Micro light-emitting diode based on nano thin film transistor driving and preparation method of micro light-emitting diode

Abstract

The invention discloses a micro light emitting diode driven by a bottom gate nano thin film transistor and a top gate nano thin film transistor. Each of the flexible LED lamp beads comprises a flexible substrate, a first dielectric layer, a first metal electrode layer, a second metal electrode layer, a passivation layer, a single-layer nano-film material, a third metal electrode layer, a fourth metal electrode layer, a fifth metal electrode layer, a sixth metal electrode layer, a seventh metal electrode layer, a Micro-LED lamp bead, an eighth metal electrode layer, a ninth metal electrode layer and a tenth metal electrode layer. The micro light-emitting diode designed based on the nano-film material and the flexible substrate can be better applied to bending, twisting, stretching and other scenes, and the integration degree of the array is further increased.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric device preparation, and in particular to a micro light emitting diode driven by a nano thin film transistor and a preparation method thereof. Background Art

[0002] With the advancement of science and technology, electronic products have been integrated into every field of people's lives and have entered thousands of households. People's demands for electronic products have also become diverse, and integrated circuits need to meet people's requirements in various application scenarios. Flexible display technology has been used in some special application scenarios due to its bendability and light weight, and its application scope has become wider and wider. However, flexible display has put forward new requirements for materials in terms of flexibility and toughness, which makes rigid and bulky Si materials no longer suitable for the development of this field. In addition, the complex preparation process of Si-based transistors also limits the development of flexible electronics. Therefore, how to design a flexible micro-light-emitting diode that can better adapt to deformations such as bending, twisting and stretching has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0003] The purpose of the present invention is to provide a micro-light emitting diode driven by a nano-thin film transistor and a preparation method, which can be better applied in scenes such as bending, twisting and stretching, and further increase the integration of the array.

[0004] To achieve the above object, the present invention provides a micro light emitting diode driven by a bottom-gate nano thin film transistor, comprising:

[0005] Flexible substrate, first dielectric layer, first metal electrode layer, second metal electrode layer, passivation layer, single-layer nano film material, third metal electrode layer, fourth metal electrode layer, fifth metal electrode layer, sixth metal electrode layer, seventh metal electrode layer, Micro-LED lamp beads, eighth metal electrode layer, ninth metal electrode layer and tenth metal electrode layer;

[0006] The third metal electrode layer is arranged on the flexible substrate; the fourth metal electrode layer is arranged on the third metal electrode layer; the two ends of the first dielectric layer are partially arranged on the flexible substrate, and the remaining part is arranged on the fourth metal electrode layer; the single-layer nano film material is arranged on the first dielectric layer and is arranged corresponding to the fourth metal electrode layer; the first metal electrode layer is partially arranged at one end of the single-layer nano film material, and partially arranged on the first dielectric layer; the fifth metal electrode layer is partially arranged at the other end of the single-layer nano film material, and partially arranged on the first dielectric layer; the tenth metal electrode layer is arranged on the first dielectric layer on one side of the fifth metal electrode layer and away from the first metal electrode layer; the second metal electrode layer is arranged on the first metal electrode layer; the passivation layer is arranged on the second metal electrode layer; the sixth metal electrode layer is arranged on the fifth metal electrode layer; the ninth metal electrode layer is arranged on the tenth metal electrode layer; the seventh metal electrode layer is arranged on the sixth metal electrode layer; the eighth metal electrode layer is arranged on the ninth metal electrode layer; the two ends of the Micro-LED lamp bead are respectively arranged on the seventh metal electrode layer and the eighth metal electrode layer.

[0007] Optionally, the first metal electrode layer is preferably metal titanium, the second metal electrode layer is preferably metal gold, the third metal electrode layer is preferably metal titanium, the fourth metal electrode layer is preferably metal gold, the fifth metal electrode layer is preferably metal titanium, the sixth metal electrode layer is preferably metal gold, the seventh metal electrode layer is preferably metal indium, the eighth metal electrode layer is preferably metal indium, the ninth metal electrode layer is preferably metal gold, and the tenth metal electrode layer is preferably metal titanium.

[0008] The present invention also discloses a method for preparing a micro-light emitting diode driven by a bottom-gate nano-thin film transistor, which is used to prepare the micro-light emitting diode driven by the bottom-gate nano-thin film transistor described above, and the preparation method comprises:

[0009] Step S1: performing patterning on the flexible substrate using a maskless photolithography device, and further using an electron beam evaporation device to evaporate metal titanium as the third metal electrode layer on the patterned substrate, and evaporating metal gold on the third metal electrode layer as the fourth metal electrode layer;

[0010] Step S2: preparing the first dielectric layer on the flexible substrate and the fourth metal electrode layer;

[0011] Step S3: using chemical vapor deposition to pattern grow molybdenum sulfide MoS2 as a single-layer nano-thin film material on the first dielectric layer;

[0012] Step S4: patterning the source region and the drain region respectively using a maskless photolithography device, and evaporating metal titanium on the patterned regions as the first metal electrode layer and the fifth metal electrode layer using an electron beam evaporation device;

