TW474036B

TW474036B - Semiconductor light-emitting device and method for manufacturing the same

Info

Publication number: TW474036B
Application number: TW89127135A
Authority: TW
Inventors: Tien-Yang Wang
Original assignee: Tien-Yang Wang
Priority date: 2000-06-21
Filing date: 2000-12-19
Publication date: 2002-01-21

Abstract

Semiconductor light-emitting devices and methods for their manufacture using an efficient reflector to minimize optical loss due to the substrate absorption. The reflector comprises a plurality of discrete quarter-wave stacks deposited on a patterned substrate, allowing for current injection around the discrete reflector stacks. The reflector is further characterized by a high refractive-index ratio suitable for broadband high-reflectance applications of the light-emitting device.

Description

4740fAR4740fAR

5 一 1 ·發明領域: 本發明係概關於半導體發光元件及其製造和用阿效率反光層使基材吸光所致發光損失降至最、，而提高元件之發光效率。進 5-2·發明背景高效率可見光發光二極體（LED)於大面積看板，父通说遠'燈和ά車照明之應用需求至殷。雖然可見光led 本身發光量子效率很高，但其亮度則受限于元件的釋光效率。除了其它因素如晶面内反射，電極接觸區阻光之外，基材吸光係導致發光損失之主要原因之一。為降低基材吸光損失，常用的方法包括使用半導體布拉格反光層（Bragg reflector)及透光基材（transparent substrate)等。 S· Murasato 等于U.S· Patent No· 5744829 中敘述在砷化鎵（GaAs)基材上生長磷化鋁鎵銦（AlGalnP) LED之方法，其基材與雙異質（DH)發光結構之間含有一由多層砷化鋁鎵（AlGaAs)組成之布拉格反光層（BR)。以由 1 0-1 2對砷化鋁鎵（A1Q 4GaG 6As -AloisGa。Q5As)組成之布拉格反光層為例，如果假定AlQ4GaG.6As之折射率為3.7，5-1 Field of the Invention: The present invention relates generally to semiconductor light-emitting elements and their manufacture and use of a high-efficiency reflective layer to minimize the loss of light caused by the substrate's absorption of light, thereby improving the light-emitting efficiency of the element. 5-2. Background of the Invention High-efficiency visible light-emitting diodes (LEDs) are used in large-area signage. Although the visible light LED itself has a high quantum efficiency, its brightness is limited by the luminous efficiency of the device. In addition to other factors such as reflection within the crystal plane, and the electrode contact area blocking light, the substrate's light absorption is one of the main reasons for the loss of luminescence. In order to reduce the light absorption loss of the substrate, commonly used methods include the use of a semiconductor Bragg reflector and a transparent substrate. S. Murasato is equivalent to US Patent No. 5744829, which describes a method for growing an AlGalnP LED on a gallium arsenide (GaAs) substrate. The substrate and the double heterostructure (DH) light emitting structure contain a Bragg reflector (BR) consisting of multiple layers of aluminum gallium arsenide (AlGaAs). Taking a Bragg reflector composed of 1 0-1 2 pairs of aluminum gallium arsenide (A1Q 4GaG 6As-AloisGa. Q5As) as an example, if the refractive index of AlQ4GaG.6As is assumed to be 3.7,

4740^« 五、發明說明（2) Αΐ〇· 95 Ga〇· 〇5 As之折射率為3· 146且不隨波長改變亦不吸光，則其反射率于570nm發光波長超過90°/。。但是低折射率層之光分散及光吸收特性對布拉格反光層之反射率影響报大，如Ε)·Ε· Aspnes 等于J· Appl.Phys· 60 ( 1 986) ρρ·754-767 所述，AlGaAs層複合折射率之實部導光（η)與虛部吸光分量（k)不為零且隨發光波長而變，上述布拉格反光層之反射率其實不到60%。第一圖（a)係光由構化銘銦（Αΐιηρ)下限層入射通過砷化鋁鎵[A1q 4GaQ 6AS -A1q 95Ga。g5As]布拉格反光層時計算所得之反射光譜，其反射率於入射角大于22 度時銳減，使光被基材吸收造成發光損失，光入射角對此反光層於570 nm波長反射率之影響如第一圖（b)所示。 H· Sugawara 等于Jpn· J· Appl· Phys· Vol.33 ( 1 994 )Ρ·1，ρρ·6 1 95-6 1 98中敘述使用10對[磷化鋁銦 (AllnP)-珅化鎵（GaAs)]或20對[填化鋁銦（AllnP)-填化鋁鎵銦（AlGalnP)]組成之布拉格反光層，其反射率高達 70%，且前者之反射光譜較寬。其計算過程假設各層之折射率與吸光係數為定值，但A 1 Gal nP之折射率於近發光能隙時隨波長變動很大，此可用分光折射儀（el 1 ipsometry) 或光反射法（reflectance)測定，如Μ· Moser 等于Appl· Phys· Let· ν〇1·64(1994) ρρ·235-237 與Y. Kaneko 等于J· Appl· Phys· Vol.76 ( 1 994 ) pp.1 809-1 8 1 8 所述。若考慮各層折射率隨波長之變化，貝I![磷化鋁銦（A11 nP) -砷化鎵（GaAs) ]2G或[磷化鋁銦（A1 InP)-磷化鋁鎵銦4740 ^ «V. Description of the invention (2) The refractive index of Αΐ〇 · 95 Ga〇〇5 As is 3.146 and does not change with the wavelength and does not absorb light, the reflectance at 570nm is more than 90 ° /. . However, the light dispersion and light absorption characteristics of the low refractive index layer have a large effect on the reflectance of the Bragg reflective layer, as described by E) · E · Aspnes equal to J · Appl. Phys · 60 (1 986) ρρ · 754-767, The real light guide (η) and imaginary light absorption component (k) of the composite refractive index of the AlGaAs layer are not zero and vary with the emission wavelength. The reflectance of the above Bragg reflector is actually less than 60%. The first picture (a) is the light incident from the lower layer of the structured indium (Aΐιηρ) through the aluminum gallium arsenide [A1q 4GaQ 6AS -A1q 95Ga. g5As] reflection spectrum calculated when the Bragg reflector is used, the reflectance decreases sharply when the incident angle is greater than 22 degrees, causing light to be absorbed by the substrate and causing luminescence loss. The influence of the light incident angle on the reflectivity of the reflector at 570 nm As shown in the first figure (b). H · Sugawara is equal to Jpn · J · Appl · Phys · Vol.33 (1 994) P · 1, ρ ·· 6 1 95-6 1 98. The use of 10 pairs of [aluminum indium (AllnP) -gallium halide ( GaAs)] or 20 pairs of [AlnP-AlGalnP] Bragg reflectors, the reflectance of which is as high as 70%, and the former has a wider reflection spectrum. The calculation process assumes that the refractive index and absorption coefficient of each layer are constant. However, the refractive index of A 1 Gal nP varies greatly with wavelength when it is near the luminous energy gap. This can be done with a spectroscopic refractometer (el 1 ipsometry) or light reflection method ( reflectance), for example, M. Moser is equal to Appl. Phys. Let. -1 8 1 8 described. If the variation of the refractive index of each layer with the wavelength is considered, I! [Indium phosphide (A11 nP)-Gallium arsenide (GaAs)] 2G or [Indium phosphide (A1 InP)-Indium aluminum gallium phosphide

