以下實施例將伴隨著圖式說明本發明之概念,在圖式或說明中,相似或相同之部分係使用相同之標號,並且在圖式中,元件之形狀或厚度可擴大或縮小。需特別注意的是,圖中未繪示或說明書未描述之元件,可以是熟習此技藝之人士所知之形式。The following embodiments will be accompanied by drawings to illustrate the concept of the present invention. In the drawings or descriptions, similar or identical parts use the same reference numerals, and in the drawings, the shape or thickness of the element can be expanded or reduced. It should be noted that the components not shown in the figure or described in the specification can be in the form known to those who are familiar with the art.
第1A圖至第1T圖所示為本發明第一實施例之發光元件及其製造方法。如第1A圖所示,首先提供一成長基板101,例如砷化鎵(GaAs),並於其上依序形成一緩衝層102,一第一接觸層103,一發光疊層104。其中,緩衝層102於後續一移除成長基板101之步驟時可阻擋蝕刻或較成長基板更不易被蝕刻,因此依據蝕刻方式,例如濕蝕刻,緩衝層102可選擇使用和成長基板101有較大蝕刻速率差異之材料,例如當成長基板101為砷化鎵基板時,緩衝層102材料可選擇使用磷化銦鎵(InGaP) 或砷化鋁鎵(AlGaAs)。在本發明的一些實施例中,若成長基板101和第一接觸層103對於同一蝕刻液有明顯的蝕刻速率差異,例如,成長基板101的蝕刻速率大於第一接觸層103的蝕刻速率至少2個數量等級,或第一接觸層103的蝕刻速率大於成長基板101的蝕刻速率至少2個數量等級,則可不設置此緩衝層102。第一接觸層103可提供低電阻接觸,例如小於10-3
Ω-cm,其材料例如是n型摻雜之砷化鎵(GaAs),且其摻雜濃度可以高於1*1018
(/cm3
)。發光疊層104包括一第一電性半導體層104a、一第二電性半導體層104c、及一活性區域104b位於第一電性半導體層104a與第二電性半導體層104c之間。第一電性半導體層104a和第二電性半導體層104c電性相異,例如第一電性半導體層104a是n型半導體層,而第二電性半導體層104c是p型半導體層。第一電性半導體層104a、活性區域104b、及第二電性半導體層104c為III-V族材料所形成,例如為磷化鋁鎵銦系列((Aly
Ga(1-y
))1-x
Inx
P,其中 0≦x≦1; 0≦y≦1)材料。Fig. 1A to Fig. 1T show the light-emitting element and its manufacturing method according to the first embodiment of the present invention. As shown in FIG. 1A, first, a growth substrate 101, such as gallium arsenide (GaAs), is provided, and a buffer layer 102, a first contact layer 103, and a light-emitting stack 104 are sequentially formed thereon. Among them, the buffer layer 102 can block the etching during the subsequent step of removing the growth substrate 101 or is less likely to be etched than the growth substrate. Therefore, depending on the etching method, such as wet etching, the buffer layer 102 can be selected for use and the growth substrate 101 is larger. Materials with different etching rates, for example, when the growth substrate 101 is a gallium arsenide substrate, the material of the buffer layer 102 can be selected to use indium gallium phosphide (InGaP) or aluminum gallium arsenide (AlGaAs). In some embodiments of the present invention, if the growth substrate 101 and the first contact layer 103 have a significant difference in etching rate for the same etching solution, for example, the etching rate of the growth substrate 101 is greater than the etching rate of the first contact layer 103 by at least 2 times If the etching rate of the first contact layer 103 is greater than the etching rate of the growth substrate 101 by at least two orders of magnitude, the buffer layer 102 may not be provided. The first contact layer 103 can provide a low-resistance contact, such as less than 10 -3 Ω-cm, and its material is, for example, n-type doped gallium arsenide (GaAs), and its doping concentration can be higher than 1*10 18 (/ cm 3 ). The light emitting stack 104 includes a first conductivity type semiconductor layer 104a, a second conductivity type semiconductor layer 104c, and an active region 104b located between the first conductivity type semiconductor layer 104a and the second conductivity type semiconductor layer 104c. The first electrical type semiconductor layer 104a and the second electrical type semiconductor layer 104c are electrically different. For example, the first electrical type semiconductor layer 104a is an n-type semiconductor layer, and the second electrical type semiconductor layer 104c is a p-type semiconductor layer. The first electrical type semiconductor layer 104a, the active region 104b, and the second electrical type semiconductor layer 104c are formed of III-V materials, such as aluminum gallium indium phosphide series ((Al y Ga( 1-y )) 1- x In x P, where 0≦x≦1; 0≦y≦1) material.
接著,如第1B圖所示,形成一第二接觸層105於發光疊層104上,可提供低電阻接觸,例如小於10-3
Ω-cm,其材料例如是磷化鎵(GaP)。於本實施例中,第二接觸層105之厚度不要太厚,例如不大於1.5μm;或第二接觸層105之厚度約為0.1μm至0.5μm之間。接著,如第1C圖所示,形成一絕緣層106於第二接觸層105上,絕緣層106的折射率可小於發光疊層104之等效折射率。絕緣層106之材料可包含一材料選自氧化矽(SiOx
)、氟化鎂(MgF2
),及氮化矽(SiNx
)所構成之群組,絕緣層106之厚度約為50nm至300nm之間,或絕緣層106之厚度約為100nm至200nm之間。接著,如第1D圖所示,以黃光及蝕刻製程,在絕緣層106中形成一第一穿孔106h穿透絕緣層106,第一穿孔106h由絕緣層106往發光疊層104的方向觀之大致為圓形(圖未示)並具有一直徑D1
,直徑D1
約介於20μm至150μm 之間,或直徑D1
約為40μm至90μm之間。Next, as shown in FIG. 1B, a second contact layer 105 is formed on the light-emitting stack 104 to provide a low-resistance contact, such as less than 10 -3 Ω-cm, and its material is, for example, gallium phosphide (GaP). In this embodiment, the thickness of the second contact layer 105 should not be too thick, for example, not more than 1.5 μm; or the thickness of the second contact layer 105 is about 0.1 μm to 0.5 μm. Next, as shown in FIG. 1C, an insulating layer 106 is formed on the second contact layer 105. The refractive index of the insulating layer 106 can be smaller than the equivalent refractive index of the light-emitting stack 104. The material of the insulating layer 106 may include a material selected from the group consisting of silicon oxide (SiO x ), magnesium fluoride (MgF 2 ), and silicon nitride (SiN x ). The thickness of the insulating layer 106 is about 50 nm to 300 nm The thickness of the insulating layer 106 is between 100 nm and 200 nm. Next, as shown in FIG. 1D, a first through hole 106h is formed in the insulating layer 106 through the insulating layer 106 by a yellow light and etching process, and the first through hole 106h is viewed from the insulating layer 106 to the direction of the light-emitting stack 104 It is roughly circular (not shown in the figure) and has a diameter D 1 , the diameter D 1 is approximately between 20 μm and 150 μm, or the diameter D 1 is approximately between 40 μm and 90 μm.
接著,如第1E圖所示,形成一第一透明導電層107於絕緣層106上並填入第一穿孔106h中,使第一透明導電層107與發光疊層104藉由第一穿孔106h形成電性連接。藉由調整第一穿孔106h尺寸大小可控制提供至發光疊層104之電流大小。然後,如第1F圖所示,形成一第二透明導電層108於第一透明導電層107上,其材料與第一透明導電層107之材料不同,甚或形成方法亦可不同。其中第二透明導電層108可具有增進橫向(亦即與發光疊層104堆疊方向相垂直之方向)電流擴散之功能或做為一透光層之功能。考量做為一透光層之功能,第二透明導電層108可選擇一折射率值較發光疊層104為低之材料。而考量提供橫向電流擴散之功能,第二透明導電層108之厚度可較第一透明導電層107之厚度更厚,例如由絕緣層106往第二透明導電層108之方向看,第一透明導電層107之厚度約為25Å至200Å之間,或為40Å至60Å之間,第二透明導電層108之厚度約為25Å至2000Å 之間,或600Å至1000Å之間。在本發明的其他實施例中,也可不形成第二透明導電層108,而是將第一透明導電層107之厚度加厚以取代第二透明導電層108之功能。第一透明導電層107與第二透明導電層108分別包含一材料選自氧化銦錫(Indium Tin Oxide, ITO)、氧化鋁鋅(Aluminum Zinc Oxide, AZO)、氧化鎘錫、氧化銻錫、氧化鋅(ZnO)、氧化鋅錫、氧化銦鋅(Indium Zinc Oxide, IZO)及石墨烯(Graphene)所構成之群組。在本實施例中,第一透明導電層107之材料為氧化銦錫(Indium Tin Oxide, ITO),第二透明導電層108之材料為氧化銦鋅(Indium Zinc Oxide, IZO)。第一透明導電層107可使用電子束槍(E-gun)所形成,而第二透明導電層108可使用濺鍍(Sputtering)所形成,但本發明不以此為限,在另一實施例中,第一透明導電層107與第二透明導電層108亦可使用相同之形成方法。另外,第二透明導電層108的密度可與第一透明導電層107的密度相同或不同,在本實施例中,第二透明導電層108較第一透明導電層107更緻密,即第二透明導電層108的密度較第一透明導電層107的密度高,以助於上述橫向電流擴散。Next, as shown in FIG. 1E, a first transparent conductive layer 107 is formed on the insulating layer 106 and filled in the first through hole 106h, so that the first transparent conductive layer 107 and the light-emitting stack 104 are formed by the first through hole 106h Electrical connection. The size of the current supplied to the light-emitting stack 104 can be controlled by adjusting the size of the first through hole 106h. Then, as shown in FIG. 1F, a second transparent conductive layer 108 is formed on the first transparent conductive layer 107. The material of the second transparent conductive layer 107 is different from that of the first transparent conductive layer 107, or the forming method may be different. The second transparent conductive layer 108 may have a function of enhancing current diffusion in the lateral direction (that is, a direction perpendicular to the stacking direction of the light-emitting stack 104) or a function of being a light-transmitting layer. Considering the function of being a light-transmitting layer, the second transparent conductive layer 108 may select a material with a lower refractive index value than that of the light-emitting stack 104. Considering the function of lateral current spreading, the thickness of the second transparent conductive layer 108 can be thicker than the thickness of the first transparent conductive layer 107. For example, when viewed from the insulating layer 106 toward the second transparent conductive layer 108, the first transparent conductive layer The thickness of the layer 107 is between 25 Å and 200 Å, or between 40 Å and 60 Å, and the thickness of the second transparent conductive layer 108 is between 25 Å and 2000 Å, or between 600 Å and 1000 Å. In other embodiments of the present invention, the second transparent conductive layer 108 may not be formed, but the thickness of the first transparent conductive layer 107 is thickened to replace the function of the second transparent conductive layer 108. The first transparent conductive layer 107 and the second transparent conductive layer 108 respectively comprise a material selected from the group consisting of indium tin oxide (Indium Tin Oxide, ITO), aluminum oxide zinc (Aluminum Zinc Oxide, AZO), cadmium tin oxide, antimony tin oxide, oxide Zinc (ZnO), zinc tin oxide, indium zinc oxide (IZO) and graphene (Graphene) form a group. In this embodiment, the material of the first transparent conductive layer 107 is indium tin oxide (ITO), and the material of the second transparent conductive layer 108 is indium zinc oxide (IZO). The first transparent conductive layer 107 can be formed using an electron beam gun (E-gun), and the second transparent conductive layer 108 can be formed using sputtering, but the present invention is not limited to this. In another embodiment Here, the first transparent conductive layer 107 and the second transparent conductive layer 108 can also be formed using the same method. In addition, the density of the second transparent conductive layer 108 may be the same as or different from the density of the first transparent conductive layer 107. In this embodiment, the second transparent conductive layer 108 is denser than the first transparent conductive layer 107, that is, the second transparent The density of the conductive layer 108 is higher than that of the first transparent conductive layer 107 to facilitate the aforementioned lateral current spreading.
