Roll-to-roll vapor deposition apparatus and method

Abstract

The present disclosure relates to a system. The system may include a first zone, a first precursor is introduced into the first zone, a second zone, a second precursor is introduced into the second zone, a third zone, the third zone is located between the first zone and the second zone, and a reactive substance is generated in the third zone, a fourth zone is located between the first zone and the third zone, a fifth zone is located between the second zone and the third zone, wherein a process gas is introduced into the fourth zone and the fifth zone, wherein the reactive substance and the first precursor are mixed in the fourth zone, and the reactive substance and the second precursor are mixed in the fifth zone, and a substrate transport mechanism.

Description

Background Art

[0001] Atomic layer deposition ("ALD"), formerly known as atomic layer epitaxy ("ALE"), is a thin film deposition process suitable for depositing conformal coatings on high aspect ratio features. On the other hand, chemical vapor deposition ("CVD") shows higher deposition rates than ALD, but has limited conformal performance. Developing thin film coating methods that can combine high conformality and high deposition rates will aid in the manufacturing development of R2R processes for metamaterials. While preparing thin film coatings is known, better processes and systems are needed to make thin films. Summary of the invention

[0002] The present disclosure relates to a roll-to-roll vapor deposition system and method for producing conformal metal oxide coatings at high speeds. The system and method of the present disclosure can achieve very high deposition rates on a variety of substrates.

[0003] In a first aspect, a system is provided. The system may include a first zone into which a first precursor is introduced, a second zone into which a second precursor is introduced, a third zone between the first zone and the second zone, and in which a reactive species is produced, a fourth zone between the first zone and the third zone, a fifth zone between the second zone and the third zone, wherein a process gas is introduced into the fourth zone and the fifth zone, wherein the reactive species and the first precursor are mixed in the fourth zone, and the reactive species and the second precursor are mixed in the fifth zone, and a substrate transport mechanism.

[0004] In another aspect, a method is provided. The method may include conveying a substrate via a first support roller and a second support roller; repeating the following sequence of steps to form a thin film on the substrate: (a) contacting the substrate with a precursor; (b) contacting the substrate with a mixture of a reactive substance and the precursor; and (c) contacting the substrate with plasma and the reactive substance.

[0005] The above summary is not intended to describe each disclosed embodiment or every implementation of the present disclosure.The following figures and detailed description more particularly illustrate illustrative embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Throughout the specification, reference is made to the accompanying drawings wherein like reference numerals represent like elements, and wherein:

[0007] Figure 1 A schematic cross-sectional view of one embodiment is shown illustrating a system and method for roll-to-roll vapor deposition;

[0008] Figure 2 A cross-sectional SEM image of Example 1 is shown.

[0009] Figure 3 A cross-sectional SEM image of Example 2 is shown.

[0010] Figure 4 A cross-sectional SEM image of Example 3 is shown.

[0011] The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it should be understood that the use of a number to refer to a component in a given figure is not intended to limit the component labeled with the same number in another figure. DETAILED DESCRIPTION

[0012] For the following Glossary of defined terms, these definitions shall govern throughout this application, unless a different definition is provided in the claims or elsewhere in the specification.

[0013] Glossary

[0014] Certain terms are used throughout the specification and claims, which, although mostly well known, may require some explanation. It should be understood that:

[0015] The term "about" or "approximately" with respect to a value or shape means + / -5% of the value or characteristic or feature, but explicitly includes the exact value. For example, a viscosity of "about" 1 Pa-sec means a viscosity of 0.95 Pa-sec to 1.05 Pa-sec, but also explicitly includes a viscosity of exactly 1 Pa-sec.

[0016] The term "substantially" with respect to a property or feature means that the property or feature is exhibited to a greater extent than the opposite side of the property or feature is exhibited. For example, a "substantially" transparent substrate refers to a substrate that transmits more radiation (e.g., visible light) than it does not transmit (e.g., absorbs and reflects). Thus, a substrate that transmits more than 50% of visible light incident on its surface is substantially transparent, but a substrate that transmits 50% or less of visible light incident on its surface is not substantially transparent.

