200841394 【發明所屬之技術領域】 本發明係關於一種p型透明導電氧化物及其製造方法，尤指 一種摻雜有氮原子之p型透明導電氧化物及其製造方法。 【先前技術】 、 P型CuAl〇2係一具有寬能隙（3·5 eV)的透明導電氧化物， 在半導體應用上有許多可發展之處，包括透明p-η接合元件、雷 射二極體等等。而習知CuAl〇2薄膜缺陷的導電機制爲一本質缺 陷，如下所述： 〇2(g) = 20〇x+ VCu~+VAi3~+4h+ 其中，〇0x、VClT、¥^^及4h+分別爲氧原子的原始晶格位置、銅 原子空缺、鋁原子空缺及電洞載子。從上述導電機制可知，多額 之氧原子或銅原子和銘原子空缺，或兩者以上缺陷共存在於爲薄 膜內，即爲提供導電主要電洞載子（Cairier)的來源，而電洞存 在於價帶中（Valance band)貢獻其導電性質。 本發明則利用外質摻雜導入具有非金屬陰離子特性之原子如 氮原子於CuA102內，而氮原子置於晶格內或間隙位置，可在能隙. 內提供一受體能階（Acceptor level)，由於受體能階接近價帶，此 能階可以接收來自於價帶的電子，而留下電洞，增加的電洞載子 濃度可貢獻於導電性質上，進而增加導電度。 5 200841394 【發明說明】 * 本發明之目的在於提供一種P型透明導電氧化物及其製造方 法，可有效增加載子濃度及改善其導電性質。 本發明之p型透明導電氧化物係將具有非金屬陰離子特性之 原子如氮原子摻雜導入一 p型金屬氧化物內而得、，以增加電洞載 子濃度；P型金屬氧化物可爲CuA102、、SrCu2〇2、CuGa〇2或 CuIn〇2 ° 上述之氮原子的摻雜濃度較佳爲0.01-10 at.%。 • 本發明製造P型透明導電氧化物之方法係將具有非金屬陰離 子特性之原子例如氮原子摻雜一 p型金屬氧化物內，以增加電洞 載子濃度；P型金屬氧化物可爲CuA102、SrCu202、CuGa02或 CuIn〇2 〇 上述之原子摻雜可藉由濺鍍程序及退火程序完成。濺鍍程序 中反應氣體的N2/02比例較佳爲20/1〜1/20。退火程序可於控制氣 氛爐內進行，溫度通常控制在100〜1000°c，時間較佳爲0.1〜100 小時，而氧氣（02)在氣氛爐內須控制通常低於l.OxIOdatn!。 【實施方法】 實施例1 於直流反應濺鍍系統（DC reactive sputtering system)中，進 tj.CuAl〇2的，沉積。真空室中的基礎壓力（Base pressure)及工作 壓力（Working pressure)分別爲 3 ·〇χ1(Γ6ωιτ 及 6·5χ1(Τ3 torr;靶 材爲熔合金屬Cu〇.5A1().5，亦即50 at·% Cu及50 at·% A1 ; DC功率 爲l5〇瓦；Ar流率爲2.2 seem ;反應氣體的N2/02比例爲7/1。鍍 膜後，將樣本置於控制氣氛爐內以800°C退火處理4小時；其中氬 6 200841394 氣（A〇的純度超過99.999%，氧氣（〇2)在氣氛爐內須控制低 於7·〇χ1(Γ5 atm，以避免過多氧氣而造成氧化鋁優先形成。退火處 理後，會形成1.1 at·%的氮摻雜（N-doped) CuA102。 實施例2 、 操作步驟同實施例1，但反應氣體的N2/02比例爲9/1，退火 處理後形成1.9 at.%的氮摻雜。 比較例1 操作步驟同實施例2，但未進行退火程序，形成2.5 at.°/◎的氮 摻雜，且非爲晶質CuA102。 比較例2 操作步驟同實施例1，但反應氣體中無N2，改用02/Ar比例 爲3/1的反應氣體，以形成未摻雜氮（undoped)的鍍膜。 爲驗證本發明方法所得之P型銅鋁氧化物的結構及特性，並 對實施例1、2、比較例1、2的鍍膜進行如下之分析。 1· X-光繞射分析（XRD) 以XRD分析晶體結構，結果如第1圖所示。其中光譜a爲代 表所有實施例1、2及比較例1，直流反應濺鍍（DC sputtering) 鍍膜後未進行退火程序的鍍膜，發現所有試片薄膜爲非晶質 (Amorphous)。光譜b、c、d則分別顯示經800°C退火處理4小 200841394 時後，比較例2、實施例1及2的鍍膜形成結晶之赤銅礦 (delafossite) CuA102結構。顯示無論爲未摻雜或是氮摻雜薄膜， 在 XRD 分析中證實其爲 CuA102 ( 006) 5 ( 101 )，（012)，（ 104)， ( 009)，（018)，（ 110)，（〇〇12)和（113)繞射面，皆有相同繞 射面且並無二次雜質相存在。 、 2· X-光光電子能譜分析（XPS ) 如第2圖所示，其中光譜a爲比較例i，未進行退火程序前氮 (N Is )於非晶質CuAl〇2的XPS鍵結能（binding energy )分析， 其鍵結能爲4〇3 eV。光譜b爲實施例1，退火後氮（n Is)於結 晶赤銅礦CuAl〇2的XPS鍵結能分析，其鍵結能爲398·2 eV。由 減少的氮（N Is)鍵結能可知，氮原子已置入結晶結構的赤銅礦 CuAl〇2內。以XPS分析實施或比較例中鍍膜組成份的結果則如表 1所示。 表1 實施例/ XPS at.% 比較例 Cu A1 0 N ~^ 實施例1 23.9 24.3 50.7 ------- 1.1 實施例2 23.0 23.6 51.5 1.9'~' 比較例1 22.7 23T5 51.3 2.5 比較例2 24.8 24.2 51.0 • ♦ · 8 200841394 3.光直接能隙分析 根據公式： (a/2V ) 1/n = A (hv~ Eg ) 利用透光性與繪圖量測，可得到能隙値大小，其中a爲吸收係數， Αν爲光子的能量，A爲常數，Eg爲能隙値，而η丨直對直接能隙與 間接能隙分別爲I/2與2。結果如第3圖所示，其中曲線a爲未摻 雜氮CuA102的直接能隙値，約爲3.U eV，證實其爲寬能隙（> 3.〇 eV)之半導體材料。直接能隙較文獻記載的3.5 eV爲低，則因於 不同的合成技術、化學組成、薄膜的點缺陷型態，所造成之差異 性。曲線b及c分別爲氮摻雜1.1 at.%及1.9 at·%的CuA102的直接 能隙（Gap 1 )値，分別爲3.25 eV及3.27 eV。而氮原子於能隙內 提供一受體能階（Acceptor level)，其激發能階內電子至導電帶所 需能量（Gap 2)分別爲 3.08 eV ( 1.1 at·%氮摻雜）及 3.09 eV ( 1.9 at·%氮摻雜）。換言之，激發價帶內電子至受體能階所需能量約爲 0.02〜〇·〇3 eV。 - .根據上述光直接能隙分析的結果，可繪出P型氮摻雜CuA102 的竃子能帶結構圖，如第4圖所示；其中Ec爲導電帶邊緣能量値， Ei爲Fermi能階，EA爲受體能階，Εν爲價帶邊緣能量値，Gap 2爲 受體能階內電子被激發至導電帶所需能量，Gap 1爲激發價帶內電 子至導電帶所需能量。 