1296162 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種電容器及其製法，特別是指一種 含有鐵酸鉍鐵電層之電容器以及其製法。 【先前技術】 一般而言，記憶體可區分為兩類：一類是強調高速存 • 取及高容量的隨機讀寫記憶體（random access memory，以下 、 簡稱「RAM」），另一類則是強調永久記憶功能的唯讀記憶 _ 體（read only memory，以下簡稱「ROM」）。RAM的讀寫速 度可在100奈秒（nanosecond)以下，且屬於揮發性記憶體 (volatile-memory)，也就是記憶體的資料會隨著電源關閉而 消失，未具有永久記憶的功能。ROM則屬於非揮發性記憶 體，也就是記憶體資料的儲存不會受到電源影響，但資料 的寫入需要微秒（microsecond)以上時間。 而隨者各種材料（如鐵電材料及磁性材料等）之研發’再 結合記憶體之原有優點，目前已研究出許多不同結構之記 憶體，例如：鐵電記憶體、磁性記憶體、相轉變記憶體等 。記憶體中的最小單位，也就是記憶體單元（memory cell)， 其一般係含有一電晶體（transistor)及一電容器（capacitor)。 而電容器之結構一般包含：一下電極（lower electrode)、一 設置於該下電極上且由一介電材料所製成之介電層 (dielectric layer)以及一設置於該介電層上之上電極（upper electrode) 〇 此外，於諸多材料的研發中，又以複鐵式材料 5 1296162 (multiferroic materials)最具有發展潛力，其是藉由結合鐵電 (ferroelectric)物質和反鐵磁（antiferromagnetic)物質而製成， 所以複鐵式材料同時具備鐵電性質（ferroelectricity)及鐵磁 性質（ferromagnetism)，且此兩性質會相互作用而產生磁電 效應（magneto-electric effect)，致使後續用途的範圍更為廣 泛，例如記憶體（memory)、轉換器（transducers)、致動器 (actuators)及感測裝置（sensors)等等，所以複鐵式材料現今 已成為產學界亟欲發展研究之方向。 目前較為熱門之複鐵式材料包含鐵酸鉍（BiFe03)、錳酸 鉍（BiMn03)及錳酸釔（ΥΜη03)等，其中又以鐵酸鉍最受注目 。這是因為鐵酸絲具有約1103 K之居禮溫度（Curie temperature)以及 643 K 之尼爾溫度（Neel temperature)，且 於室溫時表現鐵電性及反鐵磁特性，加上具有不含鉛元素 的優點，更可符合環保之要求。此外，由於鐵酸鉍為G型 磁性排列，屬於一種傾斜的自旋結構（canted spin structure) ，雖具有反鐵磁特性，但在某一方向具有一淨磁矩 (magnetic moments)，所以也會表現出弱鐵磁特性。鐵酸鉍 之複鐵及物理性質會依據結晶位向（crystalline orientation)而 改變。目前鐵酸鉍薄膜於實際應用時之問題在於材料的漏 電性，其導因包含例如：不純的結晶相、孔隙度及表面粗 糙度過大等，且鐵酸鉍於電性質上的表現會因鐵原子價數 容易變化而被影響，也就是受到鐵原子價數易變動而形成 多餘的電洞，進而造成電阻下降，或者因為Fe3+變成Fe2+所 產生之電荷補償（charge compensation)而形成氧空缺。 6 1296162 現今亦有許多運用鐵酸絲來製作記憶裝置的研究報導 ，如美國專利公開案第廳/〇〇17269 ai號，係揭示一種鐵 電記憶裝置。言亥鐵f記憶t ^ &含一石夕氧化物（smc〇n oxide)薄膜、一形成於該矽氧化物薄膜上且由鈣鈦礦 (perovskite，一般結構為AB〇3)材料所製成之電極，以及一 形成於該電極上且具有四方晶⑽ag〇nal)結構之（〇〇 i)位向 的鐵酸叙鐵電層，其中，該詞鈦礦材料係選自於SrRU〇3、 Nb-SrTi〇3、La_SrTi〇3、（Na Sr)c〇〇3 或此等之一組合且 鐵酸絲鐵電層中各鐵原子位置可被至少一磁性金屬原子所 取代’該磁性金屬原子是選自於由下列所構成之群組：論 、Ru、Co及Ni。而在此專利之—具體例中，該鐵電記憶裝 置由下至上依序皆置有.一石夕基板、一緩衝層㈣打） 、一下電極、-鐵㈣鐵電層及—上電極。該緩衝層是由 如-从0〆0。^1，Ln選自於下列構成之一群組·· γ、La 、Ce、Pr、Nd、Sm、Eu、Gd、Th、Dy、H〇、份、Tm、Yb 及Lu)所製成。該上、下電極是由SrRu〇3所製成，其中， 該巧極亦可由Pt、卜IK)x及其他f知材料所製成了此專 利疋精由以-價數高於鐵原子之磁性金屬原子來取代鐵原 ::而讓鐵酸鉍晶體可維持在中性，同時避免漏電現象， 但疋上述方式往往會讓鐵酸絲之鐵電性降低，並造成記憶 裝置之性能變差。 〜 由此可知，在該鐵電記憶裝置令，鐵酸鉍鐵電層之性 質會影響到整個裳置之性能，而—般通常是藉由改«備 方法來維持或增加鐵㈣之性f。目前常用於製備鐵酸叙 1296162 薄膜之方法主要為脈衝式雷射沉積（pulsed laser deposition) 、射頻式滅鍍（RF magnetron sputtering)及化學溶液沉積 (chemical solution deposition)，其中又以化學溶液沉積法為 目前業界研發之熱門題材。