier layer 310 including portions 310A, 310B provides a barrier layer that is superior to a barrier layer formed only of a high-density plasma or only of a lower-density plasma.

[0052] Although the barrier layer 310 is shown as including two portions 310A, 310B, in other embodiments, the barrier layer can include additional portions formed using other combinations of high-density plasma and lower-density plasma, and also include portions formed with plasmas having other densities, such as a barrier layer including three or more portions formed using at least three different plasmas, including a high-density plasma (e.g., having an electron density of at least 10 11 cm -3 ), a medium-density plasma (e.g., having an electron density of about 10 10 cm -3 ), and a lower-density plasma (e.g., having an electron density of less than 10 9 cm -3 ). Further, although only the barrier layer 310 is shown as including multiple portions formed with plasmas having different densities, in some embodiments, one or more of the barrier layers 314 and 318 can also include multiple portions formed with plasmas having different densities.

[0053] The second buffer layer 316 can be similar to the buffer layer 112 described above with reference to Figure 1 . For example, in some embodiments, the second buffer layer 316 is formed of the same material using the same method as the buffer layer 112 described above. Similarly, the second barrier layer 314 and the third barrier layer 318 can be similar to those described with reference to Figure 1the above-described first barrier layer 110 or second barrier layer 114, or similar to the reference Figure 3A barrier layer 310 described. The encapsulant 311 may have a total thickness of about to about .

[0054] According to one embodiment, Figure 3B is a schematic plan view of a cluster tool 350, which can be used to form Figure 3A an encapsulant 311 on the organic light-emitting diode 102 of the OLED device 300. The cluster tool 350 includes a conveyor belt 351 leading to a transfer chamber 352. The cluster tool 350 further includes a first process chamber 361, a second process chamber 362, a third process chamber 363, a fourth process chamber 364, and a fifth process chamber 365. Each of the process chambers 361-365 may include a corresponding plasma source 371-375. The plasma source of a given process chamber may include, for example, a linear microwave plasma source, an electron cyclotron resonance plasma source, an inductively coupled plasma (ICP) source, or a capacitively coupled plasma source. In some embodiments, the process chamber may include more than one plasma source, such as a linear microwave plasma source and a capacitively coupled plasma source.

[0055] The transfer chamber 352 may include a robot (not shown) for transferring the substrate 106 in and out of each of the process chambers 361-365 and in and out of the conveyor belt 351. A robot (not shown) in an environmentally controlled transfer chamber 352 (such as an environment with vacuum and / or low water (H2O) or oxygen (O2) content) can be used to transfer the substrate 106 to each of the different process chambers 361-365 so that each layer in the encapsulant 311 can be continuously formed to encapsulate each organic light-emitting diode 102 on each substrate 106. Although five process chambers are shown in the cluster tool 350, in other embodiments, the cluster tool may include more or fewer process chambers, such as a dual-process chamber tool, where one process chamber uses high-density plasma to form a barrier layer or part of a barrier layer, and the other process chamber uses low-density plasma to form a buffer layer and at least a part of a barrier layer.

[0056] Each of the process chambers 361-365 can be a plasma enhanced chemical vapor deposition (PECVD) chamber, and some of the process chambers 361-365 can be classified as high-density plasma chambers, such as those that can generate a plasma with 1011 cm -3 or higher electron density plasma chambers, and portions of other process chambers 361-365 may be more generally classified as lower-density plasma chambers, such as those that may produce plasmas with about 10 9 cm -3 The electron density of the plasma chamber is about 5×10 7 cm -3 About 5×10 9 cm -3 The electron density of the linear microwave plasma source is Figure 2A The process chamber 200 described above is an exemplary chamber that can be used to generate a high-density plasma chamber, but a plasma chamber including an inductively coupled plasma (ICP) source or an electron cyclotron resonance (ECR) plasma source can also be used to generate a high-density plasma for forming the encapsulation member 311. An exemplary lower-density plasma chamber may include a capacitively coupled plasma chamber.

