200924250 九、發明說明 【發明所屬之技術領域】 本發明係關於氮化物半導體裝置，尤其是 方晶構造之基板的氮化物半導體裝置相關。 【先前技術】 半導體雷射等使由由氮化物半導體所構成之發 。氮化物半導體之實例如氮化鋁（AIN )、氮化_ )、氮化銦（InN )等。代表之氮化物半導體 AlxInyGai.x.yN ( 1 ' 1 ' 0^x + y^ 1) 。其中’ GaN係含氮之六方晶構造之化合物半導體 爲大家所熟知的氮化物半導體。 —般而言，使用GaN之發光元件，具有於基 積η型GaN層、活性層及p型GaN層的構造，將 所發生之光輸出至外部。該等發光元件，例如，於 基板上層積氮化物半導體膜而形成（例如，參照專 1 ) ° 層積於藍寶石基板上之氮化物半導體膜含有超 構之氮化物半導體膜時，構成超晶格結構之層間界 成陡峭的氮化物半導體膜。其應該是因爲藍寶石基 陷密度較高的緣故。 [專利文獻1 ]日本特開2 0 0 3 - 2 3 8 2 9 7號公報 【發明內容】 具有六 光元件 (GaN ，可以 來表示 當中最 板上層 活性層 藍寶石 利文獻 晶格結 面會形 板之缺 -4- 200924250 然而，因爲藍寶石基板之缺陷密度較高，氮化物半導 體膜層積於藍寶石基板上而形成之發光元件的信賴性較低 。另一方面，氮化物半導體膜層積於缺陷密度較低之GaN 基板等氮化物半導體基板之結晶面上而形成之發光元件時 ，有構成超晶格結構之層間界面難以形成陡峭之氮化物半 導體膜的問題。 有鑑於上述問題，本發明係提供於缺陷密度較低之氮 化物半導體基板之結晶面上配置界面陡峭之超晶格結構之 氮化物半導體膜的氮化物半導體裝置。 依據本發明之一實施形態，可以提供一種氮化物半導 體裝置，具有（a)由六方晶構造之氮化物半導體所構成 ，面法線與極性面之結晶軸之夾角爲〇 ·2度至5度之角度 之基板主面的基板；及（b)配置於基板主面上’含有由 氮化物半導體所構成之超晶格結構之層的層積體。 依據本發明，可以提供於缺陷密度較低之氮化物半導 體基板之結晶面上配置界面陡峭之超晶格結構之氮化物半 導體膜的氮化物半導體裝置。 【實施方式】 其次，參照圖式，針對本發明之實施形態進行說明。 以下之圖式之記載中，相同或類似之部分賦予相同或類似 之符號。但是，圖式只是槪念，厚度及平面尺寸之關係' 各層之厚度之比率等，可能與實際之物不同。所以’具體 之厚度及尺寸，請參酌以下之說明進行判斷。此外’圖式 -5- 200924250 彼此間之尺寸之關係及比率當然也包括不同之部分。 此外’以下所示之實施形態，只是以將本發明之技術 思想具體化爲目的之裝置及方法的實例，本發明之技術思 想，構成部品之材質、形狀、構造、配置等並未受限於下 述說明。本發明之技術思想，在申請專利範圍內，可以實 施各種變更。 本發明之實施形態之半導體裝置，如第1圖所示，具 備：由六方晶構造之氮化物半導體所構成，具有面法線與 極性面（C面）之結晶軸之夾角爲0.2度至5度之角度之 基板主面11的基板10;及配置於基板主面11上，含有 由氮化物半導體所構成之超晶格結構之層的層積體20。 層積體20，具有依序層積著分別由氮化物半導體所構成 之η型半導體層21、活性層22 0、及p型半導體層23之 構造，從活性層220發生光。η型半導體層21及ρ型半 導體層23之至少任一包含超晶格結構之層。 首先，針對基板1 〇進行說明。基板1 0具有六方晶之 結晶構造，例如，可以採用GaN基板等。以下，參照第2 圖，針對六方晶之結晶構造進行說明。第2圖係六方晶之 結晶構造之晶格單元的槪念圖。 六方晶系之c軸[0 0 0 1 ]係延伸於六角柱之軸方向，以 該c軸做爲法線之面（六角柱之頂面）爲c面{ 000 1 }。c 面，+c軸側及-c軸側具有不同之性質，稱爲極性面（ Polar Plane )。此外，六方晶構造之結晶時，分極方向係 沿著c軸。 -6 - 200924250 六方晶系時，六角柱之6個側面分別爲m面（{1-100}面），通過不相鄰之一對稜線之面爲a面（{11-20} 面）。m面及a面，係垂直於c面之結晶面，因爲垂直相 交於分極方向，故爲無極性之平面，亦即，非極性面（ Nonpolar Plane) 。 基板1 〇之基板主面1 1之面法線方向，具有從c軸傾 斜之量測走離角。第3圖係基板1 0之基板主面π之面法 線方向與基板結晶軸方向之c軸方向、m軸方向及a軸方 向之關係。如第3圖所示’基板主面1 1之面法線方向與 c軸方向之夾角爲量測走離角Φ ，基板主面11之面法線 投影於基板結晶軸之m軸及c軸所定義之m軸c軸平面 之投影軸與c軸方向之夾角（以下，稱爲「朝面法線之m 軸方向之傾斜角成份」）爲Φ m，基板主面1 1之面法線 投影於基板結晶軸之a軸及c軸所定義之a軸c軸平面之 投影軸與c軸方向之夾角（以下，稱爲「朝面法線之&軸 方向之傾斜角成份」）爲Φ3。方向L係基板主面11之 面法線投影於基板結晶軸之a軸及m軸所定義之a軸m 軸平面之投影軸的延伸方向。方向L與m軸方向之夾角 爲角α。 如第5 ( a )圖所示’基板主面丨1之面法線方向具有 從c軸傾斜之量測走離角φ時，如第5 ( b )圖所示，基 板主面1 1產生平坦面之階地面1 c、及於藉由使面法線相 對於c軸傾斜而產生之段差部分的台階面1 d。 如第5(b)圖之階地面lc爲c面（〇〇〇1)，垂直於 200924250 階地面1 c之c軸，從基板主面丨丨之面法線只傾斜量測走 離角Φ。如第5(b)圖所示，台階面Id，並列於l方向 。此處，基板主面1 1之面法線只朝m軸方向傾斜時，以 第3圖、第4圖而言，係相當於0s = 9〇度時。此時，產生 平坦面之階地面1 c、及於藉由使面法線相對於c軸傾斜 而產生之段差部分之等間隔的規則性台階面1 d。此時， 台階面1 d相當於m面（1 0 -1 〇 )。 基板主面1 1不但朝m軸方向傾斜也朝a軸方向傾斜 時’形成傾斜之台階面1 d，台階面1 d，如第5 ( b )圖所 示，並列於L方向。此狀態，如第3圖及第4圖所示，以 朝m軸方向之台緣配列來呈現。因爲m面在熱及化學上 係安定面，因爲a軸方向之傾斜角成份φα的大小，而無 法保持完美之斜向台階，如第5 ( b )圖所示，台階面id 形成凹凸，台緣之配列呈現紊亂。此外，如第3圖、第4 圖所示，「台緣」係將台階面1 d之段差部分投影於m軸 及a軸所定義之m軸a軸平面者。 基板主面11上，因爲台階面Id而產生段差部分，然 而，飛至該段差部分之原子，會與階地面lc及台階面Id 之2面結合，原子會比飛至階地面1 c時更強力地與基板 主面1 1結合，而可安定地捕捉飛來之原子。表面擴散過 程中飛來之原子擴散至階地面lc內。藉由將被捕捉於結 合力較強之段差部分、及以該段差部分形成所形成之轉折 位置之飛來原子組合於結晶，可藉由結晶生長之沿面生長 而進行安定之生長。 -8 - 200924250 如此，於具有基板主面1 1之面法線相對於c軸方 具有量測走離角之基板10上，層積層積體20，層積體 以台階面1 d爲中心進行結晶生長。所以，層積於面法 相對於c軸方向呈傾斜之基板1 0 8之基板主面1 1上的 積體20含有超晶格結構之層時，構成其氮化物半導體 之超晶格結構之層間界面成爲陡峭。應該係飛至階地 lc上之原子於階地面lc上移動至最佳位置，而形成平 性良好之構成超晶格結構的層。 然而，基板主面11之面法線方向與c軸方向所夾 量測走離角φ越大，台階面1 d之間隔越窄，而使台緣 台階寬度產生紊亂。所以’飛至階地面1 c上之原子無 於階地面1 c上移動，原子無法被捕捉至最佳位置。另 方面，量測走離角Φ過小，則基板主面1 1上無法發生 地面1 e及台階面1 d，或者，台階面1 d之間隔過寬。 以，爲了使構成超晶格結構之層間界面較爲陡峭’量測 離角φ以0.2度〜5度程度爲佳。量測走離角Φ爲1 以下更佳，〇 · 3度程度最佳。 第1圖所示之氮化物半導體裝置’更具備’·接觸與 板主面1 1相對之基板1 〇之背面而配置之n側歐姆電 51 ;接觸P型半導體層23之上面（與接觸活性層220 面相對之面）而配置之絕緣膜3 0 ;配置於絕緣膜3 0上 P側歐姆電極4 1 ;以及配置於p側歐姆電極41上之p 黏結電極42。如第1圖所不，於配設在絕緣膜之開 部’ P側歐姆電極41接觸p型半導體層23° 向 20 線 層 膜 面 坦 之 及 法 階 所 走 度 基 極 之 之 側 Π -9- 200924250 η側歐姆電極5丨，例如，可以採用鋁（A1 ) —駄 )-金（Au )之層積體等。此時，Al、Ti、Au之膜 別爲 100nm、10nm、2000nm 程度。 絕緣膜3 0，例如，可以採用膜厚爲200nm程度 化銷（Zr〇2 )膜等。或者，例如，可以採用氧化矽（ )膜等做爲絕緣膜30。 P側歐姆電極41，例如，由鈀（pd) -Au之層積 所構成。此時’ Pd、Au之膜厚分別爲10nm、20nm 。P側黏結電極42，例如，可以採用Ti-Au之層積體 此時’ Ti、Au之膜厚分別爲50nm、500nm程度。 η側歐姆電極5 1，配置於省略了圖示之配線基板 配線圖案上。其次，ρ側黏結電極42與配線基板係 合線等進行電性連結。 其次’針對層積體2 0進行說明。利用有機金屬 澱積（MOCVD )法等，於基板1〇之基板主面1 1上 層積體20之生長。從η型半導體層21對活性層220 電子，從Ρ型半導體層23對活性層220注入電洞（ 孔）。活性層220藉由被注入之電子與電洞的再結合 光。亦即，如第1圖所示之氮化物半導體裝置，具有 體雷射之機能。 活性層22 0，係以藉由電子與電洞的再結合而發 並放大其所發生之光爲目的之層。活性層220，可以 由配置於由氮化銦鎵（InGaN )所構成之複數隔離層 隔離層之間的發光層所構成之量子井（MQW )構造 (Ti 厚分 之氧 Si〇2 體等 程度 等。 上之 以接 化學 實施 注入 電子 而發 半導 生光 採用 與其 。例 -10- 200924250 如，以3周期（對）程度重複層積發光層之膜厚 之InGaN層、及隔離層之膜厚爲7nm之摻雜2x1 程度矽（Si )之InGaN層而形成活性層220。但是 層220之形成工程之最後所形成之接觸p型半導彳 之最終隔離層之膜厚爲25nm程度。 此外，發光波長，藉由調整銦（In )之組成比 如，可設定成400nm〜5 50nm程度。此外，亦可以 爲In之組成比爲5%以上之帶隙相對較小的InGaN 隔離層爲帶隙相對較大之GaN層來構成量子井層。 η型半導體層21，例如，從基板1 〇側依序層 長層211、龜裂防止層212'罩蓋層213、η型包覆 、η型導引層215、以及超晶格層216而形成。 再生長層211，例如，係膜厚爲2//m程度之 。龜裂防止層2 1 2，例如，係膜厚爲1 OOnm程度之 層，用以防止形成於該龜裂防止層2 1 2上之氮化 A1 GaN)層發生龜裂。罩蓋層213，例如，係膜厚f 程度之A1 GaN層。 η型包覆層2 1 4之形成目的，係將活性層220 之光密封於η型包覆層214與ρ型包覆層233之間 「光密封效果」。η型包覆層214可以採用交互層 A1 GaN層及GaN層之超晶格結構。例如，以260 對）程度重複層積膜厚爲2.5nm程度之AlGaN層 爲2.5 nm程度之GaN層來構成n型包覆層214。η 層214，例如，係以7x1 Ο18cm·3之摻雜濃度摻雜η 爲 3 nm 018cm-3 ，活性 豊層23 等，例 發光層 層、及 積再生 層214 GaN層 InGaN 鋁鎵（ I 1 5 nm 所發生 而產生 積複數 周期（ 及膜厚 型包覆 型摻雜 -11 - 200924250 物之s i而形成。 η型導引層21 5 ’係以產生將載體（電子及電洞）密 封於活性層220之「載體密封效果」爲目的之半導體層。 藉此’提咼活性層220之電子及電洞之再結合的效率。η 型導引層2 1 5 ’例如’係於膜厚60nm程度之GaN層，以 3xl018cnT3之摻雜濃度摻雜n型摻雜物之si而形成。 超晶格層2 1 6 ’係以緩和晶格常數差較大之A1 GaN層 與GaN層之應力而容易實施活性層220之InGaN層生長 爲目的之層。超晶格層216，可以採用交互層積著複數 InGaN層及GaN層之超晶格結構。具體而言，例如，由 重複10周期（對）程度之Si摻雜濃度爲1〜5x1018cm·3 之膜厚lnm程度之InGaN層、及與InGaN層相同程度之 Si摻雜濃度之膜厚2 nm程度之GaN層來構成超晶格層 216 ° p型半導體層23 ’係於活性層220上，層積p型電子 隔離層231、p型導引層232、p型包覆層233、及p型接 觸層234而形成。 P型電子隔離層23 1，係以防止電子從活性層220流 出’而提高電子及電洞之再結合效率。p型電子隔離層 231，例如，係於膜厚13nm程度之AlGaN層，摻雜1χ 1 019cnT3之摻雜濃度之p型摻雜物之鎂（Mg)而形成。 P型導引層23 2 ’係以產生上述「載體密封效果」爲 目的之半導體層。