1221676 玖、發明說明： (一） 發明所屬之技術領域 本發明係關於一種發光二極體（LED)及其製造方法，尤其 是關於以晶圓黏合（wafer bonding)方式施行接合之具有視 窗層的發光二極體。 (二） 先前技術 發光二極體（LED )裝置在各種新穎技術不斷推陳出新狀況 下，亮度越來越高，使用壽命也逐漸增加，故應用範圍更 加廣泛。早期，因LED亮度受到材料及晶片製作技術的影 響，應用範圍受到侷限，故有許多針對晶片製作技術的改 善方案，企圖以改善晶片亮度的方式使其應用範圍更加廣 泛。 如美國專利第5 0 0 8 7 1 8號，公告於8 0年4月1 6日，由 Robert M，Flether等所發明之「具有導電視窗之發光二極 體」專利案，其係在發光二極體晶片製作過程中，將AlGalnP 材料之 PN接面作用層成長於半導體基板上，然後將材質 不同之半導體視窗層（window layer)疊覆在PN接面作用層 上。其中，該半導體視窗層具有較作用層更低的電阻，以 及較作用層更大的能帶間隙，使覆蓋視窗層的晶片亮度提 高。亦即，此技術確實可提高發光二極體晶片之晶片亮度。 然而，透明視窗層係由磊晶成長製程加以製作，其成長速 度約1 〇微米/小時，對於厚度大於1 00微米之透明視窗層， 至少須花費1 〇幾個小時，時間上並不經濟。 如美國專利編號第5 3 7 6 5 8 0號，公告於8 3年1 2月2 7日， 1221676 由Fred A .Kish等所發明之「發光二極體層之晶圓黏合」專 利案，其係在半導體基板上磊晶成長PN接面作用層，然後 在疊覆透明視窗層之後，利用化學鈾刻方法移除下層半導 體基板，再以晶圓黏合（wafer bonding)技術，將透明基板 黏合至PN接面作用層上。此晶圓黏合技術移除吸光基板， 進而使發光二極體層之晶片亮度增加。但是，在晶片製程 中，先移除不透明吸光基板再黏合透明基板之步驟，將使 晶圓在製程中具有較差的機械強度而容易破損。 以上習知技術之缺失分別爲：以磊晶成長於發光二極體 層晶片上之透明視窗層，其成長速度太慢，經濟效益較差； 在半導體基板自發光二極體晶片上移除後，再以晶圓黏合 技術，黏合透明基板，會有較差的機械強度而容易破損之 問題。 因此’爲改善上述缺失，有必要發展出一種較佳的發光 二極體製作方法，以及依此方法所製成發光二極體裝置。 (三）發明內容 鑑於上述習知技術之問題，本發明之目的在於提供一種 發光二極體（LED)及其製造方法。 本發明之發光二極體（LED)之製造方法，包括下列步驟： 提供一半導體基板；嘉晶成長一第一限制層（confining layer)於該基板上；嘉晶成長一作用層（active layer)於 該第一限制層上；磊晶成長第二限制層於該作用層上；黏 合（b ο n d i n g ) —透明視窗層於該第二限制層上，其係以晶圓 黏合（wafer bonding)方式施行；及移除該基板，其係在黏 1221676 合視窗層之後以化學蝕刻施行；成長一保護層（p a s s i v e 1 ay e r) ’其係成長於該發光二極體晶片之被移除基板側； 形成一金屬電氣銲墊，位於該透明視窗層上覆蓋其一部份 ;以及形成另一金屬電氣焊墊，位於該保護層上覆蓋其一 部份。 如上述之製造方法，其中包括在該黏合視窗層步驟中提 高溫度，以獲得較低之連接電阻；同時，包括在該黏合視 窗層步驟中施加壓力至待黏合處，以達成均勻之黏合。再 者，該視窗層之厚度係大於100微米。 如上述之製造方法，其中該保護層使用之材料不含鋁元 素（A 1 ) 〇 本發明之發光二極體（LED)，包括；一半導體基板；一第 一限制層，其係以磊晶方式成長在該基板上；一作用層， 其係以磊晶方式成長在該第一限制層上；一第二限制層， 其係以磊晶方式成長在該作用層上；一透明視窗層，其係 爲和該第二限制層材質相異之透明層，以晶圓黏合（wafer bonding)方式’黏合在該第一限制層上；一^保護層（passive 1 a y e r )，其係以磊晶或鍍膜方式成長於該發光二極體晶片 之被移除基板側；一金屬電氣銲墊，位於該視窗層上覆蓋 其一部份；以及另一金屬電氣銲墊，位於該保護層上覆蓋 其一部份。 如上述之製造方法，其中該透明視窗層之厚度係大於1 〇〇 微米。再者，其中該保護層所使用之材料不含鋁元素（A1) 1221676 (四）實施方式 下文中，將參照圖式詳細描述本發明之較佳實施例，其 中相同符號代表相同元件。 本發明之目的在於發提供一種發光二極體（LED)之製造方 法，尤其是在LED晶片上疊覆透明視窗層之方法。其中， 該視窗層已被證實爲可增加LED之發光效率，且其厚度越 厚，效果越佳。前述之製造方法包括下列步驟： a) 提供一半導體基板10，其係爲n型GaAs材質； b) 嘉晶成長一第一限制層（confining layer)ll於該半導體 基板10上，其係爲η型AlxGa^x In P材質，0<xSl; c )磊晶成長一作用層1 2於該第一限制層1 1上，其係爲i 型 AlyGa^y In P 材質，，〇Sy<l，y<x; d )磊晶成長第二限制層13上於該作用層1 2上，其係爲p 型A1XGa ^ In P材質；實際上，前述成長於基板1〇上 之三層，依其作用而言，可視爲發光二極體裝置之真正 作用層，其完成後如第1圖所示。 e )黏合（b ο n d i n g ) —透明視窗層1 4於該第二限制層1 3上， 其中該視窗層1 4已被證實爲可增加LED之發光效率，且 其厚度越厚，效果越佳。在一實施例中，透明視窗層14 之厚度係大於1 00微米。前述之黏合動作，其係以晶圓 黏合（wafer bonding)方式施行。其中，包括在該黏合視 窗層步驟中提高溫度，以獲得較低之連接電阻；再者， 包括在該黏合視窗層步驟中施加壓力至待黏合處，以達 成均勻之黏合，其完成後如第2圖所示。此視窗層1 4除 了透明之外，更具有低電阻，使LED之電流密度平均分 佈而不會產生部分電流密度過度集中之現象，進而增加 發光效率。 f )移除半導體基板1 〇，其係在黏合透明視窗層丨4之後，以 化學蝕刻方式施行，其完成後如第3圖所示。因半導體 基板1 0本身材質和顏色關係，會吸收PN接面作用層1 2 發出的光線，故將基板1 0使用化學蝕刻移除，可使亮度 增力口。 g)成長一保護層（passive layer)15，其係爲 GaP 或 GaAsP 材質或導電性氧化物諸如I TO，成長於該發光二極體晶片 之被移除基板1 0側，其完成後如第4圖所示。此保護層 之功用，肇因於PN接面使用含鋁（A 1 )之材料造成在空氣 中之不穩定現象。 h )形成金屬電氣銲墊，其係位於該透明視窗層1 3及保護層 1 5上，一般爲圓形或類似形狀，供電氣引線銲接用。 本發明之目的在於發光二極體（LED )，包括； a)—半導體基板10，在一實施例中其係爲η型GaAs材質， 其厚度大於150微米（//m); b ) —第一限制層1 1，其係以磊晶方式成長在該基板1 〇上， 在一實施例中其係爲η型AlxGai.x In P材質，厚度約爲 800 奈米（nm)，0< xg 1 ; c) 一作用層12’其係以嘉晶方式成長在該第一限制層11上 ，在一實施例中其係爲i型A 1 y G a :. y Iη P材質，厚度約 爲 500 奈米（nm)’ 〇$y<i，y<x; 1221676 d ) —第二限制層1 3，其係以磊晶方式成長在該作用層1 2上 ，在一實施例中其係爲P型AUGah In P材質，厚度約 爲 800 奈米（nm)，0<xSl; e ) —透明視窗層1 4，其係爲和該第二限制層1 3材質相異之 透明層，以晶圓黏合（wafer bonding)方式，黏合在該第 二限制層13上；在一實施例中其係爲p型GaP材質，厚 度係大於100微米（#m)。 f) 一保護層（passive layer)15，其係其係以磊晶或鑛膜方 式成長於該發光二極體晶片之被移除基板側； g ) —金屬電氣銲墊，位於該視窗層上覆蓋其一部份；以及 h)另一金屬電氣焊墊，位於該保護層上覆蓋其一部份。 