201227973 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種具新穎雙金屬陽極的蕭基能障二極 體，特別是指一種可有效調變肖特基能障高度，具有高崩潰電 壓、低漏電流密度及低順向壓降的蕭基能障二極體，以達到 實現最低功率損耗蕭基二極體之可能。 【先前技術】 Φ 蕭特基二極體待改善的問題，蕭特基二極體的基本結 構’只要在高掺雜（heavily doped)的N型石夕晶片上長一層 大約十微米低摻雜（lightly doped )N型薄膜，上下再蒸鍵上 金屬電極。金屬與低摻雜N型半導體行成蕭基接面（Sch〇ttky contact)，金屬與高摻雜N型半導體行成歐姆接面（〇hmic contact)。一般而言，蕭特基二極體要有最小功率損耗，須 使其同時具有最低之順向壓降及最小反向飽和電流操作。然 •而降低順偏壓降及減少反向飽和電流在同一二極體是背道 而驰的兩個目標。在整片石夕晶片上，元件與元件總要分開， 通常是產生二氧化梦來達到這個目的’俗稱為場氧化層 (field 〇Xlde)，我們模擬時在這樣的元件結構上加上反偏 電壓(reverse bias) ’也就是說蕭基接面的電極加正電壓， I姆接面的電極加負電麼， 結果在電極結束及元件邊緣接面201227973 VI. Description of the Invention: [Technical Field] The present invention relates to a Schottky barrier diode having a novel bimetal anode, and more particularly to an effective modulation of a Schottky barrier height with high collapse Voltage, low leakage current density and low forward voltage drop of the Schottky barrier diode to achieve the lowest power loss of the Schottky diode. [Prior Art] Φ Schottky diode to be improved, the basic structure of the Schottky diode is as long as a layer of about ten micrometers is low on a highly doped N-type slab wafer. (lightly doped) N-type film, steamed up and down on the metal electrode. The metal and the low-doped N-type semiconductor are arranged in a Schottky junction, and the metal and the highly doped N-type semiconductor are in an ohmic contact. In general, Schottky diodes must have minimal power loss and must have the lowest forward voltage drop and minimum reverse saturation current operation. However, reducing the forward bias drop and reducing the reverse saturation current are the opposite goals in the same diode. On the entire Shixi wafer, the components and components are always separated, usually to create a dioxide dream to achieve this purpose. This is commonly known as the field oxide layer (field 〇Xlde). We add a reverse bias voltage to such a component structure during simulation. (reverse bias) 'That is to say, the electrode of the Xiaoji junction is positively charged, and the electrode of the junction of I is negatively charged. The result is at the end of the electrode and the junction of the edge of the component.
度通常也是崩潰機制發生所在之處， 70仵結構裡，高電場密 因為載子在高電場的地 201227973 方被加速產生兩動能，古私执认甚 同動尨的載子撞擊原子與原子間的 共價鍵，當共價鍵被撞斷時便產生新的载子，新的載子又 被高電場加速產生高叙At Jli JS 7 & 王巧動犯，撞擊原子與原子的共價鍵再產生 新的載子，這蘇祖& # 4 β & 種現象稱為雪朋倍增（avaUnche 1 lplication)。雪崩倍增現象—產生瞬間造成相當大的 反偏電流，稱為朋潰(breakd〇wn)。如何才能達到加大反偏 電廢而兀件仍然不會崩潰呢？這是研究高功率元件人員絞 盡腦汁止圖要解決的問題，因此文獻上有相當多有關這方面 主題的响文報導。目前學術界大都趨向以碳化矽⑻。晶片 來取代石夕晶片，因碳化石夕具有寬能隙（wideband_gap)、高 導電率的特性，的確產生了良好的效果，但在成本上是以石夕 晶片為材料之一百倍，成本太高很難商業化。 【發明内容】 本發明之目的即在於提供一種在矽晶片上製作具有雙金 屬陽極的蕭基能障二極體’為使用雙金屬結構與複晶石夕護環 等結構以提升蕭基能障二極體之各項物理特性，其中雙金屬結 構乃利用低功函&電極肖高功函數電極兩種金屬同時沉積於 主動區内’調整兩者金屬之面積比來改變肖特基能障高度大 小，至於複晶矽護環之大小也可微調肖特基能障高度。基本上 雙金屬結構可使順向壓降因大部份電流流經低功函數金屬而 下降，反偏電流因高功函數之蕭基位障夾止效應而下降，以達 到降低功率損耗之目的。 201227973 ， / 本發明之次一目的係在於提供一種具雙金屬陽極的蕭基 能障二極體，包含調變肖特基能障高度之雙金屬陽極與降低 表面電場型的複晶矽護環等結構。 本發明之另一目的係在於提供一種具雙金屬陽極的蕭基 能障二極體，具備可調變肖特基能障高度，藉由調整高低功函 數之雙金屬面積比與複晶矽護環的寬度可有效地調變順向電 壓值與蕭基位障之高度等物理特性，其中雙金屬結構之主要特 Φ徵係將傳統結構之單一金屬以適當相間之高低位障金屬取 代，並利用兩者之面積比調變控制整體能障高度。此一結構之 順向壓降可藉大部份順向電流流經低位障區而下降，反偏電流 可藉高蕭基能障產生空乏區造成夾擠效應而降低，同時在順、 反偏操作獲得降低功率損耗之目的；增加複晶石夕護環的深度以 加強崩潰電壓值與降低漏電流密度及低順向偏壓等物理特性。 本發明之又一目的係在於提供一種結合雙金屬陽極與複 籲晶石夕護環的蕭基能障二極體’不僅可調變宵特基能障高度以 防止蕭基能障二極體之邊緣崩潰，更可抑制蕭基能障二極體 表面之漏電流。 可達成上述發明目的之具雙金屬陽極的蕭基能障二極 體’包括於基材第-區域上形成—n型遙晶層，及利用濕氧 化製程在該n型蟲晶層上長成具有圖樣表面的場氧化層，選 擇性地在場氧化層區域上方與所暴露出晶層之處生成 一複晶石夕層，對複晶石夕層的—部份表面上以低能量㈣子佈 201227973 •植來製作具有深度的主動區與具有寬度的複晶料環，該主 動區係具有雙金屬陽極，而該基材的第—區域具有陰極導電 層，其中該雙金屬陽極為主動區突出有低功函數電極及形成 在低功函數電極與所暴露出主動區上方的高功函數電極。 