WO2016180447A1

WO2016180447A1 - Method of manufacturing a layer for display manufacturing using hydrogen and apparatus therefore

Info

Publication number: WO2016180447A1
Application number: PCT/EP2015/060232
Authority: WO
Inventors: Daniel Severin; Andreas KLÖPPEL; Markus Hanika; Marcus Bender
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2015-05-08
Filing date: 2015-05-08
Publication date: 2016-11-17
Anticipated expiration: 2017-11-08

Abstract

A method of manufacturing a layer for a plurality of thin film transistors for display manufacturing and an apparatus therefore is described. The method includes sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere. The processing gas atmosphere includes H₂, O₂, and an inert gas, wherein the content of H₂ is from 2.2% to 20.0%, the content of O₂ is from 0.5% to 15.0%, and the content of inert gas is from 65.0% to 97.3 %. The apparatus (200) includes a vacuum chamber (210); one or more indium oxide containing targets (220a, 220b) within the vacuum chamber for sputtering a transparent conductive oxide layer; a gas distribution system (230) for providing a processing gas within the vacuum chamber; and a controller (240) connected to the gas distribution system and configured to execute a program code for conducting the method.

Description

METHOD OF MANUFACTURING A LAYER FOR DISPLAY

MANUFACTURING USING HYDROGEN AND APPARATUS THEREFORE

TECHNICAL FIELD [0001] The present disclosure relates to a method and an apparatus for coating a substrate in a vacuum process chamber. In particular the present disclosure relates to an apparatus and a method for forming at least one layer of sputtered material on a substrate for display manufacturing.

BACKGROUND [0002] In many applications, deposition of thin layers on a substrate, e.g. on a glass substrate is desired. Conventionally, the substrates are coated in different chambers of a coating apparatus. For some applications, the substrates are coated in a vacuum using a vapor deposition technique. Several methods are known for depositing a material on a substrate. For instance, substrates may be coated by a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process or a plasma enhanced chemical vapor deposition (PECVD) process, etc. Usually, the process is performed in a process apparatus or process chamber where the substrate to be coated is located.

[0003] Electronic devices and particularly opto-electronic devices show a significant reduction in costs over the last years. Further, the pixel density in displays is continuously being increased. For TFT displays, a high density TFT integration is desired. However, in spite of the increased number of thin-film transistors (TFT) within a device, an increase in the yield and a reduction in the manufacturing costs are attempted.

[0004] Accordingly, there is a continuing demand for providing methods and apparatuses for tuning the TFT display properties during manufacturing, in particular with respect to high quality and low cost. SUMMARY

[0005] In view of the above, a method of manufacturing a layer for a plurality of thin film transistors for display manufacturing and an apparatus therefore, according to the independent claims are provided. Further, an electronic device including a layer which is manufactured by the method of manufacturing a layer according to embodiments described herein is provided. Further advantages, features, aspects and details are apparent from the dependent claims, the description and drawings.

[0006] According to one aspect of the present disclosure, a method of manufacturing a layer for a plurality of thin film transistors for display manufacturing is provided. The method includes sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere. The processing gas atmosphere includes H_2, 0₂, and an inert gas, wherein the content of H₂ is from 2.2% to 20.0%, wherein the content of 0₂ is from 0.5% to 15.0%, and wherein the content of inert gas is from 65.0% to 97.3 %. [0007] According to a further aspect of the present disclosure, an electronic device is provided which includes a layer which is manufactured by the method of manufacturing a layer for a plurality of thin film transistors according to embodiments described herein.

[0008] According to a further aspect of the present disclosure, an apparatus for depositing a layer for display manufacturing is provided. The apparatus includes a vacuum chamber, one or more indium oxide containing targets within the vacuum chamber for sputtering a transparent conductive oxide layer, a gas distribution system for providing a processing gas within the vacuum chamber, and a controller connected to the gas distribution system and configured to execute a program code, wherein upon execution of the program code the method of manufacturing a layer for a plurality of thin film transistors for display manufacturing according to embodiments described herein is conducted. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] So that the manner in which the above recited features of the disclosure described herein can be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIG. 1 shows a schematic view of an apparatus for depositing a layer for display manufacturing according to embodiments described herein;

FIG. 2 shows a block diagram illustrating a method of manufacturing a layer for a plurality of thin film transistors for display manufacturing according to embodiments as described herein;

FIG. 3 shows a block diagram illustrating a method of manufacturing a layer for a plurality of thin film transistors for display manufacturing according to embodiments as described herein.