P型導引層232，例如，係於膜厚 10 0nm之GaN層，摻雜7xl〇18cm·3之摻雜濃度之p型摻 -12- 200924250 雜物之Mg而形成。 P型包覆層233，係以產生前面說明之「光密封效果 」爲目的而形成。p型包覆層233，可以採用交互層積著 複數AlGaN層及GaN層之超晶格結構等。例如，以85周 期（對）程度重複層積膜厚2.5nm程度之AlGaN層及膜 厚2·5ηιη程度之GaN層來構成p型包覆層233。p型包覆 層2 3 3，例如，以lxl〇19cm·3之摻雜温度摻雜p型摻雜物 之M g而形成。 P型接觸層234，係以降低p型半導體層23與p側歐 姆電極41間之電阻爲目的之低電阻層。p型接觸層234 ’ 例如，係於膜厚60nm之GaN層以7xl019cm·3之高濃度慘 雜P型摻雜物之Mg而形成。 藉由除去P型半導體層23之上部之一部分，形成第 1圖所示之脊條50。亦即，蝕刻除去p型接觸層234、P 型包覆層23 3及p型導引層232之一部分，而形成沿著m 軸之脊條50。脊條50係延伸於m軸方向。藉由η型導引 層215、活性層220及ρ型導引層232，形成以脊條50之 長度方向兩端之端面做爲共振器端面之法布立一柏若共振 腔（Fabry-Perot resonator)。活性層 220所發生之光’ 於脊條50之長度方向兩端之端面間往返，並藉由誘發發 射而放大。其次，被放大之光之一部分，被當做雷射光從 長度方向之端面輸出至氮化物半導體裝置之外部。 如第1圖所示，P側歐姆電極41只接觸脊條5 0之頂 面（條狀之接觸區域）之P型接觸層234之方式’配置著 -13- 200924250 覆蓋p型導引層232及p型包覆層233之露出面 30。藉此，電流集中於脊條50，可以實現效率 盪。此外，脊條5 0之表面，因爲p側歐姆電極 區域以外被絕緣膜3 0覆蓋而獲得保護，橫向之 爲緩和而容易控制，而且，可以防止從側面之漏 如以上之說明所示，於基板主面11之面法 c軸方向呈傾斜之基板1 0上，層積含有超晶格 的層積體20時，構成其超晶格結構之層間界面 亦即，可以如第1圖所示之η型包覆層214及p 233之AlGaN層及GaN層，形成界面陡峭之良 結構。所以，例如，藉由p型包覆層2 3 3爲超晶 可以提高P型包覆層233之載體濃度。此外，η 214及ρ型包覆層233，各對之膜厚爲5〜20nm 外，A1 GaN層之A1之組成比爲例如8〜1 6 %程度 AlGaN層及GaN層之平均組成比爲4〜8%程度 成比，係對應氮化物半導體裝置所輸出之光之波 〇 此外，以上，係針對p型包覆層2 3 3及n 2 1 4皆爲超晶格結構之實例進行說明。然而，例 以只有Ρ型包覆層23 3爲超晶格結構。 第6圖中，係將具有如第1圖所示之超晶格 化物半導體膜形成於以結晶面（c面）做爲主面 之樣品的X射線繞射測定結果。該等樣品之η 2 14及ρ型包覆層23 3之超晶格結構，係由膜 的絕緣膜 之雷射振 4 1之接觸 光密封較 流。 線相對於 結構之層 爲陡峭。 型包覆層 好超晶格 格結構， 型包覆層 程度。此 ，此時之 。A1之組 長來決定 型包覆層 如，亦可 結構的氮 之基板上 型包覆層 厚分別爲 -14- 200924250 5nm之Alo.bGaN層及GaN層之80對所構成。第6圖中 之特性A，係於主面之面法線與極性面之結晶軸一致之藍 寶石基板上形成上述之超晶格結構之氮化物半導體膜時之 X射線繞射測定結果。特性B，係於主面之面法線與極性 面之結晶軸之夾角爲0.3度之GaN基板上形成上述之超晶 格結構之氮化物半導體膜時之X射線繞射測定結果。特 性C，係於主面之面法線與極性面之結晶軸一致之GaN 基板上形成上述之超晶格結構之氮化物半導體膜時之X 射線繞射測定結果。 第6圖所示之強度PM係GaN基板之尖峰強度，強度 P〇係Al〇.16GaN/GaN超晶格層之0次尖峰（主峰）強度。 如第6圖之虛線所環繞者所示，0次尖峰之兩側可以觀測 到伴峰。該伴峰之發生，係具有超晶格結構之膜所特有的 現象。伴峰Al、Bl、C1係Al〇.166GaN/GaN超晶格層之-1 次尖峰。伴峰A2、B2、C2係Al〇.16GaN/GaN超晶格層之 + 1次尖峰。 第6圖所示之X射線繞射測定結果時’伴峰A1之半 寬線爲0.02度，伴峰B1之半寬線爲〇·〇2度，伴峰C1之 半寬線爲0.08度。伴峰A2之半寬線爲〇_ 〇3度’伴峰B2 之半寬線爲〇.〇3度，伴峰C1之半寬線爲0.11度。 如第6圖所示，伴峰形狀隨著基板之種類而不同。伴 峰形狀愈尖銳，則構成超晶格結構之層間界面的陡峭性愈 高，而形成較完美之超格子薄膜。所以’伴峰之強度愈低 形狀愈光滑之特性C，相較於特性A及特性B，A1 GaN層 -15- 200924250 及GaN層之界面陡峭性愈低。其係因爲於主面之面法線 與極性面之結晶軸一致之GaN基板上，未完美地形成超 晶格結構之氮化物半導體膜。因爲特性A而伴峰形狀較 爲尖銳，應該是藍寶石基板之表面存在螺旋錯位，表面呈 現斜向偏移。應該係該表面偏移取代第5 ( b )圖所示之 階地面lc及台階面Id。 由第6圖可以得知，使用主面之面法線與極性面之結 晶軸之夾角爲0.3度之GaN基板時（特性B)之AlGaN 層及GaN層之界面陡峭性，與使用藍寶石基板時（特性 A )相等。 以下，針對本發明之實施形態之氮化物半導體裝置之 製造方法進行說明。此外，以下所述之氮化物半導體裝置 之製造方法只是一例，包括該變形例在內，亦可以其以外 之各種製造方法來實現。 (a )準備具有面法線與極性面（c面）之結晶軸之 夾角爲0.2度至5度之基板主面11的基板10。基板1〇， 例如，係厚度爲3 5 0 // m程度之GaN基板。其次，利用 MOCVD法等，於基板10之基板主面11上實施層積體20 之生長。具體而言，依序層積n型半導體層21、活性層 220、及p型半導體層23。 (b )藉由電漿鈾刻等之乾蝕刻，除去p型半導體層 23之一部分而形成脊條5〇。具體而言，例如，於p型半 導體層23之全面塗佈光阻膜後，利用光刻技術除去鈾刻 部分之光阻膜而使p型半導體層23之表面之一部分露出 -16- 200924250 。其次，以光阻膜做爲遮罩，蝕刻除去P型半導體層23 之上部之一部分而形成脊條5 0。脊條5 0係延伸於m軸方 向而形成。 (c )其次’於p型半導體層23之上面，利用剥離（ liftoff)法等形成絕緣膜30。具體而言，形成光阻膜等條 狀遮罩後，以覆蓋P型導引層232、p型包覆層233、及p 型接觸層234之全體之方式形成絕緣體薄膜。剝離該絕緣 體薄膜’只使P型接觸層2 3 4之頂面露出而形成絕緣膜 30 ° (d)以接觸露出之p型接觸層234之頂面的方式， 於絕緣膜3 0上形成p側歐姆電極41後，形成p側黏結電 極4 2。此外’於基板1 0之背面，形成η側歐姆電極5 1。 藉由上述說明之製造方法，於具有面法線與極性面（ c面）之結晶軸之夾角爲0.2度至5度之基板主面11的基 板10上，層積含有超晶格結構之η型包覆層214的η型 半導體層2 1、活性層220、及含有超晶格結構之ρ型包覆 層233的ρ型半導體層23。所以，η型包覆層214及ρ型 包覆層23 3，構成超晶格結構之層（AlGaN層及GaN層） 間之界面較爲陡峭。 如以上之說明所示，本發明之實施形態之氮化物半導 體裝置時，於與極性面（c面）之結晶軸之夾角爲0.2度 至5度之的基板主面1 1上，配置層積體20。所以，藉由 第1圖所示之氮化物半導體裝置，於缺陷密度較低之GaN 基板之基板10之結晶面的基板主面11上，配置與使用藍 -17- 200924250 寶石基板時相同程度之構成超晶格結構之層間界面 η型包覆層214及P型包覆層233。結果’與使用 陷較多之藍寶石基板時相比’可以優供信賴性較高 物半導體裝置。 此外，活性層220，因爲係量子井構造’藉由 性面之結晶軸之夾角爲〇.2度〜5度之基板主面11 活性層220，可以降低半導體雷射之閾値。此外， 化物半導體之半導體雷射時，爲了降低元件阻抗’ 覆層233可以爲由AlGaN層及GaN層所構成之超 構。藉由第1圖所示之氮化物半導體裝置，可以提 輸出特性不會降低卻可實現低電阻化之半導體雷射 (其他實施形態） 如以上所述，本發明係針對實施形態進行記載 ，用以構成本發明之一部分之論述及圖式，並非用 本發明。相關業者可以依據上述說明了解各種替代 態、實施例、及運用技術。 以上之實施形態之說明時，係以具有脊條5 0 體雷射爲例，然而，亦可以爲無脊條之半導體雷射 ’只要爲含有超晶格結構之層之氮化物半導體裝置 以爲層積著η型半導體層21、活性層220、及p型 層23之發先一極體（LED)。或者，層積體20亦 有直接接合η型半導體層21及p型半導體層23 ^ 合等之其他構造。 陡峭之 結晶缺 之氮化 於與極 上形成 利用氮 ρ型包 晶格結 供雷射 ，然而 以限制 實施形 之半導 。此外 ，亦可 半導體 可以具 :ρη接 -18- 200924250 如上所述’本發明當然包含未記載於此之各種實施形 態等。所以’本發明之技術範圍，係依據上述說明而爲適 當之專利申請範圍之發明特定事項所規定者。 本發明之半導體發光裝置及其製造方法，可以應用於 包括用以製造配置於半導體基板上之發光裝置之製造業在 內的半導體產業及電子機器產業。 【圖式簡單說明】 第1圖係本發明之實施形態之氮化物半導體裝置的槪 念剖面圖。 第2圖係用以說明六方晶之結晶構造的槪念圖。 第3圖係用以說明相對於基板主面之面法線之c面之 傾斜的槪念圖。 第4圖係台緣及m軸之關係槪念圖。 第5圖係用以說明基板主面之面法線之傾斜的槪念圖 ，第5 ( a )圖係面法線朝m軸方向及a軸方向傾斜時， 第5 ( b )圖係第5 ( a )圖之主面狀態。 第6圖係於以結晶面爲主面之基板上形成超晶格結構 之氮化物半導體膜之樣品之X射線繞射測定結果圖。 【主要元件符號說明】 10 :基板 U :基板主面 20 :層積體 -19- 200924250 2 1 : η型半導體層 23 : ρ型半導體層 3 0 :絕緣膜 4 1 : ρ側歐姆電極 42 : ρ側黏結電極 5 0 :脊條 5 1 : η側歐姆電極 21 1 :再生長層 2 1 2 :龜裂防止層 213 :罩蓋層 2 1 4 : η型包覆層 215 : η型導引層 2 1 6 :超晶格層 2 2 0 :活性層 231 : ρ型電子隔離層 23 2 : ρ型導引層 23 3 : ρ型包覆層 234: ρ型接觸層BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride semiconductor device, particularly a nitride semiconductor device of a substrate having a square crystal structure. [Prior Art] A semiconductor laser or the like is made of a nitride semiconductor. Examples of the nitride semiconductor are, for example, aluminum nitride (AIN), nitrided (N), indium nitride (InN), or the like. Represented by the nitride semiconductor AlxInyGai.x.yN ( 1 ' 1 ' 0^x + y^ 1). Among them, the GaN-based compound semiconductor having a nitrogen-containing hexagonal crystal structure is a well-known nitride semiconductor. In general, a light-emitting element using GaN has a structure in which an n-type GaN layer, an active layer, and a p-type GaN layer are formed, and the generated light is output to the outside. The light-emitting elements are formed, for example, by laminating a nitride semiconductor film on a substrate (for example, refer to a specific one). When a nitride semiconductor film laminated on a sapphire substrate contains a super-structured nitride