【實施方式】 請參閱圖-，本發明所提供之具雙金屬陽極的蕭基能障 二極體，主要包括有：一基板1、一場氧化層2、一複晶矽 護環3卜一低功函數電極4卜一高功函數電極42以及一陰 極導電層5所構成。 本發明為於基板i的第二區域利用濕氧化製程在該基板 1第二區域的η型蟲晶層12上長成具有圖樣表面的場氧化層 2,且選擇性地在場氧化層2區域上方與所暴露出n型蟲晶Degree is usually also where the collapse mechanism occurs. In the 70仵 structure, the high electric field is dense because the carrier is accelerated at the high electric field 201227973 to generate two kinetic energy. The ancient and the identifiable carrier is striking between the atom and the atom. The covalent bond, when the covalent bond is broken, generates a new carrier, and the new carrier is accelerated by the high electric field to produce the high-status At Jli JS 7 & Wang Qiao, committing the covalent interaction between the atom and the atom. The key then generates a new carrier, which is called the avaUnche 1 lplication. The avalanche multiplication phenomenon - the generation of a relatively large reverse bias current, called breakd〇wn. How can we achieve an increase in anti-biasing and waste? This is a problem to be solved in the study of high-power component personnel. Therefore, there are quite a lot of reports on this topic in the literature. At present, most academic circles tend to carbonize (8). The wafer replaces the Shixi wafer. Because of the wide bandgap and high conductivity of the carbonized stone, it has produced good results, but the cost is one hundred times that of the Shixi wafer. The cost is too high. High is difficult to commercialize. SUMMARY OF THE INVENTION An object of the present invention is to provide a Schottky barrier diode having a bimetal anode on a germanium wafer, which is a structure using a bimetal structure and a polycrystalline stone guard ring to enhance the base energy barrier. The physical properties of the diode, in which the bimetal structure is changed by the low work function &electrode; the high energy function electrode is simultaneously deposited in the active region to adjust the area ratio of the two metals to change the height of the Schottky barrier As for the size of the polycrystalline ring, the Schottky barrier height can also be fine-tuned. Basically, the bimetal structure can reduce the forward voltage drop due to the flow of most of the current through the low work function metal, and the reverse bias current decreases due to the high-function function of the Schottky barrier effect to achieve the purpose of reducing power loss. . 201227973, / The second object of the present invention is to provide a Schottky barrier diode having a bimetal anode, a bimetallic anode comprising a modulated Schottky barrier height, and a polycrystalline ruthenium ring having a reduced surface electric field type And other structures. Another object of the present invention is to provide a Schottky barrier diode having a bimetal anode, having an adjustable variable Schottky barrier height, by adjusting a bimetal area ratio of high and low work functions and a complex crystal protection The width of the ring can effectively modulate the physical properties such as the forward voltage value and the height of the Xiaoji barrier. The main characteristic of the bimetal structure is to replace the single metal of the conventional structure with the appropriate level of high and low barrier metal. The overall energy barrier height is controlled by the area ratio modulation of the two. The forward voltage drop of this structure can be reduced by the flow of most of the forward current flowing through the low barrier zone, and the reverse bias current can