Micro semiconductor elements and micro semiconductor structures

Abstract

The present application provides a micro semiconductor element and a micro semiconductor structure. The micro semiconductor element includes a epitaxial structure and an optical layer. The optical layer is disposed on the epitaxial structure. The optical layer is a multi-layer film structure and includes a first film layer, a second film layer, and a third film layer disposed between the first film layer and the second film layer. The refractive index of the first film layer and the refractive index of the second film layer are both greater than the refractive index of the third film layer. The thickness of the third film layer is greater than the thickness of the first film layer and the thickness of the second film layer. The reflectivity of the optical layer to external light of the micro semiconductor element is greater than the spontaneous light of the epitaxial structure of the micro semiconductor element. The micro semiconductor element of the present application can minimize the influence of external light on the epitaxial structure to ensure the characteristics of the epitaxial structure itself, and can have better structural reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to a semiconductor element and a semiconductor structure, in particular, to a micro semiconductor element and a micro semiconductor structure. BACKGROUND

[0002] Laser transfer technology is one of the mainstream transfer technologies for mass transfer of current micro semiconductor elements. Laser itself is a high-energy collimated light source. Even if it is focused on a specific removal film layer, part of the light source will still scatter into the epitaxial structure, affecting the chip characteristics and reliability. SUMMARY

[0003] The present application is directed to a micro semiconductor element with better structural reliability.

[0004] The present application is also directed to a micro semiconductor structure including the above-mentioned micro semiconductor element, which can have better structural reliability.

[0005] According to an embodiment of the present application, the micro semiconductor element includes an epitaxial structure and an optical layer. The optical layer is disposed on the epitaxial structure. The optical layer is a multilayer film structure and includes a first film layer, a second film layer, and a third film layer disposed between the first film layer and the second film layer. The refractive index of the first film layer and the refractive index of the second film layer are both greater than the refractive index of the third film layer. The thickness of the third film layer is greater than the thickness of the first film layer and the thickness of the second film layer. The reflectivity of the optical layer to external light of the micro semiconductor element is greater than the spontaneous light of the epitaxial structure of the micro semiconductor element.

[0006] According to an embodiment of the present application, the micro semiconductor structure includes a substrate and at least one micro semiconductor element. The micro semiconductor element is disposed on the substrate, and the micro semiconductor element includes an epitaxial structure and an optical layer. The optical layer is disposed on the epitaxial structure. The optical layer is a multilayer film structure and includes a first film layer, a second film layer, and a third film layer disposed between the first film layer and the second film layer. The refractive index of the first film layer and the refractive index of the second film layer are both greater than the refractive index of the third film layer. The thickness of the third film layer is greater than the thickness of the first film layer and the thickness of the second film layer. The reflectivity of the optical layer to external light of the micro semiconductor element is greater than the spontaneous light of the epitaxial structure of the micro semiconductor element.

[0007] Based on the above, in the micro semiconductor element of the present application, the optical layer is disposed on the epitaxial structure, wherein the reflectivity of the optical layer to external light of the micro semiconductor element is greater than the spontaneous light of the epitaxial structure of the micro semiconductor element. In this way, the influence of external light on the epitaxial structure can be minimized to ensure the characteristics of the epitaxial structure itself, so that the micro semiconductor element of the present application has better structural reliability. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1Ais a cross-sectional view of a micro semiconductor structure according to an embodiment of the present application;

[0009] Figure 1B is Figure 1A is an enlarged view of the optical layer;

[0010] Figure 1C is an enlarged view of the optical layer according to another embodiment;

[0011] Figure 2 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0012] Figure 3 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0013] Figure 4 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0014] Figure 5 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0015] Figure 6 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0016] Figure 7 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application;

[0017] Figure 8 is a cross-sectional view of a micro semiconductor element according to an embodiment of the present application;

[0018] Figure 9 is a cross-sectional view of a micro semiconductor structure according to another embodiment of the present application.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h: micro semiconductor structure;

[0021] 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h1, 100h2, 100h3: micro semiconductor element;

[0022] 110: epitaxial structure;

[0023] 112: upper surface;

[0024] 114: lower surface;

[0025] 116: peripheral surface;