[0017] As used in this specification, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5).

[0018] Figure 11 is a diagram of a system 100 showing a method for manufacturing a conformal metal oxide coating at a high deposition rate. The system 100 can be contained within an inert environment and can include an unwinding roller 110 for unwinding the substrate 114 from an input roller of the substrate 114. The system 100 can include a drum 112 for receiving and moving a moving web. An optional substrate pretreatment source 116 can provide treatment of the surface of the substrate 114, for example, supplying plasma to the substrate 114. The drum 112 can advance the substrate 114 in the direction indicated by the arrow 122. In some embodiments, the system 100 can also include a heating system 124 to heat the substrate 114 before depositing the film on the substrate. The heating system 124 that can be used in the system of the present disclosure includes, for example, one or more of the following: an infrared radiation heating source, a heating drum, a conductive heat source, and an induction heater. In some embodiments, the substrate 114 can be heated to a range of 50°C to 150°C. In some embodiments, the substrate 114 can be heated to a range of 70°C to 100°C. In some embodiments, substrate 114 can be heated to 100° C. In some embodiments, substrate 114 can be heated to 80° C.

[0019] After heating the substrate 114, the substrate 114 is advanced into a coating system 126 for depositing a thin film onto the substrate 114. Figure 2 , the coating system 126 includes a first precursor zone 128 and a second precursor zone 130, respectively, and a third zone 138 in which reactive substances are produced. The coating system 126 also includes a fourth zone 129 between the first precursor zone 128 and the third zone 138, and a fifth zone 131 between the second precursor zone 130 and the third zone 138. When in use, the reactive first precursor gas and the second precursor gas (precursor 1 and precursor 2) are introduced from the first precursor delivery system and the second precursor delivery system into the corresponding first precursor zone 128 and the second precursor zone 130. The precursor delivery system may include a precursor source container (not shown) located outside or inside the first precursor zone 128 and the second precursor zone 130. Additionally or alternatively, the precursor delivery system may include pipes, pumps, valves, tanks and other associated equipment for supplying precursor gases to the first precursor zone 128 and the second precursor zone 130. Similarly, a compound delivery system is included for injecting compounds into the third zone 138 to produce reactive substances. In Figure 1In the illustrated embodiment, the first precursor zone 128, the second precursor zone 130, and the third zone 138 are defined and bounded by an outer reaction chamber housing or container 140, separated by a first partition 142 and a second partition 144. The coating system 126 may include additional zones between the first precursor zone 128 and the zone 138, such as a fourth zone 129 (a first mixing zone), separated by a first partition 142 and a third partition 143. And the coating system 126 may include a fifth zone 131 (a second mixing zone) between the second precursor zone 130 and the third zone 138, separated by a second partition 144 and a fourth partition 145. The fourth zone 129 and the fifth zone 131 (the first mixing zone and the second mixing zone) may include pipes, pumps, valves, tanks, and other associated equipment for allowing gas mixing and transport. A series of first channels 146 through the first partition 142 are spaced apart along the general direction of travel of the substrate 114, and a corresponding series of second channels 148 are provided by the second partition 144. The channels 146, 147, 148, 149 are arranged and configured to allow the substrate 114 to be passed back and forth several times between the first precursor zone 128 and the second precursor zone 130, and each time through the third zone 138, the fourth zone 129 and the fifth zone 131. For a web substrate, the channels 146, 147, 148, 149 preferably include a width (in Figure 1 The slit is slightly larger than the thickness of the substrate 114 and extends to Figure 1 The length in the plane of the substrate (not shown) (i.e., perpendicular to the page) and slightly greater than the width of the substrate. Thus, the third region 138 is preferably separated from the first precursor region 128 by a first separator 142 and is separated from the second precursor region 130 by a second separator 144 (although imperfectly).