be reduced by the pinch-in effect caused by the high-short energy barrier, and at the same time, the forward and reverse biases are The operation achieves the purpose of reducing power loss; increasing the depth of the polycrystalline stone guard ring to enhance physical properties such as breakdown voltage value and reduction of leakage current density and low forward bias. Another object of the present invention is to provide a Schiff base barrier diode that combines a bimetallic anode and a complexite stone guard ring to not only adjust the height of the barrier energy barrier to prevent the Schindler barrier diode. The edge collapses, and it can suppress the leakage current of the surface of the Xiaoji energy barrier diode. The Schiffon barrier diode having a bimetal anode capable of achieving the above object includes forming an n-type crystal layer on the first region of the substrate, and growing on the n-type crystal layer by a wet oxidation process. a field oxide layer having a patterned surface, selectively forming a polycrystalline crust layer above the exposed oxide layer region and a low energy (four) sub-layer on the surface of the polycrystalline stone layer Cloth 201227973 • Planting to produce a deep active zone with a width of a compound ring having a bimetallic anode, and a first region of the substrate having a cathode conductive layer, wherein the bimetallic anode is an active region A low work function electrode is highlighted and a high work function electrode formed between the low work function electrode and the exposed active region is formed. [Embodiment] Please refer to the figure - the Xiaoji barrier diode with bimetal anode provided by the invention mainly comprises: a substrate 1, an oxide layer 2, a polycrystalline ring, and a protective ring. The work function electrode 4 is composed of a high work function electrode 42 and a cathode conductive layer 5. In the present invention, the second region of the substrate i is grown into a field oxide layer 2 having a patterned surface on the n-type crystal layer 12 of the second region of the substrate 1 by a wet oxidation process, and selectively in the field oxide layer 2 region. Above and exposed n-type insect crystal
層12之處生成一複晶矽層3’對複晶矽層3的一部份表面上 以低能量娜子佈植來製作主動區.32與具有寬度W的複晶 梦護環(為由複晶⑦層3所形成之複晶料環川，該主 動區32係具有雙金屬陽極，而該基板j 的 一區域具有陰極 導電層5’其中該雙金屬陽極為主動區32突出有低功函數電 極41及形成在低功函數電極41與所暴露出主動區κ上方 41與高功函數 ’而該複晶矽護 的高功函數電極42，藉由調整低功函數電極 電極42之面積比來改變肖特基能障高度大小 環31之大小也可微調肖特基能障高度。 該第一區域具有一 該基板1具有第一區域及第二區域 201227973 <1〇〇>之第一晶向，該第二區域係具有_<ηι>之第二晶向該 第一區域為具有高濃度η型0+)摻雜物的基材11，第二區域為 位於基材11上之具有低濃度η型（η_)摻雜物的η型磊晶層12， 且該基板1的電阻值較一般基板丨為低，故可增加順向偏壓的 工作範圍； 該場氧化層2(場氧化矽層）為利用濕氧化製程在該基板】 的11型磊晶層12上長成具有圖樣表面的場氧化層2,該場氧 φ 化層2為形成於基板1上方約500至600奈米（nm)之氧化矽層； 將利用濕式姓刻技術定義出場氧化層2之圖樣，以利後續之製 程。 該複晶矽護環31為選擇性地在場氧化層2區域上方與所 暴露出η型磊晶層12之處生成一複晶矽層3，對複晶矽層3 的°卩伤表面上以低能量硼離子佈植來製作具有深度η的主 動區32與具有寬度W的複晶矽護環3 1。係先以低壓化學汽 ❿相沈積法（Low Pressure Chemical Vapor Deposition; LPCVD)選 擇性地在場氧化層2區域上方與所暴露出n龍晶層i2之 處形成厚度約為300奈米之複晶石夕層3(複晶石夕膜（p〇ly_Si))，接 著於複晶石夕層3中央處以低能量蝴離子（二氟化领（bf2+)離子） 佈植以製作具有深度Η的主動區32與具有寬度w的複晶石夕護 環31 ’其硼離子佈植能量約為1〇〇仟電子伏特，並以⑺“個 離子/平方公分的劑量植人複晶_層3巾，再以退火爐在95〇it 的/皿度退《退火時間為2〇至80分鐘，然後製作具有深度Η 201227973 的主動區32與具有寬度W的複晶矽護環3卜複晶矽層3可抑 制場氧化層2之表面電場，降低漏電流密度，亦即提升崩潰電 壓值； 該低功函數電極41與高功函數電極42為主動區32所具 有的雙金屬陽極，該低功函數電極41為基板丨清洗乾淨後，At the layer 12, a polycrystalline germanium layer 3' is formed on a part of the surface of the polycrystalline germanium layer 3 with low-energy nano-sheets to form an active region. 