[0013] Step S5: performing patterning on the first dielectric layer using a maskless photolithography device, and using an electron beam device to evaporate metal titanium as the tenth metal electrode layer;

[0014] Step S6: evaporating metal gold on the first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer to serve as the second metal electrode layer, the sixth metal electrode layer and the ninth metal electrode layer respectively;

[0015] Step S7: using an atomic layer deposition device to deposit aluminum oxide as the passivation layer on the second metal electrode layer;

[0016] Step S8: performing patterning on the sixth metal electrode layer and the ninth metal electrode layer respectively using a maskless photolithography device, and using an electron beam evaporation device to evaporate metal indium to serve as the seventh metal electrode layer and the eighth metal electrode layer respectively;

[0017] Step S9: hot-press bonding the Micro-LED lamp beads on the seventh metal electrode layer and the eighth metal electrode layer.

[0018] The present invention also discloses a micro light emitting diode driven by a top-gate nano thin film transistor, comprising:

[0019] Flexible substrate, first dielectric layer, first metal electrode layer, second metal electrode layer, passivation layer, single-layer nano film material, third metal electrode layer, fourth metal electrode layer, fifth metal electrode layer, sixth metal electrode layer, seventh metal electrode layer, Micro-LED lamp beads, eighth metal electrode layer, ninth metal electrode layer and tenth metal electrode layer;

[0020] The first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer are sequentially arranged on the flexible substrate;

[0021] The second metal electrode layer is arranged on the first metal electrode layer; the sixth metal electrode layer is arranged on the fifth metal electrode layer; the ninth metal electrode layer is arranged on the tenth metal electrode layer; the two ends of the single-layer nano-thin film material are respectively arranged on the end of the second metal electrode layer and the end of the sixth metal electrode layer; the two ends of the first dielectric layer are respectively arranged on the second metal electrode layer and the sixth metal electrode layer, the middle part of the first dielectric layer is arranged on the single-layer nano-thin film material, the passivation layer is arranged on the first dielectric layer, the third metal electrode layer is arranged on the passivation layer, the fourth metal electrode layer is arranged on the third metal electrode layer, the seventh metal electrode layer is arranged at one end of the sixth metal electrode layer, the eighth metal electrode layer is arranged on the ninth metal electrode layer, and the two ends of the Micro-LED lamp bead are respectively arranged at the end of the seventh metal electrode layer and the end of the eighth metal electrode layer.

[0022] Optionally, the first metal electrode layer is preferably metal titanium, the second metal electrode layer is preferably metal gold, the third metal electrode layer is preferably metal titanium, the fourth metal electrode layer is preferably metal gold, the fifth metal electrode layer is preferably metal titanium, the sixth metal electrode layer is preferably metal gold, the seventh metal electrode layer is preferably metal indium, the eighth metal electrode layer is preferably metal indium, the ninth metal electrode layer is preferably metal gold, and the tenth metal electrode layer is preferably metal titanium.

[0023] The present invention also discloses a method for preparing a micro-light emitting diode driven by a top-gate nano-thin film transistor, which is used to prepare the micro-light emitting diode driven by the top-gate nano-thin film transistor described above. The preparation method comprises:

[0024] Step S1: performing patterning on the flexible substrate using a maskless photolithography device, and also using an electron beam evaporation device to evaporate three metal titanium layers in the gaps between the patterned substrates, respectively serving as the first metal electrode layer, the fifth metal electrode layer, and the tenth metal electrode layer;

[0025] Step S2: evaporating metal gold on the first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer to serve as the second metal electrode layer, the sixth metal electrode layer and the ninth metal electrode layer respectively;

[0026] Step S3: using a plasma gas chemical vapor deposition device to pattern-grow molybdenum sulfide MoS2 as the single-layer nano-thin film material on the second metal electrode layer and the sixth metal electrode layer;

[0027] Step S4: preparing the first dielectric layer on the second metal electrode layer, the sixth metal electrode layer and the single-layer nano film material;

[0028] Step S5: depositing aluminum oxide as a passivation layer on the first dielectric layer using an atomic layer deposition device;

[0029] Step S6: using electron beam evaporation equipment to evaporate metal titanium on the passivation layer as the third metal electrode layer, and using electron beam evaporation equipment to evaporate metal gold on the third metal electrode layer as the fourth metal electrode layer;

[0030] Step S7: performing patterning on the sixth metal electrode layer and the ninth metal electrode layer respectively using a maskless photolithography device, and using an electron beam evaporation device to evaporate metal indium to serve as the seventh metal electrode layer and the eighth metal electrode layer respectively;

[0031] Step S8: hot-press bonding the Micro-LED lamp beads on the seventh metal electrode layer and the eighth metal electrode layer.

[0032] The present invention also discloses a micro-light emitting diode array driven by a bottom-gate nano-thin film transistor, the array comprising:

[0033] A plurality of micro-LEDs driven by the bottom-gate nano-film transistors as described above; the micro-LEDs driven by the bottom-gate nano-film transistors are referred to as bottom-gate driven diodes;

[0034] The drains of all bottom-gate driven diodes in the same horizontal row are connected, the sources of all bottom-gate driven diodes in the same horizontal row are connected, and the gates of all bottom-gate driven diodes in the same vertical column are connected.