[0020] A series of plasma or other free radical generating generators 150 can be operably associated with the third zone 138, wherein the free radical generators 150 operating at 50W to 1500W generate reactive species from the compound 136. The free radical generator 150 may include a radio frequency (RF) plasma generator, a microwave plasma generator, a direct current (DC) plasma generator, an alternating current (AC) plasma generator, or a UV light source, and preferably generates a free radical species population in situ continuously in the third zone 138 by means of, for example, plasma. In some embodiments, the free radical generator 150 is positioned in the third zone 138 so that only one surface of the substrate 114 can contact the reactive species. The reactive species may include, but are not limited to, reactive oxygen, ozone, water, reactive nitrogen, ammonia, and reactive hydrogen. In some embodiments, reactive species may be generated by applying energy to the compound 136, for example, cracking a dry oxygen-containing compound to generate reactive oxygen species. In some such embodiments, a plasma generator (e.g., a DC plasma source, an RF plasma source, or an inductively coupled plasma source) can be powered and decompose dry gaseous oxygen-containing compounds (e.g., dry air, O2, CO2, CO, NO, NO2, or a mixture of two or more of the foregoing, with or without the addition of nitrogen (N2) and / or another suitable inert carrier gas). In some other embodiments, oxygen-containing compounds, such as hydrogen peroxide, water, or mixtures thereof, can be decomposed or cracked via non-plasma activation (e.g., a thermal process). In still other embodiments, ozone may be generated remotely or close to the substrate or substrate path (e.g., via a corona discharge) so that ozone is supplied to the substrate surface. In some embodiments, reactive species can be generated by introducing chemical compounds into the plasma.

[0021] In some embodiments, the first precursor is supplied into the first precursor zone 128. When the substrate 114 enters the first precursor zone 128, the surface 166 of the substrate 114 contacts the first precursor 132, so that the first precursor 132 is chemically adsorbed to the substrate surface, leaving a chemically adsorbed species at the surface that reacts with the reactive species. After the first precursor is deposited on the substrate 114, the substrate 114 then enters the fourth zone 129 (first mixing zone), and in some embodiments, a mixture of the first precursor 132 and the reactive species is supplied to the fourth zone 129. After contacting the mixture of the first precursor 132 and the reactive species, the substrate 114 then enters the third zone 138, and in some embodiments, the reactive species generated in the plasma formed by the compound 136 are supplied to the third zone. After contacting the plasma and the reactive species generated in 138, the substrate 114 then enters the fifth zone 131 (second mixing zone), and in some embodiments, a mixture of the second precursor 134 and the reactive species is supplied to the fifth zone 131.

[0022] The second precursor 134 enters the second precursor zone 130. The substrate 114 enters the second precursor zone 130 and contacts the second precursor 134. Then, before a thin film is formed on the substrate 114, the substrate 114 traverses the fifth zone 131 (second mixing zone), the third zone 138, the fourth zone 129 (first mixing zone), and the first precursor zone 128 for a predetermined number of additional times. In some embodiments, the substrate 114 then traverses the fifth zone 131 (second mixing zone), the third zone 138, the fourth zone 129 (first mixing zone), and the first precursor zone 128 for 2 or more additional times to form the thin film substrate 114. In some embodiments, the substrate 114 then traverses the fifth zone 131 (second mixing zone), the third zone 138, the fourth zone 129 (first mixing zone), and the first precursor zone 128 for 2 to 5 additional times to form the thin film substrate 114. The thin film may have no more than 250nm, not more than 200nm, not more than 150nm, not more than 100nm, not more than 80nm, In some embodiments, the film may have a thickness of at least 1 nm, at least 5 nm, or at least 10 nm. In some embodiments, the film may have a thickness of 1 nm to 100 nm, 5 nm to 80 nm, or 10 nm to 60 nm, 3 nm to 80 nm, 3 nm to 60 nm, 3 nm to 50 nm, 3 nm to 30 nm, or 3 nm to 20 nm.