32 and a polycrystalline dream ring with a width W (for The composite crystal layer formed by the polycrystalline layer 7 has a bimetal anode, and a region of the substrate j has a cathode conductive layer 5', wherein the bimetal anode has an active region 32 protruding with low work The function electrode 41 and the high work function electrode 42 formed on the low work function electrode 41 and the exposed active region κ41 and the high work function' and the double crystal function are adjusted by adjusting the area ratio of the low work function electrode electrode 42 The Schottky barrier height can also be fine-tuned to change the size of the Schottky barrier height ring 31. The first region has a first region and a second region 201227973 <1〇〇> In a crystal orientation, the second region has a substrate 11 having a _<ηι> second crystal toward the first region being a high concentration η-type 0+) dopant, and the second region is on the substrate 11. The n-type epitaxial layer 12 having a low concentration of n-type (η_) dopant, and the substrate 1 has a higher resistance value than a general base丨 is low, so the operating range of the forward bias can be increased; the field oxide layer 2 (field oxide layer) is a field having a patterned surface on the 11-type epitaxial layer 12 of the substrate by a wet oxidation process. Oxide layer 2, the field oxygen φ layer 2 is a ruthenium oxide layer formed on the substrate 1 about 500 to 600 nanometers (nm); the pattern of the field oxide layer 2 will be defined by the wet-type technique to facilitate subsequent Process. The polysilicon guard ring 31 selectively forms a polycrystalline germanium layer 3 above the field oxide layer 2 region and the exposed n-type epitaxial layer 12, on the surface of the polycrystalline germanium layer 3 The active region 32 having a depth η and the polysilicon guard ring 31 having a width W are formed by low energy boron ion implantation. The low pressure chemical vapor deposition (LPCVD) method is used to selectively form a polycrystalline layer having a thickness of about 300 nm above the exposed field layer 2 and the exposed n-layer layer i2 by a low pressure chemical vapor deposition (LPCVD) method. Shixia layer 3 (p复ly_Si), followed by low-energy butterfly ions (difluorinated collar (bf2+) ions) at the center of the polycrystalline stone layer 3 to create a proactive deep enthalpy The region 32 and the polycrystalline cristobalite ring 31' having a width w have a boron ion implantation energy of about 1 〇〇仟 electron volt, and implant a polycrystalline _ layer 3 towel at a dose of (7) ions/cm 2 . Then, in the annealing furnace, the annealing time is 2〇 to 80 minutes, and then the active region 32 having the depth Η 201227973 and the polycrystalline ruthenium guard ring 3 having the width W can be suppressed. The surface electric field of the field oxide layer 2 reduces the leakage current density, that is, increases the breakdown voltage value; the low work function electrode 41 and the high work function electrode 42 are bimetal anodes of the active region 32, and the low work function electrode 41 is After the substrate is cleaned,