在一較佳實施例中，半導體基板10爲GaAs材料製成 在另一較佳實施例中，該半導體基板1 0及第一限制層i i 爲P型材質，以及該第二限制層13與透明視窗層14爲^ 型材質。 在又一較佳實施例中，以磊晶方式成長在該第_限制層 11上的作用層12係藉i型A1 Ga In Ρ材料所組成之多重 量子井（Multi-Quantum Well)結構，其中該作用層丨2可以 配合於當該半導體基板10與第一限制層11爲 及該第二限制層1 3與透明視窗層1 4爲ρ型材質··亦可以配 合於當該半導體基板10與第一限制層11爲ρ型材質及該 第二限制層1 3與透明視窗層1 4爲η型材質。 惟，熟習於本項技術者應理解的是，該等實施例僅係用於 描繪本發明，而無須解讀爲限制本發明之範圍。應注意的 -10- 1221676 是’舉凡與該等實施例等效之修正及變化，均應視爲涵蓋 於本發明附錄申請專利範圍之範疇內。 (五）圖式簡單說明 第1圖爲顯示將PN接面作用層及相關層成長於半導體基板 上之發光二極體剖面圖； 第2圖爲顯示將透明視窗層形成於第1圖上之發光二極體 剖面圖； 第3圖爲顯,示將半導體基板自第2圖中移除後之發光二極 體剖面圖； · 第4圖爲顯示將保護層形成於第3圖中發光二極體晶片被 移除基板側之剖面圖； 主要元件代表符號說明： 、 . 1 〇 半導體基板 - Π 第一限制層 12 作用層 13 第二限制層 14 透明視窗層 15 保護層 -11-1221676 (1) Description of the invention: (1) The technical field to which the invention belongs The present invention relates to a light emitting diode (LED) and a method for manufacturing the same, and more particularly to a window layer with a window layer that is bonded by wafer bonding. Light-emitting diode. (2) Prior Technology Under the continuous development of various new technologies, light-emitting diode (LED) devices have become brighter and brighter, and their service life has been gradually increased, so they have a wider range of applications. In the early days, because the brightness of LEDs was affected by materials and wafer fabrication technology, and the scope of application was limited, there were many improvements to the wafer fabrication technology in an attempt to improve the brightness of the wafer to make it more widely used. For example, U.S. Patent No. 5 0 8 7 18, published on April 16, 1980, the patent case of "light-emitting diode with conductive window" invented by Robert M, Flether, etc. During the fabrication of the diode wafer, the PN junction interface layer of AlGalnP material is grown on the semiconductor substrate, and then a semiconductor window layer of a different material is overlaid on the PN junction interface layer. Among them, the semiconductor window layer has lower resistance than the active layer and a larger band gap than the active layer, so that the brightness of the wafer covering the window layer is improved. That is, this technology can indeed increase the brightness of the wafer of the light emitting diode wafer. However, the transparent window layer is produced by an epitaxial growth process, and its growth rate is about 10 micrometers / hour. For a transparent window layer with a thickness of more than 100 micrometers, it takes at least 10 hours, which is not economical in time. For example, U.S. Patent No. 5 3 7 6 5 8 0, published on February 27, 1983, 1221676, "A wafer bonding of light-emitting diode layers" patented by Fred A. Kish et al., It is epitaxially grown on the semiconductor substrate to grow the PN junction interface layer. After the transparent window layer is overlaid, the lower semiconductor substrate is removed by a chemical uranium etching method, and then the transparent substrate is bonded to the substrate using wafer bonding technology. PN interface on the action layer. This wafer bonding technology removes the light-absorbing substrate, thereby increasing the brightness of the wafer of the light emitting diode layer. However, in the wafer manufacturing process, the steps of removing the opaque light-absorbing substrate first and then bonding the transparent substrate will cause the