例如，Uchida等人選用異戊烷 氧化叙[Bi(0-卜C5Hn)3]及乙醯基丙酮酸鐵[bismuth acetylacetonate，Bi(CH3COCHCOCH3)3]及二甲氧乙醇（2-methoxyethanol)作為先驅物，接著將此先驅物塗佈於一基板 上，再於500°C之溫度下進行退火處理而製得鐵酸鉍層 (H.Uchida et al., Jpn. J. ApplPhys.f part 2, 44? L561(2005)) 。惟，在上述文獻中，先驅物之化學活性較佳，對於濕氣 非常敏感，在製備時極難以處理，更會影響薄膜製備之再 現性。依據以上文獻，又加上鐵酸鉍薄膜需於500〜650oC 或以上之溫度進行退火，所以，針對利用化學溶液沉積法 製備鐵酸鉍薄膜，目前業界仍需尋求一較佳先驅物，以及 有效提昇製作再現性及降低退火溫度。 由上述可知，對於一具備較高穩定性及低漏電性質之 具有鐵酸鉍鐵電層之電容器，以及具備較高製作再現性之 電容器的製法，於目前業界仍有一需求。 【發明内容】 因此’本發明之目的，即在提供一種具備較高穩定性 及低漏電性質之具有鐵酸鉍鐵電層之電容器，以及具備較 高製作再現性且於較低退火溫度下製備之電容器的製法。 本發明之具有鐵酸叙鐵電層之電容器是包含一基板、 一疊置於該基板上之下電極、一形成於該下電極上之導電 8 1296162 氧化物層、一形成於該導電氧化物層上之鐵酸鉍鐵電層及 一疊置於該鐵酸鉍鐵電層上之上電極。該導電氧化物層是 由一鈣鈦礦結構材料所製成，該鈣鈦礦結構材料是鎳^ = (lanthamm nickelate，㈣叫）或鉛酸鋇（㈣㈣ metaplumbate，BaPb03) 〇 另，本發明用於製備具有鐵酸鉍鐵電層之電容器的方 法包含T列步驟··⑨-基板上依序_ 一下電極及一由一 鈣鈦礦結構材料所製成之導電氧化物層，以及於該導電氧 化物層上依序形成一鐵酸鉍鐵電層及一下電極，其中，該 躬鈦礦結構材料係選自於由下列所構成之群組：鎳酸綱及 鉛酸鋇。 ，發明之電容器由於具有該導電氧化物層，特別是該 導電氧化物層疋由-約鈦礦結構材料（鎳酸鑭或鉛酸鎖）所製 成’此材料與鐵酸鉍同樣皆為鈣鈦礦結構，故相容性較高 :而=助於提昇鐵㈣之結晶，再加上銻酸鑭或錯酸顧之 j节數（lattice constant)與鐵酸銘相近，使得鐵酸叙會沿 著鈦礦結構材料的位向成長’而讓該鐵酸秘鐵電層的 σ曰曰I·生I仏以及穩疋性較高，並使得本發明之電容器在後 續用於例如記憶體等襄置時，可降低漏電現象。此外，本 發明之電容器的製法亦因為該導電氧化物層之存在，而讓 後續鐵酸鉍鐵電層的製作再現性提高。 【實施方式】 、有關本發明之前述及其他技術内容 '特點與功效，在 、—口 >考圖式之一個較佳實施例及六具體例的詳細說 1296162 明中，將可清楚的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明内容中，類似的元件是以相同的編號來表示。 參閱圖1，本發明之具有鐵酸鉍鐵電層之電容器之較佳 實施例包含一基板1、一疊置於基板1上之下電極2、一形 成於該下電極2上之導電氧化物層3、一形成於該導電氧化 物層3上之鐵酸鉍鐵電層4及一疊置於該鐵酸鉍鐵電層* 上之上電極5。於本發明中，該導電氧化物層3是由一鈣鈦 礦結構材料所製成，該鈣鈦礦結構材料係選自於由下列所 構成之群組：鎳酸鑭及鉛酸鋇。 該基板1具有一基底層（base layer)11、一疊置於該基底 層11上之擴散阻絕層（diffusi〇n barrier layer)12，及一疊置 於該擴散阻絕層12上之附著層（adhesi〇n layer)13。需注意 的疋w亥基板1之構造不限於上述三層的組合，可另依據 實際需要進行變化或S直接選用目前市售之產品。 車父佳地，該基底層π是由石夕所製成。 該擴散阻絕層12之設置目的在於防止該基底層U於製 転:因為又熱而發生擴散，較佳地，該擴散阻絕層是由 一選自於由下列所構成群組之材料所製成··二氧化石夕、氮 化鋁、氮化鈦及氮化鈕。 該附著層13之設置目的是詩接合該下電極2與該擴 散阻絕層12，較佳地，該附著層13是由一選自於由下列所 構成群組之材料所製成：二氧化鈦、鈦及钽。 較佳地，該下電極2及上電極5分別由一導電金屬所 10 1296162 構成’該導電金屬是選自於由下列所構成之群組·始、銀 及舒。岐本發明之—鍾财，該導電金屬為銘。 另需注意的是，該電容器之各層的厚度可依據實際需 要進行調整。 / 交佳地，該電容器更包含-設置於該鐵酸鉍鐵電層4 ”上電極5之間的氧化物電極層（未示於圖工中）。該氧化 物電極層之設置目的是用於提昇整個電容之性質，且較佳 使用與料電减物層3相同之材料所製成（可由錄酸綱或 鉛酸鋇所製成）。 本發明具有鐵酸㈣電層之電容器之較佳實施例的製 備:法包含之步驟為：於—基板1上依序形成-下電極2 及一由一鈣鈦礦結構材料所製成之導電氧化物層3，以及於 V電氧化物層3上依序形成一鐵酸祕鐵電層4及一上電 ° /、中β亥飼鈦礦結構材料係選自於由下列所構成之群 組：鎳酸鑭及鉛酸鋇。 關於該電容器之各層可使用的材料如上文所述，在此 不多加贅述。 