semiconductor film, a superlattice is formed. The interlayer of the structure is a steep nitride semiconductor film. It should be due to the high density of sapphire. [Patent Document 1] Japanese Patent Laid-Open Publication No. H0 3 - 2 3 8 2 9 7 [Invention] A six-light element (GaN) can be used to represent the most active layer of the sapphire Insufficient plate -4-200924250 However, since the defect density of the sapphire substrate is high, the light-emitting element formed by the deposition of the nitride semiconductor film on the sapphire substrate has low reliability. On the other hand, the nitride semiconductor film is laminated on the substrate. When a light-emitting element formed on a crystal plane of a nitride semiconductor substrate such as a GaN substrate having a low defect density has a problem that it is difficult to form a steep nitride semiconductor film at an interlayer interface of a superlattice structure, the present invention has been made in view of the above problems. A nitride semiconductor device provided with a nitride semiconductor film having a superlattice structure having a sharp interface on a crystal plane of a nitride semiconductor substrate having a low defect density. According to an embodiment of the present invention, a nitride semiconductor device can be provided. Having (a) a hexagonal crystal nitride semiconductor, the angle between the surface normal and the crystal axis of the polar plane is a substrate on the main surface of the substrate at an angle of 2 to 5 degrees; and (b) a laminate disposed on the main surface of the substrate as a layer containing a superlattice structure composed of a nitride semiconductor. A nitride semiconductor device in which a nitride semiconductor film having a superlattice structure having a sharp interface is disposed on a crystal plane of a nitride semiconductor substrate having a low defect density. [Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or similar parts are given the same or similar symbols. However, the drawings are only mourning, the relationship between the thickness and the plane size, the ratio of the thickness of each layer, etc., may be related to the actual thing. Therefore, 'the specific thickness and size, please refer to the following instructions for judgment. In addition, the relationship between the size and the ratio of 'Figure-5-200924250' also includes different parts. In addition, the following embodiment, It is only an example of an apparatus and method for embodying the technical idea of the present invention, and the technical idea of the present invention constitutes a material of a part. The shape, the structure, the arrangement, and the like are not limited to the following description. The technical idea of the present invention can be variously modified within the scope of the patent application. As shown in Fig. 1, the semiconductor device according to the embodiment of the present invention includes: a substrate made of a nitride semiconductor having a hexagonal crystal structure, having a substrate main surface 11 having an angle between a surface normal line and a crystal plane of a polar surface (C surface) at an angle of 0.2 to 5 degrees; and being disposed on the main surface of the substrate 11 is a laminate 20 comprising a layer of a superlattice structure composed of a nitride semiconductor. The laminate 20 has an n-type semiconductor layer 21 and an active layer each composed of a nitride semiconductor. The structure of 22 0 and the p-type semiconductor layer 23 generates light from the active layer 220. At least one of the n-type semiconductor layer 21 and the p-type semiconductor layer 23 includes a layer of a superlattice structure. First, the substrate 1 〇 will be described. The substrate 10 has a hexagonal crystal structure, and for example, a GaN substrate or the like can be used. Hereinafter, the crystal structure of the hexagonal crystal will be described with reference to Fig. 2 . Fig. 2 is a commemorative diagram of a lattice unit of a hexagonal crystal structure. The c-axis [0 0 0 1 ] of the hexagonal system extends in the axial direction of the hexagonal column, and the c-axis as the normal surface (the top surface of the hexagonal column) is the c-plane { 000 1 }. The c-plane, the +c-axis side and the -c-axis side have different properties, called Polar Plane. Further, in the case of crystallization of a hexagonal crystal structure, the polarization direction is along the c-axis. -6 - 200924250 In the case of hexagonal crystal, the six sides of the hexagonal column are the m-plane ({1-100} plane), and the surface of the ridgeline that is not adjacent is the a-plane ({11-20} plane). The m-plane and the a-plane are perpendicular to the c-plane crystal plane, and because they intersect perpendicularly in the polarization direction, they are non-polar planes, that is, nonpolar planes. The normal direction of the surface of the main surface 11 of the substrate 1 of the substrate 1 has a deviation from the c-axis. Fig. 3 is a view showing the relationship between the normal direction of the surface of the substrate main surface π of the substrate 10 and the c-axis direction, the m-axis direction, and the a-axis direction of the substrate crystal axis direction. As shown in Fig. 3, the angle between the normal direction of the surface of the main surface of the substrate 1 and the direction of the c-axis is the measured deviation angle Φ, and the