[0023] The substrate conveying mechanism 151 of the system 100 includes a carriage including a plurality of turning guides for guiding the substrate 114, including a set of first support rollers 152 and a set of second support rollers 152a ( Figure 1 1 ). The substrate transport mechanism 151 may also include a set of idler rollers 154, which may be used to support the substrate 114 during a change in direction of motion of the substrate 114.

[0024] The system 100 may also include a substrate cooling system 156 to cool the substrate 114 after it leaves the ALD coating system 126. The system 100 may also include a drum 158 for receiving and moving the substrate 114. The system 100 may include a take-up roller 164 for receiving the coated substrate 114 and winding the substrate 114 into a take-up roller.

[0025] The system 100 may also include a vapor handling system. The vapor handling system may be any suitable vapor handling system, such as a vapor source for generating vapor and delivering vapor.

[0026] Suitable substrates 114 for use in the systems and methods described herein include flexible materials capable of roll-to-roll processing, such as paper, polymeric materials, metal foils, and combinations thereof. Suitable polymeric substrates include various polyolefins such as polypropylene, various polyesters (e.g., polyethylene terephthalate, fluorene polyesters, polyethylene terephthalate glycol), polymethyl methacrylate, and other polymers such as polyethylene naphthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyester carbonate, polyetherimide, polyarylate, polyimide, vinyl, cellulose acetate, cycloolefin (co)polymers, and fluoropolymers.

[0027] Suitable first precursor 132 and second precursor 134 may include those described in U.S. Publication No. 2014 / 0242736. Non-limiting examples of first precursor 132 may include non-hydroxylated silicon-containing precursors, including compounds such as tris(dimethylamino)silane (SiH[N(CH3)2]3); tetra(dimethylamino)silane (Si[N(CH3)2]4; bis(tert-butylamino)silane (SiH2[HNC(CH3)3]2); trimethylsilylamine ((SiH3)3N) (available under the trade name TSA from L'Air Liquide SA); silanediamine, N,N,N',N'-tetraethyl (SiH2[N(C2H5)2]2) (available under the trade name SAM.24 TM Available from L'Air Liquide S.A.); and hexa(ethylamino)disilane (Si2(NHC2H5)6) (available under the trade name AHEAD TM Available from L'Air Liquide S.A.). Non-limiting examples of the second precursor 134 can include metal-containing precursors such as metal halide compounds (e.g., titanium tetrachloride, tetrakis(dimethylamino)tin (TDMASn), tert-butoxyzirconium, titanium tetraisopropoxide, or TiCl4) and metal organic compounds (e.g., diethylzinc ((DEZ) or Zn(C2H5)2) and trimethylaluminum (TMA)).

[0028] Example

[0029] Material :

[0030]

[0031] Coating equipment :

[0032] The coating is deposited on Figure 1In the vacuum coater schematically shown in FIG, the vacuum coater is similar to the coater in the U.S. patent application publication, which is US20190112711A1 (Lyons et al.). It should be noted that additional separators are added to create a zone between the first precursor 132, the second precursor 134 and the compound 136, thereby creating a new zone XXX, in which the precursors are mixed with the reactive substances in a controlled manner. The entire system including the deposition zone is included in the housing, and both the pressure and the gas atmosphere are controlled within the housing.