接著,如第1G圖所示,形成一反射層109於第二透明導電層108之上,以反射發光疊層104所發出之光線,在本實施例中,反射層109可對發光疊層所發出之光線有大於85%的反射率,其中反射層109可包含一金屬材料,例如金(Au)或銀(Ag)。Next, as shown in FIG. 1G, a reflective layer 109 is formed on the second transparent conductive layer 108 to reflect the light emitted by the light-emitting laminate 104. In this embodiment, the reflective layer 109 can be used for the light-emitting laminate. The emitted light has a reflectivity greater than 85%, and the reflective layer 109 may include a metal material, such as gold (Au) or silver (Ag).
接著,如第1H圖所示,形成第一接合層110a於反射層109上,及第二接合層110b於第一接合層110a上。圖1I所示為圖1H的倒置。接著,如第1J圖所示,提供一永久基板111,並形成一第三接合層110c於永久基板111上,之後使第三接合層110c與第二接合層110b對接(bonding),接合後之情形如第1K圖所示。第一接合層110a,第二接合層110b,及第三接合層110c形成一接合結構110。接合結構110可包含一熔點小於或等於300℃之低溫熔合材料,例如銦(In)或錫(Sn)。在本實施例中,第一接合層110a之材料為金(Au),第二接合層110b之材料為低溫熔合材料銦(In),第三接合層110c之材料為金(Au),在一低溫下,例如溫度小於或等於300℃下,此第一接合層110a、第二接合層110b、及第三接合層110c可因共晶(eutectic)效應而形成合金並接合為接合結構110,其中接合結構110包含銦(In)及金(Au)之合金。在另一實施例中,第二接合層110b可以是形成在第三接合層110c上,再與第一接合層110a接合形成接合結構110。接著,將成長基板101移除,其情形如第1L圖所示。本實施例中選擇濕蝕刻之蝕刻方式移除成長基板101,蝕刻液例如選用含氨水(NH3
·H2
O)及雙氧水(H2
O2
)之蝕刻液,由於包含磷化銦鎵(Inx
Ga1-x
P, 其中 0≦x≦1)的緩衝層102較成長基板101難被蝕刻,因此可以控制移除成長基板101過程不傷害發光疊層104。接著,由於包含磷化銦鎵((Inx
Ga1-x
P, 其中 0≦x≦1)之緩衝層102可能會吸收發光疊層104發出的光,所以可進一步予以移除,移除後之情形如第1M圖所示。Next, as shown in FIG. 1H, a first bonding layer 110a is formed on the reflective layer 109, and a second bonding layer 110b is formed on the first bonding layer 110a. Figure 1I shows the inversion of Figure 1H. Next, as shown in Figure 1J, a permanent substrate 111 is provided, and a third bonding layer 110c is formed on the permanent substrate 111, and then the third bonding layer 110c and the second bonding layer 110b are bonded to each other. The situation is shown in Figure 1K. The first bonding layer 110a, the second bonding layer 110b, and the third bonding layer 110c form a bonding structure 110. The bonding structure 110 may include a low-temperature fusion material with a melting point less than or equal to 300° C., such as indium (In) or tin (Sn). In this embodiment, the material of the first bonding layer 110a is gold (Au), the material of the second bonding layer 110b is low temperature fusion material indium (In), and the material of the third bonding layer 110c is gold (Au). At low temperatures, for example, the temperature is less than or equal to 300°C, the first bonding layer 110a, the second bonding layer 110b, and the third bonding layer 110c can form an alloy due to the eutectic effect and be bonded to form the bonding structure 110, wherein The bonding structure 110 includes an alloy of indium (In) and gold (Au). In another embodiment, the second bonding layer 110b may be formed on the third bonding layer 110c, and then bonded with the first bonding layer 110a to form the bonding structure 110. Next, the growth substrate 101 is removed, and the situation is as shown in FIG. 1L. In this embodiment, the etching method of wet etching is selected to remove the growth substrate 101. The etching solution is, for example, an etching solution containing ammonia (NH 3 ·H 2 O) and hydrogen peroxide (H 2 O 2 ), since it contains indium gallium phosphide (In x Ga 1-x P, where 0≦x≦1) the buffer layer 102 is more difficult to etch than the growth substrate 101, so the process of removing the growth substrate 101 can be controlled without damaging the light-emitting stack 104. Then, since the buffer layer 102 containing indium gallium phosphide ((In x Ga 1-x P, where 0≦x≦1) may absorb the light emitted by the light-emitting stack 104, it can be further removed. The situation is shown in Figure 1M.
接著,如第1N圖所示,在第一接觸層103上形成一第二穿孔H1
穿透第一接觸層103,第二穿孔H1
由第一接觸層103往永久基板111的方向觀之大致為圓形(可參考第2圖,於後詳述)並具有一直徑D2
。直徑D2
約介於20μm至150μm之間,或約介於40μm 至90μm之間。具體地,第二穿孔H1
延著A-A’線(即與發光疊層104的堆疊方向相垂直的方向)具有一截面積。在本實施例中,第二穿孔H1
是用黃光及蝕刻方法所形成。接著,如第1O圖所示,在第一接觸層103上形成一上接觸層112並使第二穿孔H1
延伸穿透上接觸層112。在本實施例中,上接觸層112包含一合金,例如是鍺(Ge)、 金(Au)、及鎳(Ni)三種金屬之合金。然後,如第1O圖所示,藉由一黃光及蝕刻製程將自上接觸層112至第二接觸層105之各層外圍一部分移除並曝露部分之絕緣層106。接著,如第1P圖所示,在移除前述外圍一部分後所形成結構之側壁上,形成一側壁絕緣層113。側壁絕緣層113包含絕緣材料,例如氮化矽(Si3
N4
)或氧化矽(SiO2
),在本實施例中,側壁絕緣層113為包含氮化矽(Si3
N4
)與氧化矽(SiO2
)之疊層,其形成方法是先形成氮化矽(Si3
N4
)與氧化矽(SiO2
)之疊層在結構上,再藉由一黃光及蝕刻製程移除其部分,並至少在前述側壁上留下並形成此側壁絕緣層113。如第1P圖所示,在本實施例中,在前述曝露出之絕緣層106上及部分之上接觸層112上亦形成有側壁絕緣層113。Next, as shown in FIG. 1N, a second through hole H 1 is formed on the first contact layer 103 to penetrate the first contact layer 103, and the second through hole H 1 is viewed from the first contact layer 103 toward the permanent substrate 111. It is roughly circular (refer to Figure 2, detailed later) and has a diameter D 2 . The diameter D 2 is approximately between 20 μm and 150 μm, or approximately between 40 μm and 90 μm. In particular, the extension of the H 1 second perforated A-A 'line (i.e., the light emitting stack 104 to the stacking direction perpendicular to a direction) having a length area. In the present embodiment, the second perforated H 1 is formed by an etching method and yellow. Subsequently, as shown in FIG first 1O, a contact layer is formed on the first contact layer 103 and 112 penetrating the second through hole H 1 extending on the contact layer 112. In this embodiment, the upper contact layer 112 includes an alloy, such as an alloy of germanium (Ge), gold (Au), and nickel (Ni). Then, as shown in FIG. 10, a part of the outer periphery of each layer from the upper contact layer 112 to the second contact layer 105 is removed by a yellow light and etching process, and a part of the insulating layer 106 is exposed. Next, as shown in FIG. 1P, a sidewall insulating layer 113 is formed on the sidewall of the structure formed after removing a portion of the aforementioned periphery. The sidewall insulating layer 113 includes an insulating material, such as silicon nitride (Si 3 N 4 ) or silicon oxide (SiO 2 ). In this embodiment, the sidewall insulating layer 113 includes silicon nitride (Si 3 N 4 ) and silicon oxide. (SiO 2 ) laminated layer, its formation method is to first form a laminated layer of silicon nitride (Si 3 N 4 ) and silicon oxide (SiO 2 ) on the structure, and then remove part of it by a yellow light and etching process , And at least leave and form the sidewall insulation layer 113 on the aforementioned sidewalls. As shown in FIG. 1P, in this embodiment, a sidewall insulating layer 113 is also formed on the exposed insulating layer 106 and on a part of the upper contact layer 112.