以電子搶（E-gun)或蒸鍍機（Evaporation)在主動區32鍍上一突 出的低功函數電極41 |，再以微影、㈣技術定義出低功函 數電極之電極圖樣，該突出的低功函數電極41與相鄰的低 功函數電極41間距為3微来㈣以下其材料係選自於由鈦、 鶴、錄、絡及其各種組合所組成之群組； 該高功函數電極42為主動區32突出有低功函數電極^ 及形成在低功函數電極41與所暴露出主動區32上方的高功 函數電極42’為以電子搶或蒸鍍機在主動區32鍍上，高功函 數電極42為形成蕭基位障之材料，其材料係選自於由金、白 金、鈀、白金矽化物及其各種組合所組成之群組。 該陰極導電層5為形成於基板丨的第__區域為以電子 搶或蒸錢機在基板1的基材11社，該陰極導電層5為可與 基板1 #面的η型摻雜物的基材u形成歐姆接觸之材料，其 陰極^電層5材料係選自於_，合金及其所組成之群組、。 咕參閱圖二為本發明其較佳實施例之製程步驟： 步驟一， 物的基树1 1， 請參閱圖二a，該基板1由具有高濃度η型摻雜 和位於基材η上之具有低濃度„型摻雜物的η 201227973 型遙晶層12所組成，當其4cr，士 土板1月洗完畢後，基板丨其摻雜物 擴散係恤度啟動製程’亦即溫度愈高，則有愈多換雜物擴散發 生，故為達合理之氧化物厚度，同時限制播雜物之擴散，以濕 氧化製程較佳，當基板1置於高溫爐内以約H)5(TC及利用濕氧 化製程在該基板i的n型蟲晶層12上長成具有圖樣表面的 場氧化層2(為於場氧化層2上用微影，刻技術定義出後續步 驟中’形成場氧化層2與複晶石夕護環31等結構所需的形狀與 _開口），本發明為利用濕氧化製程長成熱氧化物，藉以將摻雜物 擴散效應降至最低，同時維持合理之氧化物長成速率以形成一 層厚度約為400至500奈米之場氧化層2。 步驟―，睛參閱圓二b，冑洗基板1後’以低壓化學汽相 ^#^(Low Pressure Chemical Vapor Deposition, LPCVD)^ # 性地在場氧化層2區域上方與所暴露出n型蟲晶層i2之處 成厚度约為300奈米之複晶石夕層3(複晶石夕膜（p〇iy_si)); 步驟—，睛參閲圖二C，接著於複晶石夕層3的-部份表面 ^或中央處進行娜子（二氟化娜子）之離子佈植將不必要的 场氧化層2與複晶㈣3去除’以定義製作出此蕭基能障二極 體之主動區32與由複晶石夕層3所形成之複晶石夕護環31，且該 複s曰矽濩環31具有一定的寬度w，該硼離子以能量約為1〇。 仟電子伏特，並以，個離子/平方公分的冑量植人基板i中； 製作具有寬度W的複晶矽護環3卜為將基板i置於高溫 爐中’以950°C的溫度退火、退火時間為2〇至8〇分鐘，退火 201227973 、( .· 後使獨離子由複晶石夕層3擴散至η型层晶層u +，分別形成 尚濃度P型摻雜區域33的複晶矽護環3丨，請參照表一，當複 晶矽護環31的寬度w增加至一定範圍内，將使蕭基能障二極 體的朋潰電壓稍微提高，漏電流值降低，蕭基位障之高度増 加’進而使肖特基能障高度有可調變之範圍； 參照附件1為蕭基能障二極體之電流_電壓特性曲線圖，此 蕭基能障二極體經由95〇°c退火，2〇分鐘的高溫爐反應時間， φ 製程參數為複晶矽護環31寬度W為50微米（"m)，發現⑷資 料線在順向偏壓的特性中，其理想因子（Ideal Factor)約為 1 _07，同時存在有7個對數刻度之工作範圍；而（b)資料線則為 此蕭基能障二極體崩潰電壓之特性，發現蕭基能障二極體之崩 潰電壓約為145伏特，此時反向飽和電流約為8 7微安培/平方 公分（/i A/cm2)。另外，當改變複晶矽護環31的寬度w時，將 對蕭基能障二極體之反向崩潰電壓與漏電流密度有所影響（見 φ 表一以Au*陽極金屬接觸之說明），也就是說當寬度w愈寬 時’朋潰電壓會賴微提高，同時反向漏電流也變小，蕭基位障 咼度也增加’進而可調變蕭基位障之高度。 表一 肖特基能 障高度 (eV) 複晶矽護環 之寬度 m) 順向電流密度 為1 A/cm2時之 順向偏壓 (V) 逆向偏壓為V 時之漏電流 密度 (β A/cm2) 崩潰電壓 (V) 18 0.45 0.764 8.5 131.1 26 0.48 0.771 8.3 136.4 34 0.52 0.776 7.2 140.5 50 0.56 0.784 6.9 145.7 步驟四，請參閱圖二d’於主動區32製作低功函數電極41， 為將基板1清洗乾淨後，以電子槍或蒸鍍機在主動區32鍍上一 201227973 低功函數電極41後’以微影、蝕刻技術定義出低功函數電極41Electrode (E-gun) or evaporation machine (Evaporation) is plated with a protruding low work function electrode 41 in the active region 32, and then the electrode pattern of the low work function electrode is defined by the lithography and (4) technique. The low work function electrode 41 and the adjacent low work function electrode 41 are spaced apart by 3 microseconds (4). The material is selected from the group consisting of titanium, crane, record, network and various combinations thereof; the high work function The electrode 42 has a low work function electrode protruding from the active region 32 and a high work function electrode 42' formed above the low work function electrode 41 and the exposed active region 32 for plating on the active region 32 by an electron grab or vapor deposition machine. The high work function electrode 42 is a material forming a Schottky barrier, and the material thereof is selected from the group consisting of gold, platinum, palladium, platinum telluride, and various combinations thereof. The cathode conductive layer 5 is formed in the __ region of the substrate 为 by an electronic rush or a money hopper on the substrate 11 of the substrate 1, and the cathode conductive layer 5 is an n-type dopant which can be on the surface of the substrate 1 The substrate u forms a material of ohmic contact, and the material of the cathode layer 5 is selected from the group consisting of _, an alloy and a group thereof. 2 is a process step of a preferred embodiment of the present invention: Step 1, the base tree 1 of the object, see FIG. 2a, the substrate 1 is doped with a high concentration of n-type and located on the substrate η. η 201227973 type telecrystal layer 12 with low concentration „type dopants, when its 4cr, the soil board is washed in January, the substrate 丨 its dopant diffusion enthalpy start process', that is, the higher the temperature The more the diffusion of the impurity occurs, the reason is to achieve a reasonable oxide thickness, and at the same time limit the