4740hr 五、發明說明（3) (AlGaInP)]2Q組成之布拉格反光層其反射率于57〇nm波長時低於35%，此值僅及H· Sugawara等所述之半。用[磷化|呂銦（A1 InP)-砷化鎵（GaAs) ]2Q布拉格反光層其計算所得反射光譜及光入射角對其570nm波長反射率之影響如第二圖 (a)及第二圖（b)所示，用[磷化鋁銦（All np)-磷化鋁鎵銦 (AlGaInP)]2G組成之布拉格反光層其計算結果則如第三圖 (a)及第三圖（b)所示。 H· Sugawara 等進而敘述使用複合式[磷化鋁銦 (A1 InP)-砷化鎵（GaAs)]-[磷化鋁銦（A1 InP)-磷化鋁鎵銦（AlGaInP)]組成之寬頻高反射率布拉格反光層，若假設各層之導光（η)與吸光係數（k)不隨波長改變，則其反射率于570 nm波長時高達70%。但因各層之折射率隨波長而變，此複合式反光層之反射率其實只有2 6%。由[磷化鋁銦 (A1 InP)-砷化鎵（GaAs) ]1G -[磷化鋁銦（Al InP)—磷化鋁鎵銦（AlGaInP)]1G組成之複合式布拉格反光層其計算所得反射光譜及光入射角對其570 nm波長反射率之影響如第四圖（a)及第四圖（b)所示。習知技藝布拉格反光層設計之反光率偏低且易受光入射角影響，使LED總發光效率受限。由對LED發光為四分之一光波（qUarferwave)之高低折射率層組成之布拉格反光層其高反射區頻寬比值 (fractional bandwidth)係由下式決定·· △ σ/σ0 - 4/7Γ arcsin (nH/nL-1)/(nH/nL + l)4740hr V. Description of the invention (3) (AlGaInP)] 2Q A Bragg reflector with a reflectance of less than 35% at a wavelength of 570 nm, which is only half that of H. Sugawara and others. Using [Phosphorus | Lu Indium (A1 InP) -GaAs]] 2Q Bragg reflector, the calculated reflection spectrum and light incident angle on the reflectance at 570nm wavelength are shown in the second figure (a) and the second As shown in Figure (b), the calculation results of the Bragg reflector using [All np] -AlGaInP] 2G are shown in Figure 3 (a) and Figure 3 (b). ). H. Sugawara et al. Further described the use of a composite [Indium Phosphide (A1 InP) -Gallium Arsenide (GaAs)]-[Aluminum Indium Phosphate (A1 InP) -AlGaInP) composition with a high bandwidth The reflectance of the Bragg reflective layer, if it is assumed that the light guide (η) and absorption coefficient (k) of each layer do not change with wavelength, its reflectance is as high as 70% at a wavelength of 570 nm. However, because the refractive index of each layer varies with wavelength, the reflectivity of this composite reflective layer is actually only 2 6%. A composite Bragg reflective layer composed of [Al InP (A1 InP)-Gallium Arsenide (GaAs)] 1G-[Al InP (Al InP) —AlGaInP (AlGaInP)] 1G The influence of the reflection spectrum and the angle of light incidence on the reflectance at a wavelength of 570 nm is shown in the fourth graph (a) and the fourth graph (b). Known techniques The design of the reflective layer of Prague is low in reflectivity and susceptible to the incident angle of light, which limits the total luminous efficiency of the LED. The Bragg reflector, which consists of high and low refractive index layers that emit a quarter of a light wave (qUarferwave) to the LED, has a high reflection area bandwidth ratio (fractional bandwidth) determined by the following formula: △ σ / σ0-4 / 7Γ arcsin (nH / nL-1) / (nH / nL + l)

474iV^r 五、發明說明（4) 其中σ。= 1/ λ。且對該波長λ。各層之厚度為四分之一光學波長，nH/nL係高對低折射率層之折射率比值，如〇s.474iV ^ r 5. Description of the invention (4) where σ. = 1 / λ. And the wavelength λ. The thickness of each layer is a quarter of the optical wavelength. NH / nL is the refractive index ratio of high to low refractive index layers, such as 0s.

