TWI502768B - Optoelectronic semiconductor device and method for manufacturing the same - Google Patents

Description

Photoelectric semiconductor device and method of manufacturing same

The present invention relates to an optoelectronic semiconductor device and a method of fabricating the same, and more particularly to an optoelectronic semiconductor device having a hole structure to enhance the front side light-emitting effect.

With the development of science and technology, the application of electronic products in life is more extensive, and the trend toward thinner and thinner is developing. Among them, if there is illumination or display function in the electronic product, the choice of the light source will directly affect the size of the product as well as the brightness and display performance. Light-emitting diodes (LEDs) have been widely used in lighting, signage, and displays because of their small size, fast response speed, low energy consumption, high reliability, high color gamut selectivity, and environmentally friendly mercury-free. A variety of uses such as backlights.

A conventional light-emitting diode generally includes a substrate, an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting layer between the n-type semiconductor layer and the p-type semiconductor layer. The principle of illumination is that, under a proper forward bias, electrons and holes are injected into the light-emitting layer from the n-type semiconductor layer and the p-type semiconductor layer, respectively, and combined in the light-emitting layer to release energy in the form of light. come out. In this way, as long as the electrons and the holes are continuously supplied from the n-type semiconductor layer and the p-type semiconductor layer, the combination of the electrons and the holes and the light emission are continued, so that the light-emitting layer of the light-emitting diode can be made. Continuously glowing.

Most commercial light-emitting diode systems are composed of three or five semiconductors, and the nitride-containing light-emitting diode emits blue or green light, often referred to as a nitride light-emitting diode. The blue light emitted by the nitride light-emitting diode can be modulated with white light by a suitable phosphor. However, the isotropy emission of the light system produced by the luminescent layer is not inherently difficult to present a collimation or an anisotropy light field. Therefore, how to provide various types of light fields has become one of the development topics of the current LED components.

An object of the present invention is to provide an optoelectronic semiconductor device and a method of fabricating the same, in which a hole structure is formed in the optoelectronic semiconductor device to change the direction in which the light travels toward or toward the normal direction of the carrier, thereby increasing the forward direction. The amount of light emitted.

Another object of the present invention is to provide an optoelectronic semiconductor device and a method of fabricating the same, wherein the hole structure in the optoelectronic semiconductor device forms an air lens having an optical scattering effect, preferably, for example, arranged as a Fresnel lens. To increase the amount of positive light output. The optoelectronic semiconductor device of the present invention can make a combination of different shapes of hole structures according to the size of the light emitting diodes, so as to promote the light as far as possible toward the normal direction of the carrier, and reduce the light between the optoelectronic semiconductor device and the carrier. The resulting loss, in turn, increases light extraction efficiency.

To achieve the above objective, the present invention discloses an optoelectronic semiconductor device comprising a carrier, a photoelectric conversion structure disposed on the carrier, and at least one internal surface, and the carrier can be defined on a surface of the photoelectric conversion structure. In the line direction, at least one inner surface is formed in the optoelectronic semiconductor device to define at least one hole structure, and at least one hole structure has a refractive index, when the photoelectric conversion structure can perform photoelectric conversion and emit light to be projected to at least one hole structure, The light is suitably reflected by the refractive index of at least one of the holes and travels away from the carrier and toward the normal.

The present invention further discloses a method of fabricating the above-described optoelectronic semiconductor device, comprising the steps of: (a) providing a carrier and defining a normal direction on an outer surface of one of the carriers; (b) forming a patterned nitride a layer having at least one inner surface that does not extend in a normal direction; (c) forming a photoelectric conversion structure on the carrier; and (d) forming at least one hole structure in the optoelectronic semiconductor device, wherein at least one hole structure It has a refractive index that reflects the light emitted by the photoelectric conversion structure.

The present invention further discloses another method for fabricating the above-described optoelectronic semiconductor device, comprising the steps of: (a) providing a carrier; (b) epitaxially forming a photoelectric conversion structure on the carrier; and (c) etching the photoelectric conversion structure to form At least consistently perforating; and (d) partially anisotropically etching the optoelectronic semiconductor device in at least a consistent perforation.