[0035] The present invention also discloses a micro-light emitting diode array driven by a top-gate nano-thin film transistor, the array comprising:

[0036] A plurality of micro-light emitting diodes driven by the top-gate nano-thin film transistors as described above; the micro-light emitting diodes driven by the top-gate nano-thin film transistors are referred to as top-gate driven diodes;

[0037] The drains of all the top-gate driven diodes in the same horizontal row are connected, the sources of all the top-gate driven diodes in the same horizontal row are connected, and the gates of all the top-gate driven diodes in the same vertical column are connected.

[0038] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0039] The present invention discloses a micro-light emitting diode driven by two types of nano-thin film transistors, bottom gate and top gate, each including a flexible substrate, a first dielectric layer, a first metal electrode layer, a second metal electrode layer, a passivation layer, a single layer of nano-thin film material, a third metal electrode layer, a fourth metal electrode layer, a fifth metal electrode layer, a sixth metal electrode layer, a seventh metal electrode layer, a Micro-LED lamp bead, an eighth metal electrode layer, a ninth metal electrode layer and a tenth metal electrode layer. The micro-light emitting diode designed based on nano-thin film material and a flexible substrate can be better applied to scenes such as bending, twisting and stretching, and further increase the integration of the array. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 A front view of a micro light emitting diode driven by a bottom-gate nano-thin film transistor according to an embodiment of the present invention;

[0042] Figure 2 A top view of a micro-light emitting diode driven by a bottom-gate nano-thin film transistor with the passivation layer removed according to an embodiment of the present invention;

[0043] Figure 3 A front view of a micro light emitting diode driven by a top-gate nano-thin film transistor according to an embodiment of the present invention;

[0044] Figure 4 A top view of a micro-light emitting diode driven by a top-gate nano-thin film transistor with the passivation layer removed according to an embodiment of the present invention;

[0045] Figure 5 A schematic diagram of the connection of a Micro-LED array driven by a thin film transistor according to an embodiment of the present invention;

[0046] Figure 6 A top view of a Micro-LED array driven by a bottom-gate thin-film transistor after the passivation layer is removed according to an embodiment of the present invention;

[0047] Figure 7 A top view of a Micro-LED array driven by a top-gate thin-film transistor after the passivation layer is removed according to an embodiment of the present invention;

[0048] Among them, 1. flexible substrate, 2. nano thin film transistor, 3. light emitting diode, 4. first dielectric layer, 5. first metal electrode layer, 6. second metal electrode layer, 7. passivation layer, 8. single-layer nano thin film material, 9. third metal electrode layer, 10. fourth metal electrode layer, 11. fifth metal electrode layer, 12. sixth metal electrode layer, 13. seventh metal electrode layer, 14. Micro-LED lamp beads, 15. eighth metal electrode layer, 16. ninth metal electrode layer, 17. tenth metal electrode layer. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The purpose of the present invention is to provide a micro-light emitting diode driven by a nano-thin film transistor and a preparation method, which can be better applied in scenes such as bending, twisting and stretching, and further increase the integration of the array.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] like Figure 1-2 As shown, the present invention discloses a bottom-gate nano-thin film transistor driven micro-light emitting diode (Micro-LED), comprising: a flexible substrate 1, a first dielectric layer 4, a first metal electrode layer 5, a second metal electrode layer 6, a passivation layer 7, a single layer of nano-thin film material 8, a third metal electrode layer 9, a fourth metal electrode layer 10, a fifth metal electrode layer 11, a sixth metal electrode layer 12, a seventh metal electrode layer 13, a Micro-LED lamp bead 14, an eighth metal electrode layer 15, a ninth metal electrode layer 16 and a tenth metal electrode layer 17. Figure 1 As shown, the nano thin film transistor 2 is composed of a first metal electrode layer 5, a second metal electrode layer 6, a passivation layer 7, a single layer of nano thin film material 8, a third metal electrode layer 9, a fourth metal electrode layer 10, a portion of the fifth metal electrode layer 11 and a portion of the sixth metal electrode layer 12, and the light emitting diode 3 (Micro-LED) is composed of a portion of the fifth metal electrode layer 11, a portion of the sixth metal electrode layer 12, a seventh metal electrode layer 13, a Micro-LED lamp bead 14, an eighth metal electrode layer 15, a ninth metal electrode layer 16 and a tenth metal electrode layer 17.

[0054] The third metal electrode layer 9 is arranged on the flexible substrate 1, and the fourth metal electrode layer 10 is arranged on the third metal electrode layer 9, that is, the top view of the third metal electrode layer 9 and the fourth metal electrode layer 10 are both rectangles with equal areas, and the length of the rectangle is equal to the width of the flexible substrate 1.

[0055] The first dielectric layer 4 is provided at both ends on the flexible substrate 1, and the remaining portion is provided on the fourth metal electrode layer 10. The length of the first dielectric layer 4 is equal to the length of the flexible substrate 1, and the width of the first dielectric layer 4 is less than the width of the flexible substrate 1. The top view of the first dielectric layer 4 is a rectangle. Figure 2 It can be seen that the present invention preferably sets the first dielectric layer 4 in the middle position of the flexible substrate 1, so that the edge of the first dielectric layer 4 is equidistant from the two edges of the flexible substrate 1. The present invention can also set the first dielectric layer 4 at the edge position or asymmetric position of the flexible substrate 1, and the specific setting is selected according to actual needs.

