TWI551539B - Processing method of transition metal dichalcogenide - Google Patents

Description

Method for preparing transition metal chalcogenide

The invention relates to a method for preparing a transition metal chalcogenide, and in particular to a method for preparing a metal chalcogenide at a low temperature and a normal pressure.

In recent years, due to its excellent electrical, optical and physical properties, the two-dimensional material Graphene has become one of the most popular research topics for scientists. Not only that, but in terms of practical industrial applications, new energy batteries including lithium-ion batteries and solar cells, as well as various types of electronic components such as bendable displays, capacitors and sensors, have produced remarkable high-performance.

However, graphene has no direct energy gap and is difficult to be compatible with the current tantalum process, making Transition Metal Dichalcogenide (TMD), which is similar to the two-dimensional structure of graphene, a new wave of research direction.

At present, the preparation methods of transition metal chalcogenides are commonly used in Exfoliation and Chemical Vapor Deposition (CVD). Among them, although the stripping method is simple in preparation method and can provide a high-quality two-dimensional material, the number of layers after peeling is difficult to control, and it is difficult to apply to mass production. The disadvantage of the existing chemical vapor deposition method is that a two-dimensional material must be prepared in an environment exceeding a vacuum of 500 degrees Celsius and a vacuum of more than 25 torr, and the most reproducible is chalcogen. The source is highly toxic hydrogen sulfide gas (H ₂ S).

The object of the present invention is to provide a method for preparing a transition metal chalcogenide, which can mass-produce transition metal chalcogenide in a low process temperature and a low vacuum to atmospheric environment, so that it can be avoided in the process. The use of toxic gases and significant savings in the cost of vacuum equipment.

According to an embodiment of the invention, there is provided a method of preparing a transition metal chalcogenide, the steps comprising: a preparation step of providing a transition metal substrate, a reactive gas source, and a chalcogen solid source; a vaporization step of heating the chalcogen solid source to produce a chalcogen gas; and a deposition step of introducing the reactant gas source A chalcogen element plasma is generated by assisting ionized chalcogen gas, and the transition metal substrate is heated to form a transition metal chalcogenide layer on the surface of the transition metal substrate by the chalcogen element plasma; wherein the reaction gas source is in the deposition step And the chalcogen gas system is introduced above the transition metal substrate from top to bottom, and one of the deposition steps is a vacuum degree from a low vacuum to a normal pressure, and one of the deposition steps is a process temperature of 150 to 500 degrees Celsius, respectively performing vaporization. The steps and deposition steps are carried out in the dissimilar process space such that the vaporization step of heating the chalcogen solid source does not affect the process temperature of the deposition step.

According to one embodiment of the method for preparing a transition metal chalcogenide, an oxidation step is further included to oxidize the surface of the transition metal substrate after the preparation step.

According to another embodiment of the present invention, there is provided a method of preparing a transition metal chalcogenide, the steps comprising: a preparation step of providing a carrier substrate, a transition metal solid source, a reactive gas source, and a chalcogen solid source; a pre-plating step of heating the transition metal solids from the pre-plated transition metal layer on the carrier substrate; a step of heating a source of chalcogen solids to produce a chalcogen element gas; and a deposition step of introducing a source of reactive gas to assist in ionizing the chalcogen element gas to produce a chalcogenide plasma and heating the carrier substrate to the chalcogen The elemental plasma reacts with the oxidized transition metal layer to form a transition metal chalcogenide layer; wherein, in the deposition step, the reaction gas source and the chalcogen gas system pass from top to bottom over the oxidized transition metal layer, and one of the deposition steps The process vacuum degree is from low vacuum to normal pressure, and one of the deposition steps is a process temperature of 150 to 500 degrees Celsius, and the pre-plating step, the vaporization step and the deposition step are respectively performed in the dissimilar process space to make the pre-plated oxide transition metal layer The pre-plating step and the vaporization step of heating the chalcogen solid source do not affect the process temperature of the deposition step.

According to one embodiment of the method for preparing a transition metal chalcogenide, the carrier substrate may be polyimide, stainless steel, glass, tantalum nitride (Si ₃ N ₄ ), cerium oxide (SiO ₂ ), Aluminum oxide (Al ₂ O ₃ ) or hafnium oxide (HfO ₂ ). The transition metal solid source may be tungsten (W), molybdenum (Mo), nickel (Ni), copper (Cu), indium (In), germanium (Ge), tantalum (Ta), iron (Fe), cobalt (Co). Or titanium (Ti). In the vaporization step, the chalcogen solid source may be sulfur (S), and the sulfur is heated to vaporize the sulfur at 90 to 150 degrees Celsius. The chalcogen solid source may be selenium (Se), and the heated selenium vaporizes selenium at 150 to 300 degrees Celsius. The chalcogen solid source may be neodymium (Te) and heated to a temperature of 400 to 650 degrees Celsius to vaporize the crucible. The deposition process has a process vacuum of 2 Torr or more and 760 Torr or less. One of the deposition steps may have a plasma power of 0 to 500 watts, and the oxidized transition metal layer may have a thickness of 1 to 10 nm. When the thickness of the oxidized transition metal layer is less than 7 nm and the process temperature is greater than or equal to 500 degrees Celsius, the plasma power may be 0 watt. The method for preparing a transition metal chalcogenide further comprises a step of controlling the thickness, changing the thickness of the oxidized transition metal layer to correspond to changing the number of atomic layers of the transition metal chalcogenide layer. When the thickness of the oxidized transition metal layer is 1 nm, a transition metal chalcogenide layer of 1 atomic layer can be formed. The method for preparing a transition metal chalcogenide further comprises a control conversion step of controlling a flow rate ratio of the reaction gas source to change a conversion efficiency of the transition between the chalcogenide plasma and the oxidized transition metal layer into a transition metal chalcogenide layer, the reaction The gas source can be nitrogen and hydrogen. In the control conversion step, the flow ratio of nitrogen and hydrogen may be 1:1, 1:2, 2:1 or 0:1. The pre-plating step may employ an atomic layer deposition technique, a sputtering technique, or an electron beam evaporation technique. The method for preparing a transition metal chalcogenide further comprises a transport step and a mass production step. After the deposition step is completed, the carrier substrate is driven to be transported outward, and the carrier substrate is made of a flexible material. The mass production step repeats the pre-plating step, the vaporization step, the deposition step, and the transfer step in sequence.