DETAILED DESCRIPTION OF EMBODIMENTS [0010] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. In the following, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield a further embodiment. It is intended that the description includes such modifications and variations.

[0011] In the present disclosure, the expression "processing gas atmosphere" may be understood as an atmosphere inside a processing chamber, particularly inside a vacuum processing chamber of an apparatus for depositing a layer. The "processing gas atmosphere" may have a volume which is specified by the volume inside the processing chamber.

[0012] In the present disclosure, the abbreviation "H₂" stands for hydrogen, in particular for gaseous hydrogen. [0013] Further, in the present disclosure, the abbreviation "0₂" stands for oxygen, in particular for gaseous oxygen.

[0014] In the present disclosure, the expression "degree of amorphous structure" may be understood as the ratio of amorphous structure to non-amorphous structure in the solid state. The non-amorphous structure may be a crystalline structure. The amorphous structure may be a glass-like structure.

[0015] In the present disclosure, the expression "sheet resistance" may be understood as the resistance of a layer manufactured by the method according to embodiments described herein. In particular, "sheet resistance" may refer to a case in which the layer is considered as a two-dimensional entity. It may be understood that the expression "sheet resistance" implies that the current is along the plane of the layer (i.e. the current is not perpendicular to the layer). Further, sheet resistance may refer to a case of resistivity for a uniform layer thickness.

[0016] In FIG. 1 a schematic view of an apparatus 200 for depositing a layer for display manufacturing according to embodiments described herein is shown. According to embodiments as described herein, the apparatus for depositing a layer for display manufacturing includes a vacuum chamber 210; one or more indium oxide, particularly indium tin oxide (ITO), containing targets 220a, 220b within the vacuum chamber for sputtering a transparent conductive oxide layer; a gas distribution system 230 for providing a processing gas within the vacuum chamber; and a controller 240 connected to the gas distribution system 230 and configured to execute a program code. Upon execution of the program code the method of manufacturing a layer for a plurality of thin film transistors for display manufacturing as described herein is conducted. [0017] As exemplarily shown in FIG. 1, according to embodiments which can be combined with other embodiments described herein, the vacuum chamber 210 is limited by chamber walls 211 and may be connected to the gas distribution system 230 at a first gas inlet 231 for H₂ and a second gas inlet 232 for 0₂. As shown in FIG. l, the first gas inlet 231 may be connected to the gas distribution system 230 via a first conduit having a first mass flow controller 234 configured for controlling an amount of H₂ provided to the processing gas atmosphere, for example a first valve. The second gas inlet 232 may be connected to the gas distribution system 230 via a second conduit having a second mass flow controller 235 configured for controlling an amount of 0₂ provided to the processing gas atmosphere, for example a second valve.

[0018] According to embodiments which can be combined with other embodiments described herein, the gas distribution system may include a first gas source for providing H₂ and a second gas source for providing 0₂. Accordingly, the apparatus as described herein may be configured for providing H₂ and 0₂ independently from each other, such that the H₂ content and/or the 0₂ content of the processing gas atmosphere 222 within the vacuum chamber 210 can independently be controlled.