[0026] 120a, 120a', 120b, 120e, 120g, 120h1, 120h2, 120h3: optical layer;

[0027] 120b1, 120g1: first sub-optical layer;

[0028] 120b2, 120g2: second sub-optical layer;

[0029] 122a: first film layer;

[0030] 124a: second film layer;

[0031] 125a, 125h1, 125h2, 125h3: optical stack;

[0032] 126a: third film layer;

[0033] 127a: high refractive index layer;

[0034] 129a: low refractive index layer;

[0035] 130, 135: electrode;

[0036] 140: protective layer;

[0037] 150: visible light reflecting layer;

[0038] 160, 170: external light penetrating layer;

[0039] 200a, 200b: substrate;

[0040] 210: removal layer;

[0041] E: self-emission;

[0042] L1: external light;

[0043] V: visible light;

[0044] T1, T2, T3, T4, T5, T6, T7, T8: thickness. DETAILED DESCRIPTION

[0045] Reference will now be made in detail to the exemplary embodiments of the present application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used in the drawings and the description to refer to the same or like parts.

[0046] Figure 1A is a cross-sectional schematic view of a micro semiconductor structure according to an embodiment of the present application. Figure 1B is Figure 1AAn enlarged schematic view of the optical layer. Please refer to Figure 1A With Figure 1B In the present embodiment, the micro semiconductor structure 10a includes a substrate 200a and at least one micro semiconductor element (one micro semiconductor element 100a is shown schematically). The micro semiconductor element 100a is disposed on the substrate 200a, and the micro semiconductor element 100a includes an epitaxial structure 110 and an optical layer 120a. The optical layer 120a is disposed on the epitaxial structure 110. The optical layer 120a is a multilayer film structure and includes a first film layer 122a, a second film layer 124a, and a third film layer 126a disposed between the first film layer 122a and the second film layer 124a. The refractive index of the first film layer 122a and the refractive index of the second film layer 124a are both greater than the refractive index of the third film layer 126a. The thickness T3 of the third film layer 126a is greater than the thickness T1 of the first film layer 122a and the thickness T2 of the second film layer 124a. The reflectivity of the optical layer 120a to external light L1 of the micro semiconductor element 100a is greater than the spontaneous light E of the epitaxial structure 110 of the micro semiconductor element 100a. It is particularly pointed out that the N-type semiconductor layer and the P-type semiconductor layer and the light-emitting layer of the epitaxial structure 110 are omitted here, and the spontaneous light E is the light emitted from the epitaxial structure 110. The external light L1 is used to transfer the laser light or the external environmental light of the micro semiconductor element 100a, and is not limited to the light emitted from the epitaxial structure 110.

[0047] In detail, in the present embodiment, the substrate 200a is embodied as a temporary substrate and includes a removal layer 210, wherein the removal layer 210 is disposed between the optical layer 120a and the substrate 200a, and the Young's modulus of the optical layer 120a is greater than the Young's modulus of the removal layer 210a. In subsequent processes, the substrate 200a and the removal layer 210 can be removed, and the micro semiconductor element 100a is left, so that the present micro semiconductor structure 10a belongs to a Chip on Carrier (COC) mode.

[0048] Please refer to Figure 1AThe epitaxial structure 110 of this embodiment has an upper surface 112 and a lower surface 114 opposite to each other, and a surrounding surface 116 connecting the upper surface 112 and the lower surface 114. An optical layer 120a is disposed on the upper surface 112 of the epitaxial structure 110, and self-emitting light E is emitted from the upper surface 112, meaning the upper surface 112 is the light-emitting surface. The micro-semiconductor element 100a may further include electrodes 130 and 135 and a protective layer 140. Electrodes 130 and 135 and the protective layer 140 are all disposed on the lower surface 114 of the epitaxial structure 110, wherein the protective layer 140 is located between the electrodes 130 and 135 and the epitaxial structure 110, and the electrodes 130 and 135 are electrically connected to the epitaxial structure 110 through the protective layer 140. Here, electrodes 130 and 135 are located on the same side of the epitaxial structure 110, therefore the micro-semiconductor element 100a is specifically designed as a horizontal micro-semiconductor element, such as a horizontal micro-light-emitting diode. Furthermore, the material of the protective layer 140 may be, for example, an inorganic material used for insulation and protection, such as silicon dioxide (SiO2) or silicon nitride (SiN), but is not limited thereto.