接著,如第1Q圖所示,在如第1P圖所示之結構上形成一上電極114。上電極114之材料包含金屬材料,在本實施例中,為包含以電子槍蒸鍍(E-beam evaporation)方法形成之鈦(Ti)/鉑(Pt)之疊層;在另一實例中,上電極114不包含鉑(Pt),上電極114係由鈦(Ti)組成;又一實施例中,上電極114包含鈦(Ti)與金(Au)。並且於形成後,大致對應第二穿孔H1
移除部分之鈦(Ti)/鉑(Pt)之疊層,以使第二穿孔H1
延伸並穿透上電極114。上電極114除了作為電極外,同時亦作為遮蓋本發光元件之一不透光層。由於上電極114位於發光疊層104上方,對於發光疊層104之上表面而言,對應第二穿孔H1
之區域為發光元件之出光區域,即,本發明之發光元件所發出的光係從出光孔,即第二穿孔H1
出光,未被上電極114覆蓋而暴露發光疊層104上表面之部分區域即為發光元件之出光區域,且上電極114同時遮蓋了發光疊層104上表面之其他部分。此外,上電極114所構成之不透光層更遮蓋了發光疊層104之側壁,而前述之側壁絕緣層113位於上電極114所構成之不透光層與發光疊層104之側壁之間,以避免發光疊層104因短路而失效。此外,在一實施例中,係先預設出光孔(即第二穿孔H1
) 之大小、形狀、及位置,而第一穿孔106h在大小、形狀、及位置需與第二穿孔H1
大致對應配合,使第一穿孔106h位於第二穿孔H1
的正下方,且第一穿孔106h的大小及/或形狀與第二穿孔H1
的大小及/或形狀上可設計成相同。具體而言,在如第1D圖所示的製造第一穿孔106h前,即先預設第二穿孔H1的各項參數(如上述之大小、形狀、及位置等參數),以決定第一穿孔106h之對應參數並進行製造。Next, as shown in FIG. 1Q, an upper electrode 114 is formed on the structure shown in FIG. 1P. The material of the upper electrode 114 includes a metal material. In this embodiment, it includes a stack of titanium (Ti)/platinum (Pt) formed by an electron gun evaporation (E-beam evaporation) method; in another example, the upper The electrode 114 does not include platinum (Pt), and the upper electrode 114 is composed of titanium (Ti); in another embodiment, the upper electrode 114 includes titanium (Ti) and gold (Au). And after the formation of titanium generally corresponding second perforated portion of removing H 1 (Ti) / platinum (Pt) of the stack, so that the second perforation penetrating H 1 and the upper electrode 114 extends. The upper electrode 114 not only serves as an electrode, but also serves as an opaque layer covering the light-emitting element. Since the upper electrode 114 positioned above the light emitting stack 104, stack 104 for over the light emitting surface, corresponding to the second perforated area H 1 region of the light emitting element, namely, the light emitting device of the present invention based emitted from light aperture, i.e., the second light perforated H 1, the upper electrode 114 is not covered and the exposed portion of the surface area is the area of the light emitting element of the light emitting stack 104, and the upper electrode 114 while covering the upper surface of the light emitting stack 104 other parts. In addition, the opaque layer formed by the upper electrode 114 further covers the sidewall of the light-emitting stack 104, and the aforementioned sidewall insulating layer 113 is located between the opaque layer formed by the upper electrode 114 and the sidewall of the light-emitting stack 104. In order to prevent the light-emitting stack 104 from failing due to a short circuit. In addition, in one embodiment, the size, shape, and position of the light hole (ie, the second perforation H 1 ) are preset, and the size, shape, and position of the first perforation 106h need to be approximately the same as that of the second perforation H 1 correspondence with the first through hole 106h is located directly below the second perforation 1 H, 106h and the first perforations size and / or shape of the second perforated 1 H size and / or shape may be designed to be the same. Specifically, before manufacturing the first perforation 106h as shown in Figure 1D, the parameters of the second perforation H1 (such as the above-mentioned size, shape, and position parameters) are preset to determine the first perforation. 106h corresponding parameters and manufacture.
另外,由於上電極114之材料較不易形成在側壁絕緣層113上,導致上電極114厚度可能過薄,因此在本實施例中,如第1R圖所示,可藉由形成一金屬層114S,以補強上電極114在側壁絕緣層113上之厚度的不足。金屬層114S可包含使用化鍍方法形成在上電極114上,例如將第1Q圖所示之結構浸泡在一含有金屬材料(例如金(Au)、銀(Ag)、鈦(Ti)或鉑(Pt),在本實施例中為金(Au))之溶液中,並藉由氧化還原之作用形成的金屬材料層,亦即金屬層114S可包含一金(Au)層。再大致對應第二穿孔H1
移除部分之金(Au)層,以使第二穿孔H1
延伸並穿透金屬層114S。在本發明之一實施例中,為作為遮蓋發光元件之不透光層,上電極114之厚度至少大於100Å。在本實施例中,上電極114的鈦(Ti)、鉑(Pt)及金屬層114S的金(Au)層之厚度分別約為200Å至400Å之間、2μm至4μm之間、及2000Å至4000Å之間。In addition, since the material of the upper electrode 114 is not easily formed on the sidewall insulating layer 113, the thickness of the upper electrode 114 may be too thin. Therefore, in this embodiment, as shown in FIG. 1R, a metal layer 114S can be formed. To reinforce the insufficient thickness of the upper electrode 114 on the sidewall insulating layer 113. The metal layer 114S may include a chemical plating method formed on the upper electrode 114, such as immersing the structure shown in Figure 1Q in a metal material (such as gold (Au), silver (Ag), titanium (Ti) or platinum ( Pt), which is a metal material layer formed by redox in a gold (Au) solution in this embodiment, that is, the metal layer 114S may include a gold (Au) layer. The gold (Au) layer is removed approximately corresponding to the second through hole H 1 , so that the second through hole H 1 extends and penetrates the metal layer 114S. In an embodiment of the present invention, as an opaque layer for covering the light emitting element, the thickness of the upper electrode 114 is at least greater than 100 Å. In this embodiment, the thickness of the titanium (Ti) and platinum (Pt) of the upper electrode 114 and the gold (Au) layer of the metal layer 114S are respectively about 200 Å to 400 Å, 2 μm to 4 μm, and 2000 Å to 4000 Å. between.
接著,如第1S圖所示,在如第1R圖所示之結構上形成一保護層115。保護層115沿著環繞第二穿孔H1
的側壁填入第二穿孔H1
後,保護層115內徑所構成之孔洞的直徑為D3
。保護層115之材料為絕緣材料,例如氮化矽(Si3
N4
)或氧化矽(SiO2
)。於形成後,如第1T圖所示,移除部分之保護層115,以形成第三穿孔115h,並於永久基板111上形成下電極111E。第三穿孔115h暴露出一部分之金屬層114S(在本發明另一無金屬層114S之實施例中,則係暴露出一部分之上電極114),以作為焊接墊,藉以讓外部電源進入之接線與金屬層114S(或上電極114)相接。Next, as shown in FIG. 1S, a protective layer 115 is formed on the structure shown in FIG. 1R. After the protective layer 115 is filled with the second through hole H 1 along the side wall surrounding the second through hole H 1 , the diameter of the hole formed by the inner diameter of the protective layer 115 is D 3 . The material of the protective layer 115 is an insulating material, such as silicon nitride (Si 3 N 4 ) or silicon oxide (SiO 2 ). After formation, as shown in FIG. 1T, part of the protective layer 115 is removed to form the third through hole 115h, and the bottom electrode 111E is formed on the permanent substrate 111. The third through hole 115h exposes a part of the metal layer 114S (in another embodiment of the present invention without the metal layer 114S, a part of the upper electrode 114 is exposed), which serves as a soldering pad for the wiring and The metal layer 114S (or the upper electrode 114) is in contact with each other.