[0019] According to embodiments which can be combined with other embodiments described herein, the gas distribution system may include a third gas source for providing an inert gas. The third gas source may be configured for providing the inert gas to the processing gas atmosphere separately form H₂ and/or 0₂, for example through a separate third gas inlet which connects the vacuum chamber with the third gas source of the gas distribution system. According to embodiments which can be combined with other embodiments described herein, the gas distribution system may include an inert gas flow controller (not shown) configured for controlling an amount of inert gas provided to the processing gas atmosphere. According to some embodiments, which can be combined with other embodiments described herein, the third gas source may be employed for providing an inert gas/H₂ mixture which can be provided to the processing gas atmosphere inside the vacuum chamber through the first gas inlet. Additionally or alternatively, the third gas source may be employed for providing an inert gas/0₂ mixture which can be provided to the processing gas atmosphere inside the vacuum chamber through the second gas inlet. [0020] According to embodiments which can be combined with other embodiments described herein, the first gas source of the gas distribution system 230 for providing H₂ to the processing gas atmosphere 222 in the vacuum chamber 210 may provide an inert gas/H₂ mixture. The partial pressure of the inert gas in the inert gas/H₂ mixture may be selected from a range between a lower limit of inert gas partial pressure and an upper limit of inert gas partial pressure as specified herein. Accordingly, the partial pressure of the H₂ in the inert gas/H₂ mixture may be selected from a range between a lower limit of H₂ partial pressure and an upper limit of H₂ partial pressure as specified herein.

[0021] According to embodiments which can be combined with other embodiments described herein, the second gas source of the gas distribution system 230 for providing 0₂ to the processing gas atmosphere 222 in the vacuum chamber 210 may provide an inert gas/0₂ mixture. The partial pressure of the inert gas in the inert gas/0₂ mixture may be selected from a range between a lower limit of inert gas partial pressure and an upper limit of inert gas partial pressure as specified herein. Accordingly the partial pressure of the 0₂ in the inert gas/0₂ mixture may be selected from a range between a lower limit of 0₂ partial pressure and an upper limit of 0₂ partial pressure as specified herein.

[0022] According to embodiments which can be combined with other embodiments described herein, the gas distribution system 230 may include pumps and/or compressors for providing the desired pressure of the processing gas atmosphere inside the vacuum chamber. In particular, the gas distribution system may include pumps and/or compressors for providing the partial pressure of inert gas and/or for providing the partial pressure of H₂ and/or for providing the partial pressure of 0₂ according to the respective partial pressure ranges as specified herein by the respective upper and lower partial pressure limits of inert gas, H₂, and 0₂. [0023] With exemplary reference to FIG. 1, according to embodiments which can be combined with other embodiments described herein, the vacuum chamber 210 may include an outlet port 233, connected to an outlet conduit, which is in fluid connection with an outlet pump 236 for providing the vacuum in the vacuum chamber 210.

[0024] As illustrated in FIG. 1, within the vacuum chamber 210, a first deposition source 223a and a second deposition source 223b may be provided. The deposition sources can, for example, be rotatable cathodes having targets of the material to be deposited on the substrate. In particular, the target may be an indium tin oxide (ITO) containing target, particularly an ITO 90/10 containing target. According to embodiments described herein ΓΓΟ 90/10 includes an indium oxide (In₂0₃) and a tin oxide (Sn0₂) at a ratio of ln₂0₃ : Sn0₂ = 90: 10.

[0025] According to embodiments which can be combined with other embodiments described herein, the cathodes can be rotatable cathodes with magnet assemblies 221a, 221b therein. Accordingly, with the apparatus as described herein magnetron sputtering may be conducted for depositing a layer. As exemplarily shown in FIG. 1 the cathodes of the first deposition source 223a and the second deposition source 223b can be connected to a power supply 250. The power supply 250 may be connected to the controller 240 such that the power supply can be controlled by the controller, as exemplarily shown in FIG. 1. Depending on the nature of the deposition process the cathodes may be connected to an AC (alternating current) power supply or a DC (direct current) power supply. For example, sputtering from an indium oxide target, e.g. for a transparent conductive oxide film, may be conducted as DC sputtering. In case of DC sputtering, the first deposition source 223a may be connected to a first DC power supply and the second deposition source 223b may be connected to a second DC power supply. Accordingly, for DC sputtering the second deposition source 223b and the second deposition source 223b may have separate DC power supplies. According to embodiments which can be combined with other embodiments described herein, DC sputtering may include pulsed-DC sputtering, particularly bipolar-pulsed-DC sputtering. Accordingly, the power supply may be configured for providing pulsed-DC, particularly bipolar-pulsed-DC. In particular, the first DC power supply for the first deposition source 223a and the second DC power supply for the second deposition source 223b may be configured for providing pulsed-DC power. In FIG. 1, a horizontal arrangement of deposition sources and substrate 300 to be coated is shown. In some embodiments, which may be combined with other embodiments disclosed herein, a vertical arrangement of deposition sources and substrate 300 to be coated may be used. [0026] With exemplary reference to FIG. 1, according to embodiments which can be combined with other embodiments described herein, a sensor 270 may be provided in the vacuum chamber 210 for measuring the composition of the processing gas atmosphere 222. In particular, the sensor 270 may be configured for measuring the content of inert gas, H₂, 0₂ and residual gas within the respective content ranges as specified herein.