The above objects, technical features, and advantages will be more apparent from the following description.

The optoelectronic semiconductor device of the present invention will be explained below through several embodiments. However, the description of the embodiments is merely illustrative of the invention and is not intended to limit the invention.

Referring to FIGS. 1A to 1D, a first embodiment of the present invention discloses an optoelectronic semiconductor device, wherein FIG. 1A is a top plan view of the optoelectronic semiconductor device 1, and FIG. 1B is a photo-semiconductor device 1 of FIG. A cross-sectional view of the B-B' hatching, and a schematic cross-sectional view of the optoelectronic semiconductor device 1 along the C-C' section line in the 1C and 1D drawings.

The optoelectronic semiconductor device 1 of the present embodiment includes a carrier 11 and a photoelectric conversion structure 13. Preferably, the carrier 11 is a sapphire substrate whose side facing the photoelectric conversion structure 13 defines a normal direction N. The photoelectric conversion structure 13 is a light-emitting diode and is disposed on the carrier 11. In detail, the photoelectric conversion structure 13 includes an n-nitride layer 131, a multiple quantum well (MQW) 133, and a p-nitride layer 135. Preferably, the n-type nitride layer 131 is disposed close to the carrier 11, and the multiple quantum well 133 is formed between the n-type nitride layer 131 and the p-type nitride layer 135, and the electron and the hole are respectively from the n-type. The nitride layer 131 and the p-type nitride layer 135 are implanted into the multiple quantum wells 133, and are combined in the multiple quantum wells 133 to release energy in the form of light, whereby the photoelectric conversion structure 13 can be photoelectrically converted to emit a light.

Further, the inside of the optoelectronic semiconductor device 1 is further formed with a hole structure 15 which can be respectively defined by an inner surface in the optoelectronic semiconductor device 1. Preferably, the hole structure 15 is a hollow structure defined in the process. The hole structure 15 has a refractive index, and when the light travels to the hole structure 15 in the optoelectronic semiconductor device 1, the refractive index of the material inside and outside the hole structure 15 is different (for example, the refractive index of gallium nitride is about 2 to 3) Between, the refractive index of the air is 1), the light will change direction at the hole structure 15, whereby the light can be controlled to move away from the carrier 11 and toward the normal direction N.

In the present embodiment, the hole structure 15 is formed in the photoelectric conversion structure 13 by etching in the normal direction N so as to penetrate the photoelectric conversion structure 13. The projection of the hole structure 15 in the normal direction N is presented as a circle, a ring, a rectangle, a diamond, or any combination of the foregoing. The distribution pattern of the plurality of holes 15 in the normal direction N may be a regular distribution (for example, a rectangular array distribution or a circular array distribution, as shown in FIG. 1A), or an irregular distribution. In one embodiment, the spacing between adjacent two aperture structures 15 is about 3 microns (μm). In application, the spacing of the hole structures 15 can be designed according to the optical path requirements in the photoelectric conversion structure 13 and is not limited herein.

The hole structure 15 may be formed at any position in the optoelectronic semiconductor device 1, such as between the n-type nitride layer 131 and the carrier 11, or in the n-type nitride layer 131. In addition, the optoelectronic semiconductor device 1 may further include a buffer layer 17 disposed between the photoelectric conversion structure 13 and the carrier 11. The optoelectronic semiconductor device 1 further includes a reflective layer (not shown) disposed between the multiple quantum wells 133 and the carrier 11 to reflect the light generated by the multiple quantum wells 133 away from the carrier 11 for reuse.

Referring again to FIG. 1A, the optoelectronic semiconductor device further includes a p-type electrode 21, a p-type extension electrode 211 connected to the p-type electrode, and an n-type electrode 23. As the area increases, the electrode alone cannot uniformly conduct the current. Distributed on the surface. Therefore, the optoelectronic semiconductor device 1 can further be provided with a transparent electrode layer 19 formed on the photoelectric conversion structure 13, and the transparent electrode layer 19 can increase the lateral current to improve the luminous efficiency. The p-type electrode 21 and the p-type extension electrode 211 are formed on the transparent electrode layer 19.