4.霍爾（Hall)效應量測 爲評估本發明鍍膜的載子濃度及其導電性質，則藉由霍爾效 應量測之’結果如表2所不。由於未退火的CuA1〇2鑛膜爲非晶質， 會造成載子移動率下降，.故其電阻高於霍爾效應量測儀之量測極 200841394 限，而無法測彳守其導電性質。而表2中，對於8〇〇。〇退火處理後的 CuAl〇2薄膜’霍爾係數（Rh)皆爲正値，正値的霍爾係數證明其 爲P型導電，CuAl〇2薄膜主要載子爲電洞（H〇le)。此外，載子 濃度（N)及光能隙値（Gapl)皆隨氮摻雜含量增加而增加，在實 施例1中，有較高的導電度（σ)爲0·054 (acm) ^，證明氮參 雜於CuAl〇2中，可增加其導電度率。 表2 實施例/ Gap 1 Gap 2 N Rh μ Σ 比較例 (eV) (eV) (cm*3) (m2/C) (cm2/V.S) (Ωοπι)·1 實施例1 3.25 3.08 2.13xl〇17 + 15.80 1.45 0.054 .貫施例2 3.27 3.09 2.61X1017 + 10.14 1.16 0.047 比較例2 3.11 • · · 4.81xl〇16 +25.12 4.08 0.038 由上述分析結果證明，本發明利用氮原子摻雜導入P型 CuAl〇2內，所得的P型透明導電氧化物具有良好的結晶型態及導 電性質。亦即本發明藉由間隙位置之氮原子增加電洞載子的機制 爲一外質缺陷，如下所述：BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a p-type transparent conductive oxide and a method for producing the same, and more particularly to a p-type transparent conductive oxide doped with a nitrogen atom and a method for producing the same. [Prior Art], P-type CuAl〇2 is a transparent conductive oxide with a wide energy gap (3·5 eV), which has many developments in semiconductor applications, including transparent p-η bonding elements, laser two Polar body and so on. However, the conduction mechanism of the conventional CuAl〇2 film defect is an essential defect, as follows: 〇2(g) = 20〇x+ VCu~+VAi3~+4h+ where 〇0x, VClT, ¥^^ and 4h+ are respectively The original lattice position of the oxygen atom, the copper atom vacancy, the aluminum atom vacancy and the hole carrier. It can be seen from the above-mentioned conductive mechanism that a plurality of oxygen atoms or copper atoms and a vacancies of the Ming atoms, or both of them are coexistent in the film, that is, a source of a conductive main hole carrier (Cairier), and a hole exists in the price. The Valance band contributes its conductive properties. In the present invention, an atom having a non-metal anion property such as a nitrogen atom is introduced into the CuA 102 by exogenous doping, and the nitrogen atom is placed in the crystal lattice or at a gap position to provide an acceptor level in the energy gap. Since the acceptor energy level is close to the valence band, this energy level can receive electrons from the valence band, leaving holes, and the increased hole carrier concentration can contribute to the conductive properties, thereby increasing the conductivity. 5 200841394 [Description of the Invention] It is an object of the present invention to provide a P-type transparent conductive oxide and a method for producing the same, which can effectively increase the concentration of a carrier and improve the conductive property thereof. The p-type transparent conductive oxide of the present invention is obtained by doping a non-metal anion-characteristic atom such as a nitrogen atom into a p-type metal oxide to increase the hole carrier concentration; the P-type metal oxide may be The doping concentration of the above nitrogen atom of CuA102, SrCu2〇2, CuGa〇2 or CuIn〇2 ° is preferably 0.01 to 10 at.