[0057] In one embodiment, the first process chamber 361, the third process chamber 363, and the fifth process chamber 365 may be used to deposit a barrier layer or portions of a barrier layer using a high density plasma. For example, in this embodiment, the first process chamber 361 may be used to deposit a first portion 310A of the first barrier layer 310, and the second process chamber 362 may be used to deposit a second portion 310B of the first barrier layer 310 of the encapsulation 311. In addition, in this embodiment, the third process chamber 363 may be used to deposit the buffer layers 112, 316 of the encapsulation 311. Finally, the fourth process chamber 364 and the fifth process chamber 365 may be used to deposit the second barrier layer 314 and the third barrier layer 318 of the encapsulation 311, respectively. In this embodiment, the first process chamber 361, the fourth process chamber 364, and the fifth process chamber 365 may be configured to form a high density plasma, while the second process chamber 362 and the third process chamber 363 may be configured to form a lower density plasma. For example, the first plasma source 371 , the fourth plasma source 374 , and the fifth plasma source 375 may be linear microwave plasma sources (LPS), and the second plasma source 372 and the third plasma source 373 may be capacitively coupled plasma (CCP) sources.

[0058] According to one embodiment,Figure 3C is a process flow diagram of a method 1100 for encapsulating an organic light emitting diode (OLED) 102 with an encapsulant 311 using a cluster tool 350 as denoted by Figure 3B . The method 1100 will be described below with reference to Figures 3A - 3C . Figure 3B using a cluster tool 350 and is encapsulated by an encapsulant 311 as denoted by Figure 3A . Figure 3A In block 1102, a substrate 106 is transferred from a conveyor belt 351 to a first process chamber 361 through a transfer chamber 352. In block 1104, a high density plasma (first plasma) is generated in the first process chamber 361, and a first portion 310A of a first barrier layer 310 is deposited over the organic light emitting diode 102 using the high density plasma (first plasma). In some embodiments, the substrate and the organic light emitting diode may be pre-treated before performing block 1104 using the same or similar operations as described in block 1004 above with reference to Figure 2D . Figures 3A - 3C to illustrate the method 1100.

[0059] In block 1102, a substrate 106 is transferred from a conveyor belt 351 to a first process chamber 361 through a transfer chamber 352. In block 1104, a high density plasma (first plasma) is generated in the first process chamber 361, and a first portion 310A of a first barrier layer 310 is deposited over the organic light emitting diode 102 using the high density plasma (first plasma). In some embodiments, the substrate and the organic light emitting diode may be pre-treated before performing block 1104 using the same or similar operations as described in block 1004 above with reference to Figure 2D . Figure 2D Before performing block 1104 using the same or similar operations as described in block 1004 above with reference to Figure 2D , the substrate and the organic light emitting diode may be pre-treated.

[0060] In block 1106, the substrate 106 is transferred from the first process chamber 361 to a second process chamber 362 through the transfer chamber 352. In block 1108, a lower density plasma (second plasma) is generated in the second process chamber 362, and a second portion 310B of the first barrier layer 310 is deposited over the organic light emitting diode 102 using the lower density plasma (second plasma). The density of the lower density plasma in block 1108 (e.g., 10 9 cm -3 ) may differ from the density of the high density plasma in block 1104 by at least 100 times. 9 cm -3

[0061] In block 1110, the substrate 106 is transferred from the second process chamber 362 to a third process chamber 363 through the transfer chamber 352. In block 1112, a lower density plasma (third plasma) is generated in the third process chamber 363, and a first buffer layer 112 is deposited over the first barrier layer 310 using the lower density plasma (third plasma).

[0062] In block 1114, the substrate 106 is transferred from the third process chamber 363 to a fourth process chamber 364 through the transfer chamber 352. In block 1116, a high density plasma (fourth plasma) is generated in the fourth process chamber 364, and a second barrier layer 314 is deposited over the first buffer layer 112 using the high density plasma (fourth plasma).

[0063] ​In block 1118, the substrate 106 is transferred from the fourth process chamber 364 to the third process chamber 363 through the transfer chamber 352. In block 1120, a lower density plasma (fifth plasma) is generated in the third process chamber 363, and the second buffer layer 316 is deposited over the second barrier layer 314 using the lower density plasma (fifth plasma).

[0064] In block 1122, the substrate 106 is transferred from the third process chamber 363 to the fifth process chamber 365 through the transfer chamber 352. In block 1124, a high density plasma (sixth plasma) is generated in the fifth process chamber 365, and the third barrier layer 318 is deposited over the second buffer layer 316 using the high density plasma (sixth plasma).