normal to the surface of the main surface 11 of the substrate is projected on the m-axis and the c-axis of the crystal axis of the substrate. The angle between the projection axis of the defined m-axis c-axis plane and the c-axis direction (hereinafter, referred to as "the tilt angle component of the m-axis direction toward the normal to the surface") is Φ m, and the surface normal of the main surface of the substrate 1 1 The angle between the projection axis of the a-axis c-axis plane defined by the a-axis and the c-axis defined by the c-axis of the substrate and the c-axis direction (hereinafter referred to as "the inclination angle component of the normal to the normal direction") is Φ3. The normal line of the direction L main surface 11 of the substrate is projected on the extending direction of the projection axis of the a-axis m-axis plane defined by the a-axis of the substrate crystal axis and the m-axis. The angle between the direction L and the m-axis direction is the angle α. As shown in the fifth figure (a), when the normal direction of the surface of the main surface of the substrate 1 has a deviation angle φ from the c-axis tilt, as shown in the fifth (b), the main surface of the substrate 1 1 is generated. The stepped surface 1 c of the flat surface and the stepped surface 1 d of the step portion which is generated by inclining the surface normal with respect to the c-axis. For example, the ground lc of the figure 5(b) is c-plane (〇〇〇1), perpendicular to the c-axis of the ground surface 1c of the 200924250 step, and the deviation from the surface normal of the main surface of the substrate is only measured by the inclination angle Φ. . As shown in Fig. 5(b), the step surface Id is listed in the l direction. Here, when the normal to the surface of the main surface 111 of the substrate is inclined only in the m-axis direction, it corresponds to 0s = 9〇 in the third and fourth figures. At this time, the stepped surface 1 c of the flat surface and the regular stepped surface 1 d which are equally spaced by the step portion which is caused by inclining the surface normal with respect to the c-axis are generated. At this time, the step surface 1 d corresponds to the m plane (1 0 -1 〇 ). When the main surface 1 1 of the substrate is inclined not only in the m-axis direction but also in the a-axis direction, the inclined step surface 1 d is formed, and the step surface 1 d is parallel to the L direction as shown in Fig. 5 (b). This state, as shown in Figs. 3 and 4, is presented in a matrix arrangement in the m-axis direction. Because the m-plane is thermally and chemically stable, because of the magnitude of the inclination angle component φα in the a-axis direction, it is impossible to maintain a perfect oblique step. As shown in Fig. 5(b), the step surface id is concave and convex. The arrangement of the edges is disordered. Further, as shown in Fig. 3 and Fig. 4, the "slab edge" is a projection of the step portion of the step surface 1d to the m-axis a-axis plane defined by the m-axis and the a-axis. On the main surface 11 of the substrate, a step portion is generated due to the step surface Id. However, atoms flying to the step portion are combined with the surface of the step ground lc and the step surface Id, and the atom is more than when flying to the step ground 1 c. It is strongly combined with the main surface of the substrate 1 1 to stably capture the flying atoms. The atoms that fly in the surface diffusion process diffuse into the ground lc. By combining the trapped portion which is trapped in the step of strong bonding force and the flying atom formed at the turning position formed by the stepped portion, it is possible to carry out stable growth by creeping growth of crystal growth. -8 - 200924250 In this manner, on the substrate 10 having the normal to the surface of the main surface of the substrate 1 with respect to the c-axis, the laminated body 20 is laminated, and the laminated body is centered on the stepped surface 1 d Crystal growth. Therefore, when the product 20 laminated on the substrate main surface 11 of the substrate 110 which is inclined with respect to the c-axis direction has a layer of a superlattice structure, the interlayer of the superlattice structure of the nitride semiconductor is formed. The interface becomes steep. The atoms flying on the terrace lc should be moved to the optimum position on the step ground lc to form a layer of a well-formed superlattice structure. However, the larger the normal deviation angle φ between the normal direction of the surface of the substrate main surface 11 and the c-axis direction is, the narrower the interval between the step surfaces 1 d is, and the step width of the step edge is disturbed. Therefore, the atoms flying to the ground level 1 c are not moved on the ground level 1 c, and the atoms cannot be captured to the optimum position. On the other hand, if the measurement deviation angle Φ is too small, the ground surface 1 e and the step surface 1 d cannot occur on the main surface 1 1 of the substrate, or the interval between the step surfaces 1 d is too wide. Therefore, in order to make the interface between the layers constituting the superlattice structure steep, the measurement angle φ is preferably from 0.2 to 5 degrees. It is better to measure the deviation angle Φ to be 1 or less, and the degree of 〇 · 3 degrees is the best. The nitride semiconductor device shown in Fig. 1 further includes an n-side