[0056] The single-layer nano-film material 8 is disposed on the first dielectric layer 4 and is disposed corresponding to the fourth metal electrode layer 10 , that is, the fourth metal electrode layer 10 is located below the single-layer nano-film material 8 , or the projection of the single-layer nano-film material 8 from top to bottom completely covers the fourth metal electrode layer 10 .

[0057] The first metal electrode layer 5 is partially arranged at one end of the single-layer nano-thin film material 8, and partially arranged on the first dielectric layer 4; the fifth metal electrode layer 11 is partially arranged at the other end of the single-layer nano-thin film material 8, and partially arranged on the first dielectric layer 4; the tenth metal electrode layer 17 is arranged on the first dielectric layer 4 on one side of the fifth metal electrode layer 11, and is away from the first metal electrode layer 5, and there is a gap between the tenth metal electrode layer 17 and the fifth metal electrode layer 11.

[0058] The second metal electrode layer 6 is arranged on the first metal electrode layer 5; the passivation layer 7 is arranged on the second metal electrode layer 6; the sixth metal electrode layer 12 is arranged on the fifth metal electrode layer 11; the ninth metal electrode layer 16 is arranged on the tenth metal electrode layer 17; the seventh metal electrode layer 13 is arranged at the end of the sixth metal electrode layer 12; the eighth metal electrode layer 15 is arranged on the ninth metal electrode layer 16; and the two ends of the Micro-LED lamp bead 14 are respectively arranged on the seventh metal electrode layer 13 and the eighth metal electrode layer 15.

[0059] In this embodiment, the first metal electrode layer 5 and the second metal electrode layer 6 constitute a drain, the third metal electrode layer 9 and the fourth metal electrode layer 10 constitute a gate, and the fifth metal electrode layer 11, the sixth metal electrode layer 12, the seventh metal electrode layer 13, the eighth metal electrode layer 15, the ninth metal electrode layer 16 and the tenth metal electrode layer 17 constitute a source.

[0060] In this embodiment, the flexible substrate 1 is placed at the bottom layer of the entire structure to support the entire structure. In addition, the flexible substrate 1 is preferably a polyethylene terephthalate film (PET) / polyimide film (PI).

[0061] In this embodiment, the material of the first dielectric layer 4 can be selected from any one of hafnium oxide HfO2, aluminum oxide Al2O3, boron nitride BN and silicon nitride Si3N4, preferably hafnium oxide HfO2.

[0062] Example 2

[0063] The present invention discloses a method for preparing a micro-light emitting diode (Micro-LED) driven by a bottom-gate nano-thin film transistor, comprising the following steps:

[0064] Step S1: patterning is performed on the flexible substrate 1 using a maskless photolithography device, and electron beam evaporation equipment is used to evaporate 5nm of metal titanium as the third metal electrode layer 9 on the patterned substrate, and 50nm of metal gold is evaporated on the third metal electrode layer 9 as the fourth metal electrode layer 10; in this embodiment, the third metal electrode layer 9 and the fourth metal electrode layer 10 are sequentially manufactured on the flexible substrate 1 as the gate, and the third metal electrode layer 9 and the fourth metal electrode layer 10 are interconnected, so as to further enhance the adhesion between the metal flexible substrate 1 and the fourth metal electrode layer 10.

[0065] Step S2: preparing a first dielectric layer 4 on the flexible substrate 1 and the fourth metal electrode layer 10, specifically, using atomic layer deposition of 20 nm thick hafnium oxide HfO2 as the first dielectric layer 4, or patterning high dielectric constant material aluminum oxide Al2O3, boron nitride BN or silicon nitride Si3N4 on the flexible substrate 1 and the fourth metal electrode layer 10 as the first dielectric layer 4.

[0066] Step S3: using chemical vapor deposition to pattern-grow molybdenum sulfide MoS 2 on the first dielectric layer 4 as a single-layer nano-thin film material 8 .

[0067] Step S4: Use a maskless photolithography device to pattern the source region and the drain region respectively, and use an electron beam evaporation device to evaporate 5nm of metal titanium on the patterned area as the first metal electrode layer 5 and the fifth metal electrode layer 11; the source region includes one end of the single-layer nano-thin film material 8 and a portion of the first dielectric layer 4; the drain region includes the other end of the single-layer nano-thin film material 8 and a portion of the first dielectric layer 4.

[0068] Step S5: performing patterning on the first dielectric layer 4 by using a maskless photolithography device, and using an electron beam device to evaporate metal titanium with a thickness of 5 nm as the tenth metal electrode layer 17 .

[0069] Step S6: evaporating 50 nm of metal gold on the first metal electrode layer 5 , the fifth metal electrode layer 11 and the tenth metal electrode layer 17 to serve as the second metal electrode layer 6 , the sixth metal electrode layer 12 and the ninth metal electrode layer 16 , respectively.