[0033] Test Method :

[0034] Ellipsometry :

[0035] The deposited films were characterized by spectroscopic ellipsometry in the wavelength range of 381 nm to 893 nm using an Alpha-SE spectroscopic ellipsometer purchased from JA Woolam Company, Lincoln, NE). For films deposited on PET, the films were characterized by spectroscopic ellipsometry in the wavelength range of 381 nm to 893 nm using a 3M TM Wetordry TM Sandpaper, 1000 Grit (available from 3M Company, Saint Paul, MN) was used to grind the back side of the polymer substrate to scatter light and suppress back surface reflections so that anisotropic effects from PET were minimized as described in JN Hilfiker, B. Pietz et al., "Spectroscopic ellipsometry characterization of coatings on biaxially anisotropic polymeric substrates", Appl. Surf. Sci. (2016). Samples were measured in "standard" measurement mode and sample alignment. The deposited layers were modeled with Cauchy dispersions, including appropriate surface roughness.

[0036] Methods used in Scanning Electron Microscopy (SEM) :

[0037] Imaging was performed using a model HITACHI 4700FE-SEM (purchased from Hitachi America, Ltd, Santa Clara, CA). The sample was prepared by removing the segment from the desired area and cutting the area of ​​interest with a razor blade after clamping the opposite sides of the segment between the clamps. The cross-sectional portion of the sample was mounted on an aluminum SEM pestle using conductive carbon tape, with the cross-sectional area facing upward.

[0038] All samples were coated with a thin (<2 nm) layer of AuPd alloy by DC sputtering in a Bench Turbo Coater (purchased from Denton Vacuum, Moorestown, NJ) to reduce sample charging effects in the SEM.

[0039] Example

[0040] Example 1 :

[0041] The sample of Example 1 was prepared on a vacuum coating system as described above. This system was wound with a substrate in the form of an indefinite length roll of a PET substrate. The system was evacuated again to reduce the pressure to less than 10 mTorr. 4SLM N2 was then introduced into the system to increase the pressure to about 100 mTorr, and the substrate was advanced at a constant linear speed of 3 m / min, heated to 65°C with an infrared lamp, and translated through a deposition chamber heated to 65°C to dry the substrate before the deposition process. The deposition chamber was then heated to 100°C before the deposition process began. During the deposition process, the substrate was advanced at a constant linear speed of 3 m / min. The TTIP loaded into one or more precursor bubbler sources enclosed in a heating jacket was heated to 80°C, and N2 was introduced to push gas at 300 sccm / source. The precursor delivery line connecting the heating source to the first and second zones was heated to 90°C. TTIP was continuously delivered to the first and second zones of the system. N2O and N2 process gases were introduced into the fourth and fifth zones and split between the fourth and fifth zones at flow rates of 3 SLM and 10 SLM. 2.5 SLM N2 was introduced outside the deposition zone, with a total pressure inside the system of about 1.05 Torr. The plasma array was ignited and heated at 20 kW (AC, current density = 0.6 mA / cm 2 ) power control. A mixture of reactive species, process gases and precursors is removed from the fourth and fifth zones in a balanced extraction manner. The web is translated forward and backward through the deposition chamber to achieve a target thickness.

[0042] Figure 2 A cross-sectional SEM image of Example 1 is shown.

[0043] Example 2 :

[0044] Example 2 was deposited in the same manner as Example 1, but with a line speed of 7.6 m / min. Figure 3 A cross-sectional SEM image of Example 2 is shown.

[0045] Example 3 :

[0046] Example 3 was deposited in the same manner as Example 1, but with a line speed of 0.6 m / min and a plasma power of 20 kW. Figure 4 A cross-sectional SEM image of Example 3 is shown.

[0047] The deposition rates and optical properties of the samples were determined using ellipsometry as described above. The results are reported in Table 1 below.

