U.S. patent application number 14/301492 was filed with the patent office on 2014-12-25 for light-emitting device and light-emitting array.
The applicant listed for this patent is EPISTAR CORPORATION. Invention is credited to Wei-Jung CHUNG, Jennhwa FU, Chi-Hao HUANG, Cheng-Hsien LI.
Application Number | 20140374779 14/301492 |
Document ID | / |
Family ID | 52010585 |
Filed Date | 2014-12-25 |
United States Patent
Application |
20140374779 |
Kind Code |
A1 |
CHUNG; Wei-Jung ; et
al. |
December 25, 2014 |
LIGHT-EMITTING DEVICE AND LIGHT-EMITTING ARRAY
Abstract
A light-emitting device includes a light-emitting stack
including a first semiconductor layer, a second semiconductor
layer, and an active layer between the first semiconductor layer
and the second semiconductor layer, wherein the first semiconductor
layer includes a first surface, a second surface opposite to the
first surface, a first portion connecting to the first surface, and
a second portion connecting to the first portion; an opening
penetrating the first portion from the first surface and having a
first width; a depression connecting to the opening and penetrating
the second semiconductor layer, the active layer, and the second
portion of the first semiconductor layer, wherein the depression
includes a second width greater than the first width, and the
depression includes a bottom to expose the second surface, and an
electrode located in the depression and corresponding to the
opening.
Inventors: |
CHUNG; Wei-Jung; (Hsinchu,
TW) ; FU; Jennhwa; (Hsinchu, TW) ; LI;
Cheng-Hsien; (Hsinchu, TW) ; HUANG; Chi-Hao;
(Hsinchu, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EPISTAR CORPORATION |
Hsinchu |
|
TW |
|
|
Family ID: |
52010585 |
Appl. No.: |
14/301492 |
Filed: |
June 11, 2014 |
Current U.S.
Class: |
257/88 ;
257/98 |
Current CPC
Class: |
H01L 33/38 20130101;
H01L 2924/0002 20130101; H01L 33/20 20130101; H01L 33/382 20130101;
H01L 25/0753 20130101; H01L 33/387 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
257/88 ;
257/98 |
International
Class: |
H01L 33/62 20060101
H01L033/62; H01L 25/075 20060101 H01L025/075; H01L 33/60 20060101
H01L033/60 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2013 |
TW |
102122124 |
Apr 28, 2014 |
TW |
103115304 |
Claims
1. A light-emitting device, comprising: a light-emitting stack
comprising a first semiconductor layer, a second semiconductor
layer, and an active layer between the first semiconductor layer
and the second semiconductor layer, wherein the first semiconductor
layer comprises a first surface, a second surface opposite to the
first surface, a first portion connecting to the first surface, and
a second portion connecting to the first portion; an opening
penetrating the first portion of the first semiconductor from the
first surface and having a first width; a depression connecting to
the opening and penetrating the second semiconductor layer, the
active layer, and the second portion of the first semiconductor
layer, wherein the depression has a second width greater than the
first width and comprises a bottom to expose the second surface;
and an electrode located in the depression and corresponding to the
opening.
2. The light-emitting device of claim 1, further comprising an
insulative structure filling the depression and covering the
electrode.
3. The light-emitting device of claim 2, wherein the electrode is
connected to the second surface.
4. The light-emitting device of claim 3, further comprising a
wiring electrode formed in the depression and connecting to the
electrode.
5. The light-emitting device of claim 3, wherein the insulative
structure separates the electrode, the active layer, and the second
semiconductor layer.
6. The light-emitting device of claim 2, further comprising a
conductive structure connecting to the second semiconductor layer
wherein the conductive structure comprises a conductive layer
electrically connecting with the second semiconductor layer and a
barrier covering the second semiconductor layer.
7. The light-emitting device of claim 6, wherein the conductive
layer is a metal having reflectivity and comprising nickel (Ni),
platinum (Pt), palladium (Pd), silver (Ag), chromium (Cr), or
combinations thereof, and the barrier comprises titanium (Ti),
tungsten (W), platinum (Pt), titanium tungsten (TiW), or
combinations thereof.
8. The light-emitting device of claim 6, wherein the insulative
structure is below the second semiconductor and the conductive
structure comprises conductive channels penetrating the insulative
layer and connecting to the second semiconductor layer.
9. The light-emitting device of claim 6, further comprising a metal
reflective layer below the conductive structure and the insulative
structure, a conductive joining layer below the metal reflective
layer, and a conductive substrate below the conductive joining
layer.
10. The light-emitting device of claim 1, wherein the electrode
comprises at least one of wiring electrodes and an extensive
electrode extending from the wiring electrode.