diffusion of the soot, the wet oxidation process is better, when the substrate 1 is placed in a high temperature furnace to about H) 5 (TC And using a wet oxidation process to form a field oxide layer 2 having a patterned surface on the n-type seed layer 12 of the substrate i (for lithography on the field oxide layer 2, the engraving technique defines a subsequent field oxidation) The shape and opening of the structure of the layer 2 and the polycrystalline stone guard ring 31, etc., the present invention uses a wet oxidation process to grow into a thermal oxide, thereby minimizing dopant diffusion effects while maintaining reasonable oxidation. The object grows at a rate to form a field oxide layer 2 having a thickness of about 400 to 500 nm. Step ─, see the circle b, after washing the substrate 1 'Low Pressure Chemical Vapor Deposition (LPCVD) ^ # ((Low Pressure Chemical Vapor Deposition, LPCVD) ^ above the field oxide layer 2 area and exposed n-type insects The crystal layer i2 is formed into a polycrystalline stone layer 3 (p〇iy_si) having a thickness of about 300 nm; steps - the eye is shown in Fig. 2C, followed by the polycrystalline layer 3 - Partial surface ^ or at the center of the ion implantation of Nazi (Difluoride) to remove the unnecessary field oxide layer 2 and the polycrystal (4) 3 'to define the fabrication of the Xiaoji barrier diode The active region 32 and the polycrystalline cristobalite ring 31 formed by the polycrystalline crust layer 3, and the complex sigma ring 31 has a certain width w, and the boron ion has an energy of about 1 〇. And implanted in the substrate i with an ion/square centimeter of enthalpy; making a double crystal reticle with a width W 3 to place the substrate i in a high temperature furnace 'annealing at 950 ° C, annealing time 2〇 to 8〇 minutes, annealing 201227973, (.· then diffusing the unique ions from the polycrystalline layer 3 to the n-type layer u +, respectively forming a P-type doped region 33 For the double crystal 矽 guard ring 3丨, please refer to Table 1. When the width w of the polysilicon 矽 guard ring 31 is increased to a certain range, the voltage of the Xiaoji energy barrier diode will be slightly increased, and the leakage current value will be reduced. The height of the Xiaoji barrier is increased, which in turn makes the Schottky barrier height adjustable; refer to Annex 1 for the current-voltage characteristic of the Xiaoji barrier diode, the Xiaoji barrier diode. Annealing through 95 ° °c, 2 〇 high temperature furnace reaction time, φ process parameter is the width W of the polycrystalline silicon ring 31 is 50 μm ("m), and found that (4) the data line is in the forward bias characteristic, The ideal factor (Ideal Factor) is about 1 _07, and there are 7 logarithmic scale working ranges; and (b) the data line is the characteristic of the Xiaoji barrier diode breakdown voltage, and it is found that Xiaoji Energy Barrier II The breakdown voltage of the polar body is about 145 volts, and the reverse saturation current is about 87 microamperes per square centimeter (/i A/cm 2 ). In addition, when the width w of the polysilicon guard ring 31 is changed, the reverse breakdown voltage and the leakage current density of the Schottky barrier diode will be affected (see φ Table 1 for the Au* anode metal contact description). That is to say, when the width w is wider, the voltage of the 'bumping voltage will increase slightly, and the reverse leakage current will also become smaller, and the degree of the barrier