%. The method for producing a P-type transparent conductive oxide of the present invention is to dope a non-metal anion-characteristic atom such as a nitrogen atom into a p-type metal oxide to increase the hole carrier concentration; the P-type metal oxide may be CuA102. , SrCu202, CuGaO 2 or CuIn 〇 2 〇 The above atomic doping can be completed by a sputtering process and an annealing process. The ratio of the N2/02 of the reaction gas in the sputtering process is preferably from 20/1 to 1/20. The annealing process can be carried out in a controlled atmosphere furnace, the temperature is usually controlled at 100 to 1000 ° C, and the time is preferably 0.1 to 100 hours, and the oxygen (02) must be controlled in the atmosphere furnace to be usually lower than 1.0 OxIOdatn!. [Examples of Implementation] Example 1 In a DC reactive sputtering system, deposition of tj.CuAl〇2 was carried out. The base pressure and working pressure in the vacuum chamber are 3 ·〇χ1 (Γ6ωιτ and 6.5χ1 (Τ3 torr; the target is fused metal Cu〇.5A1().5, ie 50 At·% Cu and 50 at·% A1 ; DC power is l5 〇; Ar flow rate is 2.2 seem; N2/02 ratio of reaction gas is 7/1. After coating, the sample is placed in a controlled atmosphere furnace to 800 °C annealing treatment for 4 hours; wherein argon 6 200841394 gas (A 〇 purity exceeds 99.999%, oxygen (〇 2) in the atmosphere furnace must be controlled below 7 · 〇χ 1 (Γ 5 atm to avoid excessive oxygen to cause alumina After the annealing treatment, 1.1 at·% of nitrogen-doped (N-doped) CuA 102 is formed. Example 2, the operation procedure is the same as in Example 1, but the N2/02 ratio of the reaction gas is 9/1, annealing treatment Thereafter, 1.9 at.% of nitrogen doping was formed. Comparative Example 1 The procedure was the same as in Example 2 except that no annealing procedure was performed to form a nitrogen doping of 2.5 at.°/?, and not a crystalline CuA 102. Comparative Example 2 Operation The procedure is the same as in Example 1, except that there is no N2 in the reaction gas, and a reaction gas having a ratio of 02/Ar of 3/1 is used to form undoped nitrogen (undoped). In order to verify the structure and characteristics of the P-type copper-aluminum oxide obtained by the method of the present invention, the coatings of Examples 1 and 2 and Comparative Examples 1 and 2 were analyzed as follows: 1. X-ray diffraction analysis (XRD) The crystal structure was analyzed by XRD, and the results are shown in Fig. 1. The spectrum a represents all of Examples 1, 2 and Comparative Example 1, and the coating was not performed after the DC sputtering coating, and all of the coatings were found. The test piece film was amorphous (Amorphous), and the spectra b, c, and d were respectively observed after annealing at 800 ° C for 4 hours 200841394, and then the coating films of Comparative Example 2, Examples 1 and 2 formed crystalline copper ore ( Delafossite) CuA102 structure. It shows that whether it is undoped or nitrogen-doped film, it is confirmed by XRD analysis as CuA102 ( 006) 5 ( 101 ), (012), ( 104), ( 009 ), (018), (110), (〇〇12) and (113) the diffractive surface, all have the same diffractive surface and no secondary impurity phase exists. 