A second embodiment of the present invention is shown in Fig. 2A, which is a schematic cross-sectional view of the optoelectronic semiconductor device 1 of the second embodiment. In the present embodiment, the hole structure 15 is formed in the n-type nitride layer 131 in the epitaxial process of the optoelectronic semiconductor device 1 without performing an etching process. In the hole structure 15 shown in FIG. 2A, the vertical normal direction N is a triangular shape, or the hole structure 15 may be designed to have a semicircular shape, a rectangular shape, a trapezoidal shape or the like, or a combination of various shapes; In addition, the projection of the hole structure 15 of the embodiment in the normal direction N may also be various shapes, as shown in FIG. 2B to FIG. 2D, and may be circular, rectangular, or diamond-shaped, etc., and may actually be light. The need to reflect to or toward the normal direction N is designed and selected.

The projection of the hole structure 15 of the present embodiment along the normal direction N also exhibits a distribution pattern, such as the rectangular array distribution shown in FIG. 1A or the annular array distribution shown in FIG. 2E. The hole structures 15 shown in Fig. 2E are distributed concentrically in the normal direction N, and the hole structures 15 are arranged in a Fresnel lens.

Referring again to FIG. 1C, a third embodiment of the present invention discloses a method for fabricating the optoelectronic semiconductor device of the first embodiment described above. First, epitaxial formation of the photoelectric conversion structure 13 on the carrier 11 includes sequentially forming an n-type nitride layer 131, a multiple quantum well 133, and a p-type nitride layer 135; then, the photoelectric conversion structure 13 is dry etched to The through-hole 151 is formed by punching through the photoelectric conversion structure 13.

Next, an etching liquid such as Oxalic acid is introduced into the through hole 151 to partially and non-isotropically etch the optoelectronic semiconductor device 13 to form the hole structure 15. In a preferred embodiment, the buffer layer 17 is formed between the carrier 11 and the n-type nitride layer 131, and the through hole 151 extends through the photoelectric conversion structure 13 and the buffer layer 17. Therefore, when oxalic acid is applied in the through hole 151, the buffer layer 17 may be subjected to lateral wet etching, and the underlayer of the n-type nitride layer 131 and the buffer layer 17 may be hollowed out by an etching method with a high etching selectivity ratio to form Hole structure 15. As shown in FIG. 1D, if anisotropic etching is used, the hole structure 15 can be formed as a bevel. In other words, the hole structure can be defined by the etching rate of the etching solution for different materials, crystal structures, or crystal qualities. The top angle of 15 and its corresponding size.

The fourth embodiment of the present invention is shown in Figs. 3A to 3H, which is a method of manufacturing the photovoltaic device 1 of the second embodiment. First, as shown in FIG. 3A, a carrier 11 is provided, and a nitride layer (for example, an n-type nitride layer 131) is formed on the carrier 11. The carrier 11 is preferably a sapphire substrate, and the carrier 11 An outer surface is adapted to define a normal direction N. Then, as shown in FIGS. 3B to 3F, the n-type nitride layer 131 is patterned. In detail, as shown in FIG. 3B, a photoresist layer 132 is formed on the n-type nitride layer 131. Referring further to FIG. 3C, the photoresist layer 132 is defined by a yellow light process to form a pattern. Next, as shown in FIG. 3D, an anti-etching layer 134, such as a cerium oxide (SiO ₂ ) layer, is formed, and then, as shown in FIG. 3E, a portion of the photoresist layer 132 and the anti-etching layer 134 thereon are removed. Only a portion of the anti-etching layer 134 is retained. As shown in FIG. 3F, for the portion of the n-type nitride layer 131 not covered by the anti-etching layer 134, an anisotropic etching is performed, for example, an inductive coupling plasma (ICP) etching.

Then, an etching solution such as oxalic acid, potassium hydroxide or a phosphoric acid sulfuric acid solution is applied to partially and non-isotropically wet the n-type nitride layer 131. By the above steps, a patterned n-type nitride layer 131 having at least one inner surface extending away from the normal direction N can be formed. Next, the anti-etching layer 134 can be selectively removed.