According to still another embodiment of the present invention, there is provided a method of preparing a transition metal chalcogenide, the steps comprising: a preparation step of providing a carrier substrate, a transition metal solid source, a reactive gas source, and a chalcogen solid source; a pre-plating step, heating the transition gold The solid source is pre-plated with an unoxidized transition metal layer on the carrier substrate; a vaporization step is performed to heat the chalcogen solid source to generate a chalcogen element gas; and a deposition step is passed to the reaction gas source to assist the ionized chalcogenide The elemental gas generates a chalcogenide plasma, and heats the carrier substrate to react the chalcogenide plasma with the unoxidized transition metal layer into a transition metal chalcogenide layer; wherein the reaction gas source and the chalcogen gas system are in the deposition step Passing from top to bottom over the unoxidized transition metal layer, one of the deposition steps is a vacuum degree from a low vacuum to a normal pressure, and one of the deposition steps is a process temperature of 150 to 500 degrees Celsius, and performing a pre-plating step, The vaporization step and the deposition step are performed in the dissimilar process space, and the pre-plating step of the pre-plated oxidized transition metal layer and the vaporization step of heating the chalcogen solid source do not affect the process temperature of the deposition step.

According to one embodiment of the method for preparing a transition metal chalcogenide, the carrier substrate may be polyimide, stainless steel, glass, tantalum nitride (Si ₃ N ₄ ), cerium oxide (SiO ₂ ), Aluminum oxide (Al ₂ O ₃ ) or hafnium oxide (HfO ₂ ). The source of transition metal solids can be platinum (Pt). In the vaporization step, the chalcogen solid source may be sulfur (S), and the sulfur is heated to vaporize the sulfur at 90 to 150 degrees Celsius. The chalcogen solid source may be selenium (Se), and the heated selenium vaporizes selenium at 150 to 300 degrees Celsius. The chalcogen solid source may be neodymium (Te) and heated to a temperature of 400 to 650 degrees Celsius to vaporize the crucible. The process of the deposition step has a vacuum of 2 Torr or more and 760 Torr or less. One of the deposition steps may have a plasma power of 0 to 500 watts, and the unoxidized transition metal layer may have a thickness of 1 to 50 nm. When the thickness of the unoxidized transition metal layer is less than 7 nm and the process temperature is greater than or equal to 500 degrees Celsius, the plasma power may be 0 watt. The method for preparing a transition metal chalcogenide further comprises a step of controlling the thickness, changing the thickness of the unoxidized transition metal layer to correspond to changing the number of atomic layers of the transition metal chalcogenide layer. When the thickness of the unoxidized transition metal layer is 1 nm, a transition metal chalcogenide layer of 1 atomic layer can be formed correspondingly. The method for preparing a transition metal chalcogenide further comprises a control conversion step of controlling a flow rate ratio of the reaction gas source to change a conversion efficiency of the chalcogenide plasma to the unoxidized transition metal layer to one of the transition metal chalcogenide layers, The source of the reactive gas can be nitrogen and hydrogen. In the control conversion step, the flow ratio of nitrogen and hydrogen may be 1:1, 1:2, 2:1 or 0:1. The pre-plating step may employ an atomic layer deposition technique, a sputtering technique, or an electron beam evaporation technique. The method for preparing a transition metal chalcogenide further comprises a transport step and a mass production step. After the deposition step is completed, the carrier substrate is driven to be transported outward, and the carrier substrate is made of a flexible material. The mass production step repeats the pre-plating step, the vaporization step, the deposition step, and the transfer step in sequence.

Therefore, the present invention provides a method for preparing a transition metal chalcogenide which can produce a transition metal chalcogenide at a low temperature of 150 to 500 degrees Celsius, and the source of the chalcogen element used in the deposition step is a heated solid source and The manner in which it is ionized is to obtain a chalcogenide plasma, so that it is possible to avoid the use of the highly toxic hydrogen sulfide gas conventionally used in the preparation of transition metal chalcogenide techniques in the present invention. More importantly, the present invention can use a flexible film as a substrate, and the transfer roller drives the flexible film to move to the position of each process equipment, and is matched with Atmospheric-pressure plasma technology, thereby lowering the temperature. The continuous process of mass production of transition metal chalcogenide is completed under normal pressure.