第1T圖為本發明第一實施例之發光元件之示意圖,而第2圖為第1T圖之上視示意圖,請同時參閱此兩圖,本發光元件包括:永久基板111,接合結構110位於永久基板111上方,反射層109位於接合結構110上方,絕緣層106位於反射層109上方,其中絕緣層106具一第一穿孔106h,第一透明導電層107填入絕緣層106之第一穿孔106h中,並藉由第一穿孔106h與第二接觸層105直接接觸而與發光疊層104形成電性連接。位於第一穿孔106h中且與第二接觸層105直接接觸的第一透明導電層107為一電流傳導區域,電流傳導區域其位於第二穿孔H1
以及發光疊層104的上表面的第二部分的正下方,電流傳導區域可使電流流入發光疊層104。具體地,第一透明導電層107和第二接觸層105之間的接觸電阻小於絕緣層106與第二接觸層105之間的接觸電阻,例如小於兩個數量等級或小於五個數量等級。較佳地,第一透明導電層107和第二接觸層105 之間的接觸電阻介於10-3
至10-5
Ω cm2
之間。非電流傳導區域的絕緣層106環繞第二接觸層105。發光疊層104位於絕緣層106上方,發光疊層104包含一活性區域104b且具一上表面(可參考第2圖,長方形虛線所構成區域),以及上電極114所構成之不透光層位於發光疊層上方,其中上電極114所構成之不透光層遮蓋發光疊層104之上表面之一第一部分,亦即第二穿孔H1以外之部分 (可參考第2圖,圓形虛線以外所構成區域)而曝露上表面之一第二部分,第二部分亦即位於第二穿孔H1
之正下方的部分(可參考第2圖,圓形虛線所構成區域)。即,發光疊層104之上表面位於第二穿孔H1
之正下方的第二部分以外的區域皆被上電極114所構成之不透光層所遮蓋。發光疊層104發出的光可自其上表面的第二部分以及第二穿孔H1
逃逸。第二穿孔H1
之截面積與發光疊層104上表面面積之比率約為1.5~5%。而如第2圖所示,焊接墊通常形成在被上電極114遮蓋之第一部分上,具體的,形成在第三穿孔115h中藉以和發光疊層104形成電連接,而焊接墊一般為長方形或正方形。第三穿孔115h在長方形之短邊或正方形之任一邊約為至少80μm。具體地,發光疊層104之上表面之第一部分之面積大於第二部分之面積。第一透明導電層107填入絕緣層106之第一穿孔106h中,並藉由與第二接觸層105直接接觸而與發光疊層104形成電性連接。由於絕緣層106中之第一穿孔106h在大小、形狀、及位置上大致與第二穿孔H1
相對應配合,故第一穿孔106h之截面積與發光疊層104上表面面積之比率亦約為1.5~5%。Fig. 1T is a schematic diagram of the light-emitting device according to the first embodiment of the present invention, and Fig. 2 is a schematic top view of Fig. 1T. Please refer to these two figures at the same time. Above the substrate 111, the reflective layer 109 is located above the bonding structure 110, and the insulating layer 106 is located above the reflective layer 109. The insulating layer 106 has a first through hole 106h, and the first transparent conductive layer 107 is filled in the first through hole 106h of the insulating layer 106 , And the first through hole 106h is in direct contact with the second contact layer 105 to form an electrical connection with the light-emitting stack 104. And a first perforation 106h located in the first transparent conductive layer 105 in direct contact with the second contact layer 107 is a current-conducting region, a second current-conducting region which is located on the surface of the perforated H 1 and the light emitting stack 104, a second portion Directly below, the current conducting area allows current to flow into the light-emitting stack 104. Specifically, the contact resistance between the first transparent conductive layer 107 and the second contact layer 105 is smaller than the contact resistance between the insulating layer 106 and the second contact layer 105, for example, less than two orders of magnitude or less than five orders of magnitude. Preferably, the contact resistance between the first transparent conductive layer 107 and the second contact layer 105 is between 10 -3 and 10 -5 Ω cm 2 . The insulating layer 106 in the non-current conducting area surrounds the second contact layer 105. The light-emitting stack 104 is located above the insulating layer 106, the light-emitting stack 104 includes an active area 104b and has an upper surface (refer to Figure 2, the area formed by the rectangular dotted line), and the opaque layer formed by the upper electrode 114 is located Above the light-emitting stack, the opaque layer formed by the upper electrode 114 covers a first portion of the upper surface of the light-emitting stack 104, that is, the portion other than the second through hole H1 (refer to Figure 2, except for the circle dashed line) constituting region) on one of the exposed surface of the second portion, a second portion that is located directly below the second perforated portion of H 1 (refer to FIG. 2, the dotted circle formed region). That is, the area of the upper surface of the light-emitting stack 104 outside the second portion directly below the second through hole H 1 is covered by the opaque layer formed by the upper electrode 114. Light emitted from light emitting stack 104 may be an escape from the second part of its upper surface and a second perforated H. The ratio of the cross-sectional area of the second through hole H 1 to the upper surface area of the light-emitting stack 104 is about 1.5-5%. As shown in Figure 2, the soldering pad is usually formed on the first part covered by the upper electrode 114. Specifically, it is formed in the third through hole 115h to form an electrical connection with the light-emitting stack 104. The soldering pad is generally rectangular or square. The third through hole 115h is approximately at least 80 μm on the short side of the rectangle or any side of the square. Specifically, the area of the first part of the upper surface of the light-emitting stack 104 is larger than the area of the second part. The first transparent conductive layer 107 is filled in the first through hole 106h of the insulating layer 106, and is electrically connected to the light-emitting stack 104 by directly contacting the second contact layer 105. Since the insulating layer 106 of a first substantially perforated 106h cooperate with a corresponding second perforation H in the size, shape, and position, so that a first cross-sectional area ratio of the surface area of the perforations of the light emitting stack 104 and also approximately 106h 1.5~5%.
第3圖顯示本發明實施例中,當發光元件的第二接觸層105之厚度分別為0.2μm及1μm時,在各種第一穿孔106h的直徑尺寸條件下(水平軸),分別對應發光元件之發光功率(Po,左邊垂直軸)及順向電壓(Vf,右邊垂直軸)之情形。如第3圖所示,發光元件之發光功率及順向電壓會隨第一穿孔106h之大小而變化,亦即在元件設計上具有可預測性及控制性,隨不同需求可經由調整第一穿孔106h之大小達成所需。由進一步實驗結果可知,第二接觸層105之厚度不宜大於1.5μm。當第二接觸層105之厚度太厚,例如大於1.5μm時,絕緣層106之電流阻擋之效果即不容易隨第一穿孔106h之直徑尺寸而變化,亦即此種情形下,發光元件之發光功率及順向電壓隨第一穿孔106h之直徑尺寸之變化將不明顯,而不易透過第一穿孔106h之直徑尺寸之調整來控制或預測發光元件之發光功率及順向電壓等。Figure 3 shows that in the embodiment of the present invention, when the thickness of the second contact layer 105 of the light-emitting element is 0.2 μm and 1 μm, respectively, the diameter of the first hole 106h (horizontal axis) corresponds to the light-emitting element. Luminous power (Po, vertical axis on the left) and forward voltage (Vf, vertical axis on the right). As shown in Figure 3, the luminous power and forward voltage of the light-emitting element will vary with the size of the first hole 106h, that is, the element design is predictable and controllable, and the first hole can be adjusted according to different needs. The size of 106h meets the requirements. It can be seen from further experimental results that the thickness of the second contact layer 105 should not be greater than 1.5 μm. When the thickness of the second contact layer 105 is too thick, for example, greater than 1.5 μm, the current blocking effect of the insulating layer 106 is not easily changed with the diameter of the first through hole 106h, that is, in this case, the light-emitting element emits light The power and forward voltage will not change significantly with the diameter of the first through hole 106h, and it is not easy to control or predict the luminous power and forward voltage of the light-emitting element by adjusting the diameter of the first through hole 106h.
另外,發光元件除了可在一般電流值(在本實施例中例如為50mA)條件下操作,根據元件的不同應用,部分之應用需要發光元件在相對高之電流值(在本實施例中例如為300mA)條件下操作,並以脈衝模式出光(pulse mode,亦即發光元件之出光隨時間變化為斷續斷續之型式,而非連續)。本實施例之發光元件結構,可同時滿足上述兩種情形。第4圖顯示本發明之實施例中,活性區域104b為一多重量子井(MQW)結構的發光元件在相同脈衝模式出光時,多重量子井結構分別在包含18、38、及48個井層(well)之條件下,分別對應相對高電流(300mA)之發光功率(Po,右邊垂直軸)及發光功率比例(左邊垂直軸,指發光元件在相同脈衝出光型式時,發光元件在相對高電流操作下之發光功率比在一般電流操作下之發光功率之比例)之情形。由圖顯示出,多重量子井結構分別包含38及48個井層時,發光功率比例可高達2.8以上。由進一步實驗結果可知,多重量子井(MQW)結構包含30~50個井層時,發光功率比例均可達2.6以上。In addition, the light-emitting element can be operated at a normal current value (for example, 50mA in this embodiment). According to different applications of the element, some applications require the light-emitting element to operate at a relatively high current value (for example, in this embodiment). Operate under the condition of 300mA) and emit light in a pulse mode (that is, the light emitted by the light-emitting element changes intermittently over time, rather than continuous). The light-emitting element structure of this embodiment can meet the above two situations at the same time. Figure 4 shows that in an embodiment of the present invention, the active region 104b is a light emitting element with a multiple quantum well (MQW) structure when emitting light in the same pulse mode, the multiple quantum well structure includes 18, 38, and 48 well layers, respectively. Under the condition of (well), corresponding to the relative high current (300mA) luminous power (Po, the right vertical axis) and the luminous power ratio (the left vertical axis means that when the light-emitting element is in the same pulse light emission pattern, the light-emitting element is at a relatively high current The ratio of the luminous power under operation to the luminous power under normal current operation). The figure shows that when the multi-quantum well structure contains 38 and 48 well layers, the luminous power ratio can be as high as 2.8 or more. According to further experimental results, when the multiple quantum well (MQW) structure contains 30-50 well layers, the luminous power ratio can reach more than 2.6.