[0070] Step S7: using an atomic layer deposition device to deposit 5 nm thick aluminum oxide as a passivation layer 7 on the second metal electrode layer 6, the main function of which is packaging and protection treatment to prevent the device from being damaged by water and oxygen.

[0071] Step S8: patterning the sixth metal electrode layer 12 and the ninth metal electrode layer 16 respectively using maskless photolithography equipment, and using electron beam evaporation equipment to evaporate 2 um thick metal indium as the seventh metal electrode layer 13 and the eighth metal electrode layer 15 respectively.

[0072] Step S9: thermally press-bonding the Micro-LED lamp beads 14 on the seventh metal electrode layer 13 and the eighth metal electrode layer 15 .

[0073] Example 3

[0074] like Figure 3-Figure 4 As shown, the present invention discloses a top-gate nano-thin film transistor driven micro-light emitting diode (Micro-LED), comprising: a flexible substrate 1, a first dielectric layer 4, a first metal electrode layer 5, a second metal electrode layer 6, a passivation layer 7, a single layer of nano-thin film material 8, a third metal electrode layer 9, a fourth metal electrode layer 10, a fifth metal electrode layer 11, a sixth metal electrode layer 12, a seventh metal electrode layer 13, a Micro-LED lamp bead 14, an eighth metal electrode layer 15, a ninth metal electrode layer 16 and a tenth metal electrode layer 17. Figure 1 As shown, the nano thin film transistor 2 is composed of a first metal electrode layer 5, a second metal electrode layer 6, a passivation layer 7, a single layer of nano thin film material 8, a third metal electrode layer 9, a fourth metal electrode layer 10, a portion of the fifth metal electrode layer 11 and a portion of the sixth metal electrode layer 12, and the light emitting diode 3 (Micro-LED) is composed of a portion of the fifth metal electrode layer 11, a portion of the sixth metal electrode layer 12, a seventh metal electrode layer 13, a Micro-LED lamp bead 14, an eighth metal electrode layer 15, a ninth metal electrode layer 16 and a tenth metal electrode layer 17.

[0075] The first metal electrode layer 5, the fifth metal electrode layer 11 and the tenth metal electrode layer 17 are sequentially arranged on the flexible substrate 1, there is a gap between the first metal electrode layer 5 and the fifth metal electrode layer 11, and there is a gap between the fifth metal electrode layer 11 and the tenth metal electrode layer 17; the specific gap size is selected and set according to actual needs.

[0076] The second metal electrode layer 6 is arranged on the first metal electrode layer 5; the sixth metal electrode layer 12 is arranged on the fifth metal electrode layer 11; the ninth metal electrode layer 16 is arranged on the tenth metal electrode layer 17; the two ends of the single-layer nano-thin film material 8 are respectively arranged at the end of the second metal electrode layer 6 and the end of the sixth metal electrode layer 12; the two ends of the first dielectric layer 4 are respectively arranged on the second metal electrode layer 6 and the sixth metal electrode layer 12, the middle part of the first dielectric layer 4 is arranged on the single-layer nano-thin film material 8, the passivation layer 7 is arranged on the first dielectric layer 4, the third metal electrode layer 9 is arranged on the passivation layer 7, the fourth metal electrode layer 10 is arranged on the third metal electrode layer 9, the seventh metal electrode layer 13 is arranged at one end of the sixth metal electrode layer 12, the eighth metal electrode layer 15 is arranged on the ninth metal electrode layer 16, and the two ends of the Micro-LED lamp bead 14 are respectively hot-pressed and bonded to the end of the seventh metal electrode layer 13 and the end of the eighth metal electrode layer 15.

[0077] In this embodiment, for the top gate structure, it is necessary to grow a whole layer of high dielectric constant materials such as aluminum oxide (Al2O3), boron nitride (BN), and silicon nitride (Si3N4), and then perform patterned etching with a width of 80um.

[0078] Example 4

[0079] The present invention discloses a method for preparing a micro-light emitting diode (Micro-LED) driven by a top-gate nano-thin film transistor, comprising the following steps:

[0080] Step S1: patterning the flexible substrate 1 using a maskless photolithography device, and further using an electron beam evaporation device to evaporate three 5nm metal titanium gaps in the patterned substrate, as the first metal electrode layer 5, the fifth metal electrode layer 11 and the tenth metal electrode layer 17 respectively.

[0081] Step S2: 50 nm of metal gold is evaporated on the first metal electrode layer 5, the fifth metal electrode layer 11 and the tenth metal electrode layer 17, respectively, as the second metal electrode layer 6, the sixth metal electrode layer 12 and the ninth metal electrode layer 16. In this embodiment, the first metal electrode layer 5 is interconnected with the second metal electrode layer 6 to further enhance the adhesion between the flexible substrate 1 and the second metal electrode layer 6; the fifth metal electrode layer 11 is interconnected with the sixth metal electrode layer 12 to further enhance the adhesion between the flexible substrate 1 and the sixth metal electrode layer 12; the ninth metal electrode layer 16 is interconnected with the tenth metal electrode layer 17 to further enhance the adhesion between the flexible substrate 1 and the ninth metal electrode layer 16.