100, 300‧‧‧ Plasma Auxiliary Process System

110‧‧‧Reaction chamber

111, 320‧‧‧ first gas inlet

112, 330‧‧‧second gas inlet

120‧‧‧RF generator

130‧‧‧electrode

140, 340‧‧‧ heater

150‧‧‧vacuum pump

210‧‧‧bearing substrate

220‧‧‧Oxidized transition metal layer

230‧‧‧Transition metal chalcogenide layer

310‧‧‧Normal piezoelectric slurry generator

350‧‧‧Transport wheel

420‧‧‧Oxidized transition metal layer

410‧‧‧Flexible substrate

S01, S02, S03, S04, S05, S06, S11, S12, S13, S14, S21, S22, S23, S24, S25, S26‧‧

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; A flow chart of the method.

Figure 2 is a schematic view showing the preparation of the transition metal chalcogenide in Figure 1.

3 is a flow chart showing a method of preparing a transition metal chalcogenide according to another embodiment of the present invention.

Figure 4 is a diagram showing the Raman spectrum of tungsten selenide.

Figure 5 is a diagram showing the Raman spectrum of molybdenum diselenide.

Figure 6 is a diagram showing the Raman spectrum of platinum selenide.

Figure 7A shows the Raman spectrum of different ratios of nitrogen and hydrogen when growing tungsten selenide.

Figure 7B shows the X-ray photoelectron spectroscopy of nitrogen and hydrogen in different proportions when growing tungsten selenide.

Figure 7C shows the X-ray photoelectron spectroscopy of nitrogen and hydrogen in different proportions when growing tungsten selenide.

Fig. 8A is a cross-sectional view showing a tungsten oxide having a thickness of 2 nm observed by a transmission electron microscope.

Fig. 8B is a cross-sectional view showing the growth of tungsten selenide on tungsten trioxide having a thickness of 2 nm as observed in Fig. 8A by a transmission electron microscope.

Fig. 8C is a cross-sectional view showing the thickness of tungsten trioxide having a thickness of 4 to 5 nm observed by a transmission electron microscope.

Fig. 8D is a cross-sectional view showing the growth of tungsten selenide on tungsten trioxide having a thickness of 4 to 5 nm as observed in Fig. 8C by a transmission electron microscope.

Fig. 8E is a cross-sectional view showing the thickness of tungsten trioxide having a thickness of 5 to 7 nm by a transmission electron microscope.

Fig. 8F is a cross-sectional view showing the growth of tungsten selenide on tungsten trioxide having a thickness of 5 to 7 nm as observed by a transmission electron microscope in accordance with Fig. 8C.

Fig. 9A is a graph showing the data of the plasma power of the tungsten selenide grown on the 7 nm thickness of the tungsten trioxide corresponding to the substrate temperature.

Fig. 9B is a graph showing the data of the plasma power corresponding to the substrate temperature of the tungsten di-selenide grown on the tungsten nanometer thickness of 5 nm.

Fig. 9C is a graph showing the data of the plasma power corresponding to the substrate temperature of the tungsten di-selenide grown on the tungsten dioxide of 2 nm thickness.

Figure 10 is a flow chart showing a method of preparing a transition metal chalcogenide according to still another embodiment of the present invention.

Figure 11 is a schematic view showing the preparation of a transition metal chalcogenide in Figure 10.

Please refer to FIG. 1 and FIG. 2 , wherein FIG. 1 is a flow chart showing a method for preparing a transition metal chalcogenide. Figure 2 is a schematic view showing the preparation of the transition metal chalcogenide in Figure 1. In the present embodiment, a plasma assisted process system 100 is used to prepare a transition metal chalcogenide. Therefore, the structure of the plasma assisted process system 100 illustrated in FIG. 2 is included, which includes a reaction chamber 110. An RF generator 120, an electrode 130, a heater 140, and a vacuum pump 150. The reaction chamber 110 has a first gas inlet 111 and a second gas inlet 112 for transporting a chalcogen solid source. The gas produced after heating, as well as nitrogen, and the second gas inlet 112 are used to transport hydrogen as a source of auxiliary plasma.

The method for preparing a transition metal chalcogenide comprises the following steps: Step S01: preparing a substrate, a transition metal solid source, a reactive gas source and a chalcogen solid source; step S02: a pre-plating step, Heating the transition metal solid from the pre-plated transition metal layer on the carrier substrate; step S03: vaporizing step, heating the chalcogen solid source to generate a chalcogen element gas; step S04: depositing step, introducing a reaction gas source to assist The ionized chalcogen gas generates a chalcogenide plasma, and heats the carrier substrate to react the chalcogenide plasma and the oxidized transition metal layer into a transition metal chalcogenide layer; step S05: controlling the thickness step to change the oxidized transition metal The thickness of the layer corresponds to changing the number of atomic layers of the transition metal chalcogenide layer; step S06: controlling the conversion step, controlling a flow rate ratio of the reactive gas source to change the reaction between the chalcogenide plasma and the oxidized transition metal layer to form a transition metal chalcogenide One of the chemical layers conversion efficiency.