ohmic electric 51 disposed to contact the back surface of the substrate 1 opposite to the main surface 1 1 of the board; contact with the upper surface of the P-type semiconductor layer 23 (with contact activity) The insulating film 30 disposed on the surface opposite to the surface of the layer 220; the P-side ohmic electrode 4 1 disposed on the insulating film 30; and the p-bonding electrode 42 disposed on the p-side ohmic electrode 41. As shown in Fig. 1, the ohmic electrode 41 disposed on the opening portion of the insulating film is in contact with the p-type semiconductor layer 23° toward the 20-layer film surface and the side of the base of the step. 9-200924250 η side ohmic electrode 5 丨, for example, a laminate of aluminum (A1 ) — 駄)-gold (Au) or the like can be used. At this time, the films of Al, Ti, and Au are about 100 nm, 10 nm, and 2000 nm. For the insulating film 30, for example, a film (Zr〇2) film having a film thickness of 200 nm or the like can be used. Alternatively, for example, a ruthenium oxide film or the like can be used as the insulating film 30. The P-side ohmic electrode 41 is composed of, for example, a layer of palladium (pd)-Au. At this time, the film thicknesses of 'Pd and Au were 10 nm and 20 nm, respectively. For the P-side bonded electrode 42, for example, a laminate of Ti-Au can be used. At this time, the film thicknesses of 'Ti and Au are about 50 nm and 500 nm, respectively. The η side ohmic electrode 5 1 is disposed on the wiring board wiring pattern (not shown). Next, the ρ-side bonding electrode 42 is electrically connected to the wiring board bonding wire or the like. Next, the description will be made on the layered body 20. The growth of the laminate 20 is performed on the substrate main surface 11 of the substrate 1 by an organic metal deposition (MOCVD) method or the like. Electrons (holes) are injected into the active layer 220 from the n-type semiconductor layer 21 from the n-type semiconductor layer 21 to the active layer 220. The active layer 220 is recombined with light by the injected electrons and the holes. That is, the nitride semiconductor device shown in Fig. 1 has a function of a bulk laser. The active layer 22 0 is a layer for the purpose of recombining electrons and holes to reproduce and amplify the light generated. The active layer 220 may be composed of a quantum well (MQW) structure (a Ti-thick oxygen Si〇2 body) composed of a light-emitting layer disposed between a plurality of isolation layer isolation layers made of indium gallium nitride (InGaN). Etc. In order to carry out electron injection and semi-conducting light, it is used in the same manner. Example-10-200924250 For example, repeating the thickness of the layer of the luminescent layer of the InGaN layer and the film of the spacer layer by 3 cycles (pair) The active layer 220 is formed by doping a 2 nm thick GaN (Si) layer of InGaN with a thickness of 7 nm. However, the final isolation layer of the p-type semi-conductive layer formed at the end of the formation of the layer 220 has a film thickness of about 25 nm. The wavelength of the light emission can be set to about 400 nm to 5 50 nm by adjusting the composition of indium (In ), and the band gap of the InGaN isolation layer having a relatively small band gap of 5% or more. The quantum layer is formed by a relatively large GaN layer. The n-type semiconductor layer 21 is, for example, a layer 211 from the side of the substrate 1, a cap layer 213, a cap layer 213, an n-type cladding, and an n-type. The guiding layer 215 and the superlattice layer 216 are formed. 211, for example, a film thickness of about 2 / / m. The crack prevention layer 2 1 2, for example, a layer having a film thickness of about 100 nm, for preventing formation on the crack prevention layer 2 1 2 The nitrided A1 GaN) layer is cracked. The cap layer 213 is, for example, an A1 GaN layer having a film thickness of f. The purpose of forming the n-type cladding layer 2 1 4 is to "seal the light-sealing effect" between the n-type cladding layer 214 and the p-type cladding layer 233 by light-sealing the active layer 220. The n-type cladding layer 214 may have a superlattice structure of an alternating layer A1 GaN layer and a GaN layer. For example, the n-type cladding layer 214 is formed by repeating a GaN layer having a thickness of about 2.5 nm and an AlGaN layer of about 2.5 nm. The η layer 214 is, for example, doped with a doping concentration of 7x1 Ο18 cm·3, η is 3 nm 018 cm-3 , an active germanium layer 23, etc., for example, a light-emitting layer, and a build-up layer 214 GaN layer InGaN aluminum gallium (I 1 5 nm occurs and is formed by a complex number of cycles (and a film-thickness type doped -11 - 200924250 si. The n-type guiding layer 21 5 ' is used to seal the carrier (electron and hole) The "carrier sealing effect" of the active layer 220 is a semiconductor layer for the purpose of "reducing the efficiency of recombination of electrons and holes of the active layer 220. The n-type guiding layer 2 1 5 ' is, for example, a film thickness of 60 nm. The GaN layer is formed by doping the Si of the n-type dopant at a doping concentration of 3xl018cnT3. The superlattice layer 2 1 6 ' is used to alleviate the stress of the A1 GaN layer and the GaN layer with a large difference in lattice constant. It is easy to implement a layer for the growth of the InGaN layer of the active layer 220. The superlattice layer 216 may be a superlattice