[0049] Please refer to the following at the same time: Figure 1A and Figure 1BOnce the epitaxial structure 110 is removed from the growth substrate (not shown), the optical layer 120a can be fabricated using a physical or chemical vapor deposition process. The refractive index of the first film layer 122a of the optical layer 120a is, for example, 1.9 to 2.8, and the thickness T1 of the first film layer 122a is, for example, between 10 nanometers and 30 nanometers. The material of the first film layer 122a is, for example, titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), or hafnium dioxide (HfO2), but is not limited thereto. The refractive index of the second film layer 124a of the optical layer 120a is, for example, 1.9 to 2.8, and the thickness T2 of the second film layer 124a is, for example, between 10 nanometers and 30 nanometers. The material of the second film layer 124a is, for example, titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), or hafnium dioxide (HfO2), but is not limited thereto. In one embodiment, the refractive index, thickness, and material of the first film layer 122a and the second film layer 124a are the same. In one embodiment, at least one of the refractive index, thickness, and material of the first film layer 122a and the second film layer 124a is different. The refractive index of the third film layer 126a of the optical layer 120a is, for example, 1.4 to 1.8, and the thickness T3 of the third film layer 126a is, for example, between 35 nanometers and 75 nanometers. The material of the third film layer 126a is, for example, silicon dioxide (SiO2), aluminum oxide (Al2O3), or magnesium fluoride (MgF2), but is not limited thereto. That is, the higher the refractive index of the film layer, the thinner the film layer. In particular, the stacking of the first film layer 122a, the second film layer 124a, and the third film layer 126a in this embodiment can form a long wave pass (LWP) effect.

[0050] In one embodiment, the optical layer 120a is reflective of the ultraviolet laser wavelength used for transfer. Specifically, when the wavelength of the external light L1 is, for example, between 240 nm and 400 nm, it has a band of good reflectivity (e.g., a full width at half maximum (FWHM) of less than 2 nm) within this wavelength range, with a reflectivity of at least greater than 60%. In the visible light band (e.g., between 420 nm and 700 nm), the optical layer 120a has good transmittance, here greater than 70%, in other words, a reflectivity of less than 30%. Therefore, the reflectivity of the external light L1 is greater than twice the reflectivity of the self-emitting light E of the micro-semiconductor element 100a. In one embodiment, the external light L1 may be, for example, an excimer laser, such as a 248 nm krypton fluoride (KrF) excimer laser or a diode-pumped solid-state laser (DPSS), but is not limited thereto. Furthermore, the optical layer 120a of this embodiment has, for example, a cutoff wavelength between 380 nanometers and 440 nanometers, which can more effectively increase the reflection of external light L1.

[0051] In short, since the optical layer 120a of this embodiment is disposed on the light-emitting surface (i.e., on the upper surface 112) of the epitaxial structure 110, the reflectivity of the optical layer 120a to the external light L1 of the micro-semiconductor element 100a is greater than the self-emission E of the epitaxial structure 110 of the micro-semiconductor element 100a. Therefore, during the laser transfer process, the external light L1 (such as ultraviolet laser) can separate the removal layer 210 and its substrate 200a from the optical layer 120a, and the optical layer 120a minimizes the influence of laser scattering, ensuring the characteristics of the epitaxial structure 110 itself, thus giving the micro-semiconductor structure 10a of this embodiment better structural reliability. Furthermore, the design of the optical layer 120a also allows for a larger parameter adjustment range in the laser process, preferably suitable for transfer techniques requiring multiple flipping processes, for example, enabling the use of a slightly stronger laser for transfer while ensuring that the epitaxial structure 110 is not damaged. Furthermore, the substrate 200a and the removal layer 210 in this embodiment can be removed, thus reducing the material thickness of the removal layer 210. That is, it is not necessary to make it very thick to avoid laser ablation of the epitaxial structure 110, which can increase the removal efficiency and also reduce the laser power.