The method for preparing the transition metal chalcogenide layer 230 by using the plasma assisted process system 100, the oxidized transition metal layer 220 is formed on the carrier substrate 210, and then the chalcogen gas and the reaction gas source such as nitrogen and hydrogen are simultaneously introduced. The reaction gas source assists the ionization of the chalcogen element gas into a chalcogenide plasma, and the chalcogenide plasma reacts with the oxidized transition metal layer 220 to form the transition metal chalcogenide layer 230.

It should be noted that the pre-plating step of step S02, wherein heating the transition metal solids from the pre-plated oxidized transition metal layer 220 on the carrier substrate 210 is done in advance in the process space outside the reaction chamber 110, and the pre-plating in step S02 is completed. After the step, the carrier substrate 210 having the oxidized transition metal layer 220 is placed in the reaction chamber 110 in order to prevent the temperature change caused by heating the transition metal solid source from affecting the process temperature in the reaction chamber 110.

The same is true of the vaporization step of step S03. The heating of the chalcogen solid source to generate the chalcogen gas is completed in the process space outside the reaction chamber 110, and the chalcogen gas and the reaction are completed after the vaporization step of step S03 is completed. The gas sources are introduced into the reaction chamber 110 together in order to prevent the temperature changes generated by heating the chalcogen solid source from affecting the process temperature within the reaction chamber 110.

And in the deposition step of step S04, wherein the reaction gas source and the chalcogen gas system pass from top to bottom over the oxidized transition metal layer, and one of the deposition steps has a process vacuum ranging from a low vacuum to a normal pressure, and the deposition step A process temperature is 150 to 500 degrees Celsius, and the pre-plating step of step S02, the vaporization step of step S03, and the deposition step of step S04 must be separately performed in the dissimilar process space during the entire process to make the pre-plated oxidized transition metal layer The pre-plating step of step S02 and the vaporization step of step S03 of heating the chalcogen solid source do not affect the process temperature of the deposition step of step S04.

The carrier substrate 210 may be polyimide, stainless steel, glass, tantalum nitride, hafnium oxide, aluminum oxide or hafnium oxide. The transition metal solid source can be tungsten, molybdenum, nickel, copper, indium, bismuth, antimony, iron, cobalt or titanium. And the chalcogen solid source may be sulfur, selenium or tellurium, so the deposition step in step S04 In the case where the chalcogen solid source is sulfur, the sulfur is heated to vaporize at 90 to 150 degrees Celsius. If the solid source of the chalcogen element is selenium, the selenium is heated at 150 to 300 degrees Celsius to vaporize the selenium. If the solid source of the chalcogen element is cerium, the enthalpy is vaporized at a temperature of 400 to 650 degrees Celsius. In theory, sulfur, selenium or niobium must reach the melting point to vaporize, but the actual heating temperature only needs to be close to the respective melting point temperatures, and the transition metal chalcogenide layer 230 can be separately prepared. The pre-plating step of step S02 can be achieved by an oxidized metal coating technique such as atomic layer deposition technique, sputtering technique or electron beam evaporation technique.

The plasma-assisted processing system 100 may have a process vacuum of 2 Torr or more and 760 Torr or less, and the plasma power of the ionized chalcogen gas may be 0 to 500 watts, and the substrate 210 is loaded. The temperature may range from 150 to 500 degrees Celsius, and the thickness of the oxidized transition metal layer 220 may range from 1 to 10 nanometers. When the thickness of the oxidized transition metal layer 220 is less than 7 nm and the temperature of the carrier substrate 210 is as high as 500 degrees Celsius, the plasma power of the ionized chalcogen gas can be 0 watt, because heating The temperature is sufficient to ionize chalcogen elements such as sulfur, selenium or tellurium without the need to additionally apply an electric field to the RF generator 120.

In particular, in the controlling thickness step of step S05, changing the thickness of the oxidized transition metal layer 220 will affect the number of atomic layers that the subsequent transition metal chalcogenide layer 230 can form. Therefore, when the thickness of the oxidized transition metal layer 220 is 1 nm, the transition metal chalcogenide layer 230 of 1 atomic layer can be correspondingly formed, and the thickness of the oxidized transition metal layer 220 is controlled to achieve the transition metal sulphur. The number of atomic layers of the family layer 230.

The method for preparing the transition metal chalcogenide 230 of the present embodiment can also change the flow rate of nitrogen and hydrogen in the control conversion step of step S06, in addition to effectively controlling the number of atomic layers of the grown transition metal chalcogenide layer 230. The ratio determines the conversion efficiency of the transition metal transition layer 220 to the transition metal chalcogenization layer 230, and the reaction gas source is nitrogen and hydrogen, and the flow ratio of nitrogen and hydrogen may be 1:1, 1:2, 2:1 or 0:1.

In addition, if the oxidized transition metal substrate or the transition metal substrate can be found and oxidized, the pre-plating step of the growth oxidized transition metal layer can be omitted.