[0027] As shown in FIG. 1, according to embodiments which can be combined with other embodiments described herein, the sensor 170, gas distribution system 230 including the first mass flow controller 234 and the second mass flow controller 235, and outlet pump 236 may be connected to a controller 240. The controller 240 may control the first mass flow controller 234, the second mass flow controller 235, the inert gas flow controller and the outlet pump 236, so that a atmosphere with a composition as described herein is created and maintained in the vacuum chamber 210. Accordingly, all constituents of a selected processing gas atmosphere with a composition as described herein may be controlled independently from each other. In particular, the controller may be configured for controlling the gas distribution system such that the flow of H₂, the flow of 0_¾ and the flow of inert gas can be controlled independently from each other for establishing a processing gas atmosphere with a selected composition as described herein. Accordingly, the composition of a selected processing gas atmosphere can be adjusted very accurately.

[0028] When the apparatus 200 for depositing a layer for display manufacturing as described herein is used for conducting the method of manufacturing a layer according to embodiments described herein, a substrate 300 may be disposed below the deposition sources, as exemplarily shown in FIG.l. The substrate 300 may be arranged on a substrate support 310. According to embodiments which can be combined with other embodiments described herein, a substrate support device for a substrate to be coated may be disposed in the vacuum chamber. For example, the substrate support device may include conveying rolls, magnet guiding systems and further features. The substrate support device may include a substrate drive system for driving the substrate to be coated in or out of the vacuum chamber 210.

[0029] Accordingly, the apparatus according to embodiments as described herein is configured for manufacturing a layer for a plurality of thin film transistors for display manufacturing by employing the method of manufacturing a layer according to embodiments described herein. [0030] FIG. 2 shows a block diagram illustrating a method of manufacturing a layer for a plurality of thin film transistors for display manufacturing according to embodiments as described herein. The method 100 includes sputtering 101 of a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere. In particular, the target may be an indium tin oxide (ΓΓΟ) containing target, particularly an ΓΓΟ 90/10 containing target. According to embodiments described herein ΓΓΟ 90/10 includes an indium oxide (In₂0₃) and a tin oxide (Sn0₂) at a ratio of ln₂0₃ : Sn0₂ = 90: 10.

[0031] According to embodiments which can be combined with other embodiments described herein, the processing gas atmosphere includes H₂, 0₂ and an inert gas. The inert gas may be selected from the group consisting of helium, neon, argon, krypton, xenon or radon. In particular the inert gas may be argon (Ar). It is to be understood that the content of the constituents of the processing gas atmosphere according to embodiments described herein may add up to 100%. In particular, the content of H₂, 0₂ and inert gas may add up to 100% of the processing gas atmosphere. According to embodiments which can be combined with other embodiments described herein, the method of manufacturing a layer as described herein is carried out at room temperature.

[0032] According to embodiments which can be combined with other embodiments described herein, the content of H₂ in the processing gas atmosphere may be selected from a range between a lower limit of 2.2%, particularly a lower limit of 3.0 %, particularly a lower limit of 4.2%, more particularly a lower limit of 6.1%, and an upper limit of 10%, particularly an upper limit of 15.0%, more particularly an upper limit of 20.0%. With respect to the lower limits of H₂ it is to be understood that the lower explosion limit of H₂ is 4.1% and the lower inertisation limit is 6.0 %. By sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere in which the content of H₂ in the processing gas atmosphere has been selected from a range between a lower limit and an upper limit as described herein, the degree of amorphous structure of the oxide layer may be adjusted. In particular, by increasing the content of H₂ in the processing gas atmosphere the degree of amorphous structure in the oxide layer may be increased. [0033] Accordingly, by sputtering a transparent conductive oxide layer from an indium containing target in a processing gas atmosphere having a content of H₂ as described herein, the formation of a crystalline ITO phase may be suppressed. In view of that, in the case of a subsequent patterning of the sputtered oxide layer, for example by wet chemical etching, a reduction in crystalline ITO residuals on the substrate can be achieved. Accordingly, the quality of a patterned oxide layer employed for TFT display manufacturing can be increased.

