TW201351732A - Semiconductor light-emitting chip - Google Patents

Abstract

A semiconductor light-emitting chip comprises a substrate, an epitaxial layer unit emitting light while externally supplying the electric energy, and an electrode unit, in which the electric energy is supplied to the epitaxial layer unit from the outside. The substrate contains a main body constituted by a material, which heat transfer coefficient is higher than the epitaxial material, and a heat conductor composed of the heat conduction material constituted by the material, in which the heat transfer coefficient is higher than the main body. The main body includes an upper and a lower surface opposite to each other, and a recess pattern formed from the lower surface. The heat conductor is filled into the recess pattern, and its surface and the lower surface are at a co-plane. The epitaxial layer unit is transferred and connected to the upper surface of the main body of the substrate after an epitaxy material is formed on the semiconductor. With the substrate composed of the main body and the heat conductor, waste heat generated by the epitaxial layer unit during operation can be quickly conducted away from the epitaxial layer unit via the substrate, and effectively enhancing the actuation stability and service life of the semiconductor chip.

Description

Semiconductor light emitting chip

The present invention relates to a semiconductor light-emitting wafer, and more particularly to a semiconductor light-emitting chip (LED chip) comprising a gallium nitride-based semiconductor material.

Semiconductor semiconductor light-emitting wafers, especially semiconductor wafers composed of gallium nitride-based semiconductor materials, are first developed using a sapphire substrate as an epitaxial material, and then epitaxially grown from the epitaxial growth to provide light by photoelectric effect. The layer unit is formed, and then, in view of the poor thermal conductivity of the sapphire substrate, the fabricated semiconductor light-emitting wafer affects the luminance, the stability of the operation, and the luminescence lifetime due to the accumulation of waste heat during operation. Then, the sapphire substrate is used as the epitaxial layer unit with good crystal structure and epitaxial growth, but the substrate with good thermal conductivity is replaced with the epitaxial material, and the epitaxial layer unit is fabricated. The technology of semiconductor light-emitting wafer with epitaxial quality and substrate heat dissipation problem improves the operation of the epitaxial layer unit of the semiconductor light-emitting chip, the brightness of the light-emitting layer and the actual working life by replacing the substrate with better thermal conductivity. In this regard, the relevant industry has also proposed a series of technical improvements.

However, in depth, such a replacement of the epitaxial material is a technical development of a substrate having a better heat dissipation property, and most of them focus on, for example, a wafer bonding technique of an epitaxial layer unit and a substrate, and a mirror is added to the substrate. In terms of improving the brightness of the light, there is no improvement on the substrate itself, especially how to improve the thermal conductivity of the substrate replacing the epitaxial material, which directly affects the stability of the epitaxial layer unit of the semiconductor light-emitting chip, the brightness of the light and the actual working life. Key cause It should be worthy of research and improvement by the industry and academic circles.

Accordingly, it is an object of the present invention to provide a novel semiconductor light-emitting wafer having a high thermal conductivity of a substrate in which an epitaxial material is replaced.

Thus, a semiconductor light emitting wafer of the present invention comprises a substrate, an epitaxial layer unit, and an electrode unit.

The substrate has a body composed of a material having a heat transfer coefficient higher than that of an epitaxial material, and a heat conductor composed of a heat conductive material having a heat transfer coefficient higher than a constituent material of the body, the body including an upper surface and an opposite The lower surface of the upper surface, and a groove pattern formed from the lower surface facing the upper surface direction, the heat conductor is filled in the groove pattern and the surface is coplanar with the lower surface.

After the epitaxial layer unit is epitaxially formed from the epitaxial material, the epitaxial layer unit is transferred and connected to the upper surface of the substrate body to emit light when electric energy is supplied from the outside.

The electrode unit supplies electric power to the epitaxial layer unit via the outside.

The effect of the invention is that a groove pattern is formed on the body of the substrate, and then a heat conductor with a higher heat transfer coefficient is filled in the groove pattern, thereby improving the heat transfer efficiency of the substrate, and the epitaxial layer unit is generated when the operation is performed. The waste heat is more effectively and quickly guided away from the epitaxial layer unit, so that the semiconductor light-emitting chip has better luminescent performance and actual working life.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention.

Before the present invention is described in detail, it is noted that in the following description In the content, similar elements are denoted by the same reference numerals.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , a first preferred embodiment of a semiconductor light-emitting wafer 1 includes a substrate 2 , an epitaxial layer unit 3 , and an electrode unit 4 . The semiconductor wafer 1 is a substrate 2 that is electrically conductive and cooperates with the electrode unit 4 to provide the epitaxial layer unit 3, which is fixed in a susceptor 200. A vertical-conducting semiconductor wafer of electrical energy.