Please refer to FIG. 3 , which is a flow chart of a method for preparing a transition metal chalcogenide according to another embodiment of the present invention, which is used for preparing a selenium selenide and a selenide such as tungsten selenide. The step of transition metal chalcogenide is as follows: Step S11: preparing step, providing a cerium oxide substrate, a transition metal solid source, a reactive gas source, and a selenium solid source, wherein the transition metal solid source may be molybdenum or tungsten; S12: a pre-plating step of heating a transition metal solid source to form an oxidized transition metal layer on the ceria substrate, the oxidized transition metal layer having a thickness of 1 to 20 nm; and a step S13: a vaporization step of heating the selenium solid source a selenium gas is generated at 150 to 300 degrees Celsius; step S14: a deposition step, a reaction gas source such as hydrogen and nitrogen is introduced to assist the ionization of the chalcogen element gas to produce a selenium plasma, and the cerium oxide is heated to make the selenium plasma The oxidized transition metal layer reacts as a transition metal selenide layer, transition The thickness of the metal selenide layer corresponds to a thickness of the oxidized transition metal layer of 1 to 20 nm.

Also in this embodiment, the control thickness step of step S05 of FIG. 1 and the control conversion step of step S06 may be performed after the deposition step of step S14 according to user requirements to separately control the thickness of the transition metal selenide layer or Conversion efficiency. In the embodiment, as in the previous embodiment, the selenium gas and the reaction gas source must pass from above to above the oxidized transition metal layer, and the transition metal selenide layer has a process vacuum ranging from a low vacuum to a normal pressure. When the transition metal selenide layer is grown, the process temperature, that is, the temperature of the ruthenium dioxide substrate may be 150 to 500 degrees Celsius, and the plasma power may be 0 to 500 watts. Similarly, the pre-plating step of step S12, the vaporization step of step S13, and the deposition step of step S14 must be separately performed in the dissimilar process space, the pre-plating step of step S12 of pre-plating the oxidized transition metal layer, and the heating of chalcogen elements. The vaporization step of step S13 of the solid source does not affect the process temperature of the deposition step of step S14.

Additionally, the foregoing steps can be used to generate platinum di-selenide. However, it is particularly noted that if platinum selenide is to be formed, a pure platinum metal layer, rather than an oxidized metal layer, needs to be plated in the pre-plating step of the aforementioned step S12.

Please refer to FIG. 4 to FIG. 6 , which respectively show the Raman spectrum diagrams of the aforementioned tungsten selenide, molybdenum diselenide and platinum disel selenide. The tungsten selenide diselenide diselenide selenide selenide can be seen from the position of 247 cm ^-1 and 250 cm ^{-1 in} Fig. 4 to represent the Raman absorption peak of tungsten selenide (since the two are too close, so The middle phase is combined to show a broad absorption peak. The Raman absorption peak representing molybdenum diselenide is shown at 243 cm ^-1 and 290 cm ^{-1 in} Fig. 5, and 177 cm in Fig. 6 ^- The Raman absorption peak representing platinum di-selenide was observed at positions ¹ and 205 cm ^-1 . In Figure 4 and Figure 5, the ceria substrate signal at 300 cm ^-1 is visible. Figure 7 is because the thickness of platinum selenide is thick. Raman measurement of incident light cannot penetrate selenium. Platinum is etched, so the Raman signal of the ruthenium dioxide substrate cannot be seen in the figure. The process conditions for the detailed description of tungsten diselenide, molybdenum diselenide and platinum disel selenide are as follows.

Process conditions of tungsten selenide: The temperature of the ruthenium dioxide substrate is 200 degrees Celsius. The plasma power is 500 watts. The pre-plated tungsten trioxide has a thickness of 7 nm. The heating temperature of the selenium solid source is 200 degrees Celsius.

Molybdenum diselenide process conditions: the ruthenium dioxide substrate heating temperature is 250 degrees Celsius. The plasma power is 400 watts. The pre-plated molybdenum oxide has a thickness of 7 nm. The heating temperature of the selenium solid source is 150 degrees Celsius.

Platinum diselenide process conditions: the ruthenium dioxide substrate heating temperature is 250 degrees Celsius. The plasma power is 400 watts. The pre-plated platinum has a thickness of 50 nm. The heating temperature of the selenium solid source is 150 degrees Celsius.

Please refer to FIG. 7A, FIG. 7B and FIG. 7C, which respectively show Raman spectrograms and X-ray photoelectron spectra of nitrogen and hydrogen in different proportions when growing tungsten selenide. It can be seen from Fig. 7A that as the proportion of hydrogen is higher, the absorption peak of tungsten diselenide is more obvious and the signal is stronger, which represents the higher conversion efficiency of tungsten to tungsten diselenide, and the flow rate of nitrogen and hydrogen. The ratios are 1:0, 2:1, 1:1, 1:2, and 0:1 from top to bottom, and the conversion efficiencies corresponding to the conversion of tungsten trioxide to tungsten diselenide are 0%, 40%, and 60%, respectively. , 82% and 85%. In this way, the method for preparing the transition metal chalcogenide by the plasma assisted process system of the present embodiment is also verified, and the flow ratio of the nitrogen gas and the hydrogen gas can be changed to control the conversion efficiency of the transition metal transition layer into the transition metal chalcogenide, and Display However, when the flow ratio of nitrogen to hydrogen is 1:0, the absorption peaks of tungsten diselenide and tungsten trioxide do not appear.