[0052] It is worth mentioning that this embodiment does not limit the structural form of the optical layer 120a. Although three film layers are used as an example here, in other embodiments, the number of film layers in the optical layer may be more than three.

[0053] Figure 1C This is an enlarged schematic diagram of an optical layer according to another embodiment. Please also refer to... Figure 1Band Figure 1C In this embodiment, the optical layer 120a' and Figure 1B Similar to the optical layer 120, the difference lies in that: in this embodiment, the optical layer 120a' further includes an optical stack 125a, disposed between the first film layer 122a and the second film layer 124a, and includes at least one high refractive index layer (schematically showing two high refractive index layers 127a) and at least one low refractive index layer (schematically showing two low refractive index layers 129a) arranged in pairs and alternately, wherein the thickness T5 of the low refractive index layer 129a is greater than the thickness T4 of the high refractive index layer 127a. Here, a stack of one high refractive index layer 127a and one low refractive index layer 129a constitutes a pair, while the above-mentioned two high refractive index layers 127a and two low refractive index layers 129 are stacked alternately, thus forming two pairs.

[0054] In detail, in this embodiment, the optical stack 125a is disposed between the third film layer 126a and the second film layer 124a, wherein the third film layer 126a is located between the first film layer 122a and a high refractive index layer 127a of the optical stack 125a, but this is not a limitation. In another embodiment, the optical stack 125a may also be disposed between the first film layer 122a and the third film layer 126a, wherein the third film layer 126a is located between the second film layer 124a and a low refractive index layer of the optical stack 125a. Specifically, the third film layer 126a and the optical stack 125a may form a high refractive index layer and a low refractive index layer, but this is not a limitation. The refractive index of the high-refractive-index layer 127a of the optical stack 125a is, for example, 1.9 to 2.8, and the thickness T4 of the high-refractive-index layer 127a is, for example, between 20 nm and 60 nm. The material of the high-refractive-index layer 127a is, for example, titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), or hafnium dioxide (HfO2), but is not limited thereto. The refractive index of the low-refractive-index layer 129a of the optical stack 125a is, for example, 1.4 to 1.8, and the thickness T5 of the low-refractive-index layer 129a is, for example, between 35 nm and 75 nm. The material of the low-refractive-index layer 129a is, for example, silicon dioxide (SiO2), aluminum oxide (Al2O3), or magnesium fluoride (MgF2), but is not limited thereto. The thickness T1 of the first film layer 122a or the thickness T2 of the second film layer 124a is less than 60% of the thickness T4 of the high refractive index layer 127a, preferably, for example, 50%.

[0055] Furthermore, this embodiment does not limit the number of optical layers 125a. Although two pairs (i.e., two high-refractive-index layers 127a and two low-refractive-index layers 129a stacked alternately) are used as an example here, in other embodiments, there may be only one pair (i.e., one high-refractive-index layer 127a and one low-refractive-index layer 129a), or more than three pairs of film layers, which are still within the scope of protection of this embodiment. It is worth mentioning that in one embodiment, the first film layer 122a, the second film layer 124a, the third film layer 126a and the optical layer 125a can also be completed using the same process, which can save process time.

[0056] Since the optical stack 125a in the optical layer 120a' can be formed by alternating stacks of materials with different refractive indices and thicknesses, the sensitivity to external light L1 (such as ultraviolet laser light) can be improved through optimization of the film parameters. Figure 1A The reflectivity of ).

[0057] It must be noted that the following embodiments use the component reference numerals and some content from the foregoing embodiments, with the same reference numerals used to represent the same or similar components, and descriptions of the same technical content omitted. For explanations of the omitted parts, please refer to the foregoing embodiments; these will not be repeated in the following embodiments.