[0065] As Figures 4A - 4I shown, methods 1000 and 1100 provide an example of forming an encapsulation over an organic light emitting diode (OLED) that has improved barrier properties to prevent moisture and oxygen from entering into the underlying OLED device as compared to an encapsulation formed using only a conventional capacitively coupled plasma (CCP) plasma enhanced chemical vapor deposition (PECVD) deposition process. According to the embodiments described herein, Figures 4A - 4I shows comparative measurements of the barrier properties and other properties of a silicon nitride layer deposited using a high density plasma chemical vapor deposition (HDP-CVD) process and a silicon nitride thin film deposited using a conventional capacitively coupled plasma (CCP) plasma enhanced chemical vapor deposition (PECVD) deposition.

[0066] When these silicon nitride layers are maintained at 85°C and 85% relative humidity from 0 hours to less than about 1500 hours, Figures 4A - 4B shows the Figure 4A percentage (%) of silicon-hydrogen bonds (Si-H bonds) in Figure 4B and the percentage of nitrogen-hydrogen bonds (N-H bonds) in Figure 4A formed using high density plasma chemical vapor deposition (HDP-CVD) and capacitively coupled plasma chemical vapor deposition (CCP-CVD). As can be seen from the high density plasma silicon nitride layer (HDP layer of silicon nitride) 415 of and the high density plasma silicon nitride layer 417 of The CCP silicon nitride layer 413 and The capacitively coupled plasma silicon nitride layers 411 initially show fewer Si-H bonds, but the percentage (%) of Si-H bonds in the CCP silicon nitride layers 411 and 413 decreases over time. While Si-H bonds in silicon nitride layers used as barrier layers in thin film encapsulation structures are not necessarily undesirable, The capacitively coupled plasma silicon nitride layer 413 and The decrease in the percentage (%) of silicon-hydrogen (Si-H) over time in the capacitively coupled plasma silicon nitride layer 411 indicates that Si-H bonds are being replaced by undesirable silicon-oxygen bonds (Si-O bonds). This shows the relative instability of the conventionally deposited capacitively coupled plasma silicon nitride layers 411 and 413 when compared to the HDP silicon nitride layers 415 and 417. With respect to the percentage (%) of N-H bonds over time, Figure 4B It is shown that both the high density plasma deposited layers and the CCP deposited layers are relatively stable.

[0067] When exposed to 85 °C and 85% relative humidity, Figure 4C Shows the percentage (%) change in the concentration of Si-N bonds in the deposited silicon nitride layer from 0 hours to less than about 1500 hours. Figure 4D Shows the Figure 4C Percentage (%) change in the concentration of Si-O bonds in the deposited silicon nitride layer over the same time period. Figure 4C And Figure 4D The percentage changes in the concentration values in Figure 4C And Figure 4D Have been normalized. As can be seen in Figure 4C And Figure 4D The Si-O concentration in the deposited capacitively coupled plasma silicon nitride layers 411 and 413 increases over time and predictably results in a decrease in the Si-N concentration in the deposited layers, while the high density plasma silicon nitride layers remain stable over the same time period with no to very little detectable shift in either Si-O or Si-N, showing that the high density plasma silicon nitride layers have excellent barrier properties against oxygen penetration when compared to the capacitively coupled plasma silicon nitride layers.

[0068] After exposure to 85 °C and 85% relative humidity from 0 hours to about 1400 hours and the increment between this period, Figures 4E - 4G Shows the high density plasma ( Figure 4E ) and the capacitively coupled plasma ( Figure 4F And Figure 4GFourier Transform Infrared (FTIR) spectra of the silicon nitride layer Figure 4F show that exposure of the high density plasma silicon nitride layer from 0 hours to about 1400 hours shows little to no change in the concentration of the thin film. In particular, little to no change in the concentration of the silicon-oxygen bond and silicon-nitrogen bond observed up to 1400 hours shows little to no undesirable oxygen penetration in the high density plasma layer. However, measurements from 0 hours (420) to 1300 hours (426) and as Figure 4F can be seen, the conventional silicon nitride layer shows a measurable increase in the concentration of the silicon-oxygen bond. Since when compared to the capacitively coupled plasma layer, the capacitively coupled plasma layer shows a higher concentration of the silicon-oxygen bond at increasing time intervals, possible oxygen penetration from 0 hours (420) to 680 hours (424), 820 hours (425) of exposure and 1300 hours (426) of exposure in the capacitively coupled plasma layer is even more perceptible. Compared to the conventionally deposited capacitively coupled plasma silicon nitride layer, Figures 4E - 4G shows that the high density plasma silicon nitride layer deposited according to the embodiments of the present disclosure is an excellent barrier against oxygen penetration.