2. X-optical photoelectron spectroscopy (XPS) as shown in Fig. 2 It is shown that the spectrum a is the comparative example i, and the XPS bonding energy of the nitrogen (N Is ) to the amorphous CuAl〇2 before the annealing process is performed. Binding energy analysis, the bonding energy is 4〇3 eV. The spectrum b is the first example. After annealing, the nitrogen (n Is) is analyzed by the XPS bond energy of the crystalline cuprite CuAl〇2, and the bonding energy is 398. · 2 eV. It can be seen from the reduced nitrogen (N Is ) bond energy that the nitrogen atom has been placed in the crystal structure of the cuprite CuAl〇2. The results of the composition of the coating in the XPS analysis or comparative example are shown in Table 1. Table 1 Example / XPS at.% Comparative Example Cu A1 0 N ~^ Example 1 23.9 24.3 50.7 ------- 1.1 Example 2 23.0 23.6 51.5 1.9'~' Comparative Example 1 22.7 23T5 51.3 2.5 Comparative Example 2 24.8 24.2 51.0 • ♦ · 8 200841394 3. Optical direct energy gap analysis according to the formula: (a/2V) 1/n = A (hv~ Eg ) Using the light transmission and the mapping measurement, the energy gap size can be obtained. Where a is the absorption coefficient, Αν is the energy of the photon, A is a constant, Eg is the energy gap 値, and η丨 is directly equal to the direct energy gap and the indirect energy gap I/2 and 2. The results are shown in Fig. 3, in which the curve a is a direct energy gap 未 of the undoped CuA 102, which is about 3. U eV, which is confirmed to be a semiconductor material of a wide energy gap (> 3. 〇 eV). The direct energy gap is lower than the 3.5 eV recorded in the literature, due to the differences in synthesis techniques, chemical composition, and point defect patterns of the film. Curves b and c are the direct energy gaps (Gap 1 )値 of CuA102 with nitrogen doping of 1.1 at.% and 1.9 at·%, respectively, of 3.25 eV and 3.27 eV. The nitrogen atom provides an acceptor level in the energy gap, and the energy required to excite the electrons from the energy level to the conductive band (Gap 2) is 3.08 eV (1.1 at·% nitrogen doping) and 3.09 eV ( 1.9 at·% nitrogen doping). In other words, the energy required to excite electrons in the valence band to the acceptor energy level is about 0.02 〇·〇3 eV. According to the results of the direct optical energy gap analysis described above, the structure of the scorpion band of the P-type nitrogen-doped CuA102 can be plotted, as shown in Fig. 4; where Ec is the edge energy 