[0058] Figure 2 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 1A and Figure 2 The micro-semiconductor structure 10b in this embodiment and Figure 1A Similar to the micro-semiconductor structure 10a, the difference lies in that: in this embodiment, the optical layer 120b of the micro-semiconductor element 100b includes a first sub-optical layer 120b1 and a second sub-optical layer 120b2. The first sub-optical layer 120b1 is located on the upper surface 112 of the epitaxial structure 110, while the second sub-optical layer 120b2 is located on the lower surface 114 of the epitaxial structure 110, wherein the protective layer 140 is located between the second sub-optical layer 120b2 and the epitaxial structure 110. In short, since the optical layer 120b of this embodiment is simultaneously disposed on the light-emitting surface (i.e., the upper surface 112) and the electrode surface (i.e., the lower surface 114), the epitaxial structure 110 can be effectively protected regardless of which side of the micro-semiconductor element 100b is laser-processed (i.e., when external light L1 enters the upper surface 112 or the lower surface 114), thus giving the micro-semiconductor structure 10b of this embodiment better structural reliability. In embodiments not shown, the optical layer may also serve as a protective layer, thus omitting the fabrication of the protective layer.

[0059] Figure 3 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to...Figure 1A and Figure 3 The micro-semiconductor structure 10c in this embodiment and Figure 1A Similar to the micro-semiconductor structure 10a, the difference lies in that: in this embodiment, the micro-semiconductor element 100c further includes a visible light reflective layer 150, which is disposed on the lower surface 114 (i.e., the electrode surface). Since the optical layer 120a of this embodiment is disposed on the light-emitting surface (i.e., the upper surface 112) of the epitaxial structure 110, and the visible light reflective layer 150 is disposed on the electrode surface (i.e., the lower surface 114) of the epitaxial structure 110, both external light L1 (such as ultraviolet laser light) and visible light V can be reflected. Here, the visible light reflective layer 150 is, for example, a Bragg reflector layer, which can reflect the light emitted from the epitaxial structure 110 towards the electrode surface back to the light-emitting surface to increase light emission, and can also avoid interference from external visible light V. In another embodiment, the visible light reflective layer 150 can also be disposed on the upper surface 112 of the epitaxial structure 110, and the optical layer 120a can be disposed on the lower surface 114 of the epitaxial structure 110.

[0060] Figure 4 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 1A and Figure 4 In this embodiment, the micro-semiconductor structure 10d and Figure 1A Similar to the micro-semiconductor structure 10a, the difference lies in that: in this embodiment, the micro-semiconductor element 100d further includes an external light-transmitting layer 160 disposed on the lower surface 114 (i.e., the electrode surface). Since the optical layer 120a of this embodiment is disposed on the light-emitting surface (i.e., the upper surface 112) of the epitaxial structure 110, and the external light-transmitting layer 160 is disposed on the electrode surface (i.e., the lower surface 114) of the epitaxial structure 110, it is advantageous that external light L1 (such as ultraviolet laser light in the ultraviolet band) that has accidentally entered the epitaxial structure 110 can be released and not reflected back in. In one embodiment, a layer such as... can also be provided on the lower surface 114. Figure 3 The visible light reflective layer 150, such as a distributed Bragg reflector (DBR), can reflect visible light and allow ultraviolet laser light to pass through.

[0061] Figure 5 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 1A and Figure 5 The micro-semiconductor structure 10e in this embodiment and Figure 1ASimilar to the micro-semiconductor structure 10a, the difference lies in that, in this embodiment, the optical layer 120e of the micro-semiconductor element 100e is disposed on the lower surface 114 (i.e., the electrode surface), wherein the protective layer 140 is located between the epitaxial structure 110 and the optical layer 120e. In fabrication, after the protective layer 140 is formed during the wafer fabrication process, the optical layer 120e can be fabricated using a physical or chemical vapor deposition process. Subsequently, during the laser transfer process, external light L1 (i.e., ultraviolet laser) can separate the removal layer 210 and its substrate 200a from the optical layer 120e. The optical layer 120e minimizes the influence of laser scattering light, ensuring the characteristics of the epitaxial structure 110 itself, thus giving the micro-semiconductor structure 10e of this embodiment better structural reliability.

[0062] Figure 6 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 5 and Figure 6 The micro-semiconductor structure 10f in this embodiment and Figure 5 Similar to the micro-semiconductor structure 10e, the difference lies in that: in this embodiment, the micro-semiconductor element 100f further includes an external light-transmitting layer 170 disposed on the upper surface 112 (i.e., the light-emitting surface). Since the optical layer 120e of this embodiment is disposed on the electrode surface (i.e., the lower surface 114) of the epitaxial structure 110, and the external light-transmitting layer 170 is disposed on the light-emitting surface (i.e., the upper surface 112) of the epitaxial structure 110, it is beneficial that external light L1 (such as ultraviolet laser light in the ultraviolet band) that has entered the epitaxial structure 110 can be released and not reflected back in.