[0069] Figure 4H and Figure 4I show the water vapor transmission rate of the silicon nitride layer exposed to 40 °C and 100% relative humidity, where a lower water vapor transmission rate indicates the resistance of the silicon nitride layer to water penetration. Figure 4I shows comparison with the capacitively coupled plasma silicon nitride layer 413 of the high density plasma silicon nitride layer 417, where the high density plasma layer has a relatively stable water vapor transmission rate of about 1 x 10 -4 g / m 2 day with little to no change between 0 hours and about 140 hours, while the capacitively coupled plasma silicon nitride layer 413 fails after about 120 hours and no longer shows a measurable resistance to water penetration. Figure 4H shows the deposition according to the embodiments of the present disclosure and having and The water vapor transmission rate of the silicon nitride high density plasma (HDP) layer as a function of time and up to between about 140 hours and about 275 hours. Significantly, the water vapor transmission rate of each HDP silicon nitride layer is stable over the measured time period.

[0070] It is also noted that the silicon nitride layers deposited by high density plasma and capacitively coupled plasma have substantially similar transmission and step coverage characteristics. Both the HDP thin film and the capacitively coupled plasma thin film have a transmission rate greater than 90% at a wavelength of 400 nanometers (nm), and a step coverage factor greater than 0.85 on a step height pattern of 2.5 micrometers (μm). HDP silicon nitride will also allow for a thinner desired barrier layer in a thin film encapsulation (TFE) structure. For example, a conventional capacitively coupled plasma silicon nitride layer in a TFE structure typically has a thickness between 0.5 μm and 1 μm or greater than 1 μm. As Figures 4H - 4I shown, when compared to a layer of capacitively coupled plasma (CCP) silicon nitride, the silicon nitride HDP layer has significantly improved barrier properties. This allows for the use of a silicon nitride barrier layer in a thin film encapsulation structure deposited by high density plasma to have a thickness less than about such as between about and about such as between about and about such as between about and or less than about

[0071] Table 1 (shown below) and Figures 5A - 5F illustrate that biasing the substrate support can affect the properties of the silicon nitride layers in Table 1 deposited using a high density plasma chemical vapor deposition (HDP-CVD) process. As can be seen from Table 1, compared to as Figures 4A - 4IA visible capacitively coupled plasma silicon nitride layer, applying a bias voltage to a substrate support causes deposition of a silicon nitride layer with low pressure and / or compressive stress, and maintains an improved barrier property of a high density plasma chemical vapor deposition (HDP-CVD) silicon nitride layer. Process properties shown in Table 1 and properties of the produced silicon nitride thin film use a linear microwave plasma source high density plasma assisted chemical vapor deposition of silicon nitride layer on a 500 mm by 730 mm substrate using silane (SiH4) and ammonia (NH3) precursors. The flow rate of the silane precursor is 480 sccm, and the flow rate of the ammonia precursor is 2700 sccm. If used, the silane precursor, ammonia precursor and carrier gas are mixed before being distributed into the chamber processing space. For samples HD1 to HD14, there is no carrier gas flow. Sample HD15 has an argon (Ar) carrier gas flow rate of 1350 sccm, and sample HD16 has a nitrogen (N2) gas flow rate of 1350 sccm. For each sample HD1-HD16, the substrate is initially heated to a processing temperature of 90 °C. During the deposition of samples HD3 to HD13, the substrate temperature is monitored. It can be observed that the substrate reaches a temperature as high as 155 °C. However, it can be understood that an OLED device will thermally deteriorate at a process temperature greater than about 100 °C, and during the manufacture of a TFE structure on a pre-formed OLED device, the substrate temperature should be maintained below about 100 °C. The frequency of the LPS power is 2.45 GHz. Table 1 shows the film stress of the high density plasma silicon nitride samples in response to changes in the bias voltage of the substrate support, where a positive stress value represents tensile stress and a negative stress value represents compressive stress.