Next, other processes may be continued to form the photoelectric conversion structure 13 on the carrier 11, and the hole structure 15 is left in the optoelectronic semiconductor device 1. The hole structure 15 has a refractive index suitable as an air lens to reflect/refract light emitted by the photoelectric conversion structure 13.

The fifth embodiment of the present invention is shown in Figs. 4A to 4G, which is another method of manufacturing the above-described second embodiment of the optoelectronic semiconductor device 1. First, as shown in Fig. 4A, the carrier 11 (such as sapphire) is first provided. Substrate), then a cerium oxide (SiO ₂ ) layer 130 is formed on the carrier 11; then, as shown in FIG. 4B, a patterned photoresist layer 132 is formed on the cerium oxide layer 130, preferably, The step shown in FIG. 4B is a thermal reflow process for the patterned photoresist layer 132 to form a dome-shaped or approximately dome-shaped structure; as shown in FIG. 4C, for patterning The photoresist layer 132 and the ceria layer 130 are anisotropically etched such that the dome-shaped structure can be transferred to the ceria layer 130 while the photoresist layer 13 is removed. Thereby, the patterned ceria layer 130 is formed.

As shown in FIG. 4D, a nitride layer (eg, including a gallium nitride layer) is formed to cover the patterned ceria layer 130; then, as shown in FIGS. 4E and 4F, an inductively coupled plasma is performed (inductive). Coupling plasma, ICP) etching to etch the n-type nitride layer 131 to the patterned ceria layer 130 for local exposure, and then buffering oxide etch (BOE) of the patterned ceria layer 130 The hole structure 15 is formed by hollowing out and removing the patterned ceria layer 130. However, the etching of the ceria layer 130 is not limited to the beginning but also by the side.

Finally, as shown in FIG. 4G, epitaxy is continued to form the photoelectric conversion structure 13, and the hole structure 15 is left in the optoelectronic semiconductor device 1.

In the foregoing third to fifth embodiments, the buffer layer 17 or the reflective layer (not shown) may be formed on the carrier 11 first. After the epitaxial formation of the photoelectric conversion structure 13, finally, the transparent electrode layer 19 is formed on the photoelectric conversion structure 13, and the p-type electrode 21 and the p-type extension electrode 211 connected to the p-type electrode 21 are formed on the transparent electrode layer 19. And forming an n-type electrode 23 at an appropriate position.

In summary, the optoelectronic semiconductor device and the method for fabricating the same according to the present invention can form a hole structure in the optoelectronic semiconductor device as an air lens for reflecting light, whereby the light emitted by the optoelectronic semiconductor structure can be guided to the carrier. The normal direction of the device further enhances the forward light extraction efficiency of the optoelectronic semiconductor device.

The embodiments described above are only intended to illustrate the embodiments of the present invention, and to explain the technical features of the present invention, and are not intended to limit the scope of the present invention. Any changes or equivalents that can be easily made by those skilled in the art are within the scope of the invention, and the scope of the invention should be determined by the scope of the claims.

1. . . Photoelectric semiconductor device

11. . . vehicle

13. . . Photoelectric conversion structure

130. . . Ceria layer

131. . . N-type nitride layer

132. . . Photoresist layer

133. . . Multiple quantum well

134. . . Anti-etching layer

135. . . P-type nitride layer

15. . . Hole structure

151. . . Through hole

17. . . The buffer layer

19. . . Transparent electrode layer

21p. . . Type electrode

211p. . . Extended electrode

23n. . . Type electrode

N. . . Normal direction

1A is a top view of the optoelectronic semiconductor device of the first embodiment of the present invention;

1B is a schematic cross-sectional view of the optoelectronic semiconductor device according to the first embodiment of the present invention taken along line B-B' of FIG. 1A;

1C and 1D are schematic cross-sectional views of the optoelectronic semiconductor device according to the first embodiment of the present invention taken along line C-C' of FIG. 1A;

2A is a schematic cross-sectional view showing a photoelectric semiconductor device according to a second embodiment of the present invention;

2B to 2E are schematic views showing a hole structure in the photoelectric semiconductor device according to the second embodiment of the present invention;

3A-3H are schematic diagrams of processes of an optoelectronic semiconductor device in a fourth embodiment of the present invention; and

4A to 4G are schematic views showing the process of the photoelectric semiconductor device in the fifth embodiment of the present invention.