[0063] Figure 7 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 5 and Figure 7 The micro-semiconductor structure 10g in this embodiment and Figure 5Similar to the micro-semiconductor structure 10e, the difference lies in that: in this embodiment, the optical layer 120g of the micro-semiconductor element 100g includes a first sub-optical layer 120g1 and a second sub-optical layer 120g2. The first sub-optical layer 120g1 is located on the upper surface 112 of the epitaxial structure 110, while the second sub-optical layer 120g2 is located on the lower surface 114 of the epitaxial structure 110. The external light L1 and L2 reflected by the first sub-optical layer 120g1 and the second sub-optical layer 120g2 have different wavelengths, such as wavelengths of different ultraviolet light bands. That is to say, this embodiment can be used for lift-off processes on different surfaces. The first sub-optical layer 120g1 is disposed on the upper surface 112, which can only reflect external light L2 and allows external light L1 entering the epitaxial structure 110 to pass through; while the second sub-optical layer 120g2 is disposed on the lower surface 114, which can only reflect external light L1 and allows external light L2 entering the epitaxial structure 110 to pass through. In one embodiment, the wavelength of external light L1 may be between the wavelength of external light L2 and the wavelength of visible light.

[0064] Figure 8 This is a schematic cross-sectional view of a micro-semiconductor device according to an embodiment of the present invention. Please also refer to... Figure 1A and Figure 8 The micro semiconductor element 100a in this embodiment is... Figure 1A The substrate 200a and the removal layer 210 are removed from the micro-semiconductor structure 10a. Since the optical layer 120a is disposed on the epitaxial structure 110, and the reflectivity of the optical layer 120a to the external light L1 of the micro-semiconductor element 100a is greater than the self-emission E of the epitaxial structure 110 of the micro-semiconductor element 100a, it can be ensured that the characteristics of the epitaxial structure 110 itself are not affected by the external light L1, thus giving the micro-semiconductor element 100a of this embodiment better structural reliability.

[0065] Figure 9 This is a schematic cross-sectional view of a microsemiconductor structure according to another embodiment of the present invention. Please also refer to... Figure 1A and Figure 9 The micro-semiconductor structure 10h in this embodiment and Figure 1ASimilar to the micro-semiconductor structure 10a, the difference lies in that: in this embodiment, the substrate 200b is a circuit substrate, and the micro-semiconductor elements include multiple micro-semiconductor elements 100h1, 100h2, and 100h3 with different colors of light, wherein the micro-semiconductor elements 100h1, 100h2, and 100h3 are electrically connected to the substrate 200b by flip-chip bonding. In other words, the micro-semiconductor structure 10h in this embodiment is specifically embodied as a display device. Here, the micro-semiconductor elements 100h1, 100h2, and 100h3 with different colors of light have optical layers 120h1, 120h2, and 120h3 with different thicknesses due to their different emitted light wavelengths. Specifically, in this embodiment, the optical layers 120h1, 120h2, and 120h3 respectively include optical stacks 125h1, 125h2, and 125h3 with different numbers of layers, and therefore have thicknesses T6, T7, and T8 respectively.

[0066] In summary, in the micro-semiconductor device of the present invention, the optical layer is disposed on the epitaxial structure, wherein the reflectivity of the optical layer to external light of the micro-semiconductor device is greater than the self-emission of the epitaxial structure of the micro-semiconductor device. This minimizes the influence of external light on the epitaxial structure, ensuring the characteristics of the epitaxial structure itself, and thus enabling the micro-semiconductor device of the present invention to have better structural reliability.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro semiconductor device, characterized in that, include: Epitaxial structure; as well as An optical layer is fixedly disposed on the epitaxial structure. The optical layer is an odd-layer film structure and includes a first film layer, a second film layer, and a third film layer disposed between the first film layer and the second film layer. The refractive index of the first film layer and the refractive index of the second film layer are both greater than the refractive index of the third film layer, and the thickness of the third film layer is greater than the thickness of the first film layer and the thickness of the second film layer. The refractive index, thickness, and material of the first film layer and the second film layer are different in at least one of the following: and the reflectivity of the optical layer to external light of the micro-semiconductor device is greater than the self-emission of the epitaxial structure of the micro-semiconductor device.