structure in which a plurality of InGaN layers and GaN layers are alternately laminated. Specifically, for example, by repeating 10 cycles (pair a degree of Si doping concentration of 1 to 5 x 1018 cm · 3 film thickness of 1 nm of InGaN layer, and I The nGaN layer has the same Si doping concentration as the GaN layer having a thickness of 2 nm to form the superlattice layer 216 ° The p-type semiconductor layer 23 ' is attached to the active layer 220, and the p-type electron isolation layer 231 is laminated, p-type The guiding layer 232, the p-type cladding layer 233, and the p-type contact layer 234 are formed. The P-type electron isolation layer 23 1 prevents electrons from flowing out of the active layer 220 to improve the recombination efficiency of electrons and holes. The p-type electron isolation layer 231 is formed, for example, by an AlGaN layer having a thickness of about 13 nm and doped with magnesium (Mg) of a p-type dopant having a doping concentration of 1 χ 1 019 cn T3. The P-type guiding layer 23 2 ' A semiconductor layer for the purpose of producing the above-mentioned "carrier sealing effect". The P-type guiding layer 232 is, for example, a GaN layer having a film thickness of 10 nm, and a p-type doping doped with a doping concentration of 7 x 1 〇 18 cm · 3 12- 200924250 is formed by Mg of the impurity. The P-type cladding layer 233 is formed for the purpose of producing the "light sealing effect" described above. The p-type cladding layer 233 may be formed by alternately stacking a plurality of AlGaN layers and a superlattice structure of a GaN layer, etc. For example, an AlGaN layer having a thickness of 2.5 nm is laminated at a cycle of 85 cycles (pair) A GaN layer having a thickness of about 2·5 ηηη is formed to constitute a p-type cladding layer 233. The p-type cladding layer 233 is formed, for example, by doping the Mg of the p-type dopant at a doping temperature of 1×10 〇19 cm·3. The P-type contact layer 234 is a low-resistance layer for the purpose of reducing the resistance between the p-type semiconductor layer 23 and the p-side ohmic electrode 41. The p-type contact layer 234' is formed, for example, by a Mg layer having a film thickness of 60 nm and having a high concentration of 7 x 1019 cm·3, which is miscible with Mg of the P-type dopant. The ridge strip 50 shown in Fig. 1 is formed by removing a portion of the upper portion of the P-type semiconductor layer 23. That is, a portion of the p-type contact layer 234, the p-type cladding layer 23 3 and the p-type guiding layer 232 is removed by etching to form the ridge strip 50 along the m-axis. The ridge strip 50 extends in the m-axis direction. By the n-type guiding layer 215, the active layer 220, and the p-type guiding layer 232, the end faces at both ends in the longitudinal direction of the ridge strip 50 are formed as a resonator end face by a method of bubbling-perot (Fabry-Perot) Resist). The light generated by the active layer 220 reciprocates between the end faces of both ends in the longitudinal direction of the ridge strip 50, and is amplified by induced emission. Next, a portion of the amplified light is output as the laser light from the end face in the longitudinal direction to the outside of the nitride semiconductor device. As shown in FIG. 1, the P-side ohmic electrode 41 is only in contact with the P-type contact layer 234 of the top surface (the strip-shaped contact region) of the ridge 50, and is disposed with a -13-200924250 covering the p-type guiding layer 232. And an exposed surface 30 of the p-type cladding layer 233. Thereby, current is concentrated on the ridges 50, and efficiency can be achieved. Further, the surface of the ridge strip 50 is protected by the insulating film 30 in the p-side ohmic electrode region, the lateral direction is relaxed and easy to control, and the leakage from the side can be prevented as shown in the above description. When the surface of the main surface 11 of the substrate is inclined on the substrate 10 in the c-axis direction, when the laminated body 20 including the superlattice is laminated, the interlayer interface constituting the superlattice structure, that is, as shown in FIG. The n-type cladding layer 214 and the AlGaN layer and the GaN layer of p 233 form a good structure with a steep interface. Therefore, for example, the carrier concentration of the P-type cladding layer 233 can be increased by superposing the p-type cladding layer 233. Further, the η 214 and the p-type cladding layer 233 have a film thickness of 5 to 20 nm, and the composition ratio of A1 of the A1 GaN layer is, for example, 8 to 16%. The average composition ratio of the AlGaN layer and the GaN layer is 4 The ratio of ~8% is proportional to the wavelength of light outputted by the nitride semiconductor device. Further, the above description is directed to an example in which the p-type cladding layers 2 3 3 and n 2 1 4 are superlattice structures. However, for example, only the ruthenium-type cladding layer 23 3 is a superlattice structure. In Fig. 6, the result of the X-ray diffraction measurement in which the superlattice compound semiconductor film shown in Fig. 1 is formed on a sample having a crystal face (c-plane) as a main surface is obtained. The superlattice structure of the η 2 14 and the p-type cladding layer 23 3 of the samples is sealed by the contact of the laser light 4 1 of the insulating film of the film. The line is steep relative to the layer of the