[0048] Table 1

[0049]

[0050] Comparative Example

[0051] Comparative Example 1 :

[0052] Comparative Example 1 was prepared on a vacuum coating system similar to that described in U.S. Patent No. 20190112711A1 (Lyons et al.). The system was wound with a substrate in the form of an indefinite length roll of a PET substrate. The system was evacuated again to reduce the pressure to less than 10 mTorr. The PET substrate was then dried in a manner similar to that described in Example 1 before the deposition process. The deposition chamber was then heated to 100°C before the deposition process began. During the deposition process, the substrate was advanced at a linear speed of 15.2 m / min for the first four passes through the system, and at a linear speed of 30.5 m / min for the next six passes through the system. According to previous experiments and the expected growth characteristics of the atomic layer deposition process, the thickness of each deposition is expected to be independent of the linear speed. The TTIP loaded into one or more precursor bubbler sources enclosed in a heating jacket was heated to 80°C, and N2 was introduced as a push gas at 300 sccm / source. The precursor delivery line connecting the heating source to the first zone and the second zone was heated to 90°C. TTIP was continuously delivered to the first and second zones of the system. N2O and N2 process gases were introduced to the fourth and fifth zones and split between the fourth and fifth zones at flow rates of 4 SLM and 15 SLM. 2.5 SLM N2 was introduced outside the deposition zone (sealed gas) with a total pressure of about 1.4 Torr inside the system. The plasma array was ignited and heated at 20 kW (AC, current density = 0.6 mA / cm 2 ) power control. A mixture of reactive species, process gases and precursors is removed from the first zone and the second zone in a balanced extraction manner. The web is translated forward and backward through the deposition chamber to achieve a target thickness.

[0053] Comparative Example 2 :

[0054] Comparative Example 2 was prepared in the same manner as Example 1, except that the measured PET substrate was not translated through the system during deposition, but rather the sample was fixed in the fourth zone and therefore not in direct contact with the precursors in the first or second zones, or with the plasma in the third zone. The sample was oriented in the same manner as the translated web.

[0055] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by one skilled in the art utilizing the teachings disclosed herein.

[0056] All references and publications cited herein are expressly incorporated by reference in their entirety into the present disclosure, except for the contents that they may directly conflict with the present disclosure. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that the specific embodiments shown and described may be replaced with a variety of alternative and / or equivalent implementations without departing from the scope of the present disclosure. The present application is intended to cover any modification or variation of the specific embodiments discussed herein. Therefore, the present disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. A roll-to-roll vapor deposition system, the system comprising: a first zone into which a first precursor is introduced; a second zone into which a second precursor is introduced; a third zone, the third zone being located between the first zone and the second zone and in which reactive species are produced; a fourth zone, the fourth zone being located between the first zone and the third zone; a fifth zone, the fifth zone being located between the second zone and the third zone; wherein the first zone, the second zone, and the third zone are defined by an outer reaction chamber housing; wherein a process gas is introduced into the fourth zone and the fifth zone; wherein the reactive substance and the first precursor are mixed in the fourth zone, and the reactive substance and the second precursor are mixed in the fifth zone; and Substrate conveying mechanism. 2 . The system of claim 1 , further comprising a vapor handling system comprising a vapor source for generating vapor.

3. The system of claim 1 or 2, wherein a second surface of the substrate opposite the first surface of the substrate is substantially free from contact with the reactive species.

4. The system according to claim 1 or 2, further comprising a substrate heating system for preheating the substrate.

5. The system of claim 1 or 2, further comprising a substrate cooling system for cooling the substrate.

6. The system of claim 1 or 2, wherein the mixture of the reactive species and the process gas is removed by a pump.

7. The system according to claim 1 or 2, further comprising a free radical generator for supplying reactive species to the third zone.

8. A roll-to-roll vapor deposition method, the method comprising: conveying the substrate via a first support roller and a second support roller; The following sequence of steps is repeated to form a thin film on the substrate: (a) contacting the substrate with a precursor; (b) contacting the substrate with a mixture of a reactive substance and the precursor; and (c) exposing the substrate to plasma and the reactive species. 9 . The method of claim 8 , further comprising (d) removing the mixture of the reactive species and the precursor.

10. The method of claim 8 or 9, wherein a second surface of the substrate opposite the first surface of the substrate is substantially free from contact with the reactive species.

11. The method of claim 8 or 9, wherein the reactive species is generated by applying energy to a compound.

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