of the base will also increase, which in turn will adjust the height of the base block. Table 1 Schottky barrier height (eV) The width of the polysilicon guard ring m) Forward bias voltage at a forward current density of 1 A/cm2 (V) Leak current density at a reverse bias voltage of V (β A/cm2) Crash voltage (V) 18 0.45 0.764 8.5 131.1 26 0.48 0.771 8.3 136.4 34 0.52 0.776 7.2 140.5 50 0.56 0.784 6.9 145.7 Step 4, please refer to Figure 2 d' to create low work function electrode 41 in active region 32, After the substrate 1 is cleaned, a 201227973 low work function electrode 41 is plated on the active region 32 by an electron gun or an evaporation machine, and the low work function electrode 41 is defined by lithography and etching technology.
圖樣後，以構成為蕭基能障二極體之第一陽極，該低功函數電 極41其材料係選自於由鈦、鎢、錄、鉻及其組合之群組。 步驟五，請參閱圖二e，於主動區32製作高功函數電極 42，為在主動區32突出的低功函數電極41與所暴露出主動 區32上方以電子搶或蒸鍍機鍍上一高功函數電極42，以構成 為蕭基能障二極體之第二陽極’該高功函數電⑯42其材料係 選自於由金、白金、鈀、白金矽化物及其纽合之群組，並使高 功函數電極42為足以形成蕭基位障之材料。 步驟六’於基板！的另-表面製作陰極導電層5，為以< 子搶或蒸鍍機在基!的底部（第—區域具有η型換雜物的』 材⑴錢上陰極導電層5,以構成為蕭基轉二極體之陰極㈠ 陰極導電層5為可與基板〗形成歐姆接觸之材料，其材料制 自於由銀、銘、紹合金。 二極體其物理特性對不 圖’由圖中可知有效肖 小變小而變大，複晶矽 如附件2所示，本發明的蕭基能障 同雙金屬（Ti/Au)陽極面積比大小之曲線 特基能障高度隨著雙金㈣極面積比大 12 201227973 〆〃護環31的接面深度Η愈深亦同樣變大（見表一說明）。換言之， 雙金屬陽極面積比愈小與複晶矽護環31接面深度η愈深，崩 潰電壓則有愈高之趨勢，對雙金屬結構可調變適當之肖特基能 障咼度與可接受之高溫爐反應時間而言，是一項不錯之製程選 擇。本發明為淬取約50組蕭基能障二極體所測得之平均值， 因此有一定程度之製程可靠度。 藉由上述之結構組成及實施例，本發明所製作的蕭基能障 φ 二極體與習用相較具有下列較佳之物理特性： 高崩潰電壓值大於145伏特（V);順向電流大於丨安培/平方 公分(A/cm2); 漏電流密度小於8·7微安培/平方公分（以A/cm2); 順向電流為1安培/平方公分時，順向偏壓的範圍可為〇 45到 〇·56伏特； 而肖特基能障高度可調範圍為0.764到0.554電子伏特（eV)。 # 因此結合雙金屬陽極與複晶矽護環3 1，不僅可調變肖特基 此障面度以防止蕭基能障二極體之邊緣崩潰，更可抑制蕭基能 障二極體表面之漏電流。至於雙金屬陽極中之低功函數電極 41與间功函數電極42之間距則愈小愈好（至少要小於3微After the pattern, the low-function function electrode 41 is selected from the group consisting of titanium, tungsten, chrome, chromium, and combinations thereof. Step 5, referring to FIG. 2e, a high work function electrode 42 is formed in the active region 32, and is plated by an electron rushing or vapor deposition machine above the low work function electrode 41 protruding from the active region 32 and the exposed active region 32. The high work function electrode 42 is configured as a second anode of the Schottky barrier diode. The high work function electric 1642 is selected from the group consisting of gold, platinum, palladium, platinum telluride and its combination. And the high work function electrode 42 is a material sufficient to form a Schottky barrier. Step six' on the substrate! The other surface-formed cathode conductive layer 5 is a cathode conductive layer 5 on the bottom of the base (the first region has an n-type change material) (1) on the bottom of the base; The cathode of the base-transistor (1) The cathode conductive layer 5 is a material which can form an ohmic contact with the substrate, and the material thereof is made of silver, Ming, and Shao alloy. The physical properties of the diode are not shown in the figure. The effective xiao small becomes smaller and larger, and the polycrystalline bismuth is as shown in Annex 2. The curve of the area ratio of the base of the Xiaoji energy barrier to the bimetal (Ti/Au) of the present invention is the height of the basal barrier with the double gold (four) pole. Area ratio 12 201227973 The depth of the joint of the retaining ring 31 is also deeper and deeper (see Table 1). In other words, the smaller the area ratio of the bimetal anode is, the deeper the joint depth η of the polycrystalline ring guard ring 31 is. The higher the breakdown voltage, the better the choice of the