structure. Type cladding Good superlattice structure, degree of cladding. This, at this time. The group of A1 is determined to be a type of cladding layer. For example, a substrate having a thickness of -14-200924250 5 nm Alo.bGaN layer and 80 pairs of GaN layers can be formed. The characteristic A in Fig. 6 is a result of X-ray diffraction measurement when the nitride semiconductor film of the superlattice structure described above is formed on the sapphire substrate whose normal surface of the principal surface coincides with the crystal axis of the polar surface. The characteristic B is a result of X-ray diffraction measurement when the nitride semiconductor film of the above-described superlattice structure is formed on a GaN substrate having an angle of 0.3 to the crystal axis of the principal surface and the crystal axis of the polar surface. The characteristic C is an X-ray diffraction measurement result when the nitride semiconductor film of the superlattice structure described above is formed on the GaN substrate having the normal plane of the principal surface and the crystal axis of the polar surface. The intensity of the peak of the PM-based GaN substrate shown in Fig. 6 and the intensity of the 0th peak (main peak) of the P 〇Al〇.16GaN/GaN superlattice layer. As shown by the dotted line in Figure 6, the companion peak can be observed on both sides of the zero spike. The occurrence of this companion peak is a phenomenon unique to a membrane having a superlattice structure. The peaks of the peaks of Al, B1, and C1 are -1 peaks of the Al 〇 166 GaN/GaN superlattice layer. The peaks of the peaks A2, B2, and C2 are + 1 peaks of the Al 〇 16 GaN/GaN superlattice layer. In the X-ray diffraction measurement result shown in Fig. 6, the half width line of the accompanying peak A1 is 0.02 degrees, the half width line of the peak B1 is 〇·〇 2 degrees, and the half width line of the peak C1 is 0.08 degrees. The half-width line of the accompanying peak A2 is 〇_ 〇3 degrees'. The half-width line of the peak B2 is 〇.〇3 degrees, and the half-width line of the peak C1 is 0.11 degree. As shown in Fig. 6, the shape of the peak is different depending on the type of the substrate. The sharper the shape of the accompanying peak, the higher the steepness of the interfacial interface constituting the superlattice structure, and the formation of a perfect super lattice film. Therefore, the lower the intensity of the accompanying peak, the smoother the shape C, the lower the interface steepness of the A1 GaN layer -15-200924250 and the GaN layer compared to the characteristic A and the characteristic B. This is because the nitride semiconductor film of the superlattice structure is not perfectly formed on the GaN substrate in which the normal line of the principal surface coincides with the crystal axis of the polar surface. Because the characteristic A is accompanied by a sharper peak shape, there should be a spiral misalignment on the surface of the sapphire substrate, and the surface is obliquely offset. This surface offset should be replaced by the step ground lc and the step surface Id shown in Fig. 5(b). It can be seen from Fig. 6 that the interface steepness of the AlGaN layer and the GaN layer when the normal surface of the principal surface and the crystal axis of the polar plane are 0.3 degrees (the characteristic B) and the sapphire substrate are used. (Feature A) is equal. Hereinafter, a method of manufacturing a nitride semiconductor device according to an embodiment of the present invention will be described. Further, the method of manufacturing the nitride semiconductor device described below is merely an example, and various modifications may be made in addition to the modification. (a) A substrate 10 having a substrate main surface 11 having an angle between the surface normal and the crystal plane of the polar surface (c-plane) of 0.2 to 5 degrees is prepared. The substrate 1 is, for example, a GaN substrate having a thickness of about 305 //m. Next, the growth of the laminate 20 is performed on the substrate main surface 11 of the substrate 10 by MOCVD or the like. Specifically, the n-type semiconductor layer 21, the active layer 220, and the p-type semiconductor layer 23 are laminated in this order. (b) A portion of the p-type semiconductor layer 23 is removed by dry etching by plasma uranium etching or the like to form a ridge 5〇. Specifically, for example, after the photoresist film is entirely coated on the p-type semiconductor layer 23, the photoresist film of the uranium engraved portion is removed by photolithography to expose a portion of the surface of the p-type semiconductor layer 23 -16 - 200924250. Next, a portion of the upper portion of the P-type semiconductor layer 23 is etched away by the photoresist film as a mask to form the ridges 50. The ridge strips 50 are formed extending in the m-axis direction. (c) Next, the insulating film 30 is formed on the upper surface of the p-type semiconductor layer 23 by a liftoff method or the like. Specifically, after forming a strip mask such as a photoresist film, an insulator film is formed so as to cover the entire P-type guiding layer 232, the p-type cladding layer 233, and the p-type contact layer 234. The insulating film is peeled off so that only the top surface of the P-type contact layer 234 is exposed to form an insulating film 30° (d) to contact the top surface of the exposed p-type contact layer 234, and p is formed on the insulating