Heavens 等于Appl· optics， ν〇1· 5(1966) ρρ·373-376 中所述。第五圖顯示高反射區頻寬比值隨反光層之折射率比值而增加。習知技藝半導體布拉格反光層於可見光區之折射率比值小，致使其反光範圍狹窄。以填化鋁銦 (AllnP)，砷化鋁（AlAs)，砷化鎵（GaAs)為例，其折射率各為3.289， 3.225， 3.998，用[坤化銘（AlAs)-坤化鎵 (GaAs)]或[磷化鋁銦（A1 InP)-砷化嫁（GaAs)]組成之四分之光波反光層于570 pm波長時其折射率比值只有1 2，以致習知技藝布拉格反光層所對應之反射區頻寬比值僅〇. 14，因此有必要增大其折射率比值以利寬頻高反光之應用。但是折射率比值大於2可導電並且與基材晶格匹配之二半導體材料組合則可欲而不可得。習知技藝之布拉格反光層設計因其折射率比值Heavens is equal to Appl. Optics, ν〇1 · 5 (1966) ρρ · 373-376. The fifth graph shows that the ratio of the bandwidth of the highly reflective region increases with the refractive index ratio of the reflective layer. The reflectance ratio of the Bragg reflector of the conventional technology semiconductor in the visible light region is small, resulting in a narrow reflection range. Taking filled aluminum indium (AllnP), aluminum arsenide (AlAs), and gallium arsenide (GaAs) as examples, their refractive indices are 3.289, 3.225, and 3.998, respectively. [Kunhuaming (AlAs) -Kunhua (GaAs) )] Or [A1 InP] -arsenide (GaAs)] quarter-wave light-reflective layer at 570 pm wavelength has a refractive index ratio of only 12, so that the conventional technique of the Bragg reflective layer corresponds The bandwidth ratio of the reflection zone is only 0.14, so it is necessary to increase the ratio of its refractive index to facilitate the application of broadband high-reflection. However, a combination of semiconductor materials with refractive index ratios greater than 2 that can conduct electricity and match the substrate lattice is undesirable. Design of Bragg reflectors in conventional techniques due to their refractive index ratio

Un要用很多的反射層以提高反射率’卩致長晶週期過長不利LED量產實務。更因其反光範圍狹窄，造成加工六 :=差緊縮，必須嚴密控制其磊晶製程。而L J 摩⑽寬’所以使用寬頻高反射率之布拉格層更為有發利先Un needs to use a lot of reflective layers to improve the reflectivity, and the long crystal growth period is not good for LED mass production practice. Moreover, due to its narrow reflective range, the processing of six == narrowing, and its epitaxial process must be tightly controlled. And L J Capri is wide, so using the wide band and high reflectance Bragg layer is more profitable.

第8頁五、發明說明（5) " '—-----—- 為解決習知半導體反光層之缺點，進而提升元件 ’本發明之目的係利用高效率反光層製作半導體 ^人=彳，使基材吸光所致發光損失減至最低。該反光層厣六^巴案基材上形成四分之一光波（QUarterWave)反光 I 2結構，電流則可在分散排列的反光區中間導通。該進而因其咼折射率比值（nH/nL)之特點，適於寬頻高 “率之應用以有效提高元件之發光效率。依據本發明範圍所描述之發光元件，其製作方法糸如下所述先將半導體布拉格反光層區域磊晶生長在一圖 _ ^基材上。該圖樣基材之槽溝狀表面形成高低交替的表面區域’其幾何形狀係特別選定，以促使布拉格層分別形成于其丘狀頂部與谷狀底部，而界於此分散之布拉格層中間的區域則留作電流導通之途徑。：依據本發明範圍所描述之方法製作之晶片，於長 · 兀發光結構後’在其表面形成線溝使布拉格反光層中高含銘量之神化铭鎵（AIGaAs)層露出，然後把晶片送入氧化爐通瘵氣將此高含鋁層侧向轉化成素氧化鋁（A1 〇χ)。此選擇氧化之結果使原先長成之[砷化鋁（A1 As)-砷化鎵（GaAs) ] _ 布拉格反光層轉化成[氧化鋁乂A 10x)-砷化鎵（GaAs)]布拉格反光層。因素氧化鋁（A1 Ox )之可見光折射率小於1 · 7 7，新形成之[氧化鋁（A10x)-碎化鎵（GaAs)]布拉格反光層其折射率比值可高達2 · 2 6。因此使用本發明之新式布拉格反Page 8 V. Description of the invention (5) " '---------- In order to solve the shortcomings of the conventional semiconductor light-reflective layer, and further improve the component, the purpose of the present invention is to use a high-efficiency light-reflective layer to make semiconductors. Alas, to minimize the luminescence loss caused by the substrate's light absorption. The reflective layer has a quarter-wave (QUarterWave) reflective I 2 structure formed on the substrate, and a current can be conducted in the middle of the scattered reflective regions. This is further due to the characteristics of its pseudo-refractive index ratio (nH / nL), which is suitable for the application of high bandwidth and high efficiency to effectively improve the luminous efficiency of the device. According to the light-emitting device described in the scope of the present invention, its manufacturing method is as follows: The semiconductor Bragg reflective layer region is epitaxially grown on a substrate. The groove-like surface of the patterned substrate forms an alternating surface area. Its geometric shape is specially selected to promote the formation of the Bragg layers on its mounds. The top is shaped like a valley and the bottom is shaped like a valley, and the area bounded by this dispersed Bragg layer is reserved for current conduction. A wafer made according to the method described in the scope of the present invention has a long and light-emitting structure on its surface. A trench is formed to expose the high-intensity AlGaAs layer in the Bragg reflective layer, and then the wafer is sent into an oxidizing furnace to ventilate the high-aluminum-containing layer into plain alumina (A1 ×). As a result of this selective oxidation, the original [Al arsenide (A1 As) -gallium arsenide (GaAs)] _ Bragg reflective layer was transformed into [alumina 乂 A 10x) -gallium arsenide (GaAs)] Bragg reflective layer . The visible light refractive index of plain alumina (A1 Ox) is less than 1 · 7 7, and the newly formed [aluminum oxide (A10x) -gallium gallium (GaAs)] Bragg reflector has a refractive index ratio as high as 2.26. Therefore, it is used The novel Bragg reaction of the present invention