Referring to FIG. 1 and FIG. 2, the substrate 2 has a body 21 made of a material having a heat transfer coefficient higher than that of an epitaxial material and electrically conductive, and a heat conductive material having a heat transfer coefficient higher than a material constituting the body 21. The heat conductor 22 is configured to have a substantially rectangular plate shape, and includes an upper surface 211, a lower surface 212 opposite to the upper surface 211, and a lower surface 212 formed toward the upper surface 211. The groove pattern 213, since the epitaxial material is generally sapphire, the material of the body 21 is preferably copper, tantalum, aluminum, etc., and the heat conductor 22 is filled in the groove pattern 213 and the surface is coplanar with the lower surface 212. The adhesive substrate 100 can be placed on the susceptor 200 in a flat manner without causing the problem of subsequent die bonding due to the raised thermal conductor 22. The thermal conductor 22 includes a particle size scale of nanometer scale. The heat conductive particles 221 and a bonding material 222 that connects the heat conductive particles 221 and the main body 21 of the substrate 2, in this example, the groove patterns 213 are substantially continuous crisscross patterns, and the heat conductive particles 221 are Diamond powder, or carbon nanotubes, or diamond powder and The mixing of the carbon nanotubes is different from the heat transfer coefficient of the body 21 and the heat conductor 22, and the groove pattern 213 of the body 21 is matched to form a predetermined pattern, and the upper surface 211 of the body 21 of the substrate 2 can be heated downward. table When the surface 212 is transferred in the direction, it has different transmission paths and rates, thereby effectively improving the thermal conductivity of the substrate 2 as a whole.

The epitaxial layer unit 3 is formed by epitaxial formation of a gallium nitride-based semiconductor material from an epitaxial material (ie, a conventionally used sapphire, not shown), and then by wafer bonding or electroplating. The epitaxial layer unit 3 includes a p-type cladding layer, and the epitaxial layer unit 3 includes a p-type cladding layer, which is connected to the upper surface 211 of the substrate 21 and is connected to the upper surface 211 of the substrate 2; An n-type cladding layer, an active layer formed between the p-type and n-type cladding layers, and a buffer layer, and the active layer is, for example, a homostructure (homostructure) ), single heterostructure, double heterostructure, or multiple quantum wells, etc., combined with p, n-type cladding layers to generate light when supplying electrical energy, due to such structures The principle of actuation and so on have been known to the academic community, and it is not the focus of the creation of this invention, so it is not explained in detail here.

The electrode unit 4 is disposed on the epitaxial layer unit 3, and cooperates with the substrate 2 to supply electric power to the epitaxial layer unit 3 to cause the epitaxial layer unit 3 to emit light.

When the electrode unit 4 and the substrate 2 cooperate to supply electric energy to the epitaxial layer unit 3, the epitaxial layer unit 3 emits light by photoelectric effect, and the epitaxial layer unit 3 generates heat generated by simultaneous emission of light. The upper surface 211 of the substrate 2 is transferred to the lower surface 212, in particular, the heat is first contacted to the heat conductor 22 filled in the groove pattern 213, and the design of the groove pattern 213 is matched with the heat conductor 22 to be transmitted more quickly. Dissipate outward and lead to the epitaxial layer to the susceptor 200 Unit 3, the epitaxial layer unit 3 is stably operated.

In addition, the groove pattern 213 of the body 21 may also be a concentric ring pattern, a crisscrossed square, a trapezoid, or a triangle, so that the heat conductor 22 is filled in the groove pattern. After 213, the heat can be guided away from the epitaxial layer unit 3 more quickly and efficiently by the patterning and the bonding of the heat conductor 22.

Furthermore, the heat conductor 22 may also be a diamond-like structure formed by direct growth by a coating method, such as a diamond, or a carbon nanotube.

Moreover, between the substrate 2 and the epitaxial layer unit 3, a dielectric material having a relatively high and low difference in light reflection coefficient (and having a high thermal conductivity) may be alternately stacked, or a metal having a high reflection coefficient. Or a coating of the alloy material forms a reflector mirror for reflecting the light emitted by the epitaxial layer unit 3 and traveling toward the substrate to enhance the forward light-emitting brightness of the semiconductor light-emitting chip; since the mirror related technologies have been used in the industry It is well known and not the focus of the research of the present invention, and therefore will not be described in detail herein.

Referring to FIG. 4, a second preferred embodiment of a semiconductor light-emitting wafer 1' of the present invention is similar to the first preferred embodiment except that the substrate 2' is made of a thermally conductive but insulating material. The unit 4' has two electrodes 41 disposed on the epitaxial layer unit 3 to cooperate with each other to supply electric power to the epitaxial layer unit 3, that is, the semiconductor wafer 1' of the second preferred embodiment is a The two electrodes 41 of the electrode unit 4' cooperate with a horizontal-conducting semiconductor wafer that supplies electrical power to the epitaxial layer unit 3.