[0082] Step S3: using a plasma gas chemical vapor deposition device to pattern-grow molybdenum sulfide MoS2 as a single-layer nano-thin film material 8 on the second metal electrode layer 6 and the sixth metal electrode layer 12 .

[0083] Step S4: Prepare a first dielectric layer 4 on the second metal electrode layer 6, the sixth metal electrode layer 12 and the single-layer nano-film material 8. The specific steps are: use an atomic layer deposition device to pattern-grow 20 nm thick hafnium oxide HfO2 as the first dielectric layer 4 on the second metal electrode layer 6, the sixth metal electrode layer 12 and the single-layer nano-film material 8, or pattern-grow high dielectric constant material aluminum oxide Al2O3, boron nitride BN or silicon nitride Si3N4 as the first dielectric layer 4 on the second metal electrode layer 6, the sixth metal electrode layer 12 and the single-layer nano-film material 8.

[0084] Step S5: using an atomic layer deposition device to deposit 5 nm thick aluminum oxide on the first dielectric layer 4 as a passivation layer 7, the main function of which is packaging protection treatment to prevent the device from being damaged by water and oxygen.

[0085] Step S6: using electron beam evaporation equipment to evaporate 5 nm thick metal titanium on the passivation layer 7 as the third metal electrode layer 9, and using electron beam evaporation equipment to evaporate 50 nm thick metal gold on the third metal electrode layer 9 as the fourth metal electrode layer 10; in this embodiment, the third metal electrode layer 9 and the fourth metal electrode layer 10 are sequentially manufactured on the passivation layer 7 as the gate, and the third metal electrode layer 9 and the fourth metal electrode layer 10 are interconnected.

[0086] Step S7: patterning the sixth metal electrode layer 12 and the ninth metal electrode layer 16 respectively using maskless photolithography equipment, and using electron beam evaporation equipment to evaporate 2 um thick metal indium as the seventh metal electrode layer 13 and the eighth metal electrode layer 15 respectively.

[0087] Step S8: thermally press-bonding the Micro-LED lamp beads 14 on the seventh metal electrode layer 13 and the eighth metal electrode layer 15 .

[0088] Example 5

[0089] like Figure 5 As shown, the Micro-LED array layout includes a nano-thin film transistor array and a Micro-LED array, which are displayed in the form of row selection and column selection respectively. The gates of the same column are interconnected, the drains of the same row are interconnected, and the grounds (GND) of the same row are interconnected. The micro-light-emitting diodes driven by the bottom-gate nano-thin film transistor disclosed in the present invention are combined into a micro-light-emitting diode array driven by the bottom-gate nano-thin film transistor, as shown in FIG. Figure 6 As shown, Figure 6 The passivation layer is removed to better observe the array layout connection method.

[0090] like Figure 6 As shown, the present invention discloses a bottom-gate nano-thin film transistor driven micro-light emitting diode array comprising:

[0091] The bottom-gate nano-thin film transistor driven micro-light emitting diodes described in the multiple embodiments 1; in order to simplify the name later, the present invention will refer to the bottom-gate nano-thin film transistor driven micro-light emitting diodes as bottom-gate driven diodes. Figure 6 As shown, the drains of all bottom-gate driven diodes in the same horizontal row are connected, the sources of all bottom-gate driven diodes in the same horizontal row are connected, and the gates of all bottom-gate driven diodes in the same vertical column are connected.

[0092] In the present invention, while each metal electrode layer is patterned, the array layout interconnects the corresponding column gate metal electrodes, interconnects the corresponding row drain metal electrodes, interconnects the corresponding row source metal electrodes, and interconnects the GND outputs of the same row metal electrodes 16, 17, further optimizing the layout production steps without the need to add additional isolation layers to isolate different layers, further optimizing the layout production process.

[0093] Example 6

[0094] Figure 7 Micro-LED array driven by top-gate nano-thin film transistors, such as Figure 7 As shown, a top-gate nano-thin film transistor-driven micro-light-emitting diode array disclosed in the present invention comprises:

[0095] The micro-LED driven by the top-gate nano-thin film transistor described in the multiple embodiments 3; in order to simplify the name later, the present invention will refer to the micro-LED driven by the top-gate nano-thin film transistor as the top-gate driven diode. Figure 7 As shown, the row and column gating method is the same as the bottom gate, and there is no need to add an additional isolation layer to isolate the interconnection lines.

[0096] The present invention focuses on the application of nano-thin film materials with high specific area, high optical transparency and excellent mechanical flexibility in flexible electronics. Nano-thin film materials bring better mechanical properties and thinner thickness to the devices. PI / PET flexible substrates bring better mechanical properties to display panels. Compared with traditional silicon-based transistors, they have simpler process steps and preparation methods, which greatly reduces the cost and difficulty of flexible display technology in future large-scale preparation processes, making applications such as smart displays and foldable / rollable displays possible in the future.