第9頁Page 9

=層架構可得到寬頻高反射率之特點。本發明之新式布拉格反光層其高反射率涵括很寬的光譜與入射角範圍，特別適用於製作咼焭度半導體發光元件。本發明最好參考下列說明圖式加以詳述之。 5 - 4圖式簡單說明：第一圖（a)係習知砷化鋁鎵[AlQ 4GaQ 6As Al〇.95GaQ G5As ]1δ布拉格反光層計算所得之反射光譜，第一圖（b)係光入射角對其於570ηιη波長反射率之影響。第二圖（a )係習知[磷化鋁銦（a 1 I np )—砷化鎵 (GaAs)]2。布拉格反光層計算所得之反射光譜，第二圖（b) 係光入射角對其570nm波長反射率之影響。第三圖（a )係習知[磷化鋁銦（a 11 np )—鱗化鋁鎵銦（AlGaInP)]2G布拉格反光層計算所得之反射光譜，第三圖（b)係光入射角對其570nm波長反射率之影響。第四圖（a)係習知[磷化鋁銦（Al inP)-砷化鎵 (GaAs)]1Q -[磷化铭銦（AllnP)-麟化紹鎵銦（AlGaInP)]10 複合式布拉格反光層計算所得之反射光譜，第四圖（b )係= Layer architecture can get the characteristics of wide band and high reflectivity. The novel Bragg reflector of the present invention has a high reflectivity covering a wide spectrum and a range of incident angles, and is particularly suitable for manufacturing a high-degree semiconductor light-emitting element. The invention is best described in detail with reference to the following illustrative drawings. Figures 5-4 are simple explanations: The first graph (a) is the reflection spectrum calculated by the conventional AlGa 4GaQ 6As Al0.95GaQ G5As 1δ Bragg reflector, and the first graph (b) is the light incidence The effect of angle on its reflectivity at 570nm wavelength. The second picture (a) is the conventional [Aluminum Indium Phosphide (a 1 I np) —Gallium Arsenide (GaAs)] 2. The reflection spectrum calculated by the Bragg reflector, the second figure (b) shows the influence of the light incident angle on the reflectivity at 570nm. The third figure (a) is the reflection spectrum calculated from the conventional [Aluminum Indium Phosphide (a 11 np) —Scaled AlGaInP] 2G Bragg reflector. The third figure (b) shows the pair of light incident angles. The influence of its 570nm wavelength reflectance. The fourth picture (a) is the conventional [Al inP (Al inP) -GaAs]] 1Q-[AllnP (Indium Phosphide) -AlGaInP (Indium Phosphate)] 10 Compound Bragg The reflection spectrum calculated by the reflective layer, the fourth figure (b) is

4740fAR 五、發明說明（7) 光入射角對其570nm波長反射率之影響。第五圖顯示布拉格反光層之高反射區頻寬隨其折射率比值而增加。第六圖係依據本發明範圍包含[砷化鋁（A1 As) -砷化鎵（GaAs)]n布拉格反光層架構之發光二極體（LED)示意圖。第七圖係依據本發明範圍之led示意圖，顯示經通道氧化後形成之[素氧化鋁（A10x)-砷化鎵（GaAs)]布拉格反光層架構。第八圖（a)係依據本發明範圍包含[素氧化鋁 (A10x)-砷化鎵（GaAs) %布拉格反光層架構之LEI)計算所得之反射光譜，第八圖（b)係光入射角對其57〇nm波長反射率之影響。第九圖（a)係依據本發明範圍包含[素氧化銘 (A10x)-磷化銘銦（AllnP)]3布拉格反光層架構之LE])其計算所得之反射光譜’第九圖（b)係光入射角對其”“出反射率之影響。、 ^ 第十圖（a)係依據本發明範圍包含[素氧化铭4740fAR V. Description of the invention (7) The influence of the light incident angle on the reflectivity at 570nm wavelength. The fifth figure shows that the bandwidth of the highly reflective area of the Bragg reflector increases with its refractive index ratio. The sixth diagram is a schematic view of a light emitting diode (LED) according to the scope of the present invention including [aluminum arsenide (A1 As-gallium arsenide (GaAs)] n) Bragg reflector structure. The seventh diagram is a schematic diagram of the LED according to the scope of the present invention, and shows the structure of the [plain aluminum oxide (A10x) -gallium arsenide (GaAs)] Bragg reflective layer formed after channel oxidation. The eighth figure (a) is a reflection spectrum calculated according to the scope of the present invention and includes [LEI of plain aluminum oxide (A10x) -gallium arsenide (GaAs)% Bragg reflector structure], the eighth figure (b) shows the incident angle of light Influence on the reflectivity of its 57nm wavelength. The ninth figure (a) is a reflection spectrum calculated according to the scope of the present invention including [A10x] -Phodium Indium (AllnP)] 3 Bragg reflector layer LE]) The ninth figure (b) The influence of the incident angle of light on its "out" reflectivity. The tenth figure (a) is in accordance with the scope of the present invention.

474iV^r 五、發明說明（8) (Α10χ)-磷化鋁銦（A1InP)]3 —氧化鋁（Α1〇χ)四分之一光波反光層架構之LED其計算所得之反射光譜，第十圖^^係光入射角對其570nm波長反射率之影響。第十一圖（a )顯示依據本發明範圍包含[素氧化鋁 (A10x) -磷化銘銦（Α1 ΙπΡ)]η —素氧化鋁（Α1〇χ)四分之一光波反光層之LED其計算所得反射光譜隨η值之變化，第十一圖（b)顯示當η = 5時光入射角對此[LH]5 —l反光層於570ηιη波長反射率之影響。474iV ^ r V. Description of the invention (8) (Α10χ) -Aluminum Indium Phosphide (A1InP)] 3-Alumina (Α1〇χ) quarter light wave reflective layer structure of the LED's calculated reflection spectrum, tenth Figure ^^ shows the effect of light incident angle on the reflectivity at 570nm wavelength. The eleventh figure (a) shows an LED comprising [alumina (A10x)-indium phosphide (A1 ΙπΡ)] η-alumina light-reflecting layer according to the scope of the present invention. The calculated reflection spectrum varies with the value of η. Figure 11 (b) shows the effect of the light incident angle on the reflectivity of the [LH] 5-1-1 reflective layer at a wavelength of 570ηη when η = 5.