11. The light-emitting device of claim 10, wherein the wiring
electrode is located at a corner of the light-emitting device, and
the extensive electrode extends in a direction far away from the
wiring electrode, or the wiring electrode is located at a corner of
the light-emitting device, and the extensive electrode extends
along surroundings of the light-emitting device, or the wiring
electrode is located at a geometric center of the light-emitting
device and the extensive electrode comprises a plurality of radial
branches extending from the wiring electrode, or the wiring
electrode comprises a first electrode and a second electrode on a
side of the light-emitting device, and the extensive electrode
comprises a plurality of radial branches extending from the first
electrode and the second electrode to an opposite side, opposite to
the side, and a connective electrode connecting with the first
electrode and the second electrode.
12. The light-emitting device of claim 1, wherein the first surface
of the first semiconductor layer is devoid of a structure shielding
light emitted from the active layer
13. The light-emitting device of claim 1, wherein the first
semiconductor layer comprises an n-type semiconductor layer and the
second semiconductor layer comprises a p-type semiconductor
layer.
14. The light-emitting device of claim 1, wherein a size of the
light-emitting device is 1 mil to 70 mils.
15. A light-emitting array, comprising: a substrate comprising an
upper surface; a plurality of light-emitting units on the upper
surface of the substrate wherein each of the light-emitting units
comprises a first surface and a second surface opposite to the
first surface toward to the upper surface; an insulative layer
between the substrate and the light-emitting units and covering the
second surface of each of the light-emitting units; and a wire
embedded in the insulative layer, wherein the wire comprises a
conductive channel, penetrating the insulative layer and
electrically connecting with the second surface and a bridge
connecting with the conductive channel, and the bridge electrically
connects with two of the light-emitting units via the conductive
channel.
16. The light-emitting array of claim 15, wherein the first surface
has a first polarity, the second surface comprises a first region
with the first polarity and a second region nearer the upper
surface than the first region with a second polarity, and the
conductive channel electrically connects with the first region or
the second region.
17. The light-emitting array of claim 16, wherein the substrate is
a conductive substrate, and one of the light-emitting units
comprises the conductive channel electrically connecting the second
region with the conductive substrate or electrically connecting the
first region with the conductive substrate.
18. The light-emitting array of claim 16, further comprising a
conductive joining layer between the conductive substrate and the
insulative layer.
19. The light-emitting array of claim 16, wherein each of the light
emitting units comprises a plurality of the first regions and each
of the first regions connects to a plurality of conductive
channels.
20. The light-emitting array of claim 16, further comprising an
electrode on a surface of the insulative layer opposite to the
upper surface, located outside each of the light-emitting units,
and electrically connecting with the bridge which electrically
connects with the first region or the second region of one of the
light-emitting units.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application claims the right of priority based on TW
application Serial No. 102122124, filed on Jun. 20, 2013 and Serial
No. 103115304, filed on, Apr., 28, 2014, and the content of which
is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The disclosure is related to a light-emitting device, and
more particularly, a light-emitting device and a light-emitting
array with a connecting layer between a substrate and a
light-emitting stack.
DESCRIPTION OF THE RELATED ART
[0003] The lighting theory of light-emitting diodes (LEDs) is that
electrons move between an n-type semiconductor and a p-type
semiconductor to release energy. Due to the difference of lighting
theories between LEDs and incandescent lamps, the LED is called
"cold light source". An LED has the advantages of good environment
tolerance, a long service life, portability, and low power
consumption and is regarded as another option for the lighting
application. LEDs are widely adopted in different fields, for
example, traffic lights, backlight modules, street lights, and
medical devices and replaces conventional light sources
gradually.
[0004] An LED has a light-emitting stack which is epitaxially grown
on a conductive substrate or an insulting substrate. The so-called
"vertical LED" has a conductive substrate and includes an electrode
formed on the top of a light emitting layer; the so-called "lateral
LED" has an insulative substrate and includes electrodes formed on
two semiconductor layers which have different polarities and
exposed by an etching process. The vertical LED has the advantages
of small light-shading area for electrodes, good heat dissipating
efficiency, and no additional etching epitaxial process, but has a
shortage that the conductive substrate served as an epitaxial
substrate absorbs light easily and is adverse to the light
efficiency of the LED. The lateral LED has the advantage of
radiating light in all directions due to a transparent substrate
used as the insulator substrate, but has shortages of poor heat
dissipation, larger light-shading area for electrodes, and smaller
light-emitting area caused by epitaxial etching process.
[0005] The abovementioned LED can further connects to/with other
device for forming a light-emitting device. For a light-emitting
device, the LED can connect to a carrier by a side of a substrate
or by soldering material/adhesive material between a sub-carrier
and the LED.
SUMMARY OF THE DISCLOSURE
[0006] A light-emitting device includes a light-emitting stack
including a first semiconductor layer, a second semiconductor
layer, and an active layer between the first semiconductor layer
and the second semiconductor layer, wherein the first semiconductor
layer includes a first surface, a second surface opposite to the
first surface, a first portion connecting to the first surface, and
a second portion connecting to the first portion; an opening
penetrating the first portion and having a first width; a
depression connecting to the opening and penetrating the second
semiconductor layer, the active layer, and the second portion of
the first semiconductor layer, wherein the depression includes a
second width wider than the first width, and the depression
includes a bottom to expose the second surface; and an electrode
located in the depression and corresponding to the opening.