[0097] The present invention mainly provides a novel design of a highly integrated micro-light-emitting diode display (Micro-LED) array driven by nano-thin film transistors. Top-gate and bottom-gate Micro-LED arrays driven by nano-thin film transistors are designed respectively. Nano-thin film materials are introduced to prepare transistors and flexible substrates, thereby providing thinner channel materials, better bending and folding performance, and good electrical properties. Compared with traditional silicon-based transistors, the area of ​​array device preparation, the number of lithography, deposition, and coating can be reduced, and the dielectric layer material can be fully utilized. There is no need to add an additional isolation layer to isolate different layers of metal, and the integration of the device can be further increased.

[0098] The present invention mainly provides a new type of highly integrated nano-thin film transistor driven Micro-LED array design that can effectively reduce the number of photolithography times of the array layout, and does not need to add additional isolation layers to isolate different layers of metal electrodes, and can effectively control the entire row selection and column selection signals, thereby effectively controlling the on and off of the required Micro-LEDs, which is simpler than the production process of other flexible transistors and displays. At the same time, the gate material of the transistor introduces nano-thin film materials, and the dielectric layer introduces high dielectric constant materials to make it thinner, which can better adapt to deformations such as bending, twisting and stretching, and is more in line with the application scenarios of future flexible displays; at the same time, PI / PET materials have good mechanical flexibility, thereby ensuring the stability of the panel during the bending process. In summary, the present invention can integrate more devices and Micro-LEDs in a limited space by making full use of the advantages of nano-thin film materials in material properties and good mechanical properties of flexible substrates, thereby further effectively increasing the integration of added columns.

[0099] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0100] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A micro light emitting diode driven by a bottom-gate nano thin film transistor, characterized in that: include: Flexible substrate, first dielectric layer, first metal electrode layer, second metal electrode layer, passivation layer, single-layer nano film material, third metal electrode layer, fourth metal electrode layer, fifth metal electrode layer, sixth metal electrode layer, seventh metal electrode layer, Micro-LED lamp beads, eighth metal electrode layer, ninth metal electrode layer and tenth metal electrode layer; The third metal electrode layer is arranged on the flexible substrate; the fourth metal electrode layer is arranged on the third metal electrode layer; the two ends of the first dielectric layer are partially arranged on the flexible substrate, and the remaining part is arranged on the fourth metal electrode layer; the single-layer nano film material is arranged on the first dielectric layer and is arranged corresponding to the fourth metal electrode layer; the first metal electrode layer is partially arranged at one end of the single-layer nano film material, and partially arranged on the first dielectric layer; the fifth metal electrode layer is partially arranged at the other end of the single-layer nano film material, and partially arranged on the first dielectric layer; the tenth metal electrode layer is arranged on the first dielectric layer on one side of the fifth metal electrode layer and away from the first metal electrode layer; the second metal electrode layer is arranged on the first metal electrode layer; the passivation layer is arranged on the second metal electrode layer; the sixth metal electrode layer is arranged on the fifth metal electrode layer; the ninth metal electrode layer is arranged on the tenth metal electrode layer; the seventh metal electrode layer is arranged on the sixth metal electrode layer; the eighth metal electrode layer is arranged on the ninth metal electrode layer; the two ends of the Micro-LED lamp bead are respectively arranged on the seventh metal electrode layer and the eighth metal electrode layer.

2. The bottom-gate nano-thin film transistor driven micro-light emitting diode according to claim 1, characterized in that: The first metal electrode layer is preferably metal titanium, the second metal electrode layer is preferably metal gold, the third metal electrode layer is preferably metal titanium, the fourth metal electrode layer is preferably metal gold, the fifth metal electrode layer is preferably metal titanium, the sixth metal electrode layer is preferably metal gold, the seventh metal electrode layer is preferably metal indium, the eighth metal electrode layer is preferably metal indium, the ninth metal electrode layer is preferably metal gold, and the tenth metal electrode layer is preferably metal titanium.

3. A method for preparing a micro-light-emitting diode driven by a bottom-gate nano-thin film transistor, characterized in that: A method for preparing a micro-light emitting diode driven by a bottom-gate nano-thin film transistor according to any one of claims 1 to 2, comprising: Step S1: performing patterning on the flexible substrate using a maskless photolithography device, and further using an electron beam evaporation device to evaporate metal titanium as the third metal electrode layer on the patterned substrate, and evaporating metal gold on the third metal electrode layer as the fourth metal electrode layer; Step S2: preparing the first dielectric layer on the flexible substrate and the fourth metal electrode layer; Step S3: using chemical vapor deposition to pattern grow molybdenum sulfide MoS2 as a single-layer nano-thin film material on the first dielectric layer; Step S4: patterning the source region and the drain region respectively using a maskless photolithography device, and evaporating metal titanium on the patterned regions as the first metal electrode layer and the fifth metal electrode layer using an electron beam evaporation device; Step S5: performing patterning on the first dielectric layer using a maskless photolithography device, and using an electron beam device to evaporate metal titanium as the tenth metal electrode layer; Step S6: evaporating metal gold on the first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer to serve as the second metal electrode layer, the sixth metal electrode layer and the ninth metal electrode layer respectively; Step S7: using an atomic layer deposition device to deposit aluminum oxide as the passivation layer on the second metal electrode layer; Step S8: performing patterning on the sixth metal electrode layer and the ninth metal electrode layer respectively using a maskless photolithography device, and using an electron beam evaporation device to evaporate metal indium to serve as the seventh metal electrode layer and the eighth metal electrode layer respectively; Step S9: hot-press bonding the Micro-LED lamp beads on the seventh metal electrode layer and the eighth metal electrode layer.