2. The micro semiconductor device according to claim 1, characterized in that, The reflectivity of the external light is more than twice that of the self-luminous light.

3. The micro semiconductor device according to claim 2, characterized in that, The wavelength of the external light is between 240 nanometers and 400 nanometers.

4. The micro semiconductor device according to claim 2, characterized in that, The optical layer has a cutoff wavelength between 380 nanometers and 440 nanometers.

5. The micro semiconductor device according to claim 1, characterized in that, The optical layer further includes an optical stack disposed between the first film layer and the second film layer. The optical stack includes at least one high refractive index layer and at least one low refractive index layer arranged in pairs and alternately. The thickness of the at least one low refractive index layer is greater than the thickness of the at least one high refractive index layer.

6. The micro semiconductor device according to claim 5, characterized in that, The thickness of the first film layer or the thickness of the second film layer is less than 60% of the thickness of the at least one high refractive index layer.

7. The micro semiconductor device according to claim 1, characterized in that, The epitaxial structure has an upper surface and a lower surface opposite to each other, and a surrounding surface connecting the upper surface and the lower surface. The self-luminescence is emitted from the upper surface, and the optical layer is disposed on the upper surface, the lower surface, or a combination thereof.

8. The micro semiconductor device according to claim 7, characterized in that, Also includes: A visible light reflective layer is disposed on the upper surface of the epitaxial structure and the optical layer is disposed on the lower surface, or the optical layer is disposed on the lower surface of the epitaxial structure and the optical layer is disposed on the upper surface.

9. The micro semiconductor device according to claim 7, characterized in that, Also includes: An external light-transmitting layer is disposed on the upper surface of the epitaxial structure and the optical layer is disposed on the lower surface, or the optical layer is disposed on the lower surface of the epitaxial structure and the optical layer is disposed on the upper surface.

10. The micro semiconductor device according to claim 7, characterized in that, The optical layer includes a first sub-optical layer and a second sub-optical layer, which are located on the upper surface and the lower surface, respectively, and the external light reflected by the first sub-optical layer and the second sub-optical layer has different wavelengths.

11. A micro-semiconductor structure, characterized in that, include: substrate; as well as At least one micro-semiconductor element is disposed on the substrate, the at least one micro-semiconductor element comprising: Epitaxial structure; as well as An optical layer is fixedly disposed on the epitaxial structure. The optical layer is an odd-layer film structure and includes a first film layer, a second film layer, and a third film layer disposed between the first film layer and the second film layer. The refractive index of the first film layer and the refractive index of the second film layer are both greater than the refractive index of the third film layer, and the thickness of the third film layer is greater than the thickness of the first film layer and the thickness of the second film layer. The refractive index, thickness, and material of the first film layer and the second film layer are different in at least one of the following: and the reflectivity of the optical layer to external light of the micro-semiconductor device is greater than the self-emission of the epitaxial structure of the micro-semiconductor device.

12. The microsemiconductor structure according to claim 11, characterized in that, Also includes: A removal layer is disposed between the optical layer and the substrate, wherein the substrate is a temporary substrate and the Young's modulus of the optical layer is greater than the Young's modulus of the removal layer.

13. The microsemiconductor structure according to claim 11, characterized in that, The optical layer further includes an optical stack disposed between the first film layer and the second film layer. The optical stack includes at least one high refractive index layer and at least one low refractive index layer arranged in pairs and alternately. The thickness of the at least one low refractive index layer is greater than the thickness of the at least one high refractive index layer.

14. The microsemiconductor structure according to claim 13, characterized in that, The substrate is a circuit board, and the at least one micro-semiconductor element is a plurality of micro-semiconductor elements with different colors of light, and the plurality of micro-semiconductor elements with different colors of light are respectively optical stacked with different thicknesses.

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