[0007] A light-emitting array includes a substrate having an upper
surface, light-emitting units on the upper surface of the
substrate, wherein each of the light-emitting units includes a
first surface and a second surface opposite to the first surface
and toward to the upper surface; an insulative layer, between the
substrate and the light-emitting unit, covering the second surface
of each of the light-emitting units; and at least one of wires
embedded in the insulative layer, wherein each of the at least one
of wires includes a conductive channel, penetrating the insulative
layer and electrically connecting with the second surface, and a
bridge electrically connecting with the conductive channel, and at
least one of the bridges electrically connects two of the
light-emitting units via a plurality the conductive channels.
BRIEF DESCRIPTION OF THE DRAWING
[0008] The accompanying drawing is included to provide easy
understanding of the application, and is incorporated herein and
constitutes a part of this specification. The drawing illustrates
the embodiment of the application and, together with the
description, serves to illustrate the principles of the
application.
[0009] FIGS. 1A to 1H illustrate a light-emitting device in
accordance with a manufacturing method of a first embodiment of the
application.
[0010] FIG. 2 illustrates a light-emitting device in accordance
with a second embodiment of the application.
[0011] FIG. 3 illustrates a light-emitting device in accordance
with a third embodiment of the application.
[0012] FIG. 4 illustrates an electrode layout of the light-emitting
device in accordance with the first embodiment of the
application.
[0013] FIG. 5 illustrates an electrode layout of the light-emitting
device in accordance with the forth embodiment of the
application.
[0014] FIG. 6 illustrates an electrode layout of the light-emitting
device in accordance with a fifth embodiment of the
application.
[0015] FIG. 7 illustrates an electrode layout of the light-emitting
device in accordance with a sixth embodiment of the
application.
[0016] FIG. 8 illustrates an electrode layout of the light-emitting
device in accordance with a seventh embodiment of the
application.
[0017] FIG. 9 illustrates an electrode layout of the light-emitting
device in accordance with an eighth embodiment of the
application.
[0018] FIG. 10 illustrates an electrode layout of the
light-emitting device in accordance with a ninth embodiment of the
application.
[0019] FIG. 11 illustrates a light-emitting array in accordance
with a tenth embodiment of the application.
[0020] FIG. 12 illustrates a light-emitting array in accordance
with an eleventh embodiment of the present application.
[0021] FIG. 13 illustrates a light-emitting array in accordance
with a twelfth embodiment of the application.
[0022] FIG. 14 illustrates a light-emitting array in accordance
with a thirteenth embodiment of the application.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] To better and concisely explain the disclosure, the same
name or the same reference number given or appeared in different
paragraphs or figures along the specification should has the same
or equivalent meanings while it is once defined anywhere of the
disclosure.
[0024] The following shows the description of embodiments of the
present disclosure in accordance with the drawing.
[0025] Referring to FIGS. 1A to 1H, the figures illustrate a
light-emitting device in accordance with a manufacturing method of
a first embodiment of the application. As shown in FIG. 1A, a
light-emitting stack 108 which is epitaxially grown on a growth
substrate 101 includes a first semiconductor layer 102, a second
semiconductor layer 106, and an active layer 104 between the first
semiconductor layer 102 and the second semiconductor layer 106. The
light-emitting stack 108 can be a nitride light-emitting stack and
a material of the light-emitting stack 108 containing elements like
aluminum (Al), indium (In), gallium (Ga), or nickel (N). The growth
substrate 101 can be made of a transparent insulative substrate,
such as sapphire, or a conductive substrate, such as silicon (Si)
substrate or silicon carbide (SiC) substrate. For reducing lattice
mismatch between the growth substrate 101 and the light-emitting
stack 108, a buffer layer 103 can be formed on the growth substrate
101 before forming the light-emitting stack 108. A material of the
light-emitting stack 108 can contain elements like aluminum (Al),
gallium (Ga), indium (In), phosphorus (P), or arsenic (As), and a
material of the growth substrate 101 can be gallium arsenide
(GaAs). The first semiconductor layer 102, the active layer 104,
the second semiconductor layer 106 are epitaxially grown on the
growth substrate 101. Herein, the first semiconductor layer 102 can
be an n-type semiconductor, the second semiconductor layer 106 can
be a p-type semiconductor, and a structure of the light-emitting
stack 108 includes a single heterostructure (SH), a double-side
double heterostructure (DDH), or multi-quantum well (MQW)
structure.