第5圖顯示上述實施例之發光元件中,活性區域104b為一多重量子井(MQW)結構的發光元件在相同脈衝模式出光時,多重量子井結構中之磷化鋁鎵銦系列((Aly
Ga(1-y
))1-x
Inx
P,其中 0≦x<1; 0≦y≦1)材料之阻障層(Barrier)分別在包含30%、50%、及70%之鋁(Al) (指鋁(Al)佔鋁(Al)與鎵(Ga)組成中比例,即相當上式中y)含量條件下,對應相對高電流(300mA)之發光功率(Po,右邊垂直軸)及發光功率比例(Factor,指發光元件在相同脈衝出光型式時,相對高電流之發光功率比一般電流之發光功率之比例,左邊垂直軸)之情形,其中阻障層有複數層。由圖顯示出,多重量子井結構中阻障層(Barrier)分別在包含50%及70%之鋁(Al)含量條件下,發光功率比例可高達3.1以上。考量其他發光元件之電性要求,例如順向電壓之適當範圍,經由進一步實驗可知,多重量子井結構中之阻障層(Barrier)分別在包含約40%至60%之鋁(Al)含量時,發光功率比例與順向電壓同時有良好之表現。於另一實施例中,複數阻障層中,其中兩個阻障層具有不同的鋁含量,且較靠近第一電性半導體層104a的阻障層的鋁含量低於較遠離第一電性半導體層104a的阻障層的鋁含量。較佳的,複數阻障層中,至少一半以上的靠近第一電性半導體層104a(即,n型半導體層)的阻障層具有的鋁含量低於其餘靠近第二電性半導體層104c(即,p型半導體層)的阻障層具有的鋁含量。具體的,靠近第一電性半導體層104a的阻障層包含(Ala
Ga1-a
)1-b
Inb
P,靠近第二電性半導體層104c的阻障層包含(Alc
Ga1-c
)1-d
Ind
P,在b≒d的情況下,c>a。於一實施例中,多重量子井結構包含38個阻障層,且較靠近第一電性半導體層104a的前20個阻障層包含(Al0.5
Ga0.5
)1-b
Inb
P,而較遠離第一電性半導體層104a的其餘的18個阻障層,即較靠近第二電性半導體層104c的18個阻障層包含(Al0.7
Ga0.3
)1-d
Ind
P,於此實施例中,b和d約等於0.5,但不限於此。於一實施例中,多重量子井結構包含38個阻障層,且較靠近第一電性半導體層104a的前28個阻障層包含(Al0.5
Ga0.5
)1-b
Inb
P,較靠近第二電性半導體層104c的前10個阻障層包含(Al0.7
Ga0.3
)1-d
Ind
P,於此實施例中,b和d約等於0.5,但不限於此。於一實施例中,多重量子井結構包含38個阻障層,且較靠近第一電性半導體層104a的前36個阻障層包含(Al0.5
Ga0.5
)1-b
Inb
P,較靠近第二電性半導體層104c的2個阻障層包含(Al0.7
Ga0.3
)1-d
Ind
P,於此實施例中,b和d約等於0.5,但不限於此。於一實施例中,複數阻障層中的鋁含量是自n型半導體層至p型半導體層的方向漸增,即,每一較靠近第一電性半導體層104a(即,n型半導體層)的阻障層的鋁含量皆比相鄰較靠近第二電性半導體層104c(即,p型半導體層)的阻障層的鋁含量低。於一實施例中,第二電性半導體層104c的摻雜物包含碳(C)、鎂(Mg)或鋅(Zn),較佳的,摻雜物包含鎂。本公開內容藉由阻障層具有不同的鋁含量,且較靠近n型半導體層的阻障層的鋁含量低於較遠離n型半導體的阻障層的鋁含量,可避免或是降低p型半導體層中p型摻雜物擴散進入活性區域104b的情況,進而改善發光元件的可靠度且不會使發光元件的順向電壓大幅增加。Figure 5 shows that in the light-emitting element of the above embodiment, the active region 104b is a multiple quantum well (MQW) structure light-emitting element when the light is emitted in the same pulse mode, the aluminum gallium indium phosphide series ((Al) in the multiple quantum well structure y Ga( 1-y )) 1-x In x P, where 0≦x<1; 0≦y≦1) The barrier layer of the material contains 30%, 50%, and 70% aluminum, respectively (Al) (refers to the proportion of aluminum (Al) in the composition of aluminum (Al) and gallium (Ga), which is equivalent to the y in the above formula). Under the condition of the content, the luminous power (Po) corresponding to the relatively high current (300mA), the right vertical axis ) And the ratio of luminous power (Factor, refers to the ratio of the luminous power of a relatively high current to the luminous power of a normal current when the light emitting element is in the same pulse light emission pattern, the left vertical axis), in which the barrier layer has multiple layers. The figure shows that the barrier layer (Barrier) in the multiple quantum well structure contains 50% and 70% of the aluminum (Al) content, respectively, and the luminous power ratio can be as high as 3.1 or more. Considering the electrical requirements of other light-emitting devices, such as the appropriate range of forward voltage, further experiments show that the barrier layer in the multiple quantum well structure contains about 40% to 60% aluminum (Al) content. , Luminous power ratio and forward voltage have good performance at the same time. In another embodiment, in the plurality of barrier layers, two of the barrier layers have different aluminum contents, and the barrier layer closer to the first electrical type semiconductor layer 104a has lower aluminum content than the barrier layer farther away from the first electrical type semiconductor layer 104a. The aluminum content of the barrier layer of the semiconductor layer 104a. Preferably, in the plurality of barrier layers, at least more than half of the barrier layers close to the first electrical type semiconductor layer 104a (ie, the n-type semiconductor layer) have a lower aluminum content than the rest close to the second electrical type semiconductor layer 104c ( That is, the aluminum content of the barrier layer of the p-type semiconductor layer). Specifically, the barrier layer near the first electrical type semiconductor layer 104a includes (Al a Ga 1-a ) 1-b In b P, and the barrier layer near the second electrical type semiconductor layer 104 c includes (Al c Ga 1- c ) 1-d In d P, in the case of b≒d, c>a. In one embodiment, the multiple quantum well structure includes 38 barrier layers, and the first 20 barrier layers closer to the first conductivity type semiconductor layer 104a include (Al 0.5 Ga 0.5 ) 1-b In b P, and The remaining 18 barrier layers far away from the first electrical type semiconductor layer 104a, that is, the 18 barrier layers closer to the second electrical type semiconductor layer 104c include (Al 0.7 Ga 0.3 ) 1-d In d P, which are implemented here In the example, b and d are approximately equal to 0.5, but not limited to this. In one embodiment, the multiple quantum well structure includes 38 barrier layers, and the first 28 barrier layers closer to the first conductivity semiconductor layer 104a include (Al 0.5 Ga 0.5 ) 1-b In b P, which is closer to The first 10 barrier layers of the second conductivity type semiconductor layer 104c include (Al 0.7 Ga 0.3 ) 1-d In d P. In this embodiment, b and d are approximately equal to 0.5, but are not limited thereto. In one embodiment, the multiple quantum well structure includes 38 barrier layers, and the first 36 barrier layers closer to the first electrical type semiconductor layer 104a include (Al 0.5 Ga 0.5 ) 1-b In b P, which is closer to The two barrier layers of the second conductivity type semiconductor layer 104c include (Al 0.7 Ga 0.3 ) 1-d In d P. In this embodiment, b and d are approximately equal to 0.5, but are not limited thereto. In one embodiment, the aluminum content in the plurality of barrier layers gradually increases from the n-type semiconductor layer to the p-type semiconductor layer, that is, each closer to the first conductivity type semiconductor layer 104a (ie, the n-type semiconductor layer The aluminum content of the barrier layer of) is lower than that of the barrier layer adjacent to the second conductivity semiconductor layer 104c (ie, the p-type semiconductor layer). In one embodiment, the dopant of the second conductivity type semiconductor layer 104c includes carbon (C), magnesium (Mg), or zinc (Zn). Preferably, the dopant includes magnesium. In the present disclosure, the barrier layer has different aluminum content, and the aluminum content of the barrier layer closer to the n-type semiconductor layer is lower than the aluminum content of the barrier layer farther from the n-type semiconductor, which can avoid or reduce the p-type The diffusion of the p-type dopant in the semiconductor layer into the active region 104b further improves the reliability of the light-emitting device without greatly increasing the forward voltage of the light-emitting device.