[0072] Table 1

[0073]

[0074] Figures 5A - 5F Shows the effect of substrate bias power (s bias set power (W)) on the barrier and other properties of a silicon nitride layer deposited using a linear microwave plasma source (LPS) high density plasma chemical vapor deposition method according to the embodiments described herein. Figures 5A - 5F Shows use of 2000 W as Figures 5A - 5FThe silicon nitride layers deposited by the linear microwave plasma source RF powers of 2000W MW, 2500W (2500W MW), and 3000W (3000W MW) as described in, wherein the RF power has a frequency of 2.45 GHz. A bias voltage is applied to the substrate support at a power between 0W and 4000W using an RF power source with a frequency of 373KHz. The silicon nitride layers using the 2000W, 3000W, and 5000W processes are deposited on a substrate of 500mm by 730mm. As Figures 5A - 5F It can be seen that when the substrate bias power increases from 0W to 4000W, the properties of the silicon nitride layer such as the deposition rate (DR), refractive indexes (RI), and Si-H concentration (Si-H%) remain substantially unchanged; while with the increasing substrate bias power, a slight increase in the N-H concentration (N-H%) is observed, and a slight decrease in the wet etch rates (WER) is observed. Significantly, when 2500W to 4000W is applied to the substrate support, by not applying bias power, the high tensile stress in the range from 100MPa (tensile) to 320MPa (tensile) moves to 150MPa (compressive) to 250MPa (compressive). The film stress (Stress) of the silicon nitride layer deposited by the high-density plasma is tunable based on the substrate support bias power. Overall, Figures 4A - 4I Illustrates how to form an effective silicon nitride barrier layer using high-density plasma chemical vapor deposition relative to the silicon nitride barrier layer formed using capacitively coupled plasma chemical vapor deposition (CCP-CVD); Figures 5A - 5F Illustrates how to obtain the desired stress levels of the formed barrier layer using capacitively coupled plasma chemical vapor deposition or high-density plasma chemical vapor deposition by changing the bias applied to the substrate support.

[0075] Therefore, it can be used Figures 4A - 4I and Figures 5A - 5FThe data is used to form an improved encapsulant. For example, one or more barrier layers formed by a high-density plasma can be used to form a barrier layer with improved oxygen barrier and moisture barrier properties compared to a barrier layer formed by a lower-density plasma having the same thickness. In addition, one or more barrier layers formed by a lower-density plasma can help reduce stress misalignment between the barrier layers and between the barrier layer and the buffer layer. When the OLED device is subjected to external stress, such as bending, this reduced stress misalignment can assist in preventing the encapsulant from cracking. Therefore, an encapsulant including one or more barrier layers formed by a high-density plasma and one or more barrier layers formed by a lower-density plasma can produce an encapsulant with improved oxygen barrier and moisture barrier properties and improved durability in response to external stress compared to an encapsulant including only barrier layers formed by a high-density plasma or a lower-density plasma.

[0076] Although the above content relates to embodiments of the present disclosure, other or further embodiments of the present disclosure can be designed without departing from the basic scope of the present disclosure, and the scope of protection of the present disclosure is determined by the appended claims.

Claims

1. An organic light-emitting diode (OLED) device, wherein an encapsulation structure is disposed on the OLED through the following process, including: Depositing a first barrier layer including at least one of silicon nitride (SiN), silicon oxynitride (SiON), or silicon dioxide (SiO2) on the OLED; Depositing a buffer layer on the first barrier layer; And Depositing a second barrier layer including at least one of SiN, SiON, or SiO2 on the buffer layer, wherein at least one of the first barrier layer or the second barrier layer is deposited via a high-density plasma (HDP)-assisted chemical vapor deposition (CVD) process, and at least one of the first barrier layer or the second barrier layer is deposited via a capacitively coupled plasma (CCP)-assisted chemical vapor deposition (CVD) process.

2. The OLED device according to claim 1, wherein the first barrier layer is deposited on the OLED device via the HDP-assisted CVD process, and the second barrier layer is deposited on the buffer layer via a capacitively coupled plasma (CCP)-assisted CVD process.

3. The OLED device according to claim 2, wherein the first barrier layer deposited via the HDP-assisted CVD process has a lower water vapor transmission rate (WVTR) than the second barrier layer deposited via the CCP-assisted CVD process.

4. The OLED device according to claim 1, wherein the first barrier layer is deposited on the OLED device via a capacitively coupled plasma (CCP)-assisted CVD process, and the second barrier layer is deposited on the buffer layer via the HDP-assisted CVD process.