[0026] Referring to FIG. 1B, a depression 105 is formed, penetrates
the second semiconductor layer 106 and the active layer 104, and
exposes the first semiconductor layer 102. The depression 105 has a
pattern and an electrode 110 which is corresponding to the pattern
is formed in the depression 105. Afterwards, a conductive layer 112
is formed on the second semiconductor layer 106. Herein, the
electrode 110 electrically connects with only the first
semiconductor layer 102, and in a cross-sectional view, there is a
gap between two sides of the electrode 110 and the depression 105
so the electrode 110 is insulated from the active layer 104 and the
second semiconductor layer 106. The conductive layer 112 has ohmic
contact with the second semiconductor layer 106 and can be a
transparent conductive layer, such as indium tin oxide (ITO),
indium zinc oxide (IZO) or aluminum-doped zinc oxide (A ZO), or
metal material, such as, nickel (Ni), platinum (Pt), palladium
(Pd), silver (Ag), or chromium (Cr). The electrode 110 can be
aluminum (Al), titanium (Ti), chromium (Cr), platinum (Pt), gold
(Au), or combinations thereof.
[0027] Referring to FIG. 1C, a barrier 116 covering the conductive
layer 112 and an insulative structure 114 covering the electrode
110 are formed. The barrier 116 covers all surface of the
conductive layer 112 except the region contacting the second
semiconductor layer 106. The pattern of the insulative structure
114 is substantially corresponding to the pattern of the electrode
110 while the insulative structure 114 fills a space between the
electrode 110 and the depression 105. The upper surface 114a of the
insulative structure 114 and the upper surface 116a of the barrier
116 are coplanar and the barrier 116 horizontally surrounds the
insulative structure 114, except the portion in the depression 105.
The insulative structure 114 includes transparent material and is
formed by evaporating, sputtering, or spin-on glass (SOG) to form
single-layer of SiO.sub.2, single-layer of TiO.sub.2, or
single-layer of Si.sub.3N.sub.4 and then solidifying. The barrier
116 can be single-layer or multi-layer structure and includes
titanium (Ti), tungsten (W), platinum (Pt), titanium tungsten (TiW)
or combinations thereof.
[0028] Referring to FIG. 1D, a reflective layer 118 is formed on a
plane on which the upper surface 114a of the insulated layer 114
and the upper surface 116a of the barrier 116 lie. The reflective
layer 118 can include aluminum (Al).
[0029] Referring to FIG. 1E, a conductive substrate 122 is provided
and connects to a metal layer 118 via a joining structure 120. The
joining structure 120 includes gold (Au), indium (In), nickel (Ni),
titanium (Ti), or combinations thereof. Consequentially, a process
of removing the growth substrate 101 is performed. The conductive
substrate 122 includes a semiconductor material, such as silicon
(Si), or a metal material, such as, cobalt (Cu), tungsten (W), or
aluminum (Al). Moreover, a surface of the conductive substrate 122
can be graphene.
[0030] Referring to FIG. 1F, a laser ray (not shown in FIG. 1F) is
provided to a back surface of the growth substrate 101 to dissolve
a buffer layer 103 by energy from the laser ray. For example, when
the buffer layer 103 is non-doped or unintentional-doped GaN, the
energy from the laser ray can evaporate nitrogen in gallium nitride
(GaN), so as to dissolve the buffer layer 103 and remove the growth
substrate 101 so the first semiconductor 102 is exposed.
[0031] Referring to FIG. 1G, the remaining buffer layer 103 on the
first semiconductor layer 102 is further removed. When the buffer
layer 103 is non-doped or unintentional-doped gallium nitride,
because the nitrogen in gallium nitride has been evaporated in the
abovementioned process by the laser ray, a cleaning step is
performed to mainly remove the remaining gallium in the step by
inductively coupled plasma (ICP), and the surface of the first
semiconductor layer can be further cleaned by HCl or
H.sub.2O.sub.2.
[0032] Referring to FIG. 1H, a roughed structure 126 is formed on
the first surface 102a of the first semiconductor layer 102 by
etching. The roughed structure 126 can have a regular or irregular
rough surface with a roughness of 0.5.about.1 .mu.m, and an opening
124 is formed by removing a portion of the first semiconductor
layer 102 which is on the electrode 110. The depression 105 has
width W1 greater than a width W2 of the opening 124, and therefore,
after the depression 105 and the opening are formed in sequence, a
second surface 102d opposite to the first surface 102a is formed at
the bottom of the first semiconductor layer 102 connecting to the
depression 105, and the electrode 110 connects to the second
surface 102d and is formed in the depression 105 corresponding to
the opening 124 wherein the electrode has a width W3 greater than
the width W2. The upper surface 110a of the electrode 110 has a
contact area 110b connecting to the second surface 102d of the
first semiconductor layer 102 and an exposed area 110c exposed by
the opening 124. A thickness of the first semiconductor 102 can be
3.about.4 .mu.m while the first semiconductor 102 has a first
portion 102b and a second portion 102c. The thickness of the first
portion 102b is about equal to the depth of the opening 124, which
is about 1.5.about.3 .mu.m. The thickness of the second portion
102c corresponding to the depression 105 is about 1.about.1.5
.mu.m. Because the electrode 110 electrically connects to the first
semiconductor layer 102 while is not formed on the first surface
102a, the electrode 110 does not shield the light from the
light-emitting device 100.