第6圖為本發明第二實施例之發光元件的剖面示意圖。本公開內容之第二實施例之發光元件包含的結構與第一實施例大致相同,不同之處如下所述。如第6圖所示,發光元件包含一第一半導體層116以及第二半導體層117,第一半導體層116位於第一接觸層103和發光疊層104之間,第二半導體層117位於第二接觸層105以及發光疊層104之間。第一半導體層116和第二半導體層117用於增進光取出和/或增進電流散佈使電流擴及整個發光疊層104。第一半導體層116的厚度大於第一電性半導體層104a的厚度,較佳的,第一半導體層116的厚度大於2000nm,且更佳地,介於2500nm 至7000nm之間。第二半導體層117的厚度大於第二電性半導體層104c的厚度,較佳地,第二半導體層117的厚度大於1000nm的厚度,且更佳地,介於1500nm 至2000nm之間。第一半導體層116具有一能階,其小於第一電性半導體層104a的能階。第二半導體層117具有一能階,其小於第二電性半導體層104c的能階。第一半導體層116以及第二半導體層117的能階大於活性區域104b中井層的能階。活性區域104b發出的光實質上可穿透第一半導體層116。第一半導體層116以及第二半導體層117各具有一高於1´1017
/cm3
的摻雜濃度,且第一半導體層116的摻雜濃度小於第一接觸層103的摻雜濃度,第二半導體層117的摻雜濃度小於第二接觸層105的摻雜濃度。較佳的,第一接觸層103的摻雜濃度至少為第一半導體層116的摻雜濃度的兩倍以上(含)。第二接觸層105的摻雜濃度至少為第二半導體層117的摻雜濃度的兩倍以上(含)。第一半導體層116、第二半導體層117、第一接觸層103和第二接觸層105包含三五族半導體材料,例如AlGaAs或AlGaInP。如第6圖所示,第二接觸層105具有一寬度W1
,其與發光元件之出光區域的寬度之比不小於0.5,且不大於1.1,即,在同一剖面中,第二接觸層105的寬度W1
與未被上電極114覆蓋之區域(即,發光疊層104之上表面之第二部分)的寬度之比不小於0.5,且不大於1.1。於一實施例中,第二接觸層105的寬度W1
與第二穿孔H1
的直徑D2
之比(即,W1
/D2
)不小於0.5,且不大於1.1。較佳的,第二接觸層105的寬度W1
與發光元件之出光區域的寬度之比不小於0.55,且不大於0.8。於一實施例中,第二接觸層105的寬度W1
與第二穿孔H1
的直徑D2
之比(即,W1
/D2
)不小於0.55,且不大於0.8。另外,於第二實施例中,如第6圖所示,第二接觸層105位於發光元件之出光區域的正下方,即位於未被上電極114覆蓋之區域(即,發光疊層104之上表面之第二部分)的正下方。第二接觸層105與第一透明導電層107之間的接觸電阻遠小於第一透明導電層107和第二半導體層117之間的接觸電阻,例如小於兩個數量等級或小於五個數量等級。因此,具有寬度W1
的第二接觸層105為電流傳導區域,其可使電流流入發光疊層104,而第一透明導電層107之其他未與第二接觸層105接觸且環繞第二接觸層105的區域無法使電流流入或使電流難以流入發光疊層104。於本實施例中,第二接觸層105位於第二穿孔H1
的正下方。較佳的,第二接觸層105於發光疊層104的堆疊方向上不與上接觸層112以及上電極114重疊。於本實施例中,如第6圖所示,部分第二半導體層117的厚度大於其他部分的第二半導體層117的厚度,且第二半導體層117之厚度較厚的部分對應於出光區域,即,未被上電極114覆蓋之區域(亦即發光疊層104上表面之第二部分)。於本實施例中,第二半導體層117之厚度較厚的部分對應於第二穿孔H1
。第二接觸層105位於第二半導體層117之厚度較厚的部分上。具體地,第二半導體層117之厚度較薄的部分包含一遠離發光疊層104的表面1171,第二接觸層105包含一遠離發光疊層104的表面1051,相較於第二半導體層117之厚度較薄的部分的表面1171,第二接觸層105的表面1051較遠離發光疊層104。具體地,第二接觸層105遠離發光疊層104的表面1051至第二半導體層117之遠離發光疊層104的表面1171之間的高度h不小於50nm,且不大於200nm。於一實施例中,第二接觸層105的厚度不小於20nm,且不大於0.5μm,較佳的,第二接觸層105的厚度不小於20nm,且不大於0.1μm。由於第二實施例中發光元件包含具有一寬度W1
的第二接觸層105,且第二接觸層105位於出光區域的正下方,當電流流經發光疊層104時,電流會較易集中在對應於第二接觸層105的區域,因而大幅提升電流密度,進而提升發光元件的亮度。Fig. 6 is a schematic cross-sectional view of a light-emitting device according to a second embodiment of the present invention. The structure of the light-emitting element of the second embodiment of the present disclosure is substantially the same as that of the first embodiment, and the difference is as follows. As shown in Figure 6, the light emitting element includes a first semiconductor layer 116 and a second semiconductor layer 117. The first semiconductor layer 116 is located between the first contact layer 103 and the light emitting stack 104, and the second semiconductor layer 117 is located on the second semiconductor layer. Between the contact layer 105 and the light-emitting stack 104. The first semiconductor layer 116 and the second semiconductor layer 117 are used to improve light extraction and/or improve current spreading so that the current spreads to the entire light-emitting stack 104. The thickness of the first semiconductor layer 116 is greater than the thickness of the first conductivity type semiconductor layer 104a. Preferably, the thickness of the first semiconductor layer 116 is greater than 2000 nm, and more preferably, between 2500 nm and 7000 nm. The thickness of the second semiconductor layer 117 is greater than the thickness of the second conductivity type semiconductor layer 104c. Preferably, the thickness of the second semiconductor layer 117 is greater than a thickness of 1000 nm, and more preferably, between 1500 nm and 2000 nm. The first semiconductor layer 116 has an energy level which is smaller than the energy level of the first conductivity type semiconductor layer 104a. The second semiconductor layer 117 has an energy level which is smaller than the energy level of the second conductivity type semiconductor layer 104c. The energy levels of the first semiconductor layer 116 and the second semiconductor layer 117 are greater than the energy levels of the well layer in the active region 104b. The light emitted from the active region 104b can substantially penetrate the first semiconductor layer 116. The first semiconductor layer 116 and the second semiconductor layer 117 each have a doping concentration higher than 1´10 17 /cm 3 , and the doping concentration of the first semiconductor layer 116 is less than the doping concentration of the first contact layer 103, The doping concentration of the second semiconductor layer 117 is less than the doping concentration of the second contact layer 105. Preferably, the doping concentration of the first contact layer 103 is at least twice the doping concentration of the first semiconductor layer 116 (inclusive). The doping concentration of the second contact layer 105 is at least twice the doping concentration of the second semiconductor layer 117 (inclusive). The first semiconductor layer 116, the second semiconductor layer 117, the first contact layer 103, and the second contact layer 105 comprise Group III and V semiconductor materials, such as AlGaAs or AlGaInP. As shown in Fig. 6, the second contact layer 105 has a width W 1 whose ratio to the width of the light-emitting area of the light-emitting element is not less than 0.5 and not more than 1.1. That is, in the same cross-section, the second contact layer 105 The ratio of the width W1 of φ to the width of the area not covered by the upper electrode 114 (ie, the second portion of the upper surface of the light-emitting stack 104) is not less than 0.5 and not more than 1.1. In one embodiment, the ratio of the width W 1 of the second contact layer 105 to the diameter D 2 of the second through hole H 1 (ie, W 1 /D 2 ) is not less than 0.5 and not more than 1.1. Preferably, the ratio of the width W 1 of the second contact layer 105 to the width of the light-emitting area of the light-emitting element is not less than 0.55 and not more than 0.8. In one embodiment, the ratio of the width W 1 of the second contact layer 105 to the diameter D 2 of the second through hole H 1 (ie, W 1 /D 2 ) is not less than 0.55 and not more than 0.8. In addition, in the second embodiment, as shown in FIG. 6, the second contact layer 105 is located directly under the light-emitting area of the light-emitting element, that is, located in the area not covered by the upper electrode 114 (ie, on the light-emitting stack 104). The second part of the surface) directly below. The contact resistance between the second contact layer 105 and the first transparent conductive layer 107 is much smaller than the contact resistance between the first transparent conductive layer 107 and the second semiconductor layer 117, for example, less than two orders of magnitude or less than five orders of magnitude. Therefore, the second contact layer 105 with a width W 1 is a current conducting region, which allows current to flow into the light-emitting stack 104, and the other of the first transparent conductive layer 107 is not in contact with the second contact layer 105 and surrounds the second contact layer The area of 105 cannot allow current to flow or it is difficult for current to flow into the light-emitting stack 104. In the present embodiment, the second contact layer 105 is located directly below the second perforation of H 1. Preferably, the second contact layer 105 does not overlap the upper contact layer 112 and the upper electrode 114 in the stacking direction of the light-emitting stack 104. In this embodiment, as shown in FIG. 6, the thickness of part of the second semiconductor layer 117 is greater than the thickness of other parts of the second semiconductor layer 117, and the thicker part of the second semiconductor layer 117 corresponds to the light emitting area, That is, the area not covered by the upper electrode 114 (that is, the second part of the upper surface of the light-emitting stack 104). In this embodiment, the thicker part of the second semiconductor layer 117 corresponds to the second through hole H 1 . The second contact layer 105 is located on the thicker part of the second semiconductor layer 117. Specifically, the thinner part of the second semiconductor layer 117 includes a surface 1171 away from the light-emitting stack 104, and the second contact layer 105 includes a surface 1051 away from the light-emitting stack 104, which is compared with the second semiconductor layer 117. The surface 1171 of the thinner part and the surface 1051 of the second contact layer 105 are farther away from the light-emitting stack 104. Specifically, the height h between the surface 1051 of the second contact layer 105 away from the light emitting stack 104 and the surface 1171 of the second semiconductor layer 117 away from the light emitting stack 104 is not less than 50 nm and not more than 200 nm. In one embodiment, the thickness of the second contact layer 105 is not less than 20 nm and not more than 0.5 μm. Preferably, the thickness of the second contact layer 105 is not less than 20 nm and not more than 0.1 μm. Since the second embodiment comprises a light emitting element having a width W 1 of the second contact layer 105 and located directly below the light area of the second contact layer 105, when current flows through the light emitting stack 104, current is easily concentrated The area corresponding to the second contact layer 105 can greatly increase the current density, thereby increasing the brightness of the light-emitting element.