It should be further noted that the substrate of the semiconductor light-emitting wafer 1' of the second preferred embodiment may be a sapphire that can be directly epitaxially formed (before the bottom surface 212). After the groove pattern 213 is formed, the heat conductor 22 is filled, and the heat conduction of the sapphire orite material is improved by the groove pattern 213 and the heat conductor 22. The sapphire crystal can also be used first. After crystal growth of the epitaxial layer unit 3, the wafer bonding is transferred to the prefabricated substrate 2' by a wafer bonding method to achieve a better heat dissipation effect, since the application details are Generally, the knowledgeable person can be designed and implemented according to the disclosed semiconductor light-emitting chip structure, and the implementation details are numerous, and thus will not be further described herein.

According to the above description, the present invention mainly forms the groove pattern 213 on the substrates 2, 2' of the semiconductor light-emitting wafers 1, 1', and is filled with the heat-conducting particles 221 and the bonding material 222. The heat conductor 22 effectively increases the rate of waste heat generated when the substrate 2, 2' is guided away from the operation of the epitaxial layer unit 3, and effectively improves the heat dissipation problem of the conventional semiconductor light-emitting wafer during operation, thereby improving the light-emitting of the semiconductor light-emitting chip. Performance and working life have indeed achieved the creative purpose of the present invention.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

100‧‧‧Adhesive

200‧‧‧Base

1, 1'‧‧‧ semiconductor light-emitting wafer

2, 2'‧‧‧ substrate

21‧‧‧ body

211‧‧‧ upper surface

212‧‧‧ lower surface

213‧‧‧ Groove pattern

22‧‧‧ Thermal Conductor

221‧‧‧thermal particles

222‧‧‧Combined materials

3‧‧‧ epitaxial layer unit

4, 4'‧‧‧ electrode unit

41‧‧‧Electrode

1 is a schematic cross-sectional view showing a first preferred embodiment of a semiconductor light-emitting wafer according to the present invention; FIG. 2 is a schematic bottom view, and FIG. 1 is a first preferred embodiment of a semiconductor light-emitting wafer according to the present invention; 3 is a schematic view showing a first preferred embodiment of a semiconductor light-emitting wafer according to the present invention, wherein the light-emitting component is packaged by being fixed in a pedestal; and FIG. 4 is a schematic cross-sectional view showing the present invention. A second preferred embodiment of a semiconductor light emitting wafer.

1‧‧‧Semiconductor light-emitting chip

2‧‧‧Substrate

21‧‧‧ body

211‧‧‧ upper surface

212‧‧‧ lower surface

213‧‧‧ Groove pattern

22‧‧‧ Thermal Conductor

221‧‧‧thermal particles

222‧‧‧Combined materials

3‧‧‧ epitaxial layer unit

4‧‧‧Electrode unit

Claims (9)

A semiconductor light emitting chip comprising: a substrate having a body composed of a material having a heat transfer coefficient higher than that of an epitaxial material; and a heat conductor composed of a heat conductive material having a heat transfer coefficient higher than a constituent material of the body, The body includes an upper surface, a lower surface opposite to the upper surface, and a groove pattern formed from the lower surface facing the upper surface, the heat conductor is filled in the groove pattern and the surface is coplanar with the lower surface An epitaxial layer unit is formed by epitaxial formation of the epitaxial material from a semiconductor material, and then transferred to the upper surface of the substrate body to emit light when external power is supplied from the outside; and an electrode unit is subjected to epitaxy through the outside The layer unit provides electrical energy. The semiconductor light-emitting wafer according to claim 1, wherein the heat conductor comprises thermally conductive particles having a particle size scale of a nanometer scale, and a bonding material for coupling the thermally conductive particles to the substrate body. The semiconductor light-emitting wafer of claim 2, wherein the thermally conductive particles are selected from the group consisting of diamond powder, carbon nanotubes, and combinations thereof. The semiconductor light-emitting wafer according to claim 1, wherein the heat conductor is a diamond structure formed by plating growth, a diamond-like structure, a carbon nanotube layer, or a combination thereof. The semiconductor light-emitting wafer according to claim 3, wherein the epitaxial material is sapphire, and the epitaxial layer unit is a gallium nitride-based semiconductor material. A semiconductor light-emitting wafer according to claim 5, wherein The substrate is electrically conductive and cooperates with the electrode unit to supply electrical energy to the epitaxial layer unit via the outside. The semiconductor light-emitting wafer of claim 6, wherein the epitaxial layer unit is bonded to the upper surface of the substrate body in a wafer bonding manner. The semiconductor light-emitting chip of claim 5, wherein the substrate is non-conductive, and the electrode unit has two electrodes disposed on the epitaxial layer unit to cooperate with each other to supply electrical power to the epitaxial layer unit. electrode. The semiconductor light-emitting wafer of claim 8, wherein the epitaxial layer unit is bonded to the upper surface of the substrate body in a wafer bonding manner.