1. . . Photoelectric semiconductor device

11. . . vehicle

13. . . Photoelectric conversion structure

131. . . N-type nitride layer

133. . . Multiple quantum well

135. . . P-type nitride layer

15. . . Hole structure

151. . . Through hole

17. . . The buffer layer

19. . . Transparent electrode layer

N. . . Normal direction

Claims (9)

An optoelectronic semiconductor device comprising: a carrier comprising an upper surface defining a normal direction; and a photoelectric conversion structure disposed on the carrier, the photoelectric conversion structure being photoelectrically convertible to emit a light; At least one inner surface, including a lower surface of the photoelectric conversion structure and an upper surface of the carrier, formed in the optoelectronic semiconductor device to define at least one hole structure, the at least one hole structure being at least one hollow structure, and Along the normal direction, the photoelectric conversion structure is penetrated; wherein the at least one hole structure has a refractive index that changes direction when the light travels to the at least one hole structure, and moves away from the carrier toward the normal direction . The optoelectronic semiconductor device of claim 1, wherein the projection of the at least one hole structure along the normal direction is one of a circular shape, a circular shape, a rectangular shape, and a diamond shape, and/or the at least one hole structure The section perpendicular to the normal direction is one of a triangle, a semicircle, a rectangle, and a trapezoid. The optoelectronic semiconductor device of claim 1 includes a plurality of pore structures, the projections of the pore structures along the normal direction exhibiting a distribution pattern, and/or wherein the distribution patterns are rectangular array distributions and annular arrays. One of the distributions. The optoelectronic semiconductor device of claim 1, wherein the photoelectric conversion structure comprises an n-type nitride layer, a p-type nitride layer, and a plurality of between the n-type nitride layer and the p-type nitride layer Quantum well. The optoelectronic semiconductor device of claim 4, wherein the n-type nitride layer of the photoelectric conversion structure is adjacent to the carrier. A method of fabricating an optoelectronic semiconductor device comprising the steps of: providing a carrier comprising an upper surface defining a normal direction; forming a patterned nitride layer having at least one interior surface offset from the normal direction Extending; forming a photoelectric conversion structure on the carrier, wherein the inner surface includes a lower surface of the photoelectric conversion structure and an upper surface of the carrier; and forming at least one hole structure in the optoelectronic semiconductor device, wherein The at least one hole structure is at least one hollow structure, and the at least one hole structure has an index of refraction that reflects a light emitted by the photoelectric conversion structure. The method of claim 6, wherein the step of forming a patterned nitride layer comprises: forming a nitride layer; patterning the nitride layer; and partially anisotropically etching the nitride layer, The step of anisotropically etching the nitride layer is performed by performing an inductive coupling plasma (ICP) etching or applying an oxalic acid, potassium hydroxide or phosphoric acid sulfuric acid solution to wet-etch the nitride layer. . The method of claim 6, wherein the step of forming a patterned nitride layer comprises: forming a patterned cerium oxide (SiO ₂ ) layer; forming a nitride layer to cover the patterned second a ruthenium oxide layer; and removing the patterned ruthenium dioxide layer. A method of fabricating an optoelectronic semiconductor device comprising the steps of: providing a carrier; Epitaxially forming a photoelectric conversion structure on the carrier; etching the photoelectric conversion structure to form at least a uniform via; and locally anisotropically etching the optoelectronic semiconductor device in the at least one of the through holes to form at least one hole structure Between the photoelectric conversion structure and the carrier, wherein the step of partial anisotropic etching is performed by applying oxalic acid to the at least one of the perforations to wet etch the buffer layer.