[0033] With the abovementioned processes, the light-emitting device
100 disclosed in the embodiment includes the conductive substrate
122; the joining structure 120 formed on the conductive substrate
122; the reflective layer 118 formed on the joining structure 120;
the conductive structure 117 including the barrier 116 formed on a
portion of the reflective layer 118, and the conductive layer 112
covered by the barrier 116; the light-emitting stack 108 including
the first semiconducting layer 102, the active layer 104, and the
second semiconducting layer 106 electrically connecting with the
conductive layer 112; the insulative structure 114 formed on a
portion of the reflective layer 118 and penetrating the second
semiconducting layer 106, the active layer 104, and the second part
102c of the first semiconducting layer 102; the electrode 110
covered by the insulative structure 124 wherein the upper surface
110a of the electrode 110 connects to the first semiconducting
layer 102; and the opening 124 penetrating the first portion 102b
of the first semiconducting layer 102. Herein, the insulative
structure 114 insulates the electrode 110 from the second
semiconductor 106 and the active layer 104, and the electrode 110
and the active layer 104 are on different regions along the
horizontal direction of the light-emitting device 100 while the
whole active layer 104 is located above the conductive structure
117. Therefore, the light from the active layer 104 is not shielded
by the electrode 110 of the light-emitting device 100 and the
conductive structure 117. The upper surface 110a of the electrode
110 can be connected with an external power source.
[0034] FIG. 2 illustrates a light-emitting device in accordance
with a second embodiment of the application. The second embodiment
and the first embodiment are similar, but the difference between
them is that a wiring electrode 211 is formed on an electrode 210
and the wiring electrode 211 is in an opening 204 for a soldering
ball for wiring (not shown in FIG. 2).
[0035] FIG. 3 illustrates a light-emitting device in accordance
with a third embodiment of the application. The third embodiment is
similar to the aforementioned embodiments, but the differences
between them are mentioned as follows. A conductive layer 308 which
electrically connects with a second semiconductor layer 306 is a
transparent conductive layer without reflectivity, such as indium
tin oxide (ITO), indium zinc oxide (IZO), or aluminum-doped zinc
oxide (Al ZO), and there is no barrier as shown in the first
embodiment. An insulative structure 314 can include an insulative
layer 314a between a light-emitting stack 310 and a reflective
layer 318, and an insulative portion 314b covers the electrode 311.
A plurality of conductive channels 316 penetrates the insulative
layer 314a and connects the conductive layer 308 and the reflective
layer 318 by its two ends respectively. A joining structure 320 and
a conductive substrate 322 same as those described in the first
embodiment are below the reflective layer 318. The conductive
channel 316 can be a metal well to fill pores like titanium (Ti),
aluminum (Al), nickel (Ni), chromium (Cr), or copper (Cu). The
insulative structure 314 can be a transparent insulative material
and is formed by evaporating, sputtering, or spin-on glass (SOG) to
form single-layer of SiO.sub.2, single-layer of TiO.sub.2, or
single-layer of Si.sub.3N.sub.4, and then solidifying or
alternatively stacking two different films with different index of
refraction to form a distributed Bragg reflector (DBR).
[0036] FIG. 4 illustrates an electrode layout of the light-emitting
device in accordance with the first embodiment of the application.
The electrode layout can also be utilized in the second embodiment
and the third embodiment. In the embodiment, it shows only patterns
of the electrode 110 and the conductive structure 117 for clearly
showing the pattern of the electrode. From top view, the conductive
substrate 122 of the light-emitting device 100 is a rectangle with
a size of 1 mil to 70 mils. The electrode disclosed in the
embodiment includes a wiring electrode 110 and an extensive
electrode 111 extending from the wiring electrode 110. The wiring
electrode 110 is located near a corner of the rectangle of the
light-emitting device 100, and the extensive electrode 111 includes
a first extensive electrode 111b along outer edges of the
light-emitting device 100 and a second extensive electrode 111a
surrounding by and connecting to the first extensive electrode
111b. The first extensive electrode 111b and the second electrode
111a form another rectangle. The wiring electrode 110, and/or the
extensive electrode 111, and the conductive structure 117 are
formed on different regions of the conductive substrate 122 and do
not overlap with one another. Therefore, the conductive structure
117 as shown in the region with slash lines substantially
complements the patterns of the wiring electrode 110 and the
extensive electrode 111.
[0037] FIG. 5 shows an electrode layout of a light-emitting device
in accordance with a fourth embodiment of the application. The
electrode layout can be utilized in the first embodiment to the
third embodiment. FIG. 5 illustrates only the electrodes and the
conductive structure of the above-mentioned embodiment for clearly
showing patterns on the electrodes. From top view, a conductive
substrate 522 of a light-emitting device 500 is a rectangle. The
electrodes shown in the embodiment include a wiring electrode 510
and an extensive electrode 511 extending from the wiring electrode
510. The wiring electrode 510 is substantially located at a
geometric center of the light-emitting device 500 and the extensive
electrode 511 optionally includes a plurality of radial branches
extending from the wiring electrode 510. The wiring electrode 510,
and/or the extensive electrode 511, and a conductive structure 517
are formed on different regions of the conductive substrate 522 and
do not overlap with one another. Therefore, the conductive
structure 517 as shown in the region with slash lines substantially
complements the pattern formed by the wiring electrode 510 and the
extensive electrode 511.