The spectral position of the X-ray photoelectron spectroscopy (XPS) is quite special for the bonding energy between different materials. In Figures 7B and 7C, the bonding energy of tungsten in tungsten diselenide is 32.1 eV and 34 eV, and the bonding energy of selenium is 55 eV. The bonding energy of tungsten in tungsten trioxide is 35.3 eV and 37.4 eV. And in Figures 7B and 7C, the total area under the flow ratio curves of different nitrogen and hydrogen flows is used to estimate the percentage of tungsten disulfide and tungsten trioxide in the flow ratios of different nitrogen and hydrogen, respectively, to explain the above conversion. effectiveness.

Please refer to FIG. 8A, FIG. 8B, FIG. 8C, FIG. 8D, FIG. 8E and FIG. 8F, wherein FIG. 8A, FIG. 8C and FIG. 8E are respectively used to observe 2 nm by using a transmission electron microscope. Sectional view of tungsten trioxide having a thickness of 4 to 5 nm and 5 to 7 nm, and Figs. 8B, 8D, and 8F are corresponding to the 8A, 8C, and 8E, respectively. An electron microscope was used to observe a profile of tungsten di-selenide grown on tungsten trioxide having a thickness of 2 nm, 4 to 5 nm, and 5 to 7 nm. As the thickness of the tungsten trioxide is higher, the number of atomic layers of tungsten disilicide can be generated, and the two have a certain proportion. In this way, the method for preparing the transition metal chalcogenide by the plasma assisted process system of the present embodiment is also verified, and the thickness of the oxidized transition metal layer can be changed to control the number of atomic layers in which the transition metal chalcogenide layer grows.

Please refer to FIG. 9A, FIG. 9B and FIG. 9C, which respectively show the data of the plasma power corresponding to the substrate temperature of the tungsten selenide grown on the tungsten dioxide of 7 nm, 5 nm and 2 nm thickness. Figure. In Figures 9A, 9B and 9C, the solid square points represent the better-growing tungsten di-selenide, while the hollow dots represent three Tungsten oxide and tungsten disilicide exist simultaneously. Therefore, as the temperature of the ruthenium dioxide substrate is lower, the required plasma power is relatively higher, and the plasma power required to grow tungsten diselenide using the thicker tungsten trioxide is also higher.

Please refer to FIG. 10 and FIG. 11 , wherein FIG. 10 is a flow chart showing a method for preparing a transition metal chalcogenide according to another embodiment of the present invention, and FIG. 11 is a schematic diagram showing the transition in FIG. 10 . Schematic diagram of the preparation of metal chalcogenides. The plasma assisted process system 300 used in the present embodiment includes a normal piezoelectric slurry generator 310, a first gas inlet 320, a second gas inlet 330, a heater 340, and a transfer roller 350. The first gas inlet 320 is used to transport hydrogen gas, and the second gas inlet 330 is used to transport the gas generated by heating the chalcogen solid source and nitrogen.

The method for preparing a transition metal chalcogenide is as follows: Step S21: preparing a flexible substrate, a transition metal solid source, a reactive gas source, and a chalcogen solid source; Step S22: a pre-plating step, Heating the transition metal solid from the pre-plated transition metal layer on the flexible substrate; step S23: vaporizing step, heating the chalcogen solid source to generate a chalcogen element gas; step S24: depositing step, introducing the reaction gas source To assist the ionization of the chalcogen gas at normal pressure to generate a chalcogenide plasma, and heating the flexible substrate to react the chalcogenide plasma with the oxidized transition metal layer into a transition metal chalcogenide layer; step S25: a transport step of causing a transport roller to drive the flexible substrate outward when the deposition step is completed; Step S26: The mass production step, the pre-plating step, the vaporization step, the deposition step, and the transfer step are repeatedly performed in sequence.

Basically, in the method for preparing a transition metal chalcogenide in the present embodiment, the preparation step of step S21, the pre-plating step of step S22, and the deposition step of step S23 are the same as the preparation step of step S01 of FIG. 1 and the pre-plating of step S02. The steps of step S03 and the deposition step of step S03 differ from FIG. 1 only in that the flexible substrate 410 is employed in the present embodiment. In addition, the plasma assisted process system 300 employed in the present embodiment is in a normal pressure environment throughout the transition metal chalcogenide process.

The description of the preparation step of step S21, the pre-plating step of step S22, and the vaporization step of step S23 are omitted here. In the deposition step of step S24, the oxidized transition metal layer 420 has been pre-plated on the flexible substrate 410 by vapor deposition or sputtering, and the chalcogen gas and the reactive gas source system are shown in FIG. The vertical transmission through the normal piezoelectric slurry generator 310 is introduced above the oxidized transition metal layer 420, and is heated by the heater 340 to the flexible substrate 410 to grow a transition metal chalcogenide layer (not shown). When the deposition step of step S25 is completed after the deposition step of step S24 is completed, the transport roller 350 drives the flexible substrate 210 to move outward. Then, the mass production step of step S26 is performed, and the pre-plating step, the deposition step, and the transfer step are repeatedly performed in sequence. Thus, since the transport roller 350 continuously drives the flexible substrate 410, the fixed-position normal piezoelectric slurry generator 310 can be A zonal and continuous transition metal chalcogenide mass production process is continuously performed for the portion of the un-transitioned transition metal chalcogenide layer.