4. A micro-light emitting diode driven by a top-gate nano-thin film transistor, characterized in that: include: Flexible substrate, first dielectric layer, first metal electrode layer, second metal electrode layer, passivation layer, single-layer nano film material, third metal electrode layer, fourth metal electrode layer, fifth metal electrode layer, sixth metal electrode layer, seventh metal electrode layer, Micro-LED lamp beads, eighth metal electrode layer, ninth metal electrode layer and tenth metal electrode layer; The first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer are sequentially arranged on the flexible substrate; The second metal electrode layer is arranged on the first metal electrode layer; the sixth metal electrode layer is arranged on the fifth metal electrode layer; the ninth metal electrode layer is arranged on the tenth metal electrode layer; the two ends of the single-layer nano-thin film material are respectively arranged on the end of the second metal electrode layer and the end of the sixth metal electrode layer; the two ends of the first dielectric layer are respectively arranged on the second metal electrode layer and the sixth metal electrode layer, the middle part of the first dielectric layer is arranged on the single-layer nano-thin film material, the passivation layer is arranged on the first dielectric layer, the third metal electrode layer is arranged on the passivation layer, the fourth metal electrode layer is arranged on the third metal electrode layer, the seventh metal electrode layer is arranged at one end of the sixth metal electrode layer, the eighth metal electrode layer is arranged on the ninth metal electrode layer, and the two ends of the Micro-LED lamp bead are respectively arranged at the end of the seventh metal electrode layer and the end of the eighth metal electrode layer.

5. The micro-LED driven by the top-gate nano-thin film transistor according to claim 4, characterized in that: The first metal electrode layer is preferably metal titanium, the second metal electrode layer is preferably metal gold, the third metal electrode layer is preferably metal titanium, the fourth metal electrode layer is preferably metal gold, the fifth metal electrode layer is preferably metal titanium, the sixth metal electrode layer is preferably metal gold, the seventh metal electrode layer is preferably metal indium, the eighth metal electrode layer is preferably metal indium, the ninth metal electrode layer is preferably metal gold, and the tenth metal electrode layer is preferably metal titanium.

6. A method for preparing a micro-light-emitting diode driven by a top-gate nano-thin film transistor, characterized in that: A micro-light emitting diode driven by a top-gate nano-thin film transistor according to any one of claims 4 to 5 is prepared, the preparation method comprising: Step S1: performing patterning on the flexible substrate using a maskless photolithography device, and also using an electron beam evaporation device to evaporate three metal titanium layers in the gaps between the patterned substrates, respectively serving as the first metal electrode layer, the fifth metal electrode layer, and the tenth metal electrode layer; Step S2: evaporating metal gold on the first metal electrode layer, the fifth metal electrode layer and the tenth metal electrode layer to serve as the second metal electrode layer, the sixth metal electrode layer and the ninth metal electrode layer respectively; Step S3: using a plasma gas chemical vapor deposition device to pattern-grow molybdenum sulfide MoS2 as the single-layer nano-thin film material on the second metal electrode layer and the sixth metal electrode layer; Step S4: preparing the first dielectric layer on the second metal electrode layer, the sixth metal electrode layer and the single-layer nano film material; Step S5: depositing aluminum oxide as a passivation layer on the first dielectric layer using an atomic layer deposition device; Step S6: using electron beam evaporation equipment to evaporate metal titanium on the passivation layer as the third metal electrode layer, and using electron beam evaporation equipment to evaporate metal gold on the third metal electrode layer as the fourth metal electrode layer; Step S7: performing patterning on the sixth metal electrode layer and the ninth metal electrode layer respectively using a maskless photolithography device, and using an electron beam evaporation device to evaporate metal indium to serve as the seventh metal electrode layer and the eighth metal electrode layer respectively; Step S8: hot-press bonding the Micro-LED lamp beads on the seventh metal electrode layer and the eighth metal electrode layer.

7. A bottom-gate nano-thin film transistor driven micro-light emitting diode array, characterized in that: The array includes: A plurality of micro light emitting diodes driven by bottom-gate nano-thin film transistors according to any one of claims 1 to 2; The micro-light emitting diode driven by the bottom-gate nano-thin film transistor is referred to as a bottom-gate driven diode; The drains of all bottom-gate driven diodes in the same horizontal row are connected, the sources of all bottom-gate driven diodes in the same horizontal row are connected, and the gates of all bottom-gate driven diodes in the same vertical column are connected.

8. A micro-light emitting diode array driven by a top-gate nano-thin film transistor, characterized in that: The array includes: A plurality of micro light emitting diodes driven by top-gate nano thin film transistors according to any one of claims 4 to 5; The micro-light emitting diode driven by the top-gate nano-thin film transistor is referred to as a top-gate driven diode; The drains of all the top-gate driven diodes in the same horizontal row are connected, the sources of all the top-gate driven diodes in the same horizontal row are connected, and the gates of all the top-gate driven diodes in the same vertical column are connected.

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