[0038] FIG. 6 shows an electrode layout of a light-emitting device
in accordance with a fifth embodiment of the application. The
electrode layout can be utilized in the first embodiment to the
third embodiment. From top view, a conductive substrate 622 of a
light-emitting device 600 is a rectangle. The electrodes disclosed
in the embodiment include a wiring electrode 610 and an extensive
electrode 611 extending from the wiring electrode 610. The wiring
electrode 610 is substantially located at a geometric center of the
light-emitting device 600 and the extensive electrode 611 includes
a plurality of radial branches extending from the wiring electrode
610. In comparison with the fifth embodiment, there are more radial
branches in the embodiment and lengths of the radial branches vary
with their extended directions. For example, a length of the radial
branch of the extensive electrode 611 along a diagonal of the
rectangle of the light-emitting device 600 is longer than a length
of the radial branch along a side of the rectangle. The wiring
electrode 610, and/or the extensive electrode 611, and a conductive
structure 617 are formed on different regions of the conductive
substrate 622 and do not overlap with one another. Therefore, the
conductive structure 617 as shown in the region with slash lines
complements the pattern formed by the wiring electrode 610 and
extensive electrode 611.
[0039] FIG. 7 illustrates an electrode layout of a light-emitting
device in accordance with a sixth embodiment of the application.
The electrode layout can be utilized in the first embodiment to the
third embodiment. From top view, a conductive substrate 722 of a
light-emitting device 700 is a rectangle. The electrodes disclosed
in the embodiment include a wiring electrode 710 and an extensive
electrode 711 extending from the wiring electrode 710. The wiring
electrode 710 is substantially located at a corner of the rectangle
of the light-emitting device 700, and the extensive electrode 711
includes a plurality of radial branches extending from the wiring
electrode 710 with lengths that vary with their extensive angles
respectively. The wiring electrode 710, and/or the extensive
electrode 711, and a conductive structure 717 are formed on
different regions of the conductive substrate 722 and do not
overlap with one another. Therefore, the conductive structure 717
as shown in the region with slash lines substantially complements
the pattern formed by the wiring electrode 710 and extensive
electrode 711.
[0040] FIG. 8 illustrates an electrode layout of a light-emitting
device in accordance with a seventh embodiment of the application.
The electrode layout can be utilized in the first embodiment to the
third embodiment. From top view, a conductive substrate 822 of a
light-emitting device 800 is a rectangle. The electrodes disclosed
in the embodiment include wiring electrodes 810a and 810b near a
side of the rectangle of the light-emitting device 800, an
extensive electrode 811 including radial branches 811a and 811b
extending from the wiring electrode 810a and 810b to another side
of the rectangle, a radial branch 811c connecting to the wiring
electrodes 810a and 810b by its two ends and parallel to a side of
the rectangle, and a radial branch 811d extending from the radial
branch 811c and parallel to the radial branches 811a and 811b. The
wiring electrode 810a and 810b, and/or the extensive electrode 811,
and the conductive structure 817 are formed on different regions of
the conductive substrate 822 and do not overlap with one another,
and therefore the conductive structure 817 as shown in the region
with slash lines substantially complements the patterns of the
wiring electrode 810a and 810b and extensive electrode 811.
[0041] FIG. 9 it illustrates an electrode layout of a
light-emitting device in accordance with an eighth embodiment of
the application. The electrode layout can be utilized in the first
embodiment to the third embodiment. From top view, a conductive
substrate 922 of a light-emitting device 900 is a rectangle. The
electrodes disclosed in the embodiment include wiring electrodes
910a and 910b near a side of the rectangle of the light-emitting
device 900 and an extensive electrode 911 including radial branches
911a and 911b extending from the wiring electrodes 910a and 910b to
another side of the rectangle. The embodiment is similar to the
seventh embodiment, but the differences include that the radial
branches 911a and 911b are sinuous and extending from the wiring
electrodes 910a and 910b, and there are multiple radial branches
911a and 911b extended from the wiring electrodes 910a and 910b
respectively. The wiring electrode 910, and/or the extensive
electrode 911, and the conductive structure 917 are formed on
different regions of the conductive substrate 922 and do not
overlap with one another. Therefore, the conductive structure 917
as shown in the region with slash lines substantially complements
the patterns of the wiring electrode 910 and extensive electrode
911.
[0042] FIG. 10 illustrates an electrode layout of a light-emitting
device in accordance with a ninth embodiment of the application.