値 of the conduction band, and Ei is the Fermi level EA is the acceptor energy level, Εν is the valence band edge energy 値, Gap 2 is the energy required for the electrons in the acceptor energy level to be excited to the conductive band, and Gap 1 is the energy required to excite the electrons in the valence band to the conductive band. 4. Hall effect measurement In order to evaluate the carrier concentration and the conductive property of the coating of the present invention, the results by Hall effect measurement are shown in Table 2. Since the unannealed CuA1〇2 mineral film is amorphous, the carrier mobility is reduced, so the resistance is higher than the Halleffect measuring instrument's measuring electrode limit of 200841394, and it is impossible to measure its conductive properties. In Table 2, for 8〇〇. The Hall-coefficient (Rh) of the CuAl〇2 film after annealing is positive, the Hall coefficient of the positive 证明 proves to be P-type conductivity, and the main carrier of the CuAl〇2 film is the hole (H〇le). In addition, the carrier concentration (N) and the light energy gap (Gapl) increase with increasing nitrogen doping content. In Example 1, the higher conductivity (σ) is 0·054 (acm) ^, It is proved that nitrogen is mixed in CuAl〇2, which can increase its conductivity. Table 2 Example / Gap 1 Gap 2 N Rh μ Σ Comparative Example (eV) (eV) (cm*3) (m2/C) (cm2/VS) (Ωοπι)·1 Example 1 3.25 3.08 2.13xl〇17 + 15.80 1.45 0.054 . Example 2 2.27 3.09 2.61X1017 + 10.14 1.16 0.047 Comparative Example 2 3.11 • · · 4.81xl〇16 +25.12 4.08 0.038 It is proved by the above analysis that the present invention introduces P-type CuAl〇 by nitrogen atom doping. In 2, the obtained P-type transparent conductive oxide has a good crystalline form and conductive properties. That is, the mechanism of the present invention for increasing the hole carrier by the nitrogen atom at the gap position is an external defect, as follows:
Ni^N3" +3h+ 其中，分別爲氮原子間隙、氮陰離子及電洞載子。而多額之氮原 子置於間隙位置，爲提供導電之電洞載子的來源。 200841394 【圖式簡單說明】 第1圖爲本發明P型氮摻雜CuA102的X-光繞射分析（XRD) 結果。 第2圖爲本發明P型氮摻雜CuA102的X-光免電子能譜分析 (XP S )結果。 第3圖爲本發明P型氮摻雜CuA102的能隙圖。 第4圖爲本發明P型氮摻雜CuA102的電子能帶結構圖。 11Ni^N3" +3h+ Among them, nitrogen atom gap, nitrogen anion and hole carrier. A plurality of nitrogen atoms are placed in the interstitial position to provide a source of conductive hole carriers. 200841394 [Simple Description of the Drawing] Fig. 1 is a result of X-ray diffraction analysis (XRD) of the P-type nitrogen-doped CuA102 of the present invention. Fig. 2 is a result of X-ray electron-free energy spectrum analysis (XP S ) of the P-type nitrogen-doped CuA102 of the present invention. Figure 3 is a graph showing the energy gap of the P-type nitrogen-doped CuA 102 of the present invention. Fig. 4 is a view showing the structure of an electron band of a P-type nitrogen-doped CuA102 of the present invention. 11