film 30. After the side ohmic electrode 41, the p-side bonding electrode 42 is formed. Further, on the back surface of the substrate 10, an n-side ohmic electrode 51 is formed. According to the manufacturing method described above, a superlattice structure η is laminated on the substrate 10 having the substrate main surface 11 having an angle between the surface normal and the crystal plane of the polar surface (c-plane) of 0.2 to 5 degrees. The n-type semiconductor layer 2 1 of the cladding layer 214, the active layer 220, and the p-type semiconductor layer 23 including the p-type cladding layer 233 of the superlattice structure. Therefore, the interface between the n-type cladding layer 214 and the p-type cladding layer 23 3 forming a superlattice structure (AlGaN layer and GaN layer) is steep. As described above, in the nitride semiconductor device according to the embodiment of the present invention, lamination is disposed on the main surface 11 of the substrate at an angle of 0.2 to 5 degrees from the crystal axis of the polar surface (c-plane). Body 20. Therefore, with the nitride semiconductor device shown in Fig. 1, the substrate main surface 11 of the crystal plane of the substrate 10 of the GaN substrate having a low defect density is disposed to the same extent as the blue-17-200924250 gem substrate. The interlayer interface n-type cladding layer 214 and the P-type cladding layer 233 constituting the superlattice structure. As a result, it is possible to provide a highly reliable semiconductor device as compared with when a sapphire substrate having a large number of sapphire substrates is used. Further, the active layer 220 can reduce the threshold of the semiconductor laser by the quantum layer structure 'the active layer 220 of the substrate main surface 11 having an angle of the crystal axis of the surface of the surface of 2 to 5 degrees. Further, in order to reduce the element resistance in the semiconductor laser of the semiconductor semiconductor, the cladding layer 233 may be a superstructure composed of an AlGaN layer and a GaN layer. According to the nitride semiconductor device shown in Fig. 1, it is possible to provide a semiconductor laser which can achieve low resistance without lowering the output characteristics. (Other Embodiments) As described above, the present invention is described with respect to the embodiment. The discussion and drawings which form a part of the invention are not intended to be the invention. Relevant operators can understand various alternatives, embodiments, and application techniques based on the above description. In the above description of the embodiment, a laser having a ridged body is used as an example. However, a semiconductor laser having no ridges may be used as long as it is a layer of a nitride semiconductor device having a layer of a superlattice structure. The n-type semiconductor layer 21, the active layer 220, and the first-in-one body (LED) of the p-type layer 23 are stacked. Alternatively, the laminate 20 may have another structure in which the n-type semiconductor layer 21 and the p-type semiconductor layer 23 are directly bonded. The steep crystallization of the nitriding is formed on the poles by using a nitrogen p-type lattice to provide a laser, but to limit the implementation of the semiconducting. Further, the semiconductor may have: ρη 接 -18 - 200924250 As described above, the present invention naturally includes various embodiments and the like which are not described herein. Therefore, the technical scope of the present invention is defined by the specific matters of the invention as set forth in the appended claims. The semiconductor light-emitting device and the method of manufacturing the same according to the present invention can be applied to the semiconductor industry and the electronic device industry including manufacturing industries for manufacturing light-emitting devices disposed on a semiconductor substrate. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a nitride semiconductor device according to an embodiment of the present invention. Fig. 2 is a view for explaining the crystal structure of the hexagonal crystal. Fig. 3 is a view for explaining the inclination of the c-plane with respect to the surface normal of the main surface of the substrate. Figure 4 is a diagram of the relationship between the platform edge and the m-axis. Fig. 5 is a view for explaining the inclination of the normal to the surface of the main surface of the substrate, and the fifth (a) is the fifth normal in the direction of the m-axis and the a-axis, and the fifth (b) is the first 5 ( a ) The main surface state of the figure. Fig. 6 is a graph showing the results of X-ray diffraction measurement of a sample of a nitride semiconductor film having a superlattice structure formed on a substrate having a crystal plane as a main surface. [Description of main component symbols] 10: Substrate U: Substrate main surface 20: Laminate -19- 200924250 2 1 : n-type semiconductor layer 23: p-type semiconductor layer 30: insulating film 4 1 : p-side ohmic electrode 42: ρ side bonding electrode 50: ridge strip 5 1 : η side ohmic electrode 21 1 : regrown layer 2 1 2 : crack preventing layer 213 : cap layer 2 1 4 : n type cladding layer 215 : n type guide Layer 2 1 6 : Superlattice layer 2 2 0 : Active layer 231 : p-type electron isolation layer 23 2 : p-type guiding layer 23 3 : p-type cladding layer 234: p-type contact layer