The electrode layout can be utilized in the first embodiment to the
third embodiment. From top view, a conductive substrate 1022 of the
light-emitting device is a rectangle. The electrodes disclosed in
the embodiment include two wiring electrodes 1010a and 1010b near
two corners of the rectangle of the conductive substrate 1022, and
an extensive electrode 1011 including a first radial branch 1011a
along the rectangle of the conductive substrate 1002 and connecting
to the wiring electrodes 1010a and 1010b, and a second radial
branch 1011b connecting to two opposite sides of the rectangle of
the first radial branch 1011a and forming a net pattern with the
first radial branch 1011a. The wiring electrode 1010, and/or the
extensive electrode 1011, and the conductive structure 1017 are
formed on different regions of the conductive substrate 1022 and do
not overlap with one another. Therefore, the conductive structure
1017 as shown in the region with slash lines substantially
complements the patterns of the wiring electrode 1010 and extensive
electrode 1011.
[0043] FIG.11 illustrates a light-emitting array in accordance with
a tenth embodiment of the application. The light-emitting array
1100 includes an insulative substrate 1110 including an upper
surface 1110a, a joining layer 1124 formed on the upper surface
1110a and being insulative, an insulative layer 1114 formed on the
joining layer 1124, a plurality of light-emitting units 112 formed
on the insulative layer 1114, wherein each of the light-emitting
units 112 includes a first surface 1113 and a second surface 1115.
The first surface 1113 has a first polarity, and the second surface
115 is toward to the insulative substrate 1110 opposite to the
first surface 1113 and includes a first region 1115a with the first
polarity and a second region 1115b with a second polarity. A
plurality of wires 1116 is embedded in the insulative layer 1114
and electrically connecting with two of the light-emitting units
1112, for example, connecting to the second region 1115b of at
least one of the light-emitting units 1112 and the first region
1115a of another one of the light-emitting units 1112. A first
electrode 1118 is formed on the insulative layer 1114, electrically
connecting with the first region 1115a of one of the light-emitting
units 1112, and located in different region than that of the
light-emitting units 1112 on the insulative layer 1114. A second
electrode 1120 is formed on the insulative layer 1114, electrically
connecting with the second region 1115b of one of the
light-emitting units 1112, and located in different region than
that of the light-emitting units 1112 on the insulative layer
1114.
[0044] The light-emitting units 1112 are epitaxially grown on the
same wafer (not shown in figures). After epitaxially growth, the
first surface 1113 connects to the wafer and the second surface
1115 faces up. The first region 1115a and the second region 1115b
of the second surface 1115 can be defined by an etching process as
the light-emitting units 1112 are not defined yet. After carrying
the light-emitting unit 1112 on the insulative substrate 1110 via
the joining layer 1124, the wafer can be removed and the first
surface 1113 is exposed. In sequence, a plurality of the
light-emitting units 1112 electrically insulated from one another
can be formed from the first surface 1113 by an etching process.
Additionally, the first surface 1113 similar to the one in the
first embodiment is a rough surface.
[0045] The insulative layer 1114 can include a first insulative
layer 1114a and a second insulative layer 1114b and is made of
silicon oxide SiO.sub.2, for example. The first insulative layer
1114a can cover the first region 1115a and the second region 1115b
of the second surface 1115 to form a surface substantially parallel
to the upper surface 1110a of the insulative substrate 1110. The
wire 1116 includes a conductive channel 1116a penetrating the first
insulative layer 1114a for electrically connecting with the first
region 1115a or the second region 1115b, and a bridge 1116b
laterally extending along a surface of the first insulative layer
1114a and connecting to the conductive channels 1116a of the
neighboring light-emitting units 1112. The bridge 1116b can connect
to identical/different polarities of two different light-emitting
units 1112 for forming a serial/parallel/in inverse-parallel
connection. The second insulative layer 1114b can cover the
insulative layer 1114a and the bridge 1116b.
[0046] The light-emitting unit 1112 includes a first semiconductor
layer 1101 having the first surface 1113 and the first region 1115a
of the second surface 1115, a second semiconductor layer 1102
having the second region 1115b of the second surface 1115, and an
active layer 1103 between the first semiconductor layer 1101 and
the second semiconductor layer 1102. The first semiconductor layer
1101 has the first polarity and the second semiconductor layer 1102
has the second polarity different from the first polarity. In the
embodiment, the first polarity of the first semiconductor layer
1101 is n-type; the second polarity of the semiconductor layer 1102
is p-type. The first region 1115a of the second surface 1115 is
farther from the insulative substrate 1110 than the second region
1115b to expose the first semiconductor layer 1101. The insulative
layer 1114 covers the second surface 1115 and fills a
convex-concave structure formed by the first region 1115a and the
second region 1115b. There can be multiple first regions 1115a of
the light-emitting unit 1112 which connect to a plurality of the
conductive channels 1116a, and lateral sides of the conductive
channels 1116a which connect to the first regions 1115a are covered
by the first insulative layer 1114a so as to be electrically
insulated from the second region 1115b of the second semiconductor
1102 of the individual light-emitting unit 1112. Similar to the
first embodiment, a conductive layer 1104 with reflectivity and a
barrier 1105 covering the conductive layer 1104 can be formed on
the second region 1115b. The first electrode 1118 can electrically
connect with the first region 1115a of the light-emitting unit 1112
via the bridge 1116b; the second electrode 1120 can electrically
connect with the second region 1115b of the light-emitting unit
1112 via the barrier 1105. The bridge 1116b connecting to the first
electrode 1118 is co-planar with a first exposing surface 1114c of
the second insulative layer 1114b; the barrier 1105 connecting to
the second electrode 1120 is co-planar with a second exposing
surface 1114d of the first insulative layer 1114a wherein the first
exposing surface 1114c is closer to the insulative substrate 1110
than the second exposing surface 1114d. A light-emitting array 1100
including a circuit in series/in parallel/in inversed-parallel can
be formed between the first electrode 1118 and the second electrode
1120.