5 - 5 發明詳細說明：5-5 Detailed description of the invention:

依據本發明範圍所具體詳述，先在圖樣基材上磊晶生長一半導體布拉格反光層（BR)，第六圖顯示依據本發明範圍所述製造之發光元件之橫截面。如第六圖所描述之發明範圍，雙異質發光結構（DH-LED)係長在砷化鎵（GaAs) 圖樣基材10上並且包含至少一布拉格反光層18。該布拉格反光層18係先長在砷化鎵（GaAs)圖樣基材10上，由交替之低折射率層18A與高折射率層18B所組成，接著長磷化鋁鎵銦（AlGalnP)雙異質發光結構12，包含 η - AlGalnP 下限層 120，AlGalnP 發光層 122，p-AlGalnP 上限層124。其上再長一 p-GaP窗層14及p-GaAs接觸層 16 °p-電極22與η-電極24則可各別使用AuZn/Au與According to the detailed description of the scope of the present invention, a semiconductor Bragg reflector (BR) is first epitaxially grown on a pattern substrate, and the sixth figure shows a cross section of a light-emitting element manufactured according to the scope of the present invention. In the scope of the invention described in the sixth figure, the double hetero-luminescent structure (DH-LED) is grown on a gallium arsenide (GaAs) pattern substrate 10 and includes at least one Bragg reflective layer 18. The Bragg reflective layer 18 is first grown on a gallium arsenide (GaAs) pattern substrate 10, and is composed of alternating low-refractive index layers 18A and high-refractive index layers 18B, and then double-gallium indium phosphide (AlGalnP). The light emitting structure 12 includes an n-AlGalnP lower limit layer 120, an AlGalnP light emitting layer 122, and a p-AlGalnP upper limit layer 124. A p-GaP window layer 14 and a p-GaAs contact layer 16 are further grown thereon. The p-electrode 22 and the η-electrode 24 can each use AuZn / Au and

第12頁Page 12

4740fAR 五、發明說明（9)4740fAR V. Description of Invention (9)

AuGe/Au 形成。AiGalnp 層之厚度以〇· 5-1 為佳，p —Gap 窗層14之厚度則以2 —15⑽為宜。有機金屬氣相磊晶法（MOVPE)係製做AlGalnP之最仏方法吊用之二族原料包括三甲基化合物例如三甲基鎵 (TMfaj，三甲基銦（TMln)，三曱基鋁（TMA1)，五族原料包括五族氫化物例如氫化砷（AsH3)與氫化磷（p^)，雙矽甲烷 (Si 4 )2及—甲基鋅zn(cH3 )2則各別用作n一形與p一形雜質。尚含銘層之長晶係於約〇1 atm低壓反應器内在基材溫度約760度攝氏進行。A1GaInp層長晶製程宜使用大v/羾比且令基材旋轉以促進均勻生長。 — 此實例用高含鋁量之砷化鋁鎵（AlGaAs)如砷化鋁蘇（AlofauAs)與砷化銘（A1As)作低折射率層m，用低含紹ϊ之坤化銘鎵如砷化鎵（GaAs)作高折射率層i8B，並選定該圖樣基材之幾何形狀以促使布拉格層分別形成于其丘狀頂部與谷狀底部。槽溝可用習知方法蝕刻成形，其方向以沿[oil]方向為佳。Μ〇νρΕ在圖樣基材上之磊晶生長如S.D· Hersee 等於 j. Crystal Growth Vol.77 ( 1 986) ρρ·310-320 與 H.F.J· Van，T BHk 等於 j· CrystalAuGe / Au is formed. The thickness of the AiGalnp layer is preferably 0.5 to 5-1, and the thickness of the p-Gap window layer 14 is preferably 2 to 15 ⑽. Organometallic vapor phase epitaxy (MOVPE) is the most common method for making AlGalnP. Group II raw materials used include trimethyl compounds such as trimethylgallium (TMfaj, trimethylindium (TMln), and trifluoride aluminum ( TMA1), Group 5 raw materials include Group 5 hydrides such as arsenic hydride (AsH3) and phosphorus hydride (p ^), disilazane (Si 4) 2 and -methyl zinc zn (cH3) 2 are each used as n- Shaped and p-shaped impurities. The crystals with the Ming layer are carried out in a low-pressure reactor at about 0 1 atm at a substrate temperature of about 760 degrees Celsius. A1GaInp layer crystal growth process should use a large v / 羾 ratio and rotate the substrate To promote uniform growth. — This example uses a high aluminum content aluminum gallium arsenide (AlGaAs) such as aluminum arsenide (AlofauAs) and arsenide (A1As) as the low refractive index layer m, using a low Gallium gallium such as gallium arsenide (GaAs) is used as the high refractive index layer i8B, and the geometric shape of the pattern substrate is selected to promote the formation of the Bragg layer on its mound-shaped top and valley-shaped bottom, respectively. The grooves can be etched by conventional methods , Its direction is preferably along the [oil] direction. The epitaxial growth of Μ〇νρΕ on the pattern substrate such as SD · Hersee is equal to j. Crystal Growt h Vol.77 (1 986) ρρ · 310-320 and H.F.J · Van, T BHk is equal to j · Crystal

Growth、Vol.92 ( 1 988) ρρ·ΐ65-170 所述。MOVPE 於[Oil] 方向槽溝磊晶生長時之特點為其（1 1〇B側面係非生長面，使分別在其丘狀了員部與谷狀底部長成之布拉格反光層被互相隔離’而界於此分散之布拉格層中間的區域則留作電流Growth, Vol. 92 (1 988) ρρ · ΐ 65-170. The characteristic of MOVPE during the epitaxial growth of grooves in the [Oil] direction is (1 10B side is a non-growth surface, so that the Bragg reflectors grown on its hill-shaped member and valley bottom are isolated from each other ' The area bounded by this scattered Bragg layer is left as a current