5. The OLED device according to claim 1, wherein the first barrier layer further includes: A first portion deposited via the HDP-assisted CVD process; And A second portion deposited on the first portion via a capacitively coupled plasma (CCP)-assisted CVD process.

6. The OLED device according to claim 1, wherein the first barrier layer, the buffer layer, and the second barrier layer have a total thickness ranging from about to about .

7. An organic light-emitting diode (OLED) device, wherein an encapsulation structure is disposed on the OLED through the following process, including: Depositing a first barrier layer including at least one of silicon nitride (SiN), silicon oxynitride (SiON), or silicon dioxide (SiO2) on the OLED via at least one of a high-density plasma (HDP)-assisted chemical vapor deposition (CVD) process or a capacitively coupled plasma (CCP)-assisted CVD process; Depositing a buffer layer on the first barrier layer; And Depositing a second barrier layer including at least one of SiN, SiON, or SiO2 on the buffer layer via at least one of the HDP-assisted CVD process or the CCP-assisted CVD process, wherein at least one of the first barrier layer or the second barrier layer is deposited via the HDP-assisted CVD process, and at least one of the first barrier layer or the second barrier layer is deposited via the CCP-assisted CVD process.

8. The OLED device according to claim 7, wherein: The first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer; One of the first SiN layer or the second SiN layer is deposited via the HDP-assisted CVD process, and one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; And One of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-oxygen bonds than one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

9. The OLED device according to claim 7, wherein: The first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer; At least one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; And At least one of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-nitrogen bonds than at least one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

10. The OLED device according to claim 7, wherein the thickness of at least one of the first barrier layer or the second barrier layer deposited via the HDP-assisted CVD process is between about and about ​ 11. The OLED device according to claim 7, wherein: The first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer; At least one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; And At least one of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-hydrogen bonds than at least one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

12. A method for encapsulating an organic light-emitting diode (OLED) device, comprising: Depositing a first barrier layer comprising at least one of silicon nitride (SiN), silicon oxynitride (SiON), or silicon dioxide (SiO2) over the OLED device via at least one of a high-density plasma (HDP)-assisted chemical vapor deposition (CVD) process or a capacitively coupled plasma (CCP)-assisted CVD process; Depositing a buffer layer over the first barrier layer; And Depositing a second barrier layer comprising at least one of SiN, SiON, or SiO2 over the buffer layer via at least one of the HDP-assisted CVD process or the CCP-assisted CVD process, wherein at least one of the first barrier layer or the second barrier layer is deposited via the HDP-assisted CVD process, and at least one of the first barrier layer or the second barrier layer is deposited via the CCP-assisted CVD process.

13. The method according to claim 12, wherein the HDP-assisted CVD process includes generating HDP via an HDP source selected from the group consisting of a linear microwave plasma source (LPS), an electron cyclotron resonance (ECR) plasma source, and an inductively coupled plasma (ICP) source.

14. The method according to claim 12, wherein the HDP in the HDP-assisted CVD process has an electron density of at least 10 11 cm -3 .

15. The method according to claim 12, wherein the second barrier layer is deposited via the CCP-assisted CVD process, and the electron density of the plasma in the HDP-assisted CVD process is greater than the electron density of the plasma in the CCP-assisted CVD process.

16. The method according to claim 12, wherein the thickness of at least one of the first barrier layer or the second barrier layer deposited via the HDP-assisted CVD process is between about and about ​ 17. The method according to claim 12, wherein the first barrier layer, the buffer layer, and the second barrier layer have a total thickness of about to about .

18. The method according to claim 12, wherein: the first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer; at least one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; and at least one of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-oxygen bonds than at least one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

19. The method according to claim 12, wherein: the first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer. at least one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; and at least one of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-nitrogen bonds than at least one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

20. The method according to claim 12, wherein: the first barrier layer is a first SiN layer, and the second barrier layer is a second SiN layer. at least one of the first SiN layer or the second SiN layer is deposited via the CCP-assisted CVD process; and at least one of the first SiN layer or the second SiN layer deposited via the HDP-assisted CVD process has a lower percentage change in the concentration of silicon-hydrogen bonds than at least one of the first SiN layer or the second SiN layer deposited via the CCP-assisted CVD process.

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