該下電極2及上電極5可使用例如濺鍍法、電子槍蒸 鍍法來形成，而於本發明之一具體例中，該下電極2及上 電極5是分別以鉑為靶材，並使用濺鍍法來形成。 該導電氧化物層3可參考以下文獻進行製備：c· c. Yailg? Μ· S* Chen^ Τ· J. Hong? C. M. Wu5 J. M. Wu and T. B. WU? ApPl Phys· Lett., 66, 2643(1995) ^ M. S. Chen5 T. B. Wu5 and J. M. Wu5 AppL Phys, Lett.. 685 1430(1996) ^ Y. R. Luo 1296162 咖 J. M. Wu，柳/. ~· Ze"，79, 3669(2〇〇ι)，及c & Liang, J. M. Wu, and M. C. Chang, Appl. Phys. Letu> 81j 3624 (2002)。而於本發明之_具體例中，該導電氧化物層3是以 錦酸鑭或錯酸财為③材，並利用射頻㈣⑽咖_削 sputtering)法所製成。 較佳地，該鐵酸鉍鐵電層4是利用射頻濺鍍法或化學 溶液沉積法所製成。 S利用射頻歲鐘法來製備該鐵酸絲鐵電層4時，係先 利用特定比例（1 ·· 1〜2 :丨）之Bi2Q3& Fe2〇3粉末，再以傳統 陶瓷製法製備鐵酸鉍靶材（BixFe〇3，，最後再利用 射頻濺鍍法，將所使用機器之背景壓力控制在1(r5 t〇rr，接 者通入氧氣與氬氣，再維持20〜40 mtorr之工作壓力以及將 省基板1加熱至350。(：進行濺鍍，歷時一段時間後便形成 該鐵酸鉍鐵電層4。 當利用化學溶液沉積法來製備該鐵酸鉍鐵電層4時， 係藉由製備一先驅物，再將該先驅物塗佈於該導電氧化物 層3上’並於適當溫度下進行退火處理，以製成該鐵酸鉍 鐵電層4，該先驅物具有一鐵之酸鹽（acid-radicai salt 〇f Fe) 、一鉍之酸鹽及一溶劑。 較佳地’該鐵之酸鹽係選自於由下列所構成之群組： 乙醯基丙酮酸鐵、硝酸鐵[ferric nitrate，Fe(N〇3)3]、醋酸鐵 [ferric acetate，Fe(C2H302)3]及此等之一組合。 較佳地，該鉍之酸鹽係選自於由下列所構成之群組·· 乙酿基丙 g同酸纽[bismuth acetylacetonate ， 12 12961621296162 IX. Description of the Invention: [Technical Field] The present invention relates to a capacitor and a method of manufacturing the same, and more particularly to a capacitor containing a ferroelectric layer of ferrite ferrite and a method of manufacturing the same. [Prior Art] In general, memory can be divided into two categories: one is to emphasize high-speed storage and high-capacity random access memory (hereinafter, referred to as "RAM"), and the other is to emphasize The only memory of the permanent memory function is read only memory (hereinafter referred to as "ROM"). The read/write speed of the RAM can be below 100 nanoseconds, and it is a volatile-memory. That is, the data of the memory disappears with the power off, and there is no permanent memory function. ROM is a non-volatile memory, that is, the storage of memory data is not affected by the power supply, but the data is written in microseconds or more. With the development of various materials (such as ferroelectric materials and magnetic materials), combined with the original advantages of memory, many different structures of memory have been developed, such as: ferroelectric memory, magnetic memory, phase Change memory and so on. The smallest