[0047] Light from each of the light-emitting unit 1112 emits out of
the first surface 1113, the wires 1116 are located below all of the
light-emitting units 1112, and the first electrode 1118 and the
second electrode 1120 are side by side with all of the
light-emitting units 1112. Accordingly, the light is not shaded by
the wires 1116, the first electrode 1118, and the second electrode
1120 disclosed in the embodiment.
[0048] FIG. 12 illustrates a light-emitting array in accordance
with an eleventh embodiment of the application. The embodiment is
similar to the tenth embodiment but the differences are as follows.
Each of light-emitting units 1222 disclosed in the embodiment is
similar to those in the first embodiment, a first region 1215a and
a second region 1215b can have patterns as shown in FIG. 4 to FIG.
10. The first region 1215a of each of the light-emitting units 1222
has only a conductive channel 1216a connecting to a bridge 1216b,
and a cross section of the conductive channel 1216a is bigger than
that of the tenth embodiment, wherein two of the conductive
channels 1216 respectively electrically connect with the first
region 1215a of one of the light-emitting unit 1212 and the second
region 1215b of another one of the light-emitting unit 1212 and
extend to a surface of a second insulative layer 1214b devoid of
the light-emitting units 1212. A first electrode 1218 and a second
electrode 1220 can be formed on two of the conductive channels
1216. A light-emitting array 1200 including a circuit in series/in
parallel/in inversed-parallel can be formed between the first
electrode 1218 and the second electrode 1220.
[0049] FIG. 13 illustrates a light-emitting array in accordance
with a twelfth embodiment of the application. The embodiment is
similar to the tenth embodiment but the differences are as follows.
A conductive substrate 1310 disclosed in the embodiment replaces
the insulative substrate disclosed in the tenth embodiment; a
conductive joining layer 1324 replaces the insulative joining layer
disclosed the tenth embodiment. Additionally, conductive channels
1316a are connected to a first region 1315a of a light-emitting
unit 1312, penetrate a first insulative layer 1314a and a second
insulative layer 1314b, and electrically connect with a conductive
joining layer 1324. An electrode 1320 electrically connects with a
second region 1315b of the light-emitting unit 1312, and a
light-emitting array 1300 including a circuit in series/in
parallel/in inverse-parallel can be formed between the electrode
1320 and the conductive substrate 1310. As the tenth embodiment
recited, the first region 1315a has the n-type polarity and the
second region 1315b has the p-type polarity. Accordingly, for the
embodiment, the n-type polarity is conducted to the conductive
substrate 1310. In other embodiments, the p-type polarity can be
conducted to the conductive substrate 1310. The material of the
conductive substrate 1310 can be referred those disclosed in the
first embodiment.
[0050] FIG. 14 illustrates a light-emitting array in accordance
with a thirteenth embodiment of the application. The embodiment is
similar to the eleventh embodiment but the differences are as
follows. A conductive substrate 1410 disclosed in the embodiment
replaces the insulative substrate of the eleventh embodiment, and a
conductive joining layer 142 disclosed in the embodiment replaces
the joining layer of the eleventh embodiment. A conductive channel
1416b connects to a second region 1415b of a light-emitting unit
1412, penetrates a first insulative layer 1414a and a second
insulative layer 1414b, and electrically connects with a conductive
joining layer 1424. An electrode 1418 electrically connects with a
first region 1415a of the light-emitting unit 1412 and a
light-emitting array 1400 including a circuit in series/in
parallel/in inverse-parallel can be formed between the electrode
1418 and the conductive substrate 1410. As the tenth embodiment
recited, the first region 1415a has the n-type polarity and the
second region 1415b has the p-type polarity. Accordingly, in the
embodiment, the p-type polarity is conducted to the conductive
substrate 1410; in other embodiments, the n-type polarity can be
conducted to the conductive substrate 1410. The material of the
conductive substrate 1410 can be referred to those disclosed in the
first embodiment.
[0051] The principle and the efficiency of the present application
illustrated by the embodiments above are not the limitation of the
application. Any person having ordinary skill in the art can modify
or change the aforementioned embodiments. Therefore, the protection
range of the rights in the application will be listed as the
following claims.
* * * * *