本公開內容之第二實施例之發光元件之製造方法與第一實施例之製造方法大致相同,不同之處包括,於形成發光疊層104之前,更包含形成第一半導體層116於第一接觸層103上,且於形成發光疊層104之後以及形成第二接觸層105之前,更包含形成如前所述的第二半導體層117。於形成第二接觸層105後,以黃光及蝕刻製程圖案化第二接觸層105,使第二接觸層105具有寬度W1
,再接續如第一實施例之製造方法中的形成第一透明導電層107、第二透明導電層108等後續步驟。本實施例之製造方法相較於第一實施例之製造方法,由於不需要形成絕緣層106以及不需要使用黃光及蝕刻製程以在絕緣層106形成第一穿孔106h,大幅降低製程的成本且增加製程簡易性。The manufacturing method of the light-emitting element of the second embodiment of the present disclosure is substantially the same as the manufacturing method of the first embodiment. The difference includes that before forming the light-emitting stack 104, it further includes forming the first semiconductor layer 116 on the first contact. On the layer 103, after forming the light-emitting stack 104 and before forming the second contact layer 105, the second semiconductor layer 117 as described above is further formed. After the second contact layer 105 is formed, the second contact layer 105 is patterned by yellow light and an etching process so that the second contact layer 105 has a width W 1 , and then the first transparent layer is formed as in the manufacturing method of the first embodiment. The conductive layer 107, the second transparent conductive layer 108 and other subsequent steps. Compared with the manufacturing method of the first embodiment, the manufacturing method of this embodiment does not need to form the insulating layer 106 and does not need to use yellow light and etching process to form the first through hole 106h in the insulating layer 106, which greatly reduces the cost of the manufacturing process and Increase process simplicity.
於一實施例中,發光元件不包含第二穿孔H1,具有一寬度W1
的第二接觸層105位於發光元件之出光區域的正下方,即位於未被上電極114覆蓋之區域(即,發光疊層104之上表面之第二部分)的正下方。In one embodiment immediately below, the light emitting element does not comprise a second perforated H1, having a width W region of the light-emitting element 1 of the second contact layer 105, i.e. not located on the coverage area of electrode 114 (i.e., the light emitting The second part of the upper surface of the laminate 104) is directly below.
第7圖為本發明第三實施例之發光元件的剖面圖。與前述之本發明各實施例相較,本實施例之發光元件更包含一導熱層118設於發光疊層104的上表面的第二部份上。詳言之,導熱層118設於由第二穿孔H1
所暴露出的發光疊層104的上表面上,且導熱層118具有較發光疊層104更高的導熱係數(thermal conductivity),使發光元件在運作時,由發光疊層104產生的熱可通過導熱層118以傳導或輻射方式逸散至外部,如此可減少熱在第二穿孔H1
下方的發光疊層104中堆積,而減緩發光元件內部因熱造成的材料衰變,並增加發光元件的使用壽命與可靠度。導熱層118可包含導熱係數不小於100W/(mÏK)的材料,舉例可為金剛石、石墨烯、或導熱係數約為140W/(mÏK)~180W/(mÏK)的氮化鋁(AlNX
),本發明並不以此為限。更詳言之,在本實施例中,導熱層118係沿著第二穿孔H1
的側壁填入第二穿孔H1
,並覆蓋於第二穿孔H1
所暴露出的第一電性半導體層104a上,且往遠離第二穿孔H1
的方向向發光元件周圍延伸,並與金屬層114S或上電極114接觸,以將發光疊層104中產生的熱透過導熱層118傳遞至金屬層114S或上電極114,由於金屬層114S、上電極114通常選擇為金屬,導熱係數高,發光元件內部的熱便能藉由導熱層118及金屬層114s或上電極114排出。在一些實施例中,導熱層118亦可不與金屬層114S或上電極114接觸,發光疊層104中產生的熱可經由導熱層118以輻射方式逸散到外部,或導熱層118可與外部導熱結構作連接,使發光疊層104中產生的熱可以經由導熱層118以傳導方式逸散到外部。與第一實施例相較,本實施例中的發光元件除包含一保護層115覆蓋於金屬層114S上,保護層115亦覆蓋於導熱層118上,在本實施例中,保護層115可以完整覆蓋於導熱層118上,詳言之,本實施例的導熱層118具有一頂面118t及一側面118s,頂面118t平行於發光疊層104的上表面,側面118s連接於頂面118t且不平行於發光疊層104的上表面,而保護層115同時覆蓋於導熱層118的頂面118t及側面118s,藉此避免導熱層118的材料在發光元件運作時與外界環境接觸而產生質變,但本發明不以此為限;在另一實施例中,亦可以導熱層118取代保護層115,使導熱層118全面覆蓋除了第三穿孔115h的位置之外的上電極114或金屬層114S表面上,以增加發光元件的導熱面積。在一實施例中,導熱層118對發光疊層104所發射的光具有高穿透度,例如導熱層118包含一材料對於活性區域104b的發射光具有高於85%的穿透度;此外,在另一實施例中,導熱層118還具有一折射率大於1.5,或為2.1~2.5,且導熱層118與第一電性半導體層104a的折射率差異不超過1.5,如此可降低在第一電性半導體層104a與導熱層118的界面產生全反射的機率,增加發光元件的光取出效率。導熱層118的厚度可以為300~2000Å,在本實施例中,導熱層118的厚度為1000Å,但不以此為限。導熱層118係可以在如第1Q圖所示的形成上電極114後形成,或者在如第1R圖所示的形成在金屬層114S成形後,以覆蓋於上電極114或金屬層114S上。Fig. 7 is a cross-sectional view of a light-emitting device according to a third embodiment of the present invention. Compared with the foregoing embodiments of the present invention, the light-emitting element of this embodiment further includes a thermally conductive layer 118 disposed on the second portion of the upper surface of the light-emitting stack 104. In detail, the thermally conductive layer 118 is disposed on the upper surface of the light emitting stack 104 by a second perforated exposed by H 1, and the thermally conductive layer 118 having a higher thermal conductivity than the light emitting stack 104 (thermal conductivity), the light emitting element in operation, heat generated by the light emitting stack 104 by a thermally conductive layer 118 may be conductive or radiation to escape to the outside, so can reduce the heat accumulated in the second light emitting stack 104 perforation H 1 below, the emission mitigation Material decay caused by heat inside the element, and increase the service life and reliability of the light-emitting element. The thermal conductive layer 118 may include a material with a thermal conductivity of not less than 100W/(mÏK), for example, diamond, graphene, or aluminum nitride (AlN X ) with a thermal conductivity of about 140W/(mÏK)~180W/(mÏK), The present invention is not limited to this. More detail, in the present embodiment, the thermally conductive layer 118 along the second perforation line sidewall 1 H H 1 filled in the second perforation, and covers the first layer of the second conductivity type semiconductor exposed by a perforated H on 104a, and extending to a direction away from the second perforated H 1 around the light emitting element, and in contact with the metal layer 114S or the upper electrode 114, the light emitting stack 104 to the heat generated is transmitted to the metal layer through the thermally conductive layer 118 or 114S As for the upper electrode 114, since the metal layer 114S and the upper electrode 114 are usually selected as metal, the thermal conductivity is high, and the heat inside the light emitting element can be discharged through the thermal conductive layer 118 and the metal layer 114s or the upper electrode 114. In some embodiments, the thermally conductive layer 118 may not be in contact with the metal layer 114S or the upper electrode 114, the heat generated in the light-emitting stack 104 can be radiated to the outside through the thermally conductive layer 118, or the thermally conductive layer 118 can conduct heat to the outside. The structures are connected, so that the heat generated in the light-emitting stack 104 can be dissipated to the outside through the heat-conducting layer 118 in a conductive manner. Compared with the first embodiment, the light-emitting element in this embodiment includes a protective layer 115 covering the metal layer 114S, and the protective layer 115 also covers the thermally conductive layer 118. In this embodiment, the protective layer 115 can be intact. Covers the thermal conductive layer 118. In detail, the thermal conductive layer 118 of this embodiment has a top surface 118t and a side surface 118s. The top surface 118t is parallel to the upper surface of the light-emitting stack 104. Parallel to the upper surface of the light-emitting stack 104, the protective layer 115 simultaneously covers the top surface 118t and the side surface 118s of the heat-conducting layer 118, so as to prevent the material of the heat-conducting layer 118 from contacting the external environment and causing qualitative changes during the operation of the light-emitting element. The present invention is not limited to this; in another embodiment, the protective layer 115 may be replaced by the thermally conductive layer 118, so that the thermally conductive layer 118 fully covers the surface of the upper electrode 114 or the metal layer 114S except the position of the third through hole 115h , In order to increase the heat conduction area of the light-emitting element. In one embodiment, the thermally conductive layer 118 has a high transmittance to the light emitted by the light-emitting stack 104. For example, the thermally conductive layer 118 includes a material that has a transmittance higher than 85% for the emitted light from the active region 104b; in addition, In another embodiment, the thermal conductive layer 118 also has a refractive index greater than 1.5, or 2.1 to 2.5, and the refractive index difference between the thermal conductive layer 118 and the first electrical type semiconductor layer 104a is not more than 1.5, which can reduce the The interface between the electrical semiconductor layer 104a and the thermal conductive layer 118 has a probability of total reflection, which increases the light extraction efficiency of the light-emitting element. The thickness of the thermally conductive layer 118 may be 300-2000 Å. In this embodiment, the thickness of the thermally conductive layer 118 is 1000 Å, but it is not limited thereto. The thermal conductive layer 118 may be formed after the upper electrode 114 is formed as shown in FIG. 1Q, or after the metal layer 114S is formed as shown in FIG. 1R, so as to cover the upper electrode 114 or the metal layer 114S.