Furthermore, the aforementioned method of preparing a transition metal chalcogenide can of course add a step of controlling the thickness and controlling the conversion step. And in its implementation Among them, the aforementioned oxidized transition metal layer may be replaced by an unoxidized transition metal layer depending on the transition metal property.

Therefore, the method for preparing a transition metal chalcogenide using the plasma assisted process system of the present invention compares the conventional transition metal chalcogenide production technology with not only a lower substrate temperature and a process vacuum, but also eliminates the use of highly toxic hydrogen sulfide. Gas, such a simple process can greatly reduce the manufacturing cost of producing transition metal chalcogenide, and it is of great help to promote the development of metal-chalcogenide-related industries. Most importantly, if the present invention employs a flexible substrate and a normal piezoelectric slurry technology, a continuous process for mass production of a transition metal chalcogenide can be established.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

S01, S02, S03, S04, S05, S06‧‧ steps

Claims (34)

A method for preparing a transition metal chalcogenide, the method comprising: a preparation step of providing a transition metal substrate, a reactive gas source, and a chalcogen solid source; and a vaporization step of heating the chalcogen solid source to generate a a chalcogen element gas; and a deposition step of introducing the source of the reaction gas to assist ionization of the chalcogen element gas to produce a chalcogenide plasma, and heating the transition metal substrate to plasma the chalcogen element to the transition metal Forming a transition metal chalcogenide layer on the surface of the substrate; wherein, in the depositing step, the reactive gas source and the chalcogen gas system pass from above to above the transition metal substrate, and one of the deposition steps is vacuum The degree of low vacuum to normal pressure, one of the deposition steps is a process temperature of 150 to 500 degrees Celsius, respectively performing the vaporization step and the deposition step in the dissimilar process space, so that heating the chalcogen solid source does not affect The process temperature. The method for preparing a transition metal chalcogenide according to claim 1, further comprising: an oxidation step of oxidizing the surface of the transition metal substrate after the preparing step. A method for preparing a transition metal chalcogenide, the method comprising: a preparation step of providing a carrier substrate, a transition metal solid source, a reactive gas source, and a chalcogen solid source; a pre-plating step of heating the transition metal The solid is derived from the pre-plated oxidized transition metal layer on the carrier substrate; a vaporization step of heating the chalcogen solid source to generate a chalcogen gas; and a deposition step of introducing the reactive gas source to assist ionization The chalcogen gas generates a chalcogenide plasma, and heats the carrier substrate to react the chalcogenide plasma with the oxidized transition metal layer into a transition metal chalcogenide layer; wherein the reaction gas source is in the deposition step And the chalcogen gas system is passed from above to below the oxidized transition metal layer, and one of the deposition steps has a process vacuum ranging from a low vacuum to a normal pressure, and one of the deposition steps has a process temperature of 150 to 500 Celsius. And performing the pre-plating step, the vaporizing step and the depositing step respectively in the dissimilar process space, pre-plating the oxidized transition metal layer and heating the chalcogen element Precursor source does not affect the process temperature. The method for preparing a transition metal chalcogenide according to claim 3, wherein the carrier substrate is polyamidamine, stainless steel, glass, tantalum nitride, cerium oxide, aluminum oxide or cerium oxide. . The method for preparing a transition metal chalcogenide according to claim 3, wherein the transition metal solid source is tungsten, molybdenum, nickel, copper, indium, lanthanum, cerium, iron, cobalt or titanium. The method for producing a transition metal chalcogenide according to claim 3, wherein the vaporization step heats the chalcogen solid source to 90 to 150 degrees Celsius, and the chalcogen solid source is sulfur. The method for preparing a transition metal chalcogenide according to claim 3, wherein: the vaporization step heats the chalcogen solid source to 150 to 300 degrees Celsius, and the chalcogen solid source is selenium. The method for producing a transition metal chalcogenide according to claim 3, wherein the vaporization step heats the chalcogen solid source to 400 to 650 degrees Celsius, and the chalcogen solid source is cerium. The method for preparing a transition metal chalcogenide according to claim 3, wherein in the depositing step, the process vacuum degree is 2 Torr or more and 760 Torr or less. A method of preparing a transition metal chalcogenide as described in claim 3, wherein: one of the deposition steps has a plasma power of from 0 to 500 watts. The method for preparing a transition metal chalcogenide according to claim 10, wherein: in the pre-plating step, the oxidized transition metal layer has a thickness of 1 to 10 nm. The method for preparing a transition metal chalcogenide according to claim 11, wherein the plasma power is when the thickness of the oxidized transition metal layer is less than 7 nm and the process temperature is greater than or equal to 500 degrees Celsius It is 0 watts. The method for preparing a transition metal chalcogenide according to claim 3, further comprising: a thickness controlling step of changing a thickness of the oxidized transition metal layer to correspondingly change the number of atomic layers of the transition metal chalcogenide layer. The method for preparing a transition metal chalcogenide according to claim 13, wherein: in the controlling thickness step, when the thickness of the oxidized transition metal layer is 1 nm, the