[0034] According to embodiments which can be combined with other embodiments described herein, the content of 0₂ in the processing gas atmosphere may be from a range between a lower limit of 0.5%, particularly a lower limit of 1.0%, more particularly a lower limit of 1.5%, and an upper limit of 8.0%, particularly an upper limit of 10.0%, more particularly an upper limit of 15.0%. By sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere in which the content of 0₂ in the processing gas atmosphere has been selected from a range between a lower limit and an upper limit as described herein, the sheet resistance of the oxide layer may be adjusted and optimized with respect to low resistance. In particular, for optimizing the sheet resistance with respect to low resistance, the content of 0₂ has to be selected from a range between a lower critical value and an upper critical value. For, example in case the content of 0₂ is below the lower critical value or above the upper critical value, relatively high values for the sheet resistance may be obtained. Accordingly, embodiments as described herein provide for adjusting and optimizing the sheet resistance oxide layers with respect to low resistance.

[0035] According to embodiments which can be combined with other embodiments described herein, the content of inert gas is in the processing gas atmosphere may be from a range between a lower limit of 65%, particularly a lower limit of 81%, more particularly a lower limit of 87%, and an upper limit of 91.5%, particularly an upper limit of 94.0%, more particularly an upper limit of 97.3%. By sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere in which the content of inert gas in the processing gas atmosphere has been selected from a range between a lower limit and an upper limit as described herein, the quality of the transparent conductive oxide layer can be ensured. In particular, by providing a processing gas atmosphere with inert gas as described herein, the risk of flammability and explosion of H₂ in the processing gas atmosphere can be reduced or even eliminated.

[0036] According to embodiments which can be combined with other embodiments described herein, the processing gas atmosphere consists of H₂, 0₂, an inert gas and a residual gas. The content of H₂, 0₂ and inert gas in the processing gas atmosphere consisting of H₂, 0₂ and inert gas may be selected from a range between a respective lower limit and a respective upper limit as described herein. The residual gas may be any impurity or any contaminant in the processing gas atmosphere. In the processing gas atmosphere consisting of H₂, 0₂, inert gas and a residual gas, the content of residual gas may be from 0.0% to 1.0% of the processing gas atmosphere. According to embodiments which can be combined with other embodiments described herein, the content of residual gas is 0.0% of the processing gas atmosphere. It is to be understood that the content of the constituents of the processing gas atmosphere according to embodiments described herein may add up to 100%. In particular, the content of H₂, 0₂, inert gas and residual gas may add up to 100% of the processing gas atmosphere in the case that residual gas is present in the processing gas atmosphere or in the case that the processing gas atmosphere contains no residual gas, i.e. the content of the residual gas is 0.0%.

[0037] According to embodiments which can be combined with other embodiments described herein, the total pressure of the processing gas atmosphere may be from a range between a lower limit of 0.2 Pa, particularly a lower limit of 0.3 Pa, more particularly a lower limit of 0.4 Pa, and an upper limit of 0.6 Pa, particularly an upper limit of 0.7 Pa, more particularly an upper limit of 0.8 Pa. In particular, the total pressure of the processing gas atmosphere may be 0.3 Pa. By sputtering a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere in which the total pressure of the processing gas atmosphere has been selected from a range between a lower limit to an upper limit as described herein, the degree of amorphous structure of the oxide layer may be adjusted. In particular, by increasing the total pressure of the processing gas atmosphere the degree of amorphous structure in the oxide layer may be increased.