第8A~8B圖為本發明第四實施例之發光元件的剖面示意圖及上視示意圖。與前述實施例相較,本實施例的發光元件的導熱層118設於發光疊層104中,且導熱層118具有一第四穿孔H4
大致對位於第二穿孔H1
,由絕緣層106往發光疊層104的方向觀之,第四穿孔H4
第一大致為圓形(請見第8B圖所示),且第四穿孔H4
的上視面積大於發光疊層104的第二部分的上視面積,換言之,第四穿孔H4
的上視面積大於第二穿孔H1
的上視面積。詳言之,導熱層118係位於發光疊層104、第一接觸層103及絕緣層106之間,更詳言之,本實施例之導熱層118貫穿發光疊層104之第一電性半導體層104a、活性區域104b、第二電性半導體層104c及第二接觸層105,使導熱層118被發光疊層104、第一接觸層103及絕緣層106環繞;在另一實施例中,導熱層118貫穿第一電性半導體層104a、活性區域104b、第二電性半導體層104c而未貫穿第二接觸層105,使導熱層118被發光疊層104、第一接觸層103及第二接觸層105環繞,惟,導熱層118的結構並不以上述實施例為限。導熱層118的第四穿孔H4
具有一直徑D4
大於第二穿孔H1之直徑D2
,直徑D4
約介於30μm至200μm 之間,或直徑D4
約為50μm至120μm之間。如第8B圖所示,本實施例之導熱層118具有一內輪廓118a及一外輪廓118b環繞內輪廓118a,內輪廓118a為環狀以環繞第二穿孔H1
下方的發光疊層104並形成第四穿孔H4
。由上視觀之,本實施例的內輪廓118a的形狀為圓形,且其圓心大致對位於第二穿孔H1
的圓心,而外輪廓118b與內輪廓118a的最小距離d介於10μm至50μm之間。此外,本實施例的導熱層118穿過第二接觸層105,且在平行於發光疊層104的堆疊方向上,導熱層118具有一厚度W介於2μm至15μm之間。再一實施例中,導熱層118的內輪廓118a及外輪廓118b之圓心皆大致對位於第二穿孔H1
的圓心。8A to 8B are a schematic cross-sectional view and a schematic top view of a light-emitting device according to a fourth embodiment of the present invention. Compared with the previous embodiment, the thermally conductive layer of the light emitting device 118 according to the present embodiment is provided on the light emitting stack 104, and the thermally conductive layer 118 having a substantially H 4 fourth perforations in the second perforation of the H 1, the insulating layer 106 to Viewed from the direction of the light-emitting stack 104, the fourth through hole H 4 is first substantially circular (see FIG. 8B), and the top view area of the fourth through hole H 4 is larger than that of the second portion of the light-emitting stack 104 The top view area, in other words, the top view area of the fourth through hole H 4 is larger than the top view area of the second through hole H 1 . In detail, the heat-conducting layer 118 is located between the light-emitting stack 104, the first contact layer 103 and the insulating layer 106. In more detail, the heat-conducting layer 118 of this embodiment penetrates the first electrical semiconductor layer of the light-emitting stack 104 104a, the active region 104b, the second conductivity type semiconductor layer 104c, and the second contact layer 105, so that the thermally conductive layer 118 is surrounded by the light-emitting stack 104, the first contact layer 103, and the insulating layer 106; in another embodiment, the thermally conductive layer 118 penetrates the first electrical type semiconductor layer 104a, the active region 104b, and the second electrical type semiconductor layer 104c but does not penetrate the second contact layer 105, so that the thermally conductive layer 118 is covered by the light-emitting stack 104, the first contact layer 103, and the second contact layer 105 surrounds, but the structure of the thermal conductive layer 118 is not limited to the above-mentioned embodiment. The fourth through hole H 4 of the thermal conductive layer 118 has a diameter D 4 greater than the diameter D 2 of the second through hole H 1, and the diameter D 4 is approximately between 30 μm and 200 μm, or the diameter D 4 is approximately between 50 μm and 120 μm. As shown in Figure 8B, 118 having an inner contour and an outer contour 118a 118b surrounding the inner contour of the embodiment of the present embodiment thermally conductive layer 118a, 118a of the inner ring to surround the contour of the second perforation H 1 and the light emitting stack 104 is formed below The fourth perforation H 4 . Depends on the minimum distance d from the concept of the present embodiment, the shape of the inner contour 118a is circular, and its center is located substantially on the center of the second through hole H 1, the inner contour of the outer profile 118a and 118b is between 10μm to 50μm between. In addition, the heat-conducting layer 118 of this embodiment passes through the second contact layer 105, and in the stacking direction parallel to the light-emitting stack 104, the heat-conducting layer 118 has a thickness W between 2 μm and 15 μm. Another embodiment, the inner contour of the outer profile 118a and 118b of the center of the thermally conductive layer 118 are located in substantially the center of the second through hole H 1 of the embodiment.
第9圖為本發明第五實施例之發光元件的剖面示意圖。與前述實施例相較,本實施例之發光元件的導熱層118位於發光疊層104中,且導熱層118的範圍較第四實施例大。詳言之,如第9圖所示,由剖視觀之,發光元件之導熱層118的總面積可大於發光疊層104的面積,以更有效率地將發光元件運作時產生的熱量傳遞至外界。本發明之第四、五實施例的發光元件可以透過如第1A~1Q圖的步驟形成,並且在第二接觸層105形成於發光疊層104上後,將預定形成導熱層118的位置上的部分發光疊層104及其上的第二接觸層105移除,移除的方式可以是透過感應耦合電漿(inductively coupled plasma,ICP)做反應離子蝕刻,但並不以此為限,在第五實施例中,此步驟移除的發光疊層104的區域較第四實施例所移除的發光疊層104的區域多。詳言之,在一實施例中,形成導熱層118之前係可將預定形成導熱層118的位置上之第二接觸層105、活性區域104b、第二電性半導體層104c及第一電性半導體層104a等部分的發光疊層104移除,在此情況下,該第一接觸層103與第一電性半導體層104a之間另設有一蝕刻阻擋層(圖未示),避免在移除部分發光疊層104時破壞第一接觸層103。接著,沉積導熱層118於已移除發光疊層104之處,且在平行於發光疊層104的堆疊方向上,導熱層118具有一厚度W,厚度W較佳係可使導熱層118的頂面118t與發光疊層104之表面的第二部分齊平。沉積導熱層118的方式可以為濺鍍或蒸鍍,例如透過原子層化學氣相沉積(Atomic Layer Chemical Vapor Deposition,ALD)或電子束物理氣相沉積(Electron beam physical vapor deposition,EBPVD)等方式形成,本實施例之導熱層118係透過兩階段成長方法形成,即先透過原子層化學氣相沉積方式先沉積較緻密的導熱層118的第一部分,再以電子束於導熱層118的第一部分上繼續沉積導熱層118的第二部份,但形成導熱層118的方式並不以此為限。Fig. 9 is a schematic cross-sectional view of a light-emitting device according to a fifth embodiment of the present invention. Compared with the foregoing embodiment, the heat-conducting layer 118 of the light-emitting element of this embodiment is located in the light-emitting stack 104, and the range of the heat-conducting layer 118 is larger than that of the fourth embodiment. In detail, as shown in FIG. 9, the total area of the heat conducting layer 118 of the light-emitting element can be larger than the area of the light-emitting stack 104 from the cross-sectional view, so as to more efficiently transfer the heat generated during the operation of the light-emitting element to outside world. The light-emitting elements of the fourth and fifth embodiments of the present invention can be formed through the steps shown in Figures 1A to 1Q, and after the second contact layer 105 is formed on the light-emitting stack 104, the position where the thermally conductive layer 118 is scheduled to be formed Part of the light-emitting stack 104 and the second contact layer 105 on it are removed. The method of removal can be reactive ion etching through inductively coupled plasma (ICP), but it is not limited to this. In the fifth embodiment, the area of the light-emitting stack 104 removed in this step is larger than the area of the light-emitting stack 104 removed in the fourth embodiment. In detail, in one embodiment, before forming the thermal conductive layer 118, the second contact layer 105, the active region 104b, the second electrical type semiconductor layer 104c, and the first electrical type semiconductor layer at the positions where the thermal conductive layer 118 is formed The light-emitting stack 104 of the layer 104a and other parts is removed. In this case, an etching stop layer (not shown) is provided between the first contact layer 103 and the first conductivity semiconductor layer 104a to avoid removing the part The first contact layer 103 is destroyed when the light-emitting stack 104 is lit. Next, deposit the thermally conductive layer 118 where the light-emitting stack 104 has been removed, and in the stacking direction parallel to the light-emitting stack 104, the thermally conductive layer 118 has a thickness W. The thickness W is preferably such that the top of the thermally conductive layer 118 The surface 118t is flush with the second portion of the surface of the light-emitting stack 104. The thermally conductive layer 118 can be deposited by sputtering or evaporation, for example, formed by atomic layer chemical vapor deposition (ALD) or electron beam physical vapor deposition (EBPVD). The thermal conductive layer 118 of this embodiment is formed by a two-stage growth method, that is, the first part of the denser thermal conductive layer 118 is deposited by atomic layer chemical vapor deposition, and then the first part of the thermal conductive layer 118 is deposited with an electron beam The second part of the thermal conductive layer 118 is continuously deposited, but the method of forming the thermal conductive layer 118 is not limited to this.
需注意的是,本發明所列舉之各實施例僅用以說明本發明,並非用以限制本發明之範圍。任何人對本發明所作顯而易見的修飾或變更皆不脫離本發明之精神與範圍。不同實施例中相同或相似的構件,或者不同實施例中具相同標號的構件皆具有相同的物理或化學特性。此外,本發明中上述之實施例在適當的情況下,是可互相組合或替換,而非僅限於所描述之特定實施例。在一實施例中詳細描述之特定構件與其他構件的連接關係亦可以應用於其他實施例中,且均落於如後所述之本發明之權利保護範圍的範疇中。It should be noted that the various embodiments listed in the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the present invention. Any obvious modification or alteration made by anyone to the present invention does not depart from the spirit and scope of the present invention. The same or similar components in different embodiments, or components with the same number in different embodiments, all have the same physical or chemical properties. In addition, the above-mentioned embodiments of the present invention can be combined or replaced with each other under appropriate circumstances, and are not limited to the specific embodiments described. The connection relationship between specific components and other components described in detail in one embodiment can also be applied to other embodiments, and all fall within the scope of protection of the present invention as described later.