transition metal corresponding to the one atomic layer is formed. Chalcogenide layer. The method for preparing a transition metal chalcogenide according to claim 3, further comprising: a control conversion step of controlling a flow rate ratio of the reaction gas source to change the chalcogenide plasma and the oxidized transition metal layer The reaction is one of the conversion efficiencies of the transition metal chalcogenide layer, which is nitrogen and hydrogen. The method for preparing a transition metal chalcogenide according to claim 15 further comprises: in the control conversion step, the flow ratio of nitrogen and hydrogen is 1:1, 1:2, 2:1 or 0:1 . The method for preparing a transition metal chalcogenide according to claim 3, wherein the pre-plating step employs an atomic layer deposition technique, a sputtering technique or an electron beam evaporation technique. The method for preparing a transition metal chalcogenide according to claim 3, further comprising: a transport step, after the depositing step is completed, driving the carrier substrate to be transported outward, and the carrier substrate is made of a flexible material And the mass production step, the pre-plating step, the vaporization step, the deposition step, and the transferring step are repeatedly performed in sequence. A method for preparing a transition metal chalcogenide, the method comprising: a preparation step of providing a carrier substrate, a transition metal solid source, a reactive gas source, and a chalcogen solid source; a pre-plating step of heating the transition metal The solid source is pre-plated with an unoxidized transition metal layer on the carrier substrate; a vaporization step of heating the chalcogen solid source to generate a chalcogen element gas; and a deposition step of introducing the reaction gas source to assist ionization The chalcogen gas generates a chalcogen plasma and heats the carrier substrate to react the chalcogenide plasma with the unoxidized transition metal layer into a transition metal chalcogenide layer; wherein the deposition step The gas source and the chalcogen gas system are passed from top to bottom over the unoxidized transition metal layer. One of the deposition steps is a vacuum degree from a low vacuum to a normal pressure, and one of the deposition steps is a Celsius temperature. 150 to 500 degrees, and respectively performing the pre-plating step, the vaporizing step and the depositing step in the dissimilar processing space, pre-plating the unoxidized transition metal layer and heating the layer Solid source elements do not affect the process temperature. The method for preparing a transition metal chalcogenide according to claim 19, wherein the carrier substrate is polyamidoamine, stainless steel, glass, tantalum nitride, cerium oxide, aluminum oxide or cerium oxide. . A method of preparing a transition metal chalcogenide according to claim 19, wherein the transition metal solid source is platinum. The method for producing a transition metal chalcogenide according to claim 19, wherein: the vaporization step heats the chalcogen solid source to 90 to 150 degrees Celsius, and the chalcogen solid source is sulfur. The method for preparing a transition metal chalcogenide according to claim 19, wherein: the vaporization step heats the chalcogen solid source to 150 to 300 degrees Celsius, and the chalcogen solid source is selenium. The method for producing a transition metal chalcogenide according to claim 19, wherein the vaporization step heats the chalcogen solid source to 400 to 650 degrees Celsius, and the chalcogen solid source is cerium. The method for preparing a transition metal chalcogenide according to claim 19, wherein in the depositing step, the process vacuum is 2 torr or more and 760 torr or less. A method of preparing a transition metal chalcogenide according to claim 19, wherein: one of the vaporization steps has a plasma power of 0 to 500 watts. The method for preparing a transition metal chalcogenide according to claim 26, wherein: in the pre-plating step, the unoxidized transition metal layer has a thickness of 1 to 50 nm. The method for preparing a transition metal chalcogenide according to claim 27, wherein: when the thickness of the unoxidized transition metal layer is less than 7 nm, and the process temperature is greater than or equal to 500 degrees Celsius, the plasma The power is 0 watts. The method for preparing a transition metal chalcogenide according to claim 19, further comprising: a thickness controlling step of changing a thickness of the unoxidized transition metal layer to correspondingly change a number of atomic layers of the transition metal chalcogenide layer . The method for preparing a transition metal chalcogenide according to claim 29, wherein: in the controlling thickness step, when the thickness of the unoxidized transition metal layer is 1 nm, the transition corresponding to the formation of an atomic layer Metal chalcogenide layer. The method for preparing a transition metal chalcogenide according to claim 19, further comprising: a control conversion step of controlling a flow rate ratio of the reaction gas source to change the chalcogen plasma and the unoxidized transition metal The layer reaction is one of the conversion efficiencies of the transition metal chalcogenide layer, and the source of the reaction gas is nitrogen and hydrogen. The method for preparing a transition metal chalcogenide according to claim 31, further comprising: the ratio of nitrogen to hydrogen flow in the control conversion step is 1:1, 1:2, 2:1 or 0:1 . The method for preparing a transition metal chalcogenide according to claim 19, wherein the pre-plating step employs an atomic layer deposition technique, a sputtering technique or an electron beam evaporation technique. The method for preparing a transition metal chalcogenide according to claim 19, further comprising: a transport step, after the depositing step is completed, driving the carrier substrate to be transported outward, and the carrier substrate is made of a flexible material And the mass production step, the pre-plating step, the vaporization step, the deposition step, and the transferring step are repeatedly performed in sequence.