[0038] According to embodiments which can be combined with other embodiments described herein, all constituent gases of the processing gas atmosphere may be mixed prior to establishing the processing gas atmosphere in the vacuum chamber. Accordingly, prior to sputtering or during sputtering the transparent conductive oxide layer all constituent gases of the processing gas atmosphere may be supplied to the vacuum chamber through the same gas showers. In particular, depending on the selected composition of the processing gas atmosphere as described herein, H_2, 0₂ and inert gas may be supplied to the vacuum chamber through the same gas showers. For example, the gaseous constituents of a selected processing gas atmosphere may be mixed in a mixing unit before the gaseous constituents of the selected processing gas are provided into the vacuum chamber via the gas showers. Accordingly, according to some embodiments o which can be combined with other embodiments describe herein, the apparatus for depositing a layer may include a mixing unit for mixing the gaseous constituents of the selected processing gas before the gaseous constituents of the selected processing gas are provided into the vacuum chamber via the gas showers. Accordingly, a very homogenous processing gas atmosphere can be established in the vacuum chamber. [0039] According to embodiments which can be combined with other embodiments described herein, the partial pressure of H₂ in the processing gas atmosphere may be from a range between a lower limit of 0.0044 Pa, for example in a case in which the lower limit of the H₂ content of 2.2% has been selected for a processing gas atmosphere with the lower limit of the total pressure of 0.2 Pa, and an upper limit of 0.16 Pa, for example in a case in which the upper limit of the H₂ content of 20.0% has been selected for a processing gas atmosphere with the upper limit of the total pressure of 0.8 Pa.

[0040] Accordingly, it will be understood that the partial pressure of H₂ in the processing gas atmosphere can be calculated by the product of the selected H₂ content in percent [%] of the processing gas atmosphere and the selected total pressure of the processing gas atmosphere in Pascal [Pa]. Accordingly, depending on the selected values of the upper and lower limits of H₂ content in the processing gas atmosphere and the selected values of the upper and lower limits of the total pressure of the processing gas atmosphere, the corresponding values for the lower and upper limit of the partial pressure of H₂ in the processing gas atmosphere can be calculated and selected. [0041] According to embodiments which can be combined with other embodiments described herein, the partial pressure of 0₂ in the processing gas atmosphere may be from a range between a lower limit of 0.001 Pa, for example in a case in which the lower limit of the 0₂ content of 0.5% has been selected for a processing gas atmosphere with the lower limit of the total pressure of 0.2 Pa, and an upper limit of 0.12 Pa, for example in a case in which the upper limit of the 0₂ content of 15.0% has been selected for a processing gas atmosphere with the upper limit of the total pressure of 0.8 Pa.

[0042] Accordingly, it will be understood that the partial pressure of 0₂ in the processing gas atmosphere can be calculated by the product of the selected 0₂ content in percent [%] of the processing gas atmosphere and the selected total pressure of the processing gas atmosphere in Pascal [Pa]. Accordingly, depending on the selected values of the upper and lower limits of 0₂ content in the processing gas atmosphere and the selected values of the upper and lower limits of the total pressure of the processing gas atmosphere, the corresponding values for the lower and the upper limit of the partial pressure of 0₂ in the processing gas atmosphere can be calculated and selected.

[0043] According to embodiments which can be combined with other embodiments described herein, the partial pressure of inert gas in the processing gas atmosphere may be from a range between a lower limit of 0.13 Pa, for example in a case in which the lower limit of the inert gas content of 65% has been selected for a processing gas atmosphere with the lower limit of the total pressure of 0.2 Pa, and a upper limit of 0.7784 Pa, for example in a case in which the upper limit of the inert gas content of 97.3% have been selected for a processing gas atmosphere with the upper limit of the total pressure of 0.8 Pa.

[0044] Accordingly, it will be understood that the partial pressure of inert gas in the processing gas atmosphere can be calculated by the product of the selected inert gas content in percent [%] of the processing gas atmosphere and the selected total pressure of the processing gas atmosphere in Pascal [Pa]. Accordingly, depending on the selected values of the upper and lower limits of inert gas content in the processing gas atmosphere and the selected values of the upper and lower limits of the total pressure of the processing gas atmosphere, the corresponding values for the lower and the upper limit of the partial pressure of inert gas in the processing gas atmosphere can be calculated and selected.

