15  EP 2 000 008 B1 16  [0049] Systems and methods consistent with the em- bodiments disclosedherein may operateoverarelatively wide range of temperatures and pressures. Necessary operating temperaturesandpressures willlargely be de- termined byspecificprocesschemistry. However, for ex- ample, operating pressures may range from relatively low vacuum environments of approximately 0,13 Pa (1 millitorr), to positive pressure environments of 667-2000 hPa (500-1500Torr (approximately 1 to2 atmospheres)) Pressures may be different in different precursor zones, to accommodate the use of precursors having different vapor pressure, molecular mobility, and reactivity char- acteristics, for example. In some embodiments, two or more precursor zones and the inert gas zone may be maintained at different temperatures to optimize f ilm properties and/or throughput. Operating temperatures may also vary frombelowroomtemperature to well above room temperature, at operating temperatures typical of traveling wave ALD reactors. [0050] Heated rollers or turning guides 64, 66, 164, 166, 364, 366 may be utilized in some embodiments, to heat the substrate and promote thin film growth via ALD. One or more of the precursor zones 14, 16, 114, 116, 314, 316and/or theisolationzone 20,120,320 mayalso be heated. The passageways54, 56, 154, 156, 354, 356 may be heated by injecting a heated inert gas directly into the passageways. [0051] In oneembodiment, aplasmadischarge oroth- er source of radicals is included in one or more of the precursor zones, or in an adjacent chamber, to enable plasma- or radical-assisted ALD film growth. [0052] Thesystems and methodsdescribedhereinwill normally result in deposition on both faces of the sub- strate. To achieve single-sided deposition, the substrate may be layered, folded, or masked for deposition, then peeled apart, unfolded, or the mask removed to result in a finishedproduct. Other possible methods of single- sid- ed deposition include deposition on a flattened tubular substrate followed by slitting lengthwise, or slitting of a solid substrate after double-sided deposition. [0053] The systemsand methodsdescribedhereinare notlimitedto deposition onwebsubstratessuchasplas- ticfilms or metal foil. The same basicconfigurationcould be used to coat wire, flexible tubing, woven materials, such as cloth, braided materials such as braided wire or rope, non-woven sheet materials such as paper, con- struction vapor barrier, etc. [0054] The following are further examples of potential applications for the systems and methods disclose herein: 1) On plastic or metal foil, as a gas or chemical bar- rier, as an electrical insulator, as an electrical con- ductor, or as a semiconductor. Specific applications include oxygen and moisture barriers for food or medical packaging, electrically insulating, conduct- ing orsemi- conducting films for largeareasolarcells, flexible displays, and flexible electronics. 2) Coatingson woven materials suchascloth topro- vide fire retardation, or functionalize the surface - to provide moisture or stain resistance, for example. 3) Gasorchemicalbarriers or tubing, suchasplastic tubing used in chemical or medical applications. 4) Mechanical/physical property improvements in woven or pressed-sheet materials - for example, a film that could provide "filler" to join and bind the in- dividual particles or fibers. [0055] Throughout thisspecification,referenceto "one embodiment," or "an embodiment," or "some embodi- ments" means that a particular described feature, struc- ture, or characteristic is included in at least one embod- iment. Thus appearances of the phrases "in one embod- iment," "in an embodiment,""in some embodiments,"and the like, in various places throughout this specification are not necessarilyallreferring to thesameembodiment. Furthermore,thedescribedfeatures, structures, orchar- acteristics may be combined in any suitable manner in one or more embodiments. In some cases, the invention may be practiced without one or more of the specific de- tails or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or not described in detail to avoid obscuring aspects of the embodiments. [0056] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims. a first precursor zone (14, 114, 314) into which a first precursor gas is introduced when the sys- tem is in use; a second precursor zone ( 16, 116, 316) into which a second precursor gas different from the first precursor gas is introduced when the sys- tem is in use; an isolation zone (20, 120, 320)interposed be- tween the first and second precursor zones and into which an inert gas is introduced when the system is in use, the isolation zone including a series of flow-restricting passageways (54, 56, 154, 956, 354, 356) opening into the first and second precursor zones and arranged to pro- vide a series of pathways along which a flexible substrate (12, 112,312) is threaded to traverse back and forth between the first precursor zone and the second precursor zone multiple times and each time through the isolation zone; and a Claims 1. A system (10, 110,310) for depositing a thin film on a flexible substrate (12, 112, 312), comprising: 9