unit in memory, that is, the memory cell, generally contains a transistor and a capacitor. The capacitor structure generally includes: a lower electrode, a dielectric layer formed on the lower electrode and made of a dielectric material, and an electrode disposed on the dielectric layer. In addition, in the development of many materials, the multiferroic materials 5 1296162 (multiferroic materials) have the most potential for development by combining ferroelectric materials and antiferromagnetic substances. And made, so the complex iron material has both ferroelectricity and ferromagnetism, and the two properties interact to produce a magneto-electric effect, resulting in a wider range of subsequent uses. Widely used, such as memory, transducers, actuators, and sensors, so the complex iron material has become the direction of the industry. At present, the more popular complex iron materials include barium ferrite (BiFe03), barium manganate (BiMn03) and barium manganate (ΥΜη03), among which barium ferrite is the most popular. This is because the ferrite wire has a Curie temperature of about 1103 K and a Neel temperature of 643 K, and exhibits ferroelectricity and antiferromagnetic properties at room temperature, plus The advantages of lead elements are more environmentally friendly. In addition, since barium ferrite is a G-type magnetic arrangement, it belongs to a tilted spin structure. Although it has antiferromagnetic characteristics, it has a magnetic moment in a certain direction, so it will also Shows weak ferromagnetic properties. The complex iron and physical properties of barium ferrite will vary depending on the crystalline orientation. At present, the problem of the barium ferrite film in practical application lies in the leakage of the material, and its causes include, for example, impure crystal phase, porosity and surface roughness, etc., and the performance of barium ferrite in electrical properties is due to iron. The number of valences is easily changed and is affected, that is, the valence of iron atoms is easily changed to form excess holes, which causes a decrease in electrical resistance, or an oxygen vacancy due to charge compensation caused by Fe3+ becoming Fe2+. 6 1296162