Schottky barrier and the acceptable high temperature furnace reaction time for the bimetallic structure. The invention is a quenching process. The average value measured by about 50 sets of Xiaoji energy barrier diodes, so there is a certain degree of process. With the above structural composition and embodiment, the Xiaoji energy barrier φ diode fabricated by the present invention has the following preferred physical characteristics as compared with the conventional one: high breakdown voltage value is greater than 145 volts (V); The current is greater than 丨 ampere/cm 2 (A/cm 2 ); the leakage current density is less than 8·7 microamperes/cm 2 (in A/cm 2 ); when the forward current is 1 amp/cm 2 , the range of forward bias can be The thickness of the Schottky barrier is 0.764 to 0.554 eV. The barrier is prevented to prevent the edge of the Xiaoji barrier diode from collapsing, and the leakage current of the surface of the Xiaoji barrier diode can be suppressed. As for the low work function electrode 41 and the work function electrode 42 in the bimetal anode. The smaller the distance, the better (at least less than 3 micro
米）k樣蕭基能障二極體於反向偏壓操作電流有被夾住（PM )之作用#照圖二e模擬之說明，其中附件3是順向偏壓 二乍夺之電〇,L /爪動分佈，而附件*是反向偏壓操作時之空乏區 分佈。 13 201227973 ， l" 綜上所述，本案不彳Θ為& ^ 禾隹空間型態上確屬創新，並能較習 用物品增進上述多項功效，庙 双應已充分符合新穎性及進步性之m) k-like Xiaoji energy barrier diode in the reverse bias operating current has the effect of being clamped (PM) #照图二e simulation description, in which the accessory 3 is the forward biased two 乍 之 〇 , L / claw movement distribution, and the attachment * is the distribution of the depletion zone during reverse bias operation. 13 201227973 , l" In summary, the case is considered to be & ^ the spatial type of Wo is indeed innovative, and can enhance the above-mentioned multiple functions compared with the conventional items, the temple should fully comply with the novelty and progressive
法定發明專利要件，爰依法M A 犮依·忐铖出申請，懇請貴局核准本件 發明專利申請案’以勵發明，至感德便。 【圖式簡單說明】 圖為本發明具雙金屬陽極的蕭基能障二極體之結構 @1 · 圓， φ 圖二a至圖二e為該具雙金屬陽極的蕭基能障二極體之 實施步驟流程示意圖； 附件1為該具雙金屬陽極的蕭基能障二極體之電流-電壓 特性曲線圖； 附件2為該具雙金屬陽極的蕭基能障二極體之物理特性 對不同雙金屬（Ti/Au)陽極面積比大小之曲線圖； 附件3為該具雙金屬陽極的蕭基能障二極體之順向偏壓 • 操作時之電流流動分佈視圖；以及 附件4為該具雙金屬陽極的蕭基能障二極體之反向偏壓 操作時之空乏區分佈視圖。 【主要元件符號說明】 1基板 11 基材 12 η型磊晶層 201227973 場氧化層 複晶矽層 複晶矽護環 主動區 Ρ型摻雜區域 寬度 深度 低功函數電極 ifj功函數電極 陰極導電層 15The statutory invention patent requirements, 爰 M M M M 忐铖 忐铖 忐铖 忐铖 申请 M M M M M M M M M M M M M M M M M M M M M M M M M M M [Simple diagram of the diagram] The figure shows the structure of the Xiaoji barrier diode with bimetal anode in the present invention @1 · circle, φ Fig. 2a to Fig. 2e show the Xiaoji barrier diode with the bimetal anode Schematic diagram of the implementation steps of the body; Annex 1 is the current-voltage characteristic curve of the Xiaoji barrier diode with bimetal anode; Annex 2 is the physical characteristics of the Xiaoji barrier diode with bimetal anode Graph of anode area ratio of different bimetals (Ti/Au); Annex 3 is the forward bias of the Schiff base diode with bimetal anodes; current flow distribution view during operation; and Annex 4 A view of the distribution of the depletion region in the reverse bias operation of the Schottky barrier diode with the bimetal anode. [Main component symbol description] 1 substrate 11 substrate 12 η-type epitaxial layer 201227973 field oxide layer polycrystalline germanium layer polycrystalline germanium guard ring active region 掺杂 type doped region width depth low work function electrode ifj work function electrode cathode conductive layer 15