[0045] As exemplarily shown in the block diagram of FIG. 3, the method of manufacturing a layer for a plurality of thin film transistors for display manufacturing according to embodiments as described herein may further include providing H₂ and 0₂ separately (102) to the processing gas atmosphere. Accordingly, the content of H₂ and 0₂ in the processing gas atmosphere may be controlled independently from each other. Accordingly, high control over the properties of the transparent conductive oxide layer, e.g. the degree of amorphous structure and the sheet resistance, can be achieved. [0046] According to embodiments which can be combined with other embodiments described herein, H₂ may be provided to the processing gas atmosphere in an inert gas/H₂ mixture. By providing H₂ to the processing gas atmosphere in an inert gas/H₂ mixture, the risk of flammability and explosion of H₂ in the gas distribution system can be reduced or even eliminated. The partial pressure of the inert gas in the inert gas/H₂ mixture may be selected from a range between a lower limit of inert gas partial pressure and an upper limit of inert gas partial pressure as specified herein. The partial pressure of the H₂ in the inert gas/H₂ mixture may be selected from a range between a lower limit of H₂ partial pressure and an upper limit of H₂ partial pressure as specified herein.

[0047] According to embodiments which can be combined with other embodiments described herein, 0₂ is provided to the processing gas atmosphere in an inert gas/0₂ mixture. The partial pressure of the inert gas in the inert gas/0₂ mixture may be selected from a range between a lower limit of inert gas partial pressure and an upper limit of inert gas partial pressure as specified herein. The partial pressure of the 0₂ in the inert gas/0₂ mixture may be selected from a range between a lower limit of 0₂ partial pressure and an upper limit of 0₂ partial pressure as specified herein.

[0048] With exemplarily reference to FIG. 3, according to embodiments which can be combined with other embodiments described herein, the method may further include controlling the degree of amorphous structure 103 of the oxide layer by the content of H₂ in the processing gas atmosphere. In particular, by increasing the content of H₂ in the processing gas atmosphere, the degree of amorphous structure in the oxide layer may be increased. In particular, by increasing the content of H₂ in the processing gas atmosphere the number of crystalline grains, particularly at the substrate layer interface may be decreased.

[0049] Further, as exemplarily shown in the block diagram of FIG.3, according to embodiments which can be combined with other embodiments described herein, the method may further include controlling the sheet resistance 104 of the oxide layer with the content of 0₂ in the processing gas atmosphere. In particular, for optimizing the sheet resistance with respect to low resistance after an annealing, the content of 0₂ in the processing gas atmosphere during layer deposition has to be selected from a range between a lower limit and an upper limit as described herein. According to embodiments, after layer deposition an annealing procedure may be performed, for example in a temperature range from 200°C to 250°C.

[0050] According to embodiments which can be combined with other embodiments described herein, the resistivity after annealing of the oxide layer may be from a range between a lower limit 100 μ Ohm cm, particularly a lower limit of 125 μ Ohm cm, more particularly a lower limit of 150 μθΐιιη cm, and an upper limit of 250 μθΐιιη cm, particularly an upper limit 275 μθΐιιη cm, more particularly an upper limit 300 μθΐιιη cm. In particular, the resistivity after annealing of the oxide layer may be approximately 230 μθΐιιη cm. [0051] According to embodiments which can be combined with other embodiments described herein, the method of manufacturing a layer for a plurality of thin film transistors for display manufacturing may further include patterning the layer, for example by etching, in particular wet chemical etching. Further, the method of manufacturing a layer according to embodiments described herein may include annealing the layer, for example after patterning.

[0052] According to embodiments described herein, the layer manufactured by the method of manufacturing a layer according to embodiments described herein may be employed in an electronic device, particularly in an opto-electronic device. Accordingly, by providing an electronic device with a layer according to embodiments described herein, the quality of the electronic device can be improved. In particular, it will be understood by the skilled person, that the method of manufacturing a layer for a plurality of thin film transistors for display manufacturing and an apparatus therefore according to embodiments described herein provide for tuning TFT display properties during manufacturing, in particular with respect to high quality and low cost.