wafer to have poor mechanical strength and be easily damaged during the manufacturing process. The shortcomings of the above conventional technologies are: the transparent window layer grown on the light-emitting diode layer wafer by epitaxy, its growth rate is too slow, and the economic efficiency is poor; after the semiconductor substrate is removed from the light-emitting diode wafer, the With the wafer bonding technology, there is a problem that the transparent substrate is bonded, which has poor mechanical strength and is easy to break. Therefore, in order to improve the above-mentioned defects, it is necessary to develop a better light-emitting diode manufacturing method and a light-emitting diode device made according to this method. (3) Summary of the Invention In view of the problems of the conventional technology, an object of the present invention is to provide a light emitting diode (LED) and a manufacturing method thereof. The method for manufacturing a light emitting diode (LED) of the present invention includes the following steps: providing a semiconductor substrate; Jiajing grows a first confining layer on the substrate; Jiajing grows an active layer On the first confinement layer; epitaxial growth of the second confinement layer on the active layer; bonding (b ο nding)-a transparent window layer on the second confinement layer, which is wafer bonding (wafer bonding) Performing; and removing the substrate, which is performed by chemical etching after bonding the 1221676 window layer; growing a protective layer (passive 1 ayer) 'which is grown on the removed substrate side of the light-emitting diode wafer; A metal electrical pad is formed on the transparent window layer to cover a portion thereof; and a metal electrical pad is formed on the protective layer to cover a portion thereof. The manufacturing method as described above includes raising the temperature in the step of bonding the window layer to obtain a lower connection resistance; meanwhile, applying pressure to the portion to be bonded in the step of bonding the window layer to achieve uniform bonding. Furthermore, the thickness of the window layer is greater than 100 microns. The manufacturing method as described above, wherein the material used for the protective layer does not contain an aluminum element (A 1). The light emitting diode (LED) of the present invention includes: a semiconductor substrate; a first confinement layer, which is made of epitaxial Growing on the substrate; an active layer, which is grown on the first confinement layer in an epitaxial manner; a second constraining layer, which is grown on the active layer in an epitaxial manner; a transparent window layer, It is a transparent layer with a material different from that of the second limiting layer, and is 'bonded' to the first limiting layer by wafer bonding; a protective layer (passive 1 ayer), which is epitaxial Or coated on the light-emitting diode wafer's removed substrate side; a metal electrical pad is located on the window layer to cover a part of it; and another metal electrical pad is located on the protective layer to cover it a part. The manufacturing method as described above, wherein the thickness of the transparent window layer is greater than 1000 microns. Furthermore, the material used for the protective layer does not contain aluminum element (A1) 1221676 (IV) Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings, wherein the same symbols represent the same elements. An object of the present invention is to provide a method for manufacturing a light emitting diode (LED), and particularly a method for stacking a transparent window layer on an LED chip. Among them, the window layer has been proven to increase the light emitting efficiency of the LED, and the thicker the thickness, the better the effect. The aforementioned manufacturing method includes the following steps: a) providing a semiconductor substrate 10, which is made of n-type GaAs material; b) Jiajing grows a first confining layer on the semiconductor substrate 10, which is η Type AlxGa ^ x In P material, 0 <xSl; c) epitaxial growth an active layer 12 on the first limiting layer 11, which is i-type AlyGa ^ y In P material, 〇Sy < l, y <x; d) epitaxial growth on the second limiting layer 13 on the active layer 12, which is a p-type A1XGa ^ In P material; in fact, the aforementioned three layers grown on the substrate 10, according to which In terms of function, it can be regarded as the real active layer of the light-emitting diode device, and its completion is shown in FIG. 1. e) Adhesion (b ο nding)-a transparent window layer 14 on the second limiting layer 13, wherein the window layer 14 has been proven to increase the light emitting efficiency of the LED, and the thicker the thickness, the better the effect . In one embodiment, the thickness of the transparent window layer 14 is greater than 100 microns. The aforementioned bonding operation is performed by wafer bonding. This includes raising the temperature in the step of bonding the window layer to obtain a lower connection resistance; further, applying pressure to the portion to be bonded in the step of bonding the window layer to achieve uniform bonding, and the completion is as described in the first step. Figure 2 shows. In addition to being transparent, this window layer 14 also has low resistance, so that the current density of the LEDs is evenly distributed without causing partial current density to be excessively concentrated, thereby increasing luminous efficiency. f) The semiconductor substrate 10 is removed, which is performed by chemical etching after the transparent window layer 4 is adhered, as shown in FIG. 3 after completion. Because the material and color relationship of the semiconductor substrate 10 itself can absorb the light emitted from the PN interface active layer 12, removing the substrate 10 by chemical etching can increase the brightness. g) A passive layer 15 is grown, which is made of GaP or GaAsP material or a conductive oxide such as I TO, and is grown on the removed substrate 10 side of the light-emitting diode wafer. Figure 4 shows. The function of this protective layer is due to the instability in the air caused by the use of aluminum (A 1) containing materials on the PN junction. h) forming a metal electrical pad, which is located on the transparent window layer 13 and the protective layer 15 and is generally circular or similar in shape, and is used for welding power supply leads. The object of the present invention is a light-emitting diode (LED), including: a) a semiconductor substrate 10, which is an n-type GaAs material in one embodiment, and has a thickness greater than 150 micrometers (// m); b)-the first A confinement layer 11 is epitaxially grown on the substrate 10. In one embodiment, it is made of η-type AlxGai.x In P material and has a thickness of about 800 nanometers (nm), 0 < xg 1; c) An active layer 12 'is grown on the first confinement layer 11 in a Jiajing manner. In one embodiment, it is an i-type A 1 y G a:. Y Iη P material, with a thickness of about 500 nanometers (nm) '〇 $ y < i, y <x; 1221676 d)-a second confinement layer 13 which is epitaxially grown on the active layer 12 and in an embodiment it is It is a P-type AUGah In P material with a thickness of about 800 nanometers (nm), 0 <xSl; e)-a transparent window layer 14 which is a transparent layer different from the material of the second limiting layer 13 and is A wafer bonding method is used to adhere to the second limiting layer 13. In one embodiment, it is made of p-type GaP and has a thickness greater than 100 micrometers (#m). f) a protective layer (passive layer) 15, which is grown on the removed substrate side of the light-emitting diode wafer in an epitaxial or mineral film manner; g) a metal electrical pad on the window layer Cover a part of it; and h) another metal electrical pad on the protective layer covering a part of it. In a preferred embodiment, the semiconductor substrate 10 is made of GaAs material. In another preferred embodiment, the semiconductor substrate 10 and the first limiting layer ii are P-type materials, and the second limiting layer 13 is transparent. The window layer 14 is made of ^ type material. In another preferred embodiment, the active layer 12 grown on the _ constrained layer 11 in an epitaxial manner is a multi-quantum well structure composed of an i-type A1 Ga In P material, wherein The active layer 2 can be used when the semiconductor substrate 10 and the first confinement layer 11 are formed, and the second confinement layer 13 and the transparent window layer 14 are p-type materials. It can also be used when the semiconductor substrate 10 and The first restriction layer 11 is a p-type material, and the second restriction layer 13 and the transparent window layer 14 are an n-type material. However, those skilled in the art should understand that these embodiments are only used to describe the present invention, and need not be interpreted as limiting the scope of the present invention. It should be noted that -10- 1221676 is ‘for all amendments and changes equivalent to these embodiments, all shall be deemed to be covered by the scope of patent application of the appendix of the present invention. (V) Brief description of the diagram. The first diagram is a cross-sectional view of a light-emitting diode in which a PN interface layer and a related layer are grown on a semiconductor substrate. The second diagram is a diagram showing the formation of a transparent window layer on the first diagram. Cross-sectional view of a light-emitting diode; FIG. 3 is a cross-sectional view of a light-emitting diode after a semiconductor substrate is removed from FIG. 2; FIG. 4 is a view showing a protective layer formed in FIG. Cross section of the substrate on which the polar body wafer is removed; the main components are represented by symbols: 1. 10 semiconductor substrate-Π first limiting layer 12 active layer 13 second limiting layer 14 transparent window layer 15 protective layer -11-