I1H 第13頁 474n：^f- 五、發明說明（10) f通之用。適當設計槽溝的幾何形狀，可使發光層與LED 晶片表面平坦或呈圖案狀。卜本發明製程次一步驟係將該高含鋁層通蒸氣選擇氧化以提高布拉格反光層之折射率比值。例如在長完發光結構後，將晶面刻線使布拉格反光層中高含鋁量之砷化鋁嫁層露出，然後把晶片送入氧化爐中通蒸氣將該高含鋁層經側向轉化成素氧化鋁（native Αι〇χ)溝層。以先前長成之[坤化紹（A1 As)-砷化鎵（GaAs)]布拉格層18為例，其石申化銘層經選擇氧化之結果轉化成[素氧化鋁（A丨〇χ )—砷化鎵（GaAs)]布拉格反光層20。第七圖係依據發明範圍之 LED示意圖，顯示經由通道氧化後所形成之[素氧化鋁 (A10x)-砷化鎵（GaAs) 布拉格反光層2〇架構。濕式氧化完成之後，繼續將晶片加工成晶粒並用環氧樹脂加以封裝。常用之氧化條件為430。(：以氮氣作載體通蒸氣進行，其細節如 J.M· Dallasasse 等於 Appl· Phys. Lett. Vol. 57 (1990) pp.2844-2846中所述。垂直光腔面射型雷射 (VCSEL)的光腔孔徑亦可用此法行形成，如j · j · Wierer等於 Appl· Phys· Lett· ν〇1·74 (1999) ρρ·926-928 中所述。氧化速率隨材料不同而異，對砷化鋁（A1As)高達62 //m/hr ’對珅化錁（GaAs)為4 /zm/hr，對構化銦 (A1 InP)則小於〇· 1 # m/hr。本發明製程之另一優點係因濕式氧化在碟化鋁鎵銦（AlGalnP)層表面形成一氧化薄膜’此氧化保護膜可增進發光元件於濕熱環境下操作之耐I1H Page 13 474n: ^ f- 5. Explanation of the invention (10) f is used in general. Properly designing the geometry of the grooves can make the light emitting layer and the surface of the LED chip flat or patterned. The next step in the process of the present invention is to selectively oxidize the high aluminum-containing layer by vapor to increase the refractive index ratio of the Bragg reflective layer. For example, after growing the light-emitting structure, the engraved lines on the crystal plane expose the high-aluminum-containing aluminum arsenide graft layer in the Bragg reflective layer, and then send the wafer into an oxidation furnace to vaporize the high-aluminum-containing layer into Plain alumina trench layer. Taking the previously grown [Kun Huashao (A1 As) -GaAs]] Bragg layer 18 as an example, the result of selective oxidation of the Shishenhua Ming layer was converted into [plain alumina (A 丨〇χ) —arsenic Gallium (GaAs)] Bragg reflective layer 20. The seventh figure is a schematic diagram of an LED according to the scope of the invention, showing the [plain aluminum oxide (A10x) -gallium arsenide (GaAs) Bragg reflector 20 structure formed after channel oxidation. After the wet oxidation is completed, the wafer is further processed into grains and encapsulated with epoxy resin. A common oxidation condition is 430. (: Nitrogen is used as the carrier to carry out the steam. The details are as described in JM. Dallasasse equals Appl. Phys. Lett. Vol. 57 (1990) pp. 2844-2846. The vertical light cavity surface-emitting laser (VCSEL) The optical cavity aperture can also be formed by this method, as described in j · j · Wierer is equal to Appl · Phys · Lett · ν〇1 · 74 (1999) ρρ · 926-928. The oxidation rate varies with different materials. Aluminium (A1As) is as high as 62 // m / hr 'GaAs is 4 / zm / hr, and A1 InP is less than 0.1 # m / hr. The process of the present invention is another One advantage is that an oxide film is formed on the surface of the aluminum gallium indium (AlGalnP) layer due to wet oxidation. This oxidation protection film can improve the resistance of the light-emitting element to operation in hot and humid environments.

第14頁 474Π·Ίί：五、發明說明（11) 久性，如Ν· Holonyak 等於 USPatent 5517039 中所述。因氧化鋁（A10x)之可見光折射率小於1· 77，如a.Page 14 474Π · Ίί: 5. Description of the invention (11) Persistence, as described in NL Holonyak equal to US Patent 5517039. Because the visible light refractive index of alumina (A10x) is less than 1. 77, such as a.

Bek 等於 IEEE Photonic Technology Letters, Vol· 11 (1999) ρρ·436-438中所測定，新形成之[氧化鋁（Αΐ〇χ) 一砷化鎵（GaAs)]布拉格反光層其折射率比值可高達2.26。因此使用本發明之新式布拉格反光層架構可實現寬頻高反射率之特點。第八圖（a)顯示依據本發明範圍使用3對[素氧化銘（A10x)-坤化鎵（GaAs)]布拉格反光層架構之led其計算所得之反射光譜，第八圖（b)顯示光入射角對其57〇nm 波長反射率之影響。此布拉格層具有很寬的反射頻譜，且其反射率於500 nm至700 nm波長範圍超過70%。尤其反射率對發光入射角之關係呈V形曲線，大部份向下發射的光將被反射折回，使LED之表面發光效率大增。相較之習知技藝布拉格層其反光率受光入射角所限制，以致發光大都被基材吸收而損失。第九圖（a)顯示依據本發明範圍使用3對[素氧化無（A10x)-磷化鋁銦（AllnP)]布拉袼反光層之led其計算所得反射光譜，第九圖（b)顯示光入射角對其57〇nm波長反射率之影響。此布拉格層具有很寬的反射頻譜，且其反射率於570nm發光波長高達90%。其反射率與入射角之關係顯示以磷化鋁銦取代神化鎵更能有效減少基材吸收而提高發光效率。若使用[LH]n-L改良型設計則效果更佳，第十圖Bek is equal to that determined in IEEE Photonic Technology Letters, Vol. 11 (1999) ρ · 436-438. The refractive index ratio of the newly formed [alumina (Αΐ〇χ) -gallium arsenide (GaAs)] Bragg reflector can be as high as 2.26. Therefore, the novel Bragg reflector structure of the present invention can realize the characteristics of wide frequency and high reflectance. The eighth figure (a) shows the reflection spectrum calculated by using three pairs of [PrOx (A10x) -gallium (GaAs)] Bragg reflector structures according to the scope of the present invention. The eighth figure (b) shows light The effect of the angle of incidence on the reflectance at a wavelength of 57nm. This Bragg layer has a wide reflection spectrum and its reflectivity exceeds 70% in the 500 nm to 700 nm wavelength range. In particular, the relationship between the reflectance and the incident angle of light is a V-shaped curve. Most of the downwardly emitted light will be reflected back, which will greatly increase the surface luminous efficiency of the LED. Compared with the conventional technique, the reflectance of the Bragg layer is limited by the incident angle of light, so that most of the luminescence is absorbed by the substrate and lost. The ninth figure (a) shows the calculated reflection spectrum using three pairs of [Proxidized Oxide Free (A10x) -Al InP (AllnP)] Brass reflectors according to the scope of the present invention. The ninth figure (b) shows The influence of the angle of light incidence on the reflectance at a wavelength of 57nm. This Bragg layer has a wide reflection spectrum, and its reflectance is as high as 90% at 570nm. The relationship between the reflectance and the incident angle shows that replacing indium aluminide with gallium indium phosphide can effectively reduce the absorption of the substrate and improve the luminous efficiency. If [LH] n-L improved design is used, the effect will be better.

4740：^ 五、發明說明（12) (a)顯示依據本發明範圍使用[素氧化鋁（Α10χ)—磷化鋁銦： (AllnP)]3 -素氧化鋁（Α10χ)布拉格反光層架構之LED其計 * 算所得反射光譜，第十圖（b)顯示光入射角對其57〇nm波長反射率之影響。其反射率於5〇〇 nm至650 nm波長範圍超過 90%，且能全數回收超過50度之入射光。第十一圖（a)顯示依據本發明範圍使用[素氧化鋁 · (A10x)-磷化鋁銦（Α1ΙηΡ)]η -素氧化鋁（A10x)四分之一光波反光層之LED其計算所得反射光譜隨η值之變化，第十一圖（b)顯示於η = 5時光入射角對其57 〇nm波長反射率之影 _ 響。當η增大至5時此反光層於5〇〇ηιη至680nm波長範圍之反光特性幾近理想，能全數反射回收高與低角度之入射光，其V型曲線之最低反射率亦達50 %左右。由於本發明之四分之一光波反光層其折射率比值大，僅需少數反光層即可達：到寬頻高反射率之優良特性。 - : 依據本發明範圍之四分之一光波反光層具有报寬的反射光譜，所以同樣的反光層設計可適用於不同顏色的 LED ’其製程因而大為簡化。且其反射率非常高，能將向下射入基材所致發光損失減至最低。因此本發明範圍之製| · 造方法特別適用於製作高效率，高亮度半導體發光元件。4740: ^ V. Description of the invention (12) (a) Shows the use of [plain aluminum oxide (Α10χ) —indium aluminum phosphide: (AllnP)] 3-plain aluminum oxide (Α10χ) Bragg reflector structure LED according to the scope of the present invention The calculated reflection spectrum is calculated. The tenth figure (b) shows the influence of the light incident angle on the reflectance at a wavelength of 57 nm. Its reflectivity is more than 90% in the wavelength range of 500 nm to 650 nm, and it can fully recover incident light exceeding 50 degrees. The eleventh figure (a) shows the calculation result of the LED using [plain aluminum oxide (A10x) -indium aluminum phosphide (Α1ΙηΡ)] η-primary aluminum oxide (A10x) quarter light reflecting layer according to the scope of the present invention. The reflection spectrum changes with the value of η. Figure 11 (b) shows the effect of the light incident angle on the reflectance of its 57 nm wavelength at η = 5. When η is increased to 5, the reflective characteristics of the reflective layer in the wavelength range of 500nm to 680nm are nearly ideal, and it can fully reflect the incident light at high and low angles. The minimum reflectivity of its V-shaped curve is also 50%. about. Since the quarter light reflecting layer of the present invention has a large refractive index ratio, only a few reflecting layers are needed to achieve the excellent characteristics of wideband and high reflectance. -: A quarter of the light wave reflective layer according to the present invention has a wide reflection spectrum, so the same reflective layer design can be applied to LEDs of different colors, and the manufacturing process is greatly simplified. And its reflectivity is very high, and it can minimize the loss of luminescence caused by falling downward into the substrate. Therefore, the manufacturing method in the scope of the present invention is particularly suitable for manufacturing high-efficiency, high-brightness semiconductor light-emitting devices.

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Claims

4 74娜六、申請專利範圍 1· 一種半導體發光元件，包含下列層次：一半導體圖樣基材； β <第一電極配置於該圖樣基材之第/表面上’ 一第一反射區排列於該圖樣基材之第二表面上’ * 一第二反射區排列於該圖樣基材之第二表面上’該第二反射區與該第一反射區彼此高低交錯棑列而互相隔離’其中間的區域則作為電流導通之途徑；一活性層介於下限層與上限層中間炎配置於一包含該第一與該第二反射區之表面上；一窗層配置於該上限層表面上；一接觸層配置於該窗層表面上；一第二電極配置於該接觸層表面上。 2 ·如申請專利範圍第1項之元件，其中所述之各反射區係由多層厚度對LED發光為四分之一光波（Quarterwave)之高低折射率層組成之布拉格反光層。 3·如申請專利範圍第2項之元件，其中所述之四分之一光波反射層包含例如砷化鋁鎵（A1 GaAs)與磷化鋁鎵銦 (AlGalnP)等化合物，其含鋁量界於〇與1。 4.如申請專利範圍第丨項之元件，其中所述之各反射區包含多層對1^〇發光波長為四分之一光波（(111&1_1^1^^6)之低折射率層。4 74 Na VI. Scope of patent application 1. A semiconductor light-emitting device including the following layers: a semiconductor pattern substrate; β < the first electrode is arranged on the / th surface of the pattern substrate '; a first reflection area is arranged on the On the second surface of the pattern substrate, a second reflection region is arranged on the second surface of the pattern substrate. The second reflection region and the first reflection region are staggered in line with each other to isolate each other. A region is used as a current conduction path; an active layer is disposed between the lower limit layer and the upper limit layer, and is disposed on a surface including the first and the second reflection areas; a window layer is disposed on the surface of the upper layer; The contact layer is disposed on the surface of the window layer; a second electrode is disposed on the surface of the contact layer. 2. The element according to item 1 of the scope of patent application, wherein each of the reflection regions is a Bragg reflector layer composed of a high- and low-refractive-index layer with a quarter-wave light emission to the LED. 3. The element according to item 2 of the patent application scope, wherein the quarter light reflection layer includes compounds such as aluminum gallium arsenide (A1 GaAs) and aluminum gallium indium phosphide (AlGalnP), and the aluminum content limit In 0 and 1. 4. The element according to item 丨 of the patent application range, wherein each of said reflection regions includes a multilayer pair of low-refractive-index layers with a light emission wavelength of 1 ^ 0 ((111 & 1_1 ^ 1 ^^ 6)).

4 740.^ π 六、申請專利範圍 5·如申請專利範圍第4項之元件，其中所述之四分之一光波反射層包含例如砷化鋁鎵（A1GaAs)與磷化鋁鎵銦 (AlGalnP)等化合物，其含鋁量界於^與}。 6·如申請專利範圍第2項之元件，其中所述之各反射區包含η組四分之一光波之高低折射率層，其^值界於1與25。 7·如申請專利範圍第4項之元件，其中所述之各反射區包含η組四分之一光學波長之高低折射率層，其η值界於1與 25 〇 8·如申请專利範圍第2項之元件，其中所述之各反射區之高低折射率比值（nH/nL)大於1。 9·如申請專利範圍第4項之元件，其中所述之各反射區之高低折射率比值（nH/nL)大於1。 10·如申請專利範圍第2項之元件，其中所述之各反射區對 LED發光波長具有一寬頻高反光率。 11 ·如申請專利範圍第4項之元件，其中所述之各反射區對 LED發光波長具有一寬頻高反光率。4 740. ^ π 6. The scope of patent application 5. The element according to item 4 of the scope of patent application, wherein the quarter light reflection layer includes, for example, aluminum gallium arsenide (A1GaAs) and aluminum gallium indium phosphide (AlGalnP) ) And other compounds whose aluminum content is bounded by ^ and}. 6. The element according to item 2 of the scope of patent application, wherein each of the reflection regions includes a high and low refractive index layer of a group of quarter light waves, whose ^ value ranges between 1 and 25. 7. The element according to item 4 of the scope of patent application, wherein each of the reflection regions includes high and low refractive index layers with a quarter optical wavelength of the η group, and the value of η is within the range of 1 and 25. The element of item 2, wherein each of the reflective regions has a high-low refractive index ratio (nH / nL) greater than 1. 9. The element according to item 4 of the scope of patent application, wherein the high-low refractive index ratio (nH / nL) of each reflection region is greater than 1. 10. The element according to item 2 of the scope of patent application, wherein each of said reflection regions has a broadband high reflectance to the light emitting wavelength of the LED. 11. The element according to item 4 of the scope of patent application, wherein each of said reflection regions has a broadband high reflectance to the light emitting wavelength of the LED.

第18頁 474frn 六、申請專利範圍 12·如申請專利範圍第2項之元件，其中所述之低折射率層 (L)包含素氧化鋁（A10x)。 13·如申請專利範圍第4項之元件，其中所述之低折射率層 (L)包含素氧化鋁（Α1〇χ)。 14·如申請專利範圍第4項之元件，其中所述之低（L)高（Η) 折射率層組成對LED發光為四分之一光波之[L — H]n — L反射層。 1 5· —種半導體發光元件製作之方法，至少包含下列步驟：預備一具有第一表面及第二表面之半導體圖樣基材，該第二表面上區分成各別高低不同之表面區域；於苐一該表面區域配置第一反射區，並於第二該表面區域配置第二反射區，該第二反射區與該第一反射區高低交錯排列而互相隔離，其中間的區域則作為電流導通之途徑。 16·如申請專利範圍第15項之方法，其中所述之預備步驟包含於该第二表面至少鍅刻一槽溝以區分成高低不同之該表面區域。 1 7·如申請專利範圍第1 5項之方法，其中所述之第一與第二反射區係利用有機金屬氣相磊晶法（MOVPE)生長。Page 18 474frn VI. Patent application scope 12. The element according to item 2 of the patent application scope, wherein the low refractive index layer (L) includes plain alumina (A10x). 13. The element according to item 4 of the patent application range, wherein said low-refractive index layer (L) comprises plain aluminum oxide (A1χ). 14. The element according to item 4 of the scope of patent application, wherein the low (L) high (Η) refractive index layer constitutes a [L — H] n — L reflective layer that emits a quarter of a light wave to the LED. 1 5 · —A method for manufacturing a semiconductor light-emitting element, including at least the following steps: preparing a semiconductor pattern substrate having a first surface and a second surface, the second surface being divided into surface areas of different heights; A surface area is provided with a first reflection area, and a second surface area is provided with a second reflection area. The second reflection area and the first reflection area are arranged in a staggered arrangement to isolate each other, and the middle area is used for conducting current. way. 16. The method according to item 15 of the patent application scope, wherein said preliminary step includes engraving at least one groove on the second surface to distinguish the surface area with different heights. 17. The method according to item 15 of the scope of patent application, wherein the first and second reflective regions are grown by an organic metal vapor phase epitaxy (MOVPE) method.

i74iVAR 六、申請專利範圍 1 8·如申請專利範圍第1 5項之方法，與第二反射區之表面上形成一介一步包含於該第一活性層。於下限層與上限層中間之 19·如申請專利範圍第18項之方法，進_ 層表面形成一窗層。 ^包含於該上限 20·如申請專利範圍第19項之方法，進一牛表面形成一接觸層，並於該接觸少包含於該窗層觸碉層表面形成第二電極接 2丄：:Λ專，第15項之方*，進-步包含於該半導體圖樣基材之第一表面上形成第一電極接觸。 22·如申請專利範圍第15項之方法，其中所述之第一與第一反射區、、二轉化成為含素氧化鋁（A 1 & )之高折射率比值反射區。 2 3·如申請專利範圍第22項之方法，其中所述之高折射率比值反射區係將該第一與第二半導體反射區利用選擇氧化加工製成。i74iVAR 6. Application scope of patent 18: If the method of scope of patent application No. 15 is applied, a step is formed on the surface of the second reflection area to be included in the first active layer. In the middle of the lower limit layer and the upper limit layer, the method of item 18 of the scope of patent application, a window layer is formed on the surface of the layer. ^ Contained in the upper limit of 20 · As in the method of claim 19 of the scope of patent application, a contact layer is formed on the surface of the cow, and a second electrode contact is formed on the surface of the contact layer that is less in the contact. 2 :: Λ 专The method of item 15 *, further includes forming a first electrode contact on the first surface of the semiconductor pattern substrate. 22. The method according to item 15 of the scope of patent application, wherein said first and first reflection regions, and two are converted into high refractive index ratio reflection regions of prime alumina (A 1 &). 2 3. The method according to item 22 of the scope of patent application, wherein the high-refractive-index-ratio reflective region is made by selectively oxidizing the first and second semiconductor reflective regions.