Claims

1. Method (100) of manufacturing a layer for a plurality of thin film transistors for display manufacturing, comprising: sputtering (101) a transparent conductive oxide layer from an indium oxide containing target in a processing gas atmosphere (222), wherein the processing gas atmosphere (222) comprises H_2i 0₂, and an inert gas,

wherein the content of H₂ is from 2.2 % to 20.0%, wherein the content of 0₂ is from 0.5% to 15.0%, and wherein the content of inert gas is from 65.0% to 97.3 %.

2. Method (100) according to claim 1,

wherein the total pressure of the processing gas atmosphere (222) is from 0.2 Pa to 0.8 Pa.

3. Method (100) according to claim 1 or 2,

wherein the partial pressure of H₂ in the processing gas atmosphere (222)is from 0.0044 Pa to 0.16 Pa.

4. Method (100) according to any of claims 1 to 3,

wherein the partial pressure of 0₂ in the processing gas atmosphere (222) is from 0.001 Pa to 0.12 Pa.

5. Method (100) according to any of claims 1 to 4,

wherein the partial pressure of inert gas in the processing gas atmosphere (222) is from 0.13 Pa to 0.7784 Pa.

6. Method (100) according to any of claims 1 to 5,

further comprising providing H₂ and 0₂ separately (102) to the processing gas atmosphere (222).

7. Method (100) according to any of claims 1 to 6,

wherein H₂ is provided to the processing gas atmosphere (222) in an inert gas/H₂ mixture.

8. Method (100) according to any of claims 1 to 7,

wherein 0₂ is provided to the processing gas atmosphere (222) in an inert gas/0₂ mixture.

9. Method (100) according to any of claims 1 to 8,

further comprising controlling the degree of amorphous structure (103) of the oxide layer with the content of H₂ in the processing gas atmosphere (222).

10. Method (100) according to any of claims 1 to 9, further comprising controlling the sheet resistance (104) of the oxide layer with the content of 0₂ in the processing gas atmosphere (222).

11. Method (100) according to any of claims 1 to 10,

wherein the processing gas atmosphere (222) consists of H_2, 0₂, an inert gas and a residual gas,

wherein the content of H₂ is from 2.2% to 20.0%, wherein the content of 0₂ is from 0.5% to 15.0%, wherein the content of inert gas is from 65.0% to 97.3 %, and wherein the content of residual gas is from 0.0 to 1.0%.

Method (100) according to claim 11,

wherein the target is an indium tin oxide (ITO) containing target, particularly ITO 90/10,

wherein the partial pressure of H₂ in the processing gas atmosphere (222) is from 0.0044 Pa to 0.16 Pa, wherein the partial pressure of 0₂ in the processing gas atmosphere (222) is from 0.001 Pa to 0.

12 Pa, wherein the partial pressure of inert gas in the processing gas atmosphere (222) is from 0.

13 Pa to 0.7784 Pa, further comprising: providing H₂ and 0₂ separately to the processing gas atmosphere (222), controlling the degree of amorphous structure of the oxide layer with the content of H_2i and controlling the resistance of the oxide layer with the content of 0_2. wherein the resistivity is from 100 μθΐιιη cm to 300 μθΐιιη cm.

An electronic device comprising a layer which is manufactured by the method (100) according to any of claims 1 to 12.

14. Apparatus (200) for depositing a layer for display manufacturing, comprising: a vacuum chamber (210); one or more indium oxide, particularly indium tin oxide (ITO), containing targets (220a, 220b) within the vacuum chamber for sputtering a transparent conductive oxide layer; a gas distribution system (230) for providing a processing gas within the vacuum chamber; and a controller (240) connected to the gas distribution system (230) and configured to execute a program code, wherein upon execution of the program code a method according to any of claims 1 to 12 is conducted.

15. Apparatus (200) according to claim 14,

wherein the vacuum chamber (210) is connected to the gas distribution system (230) at a first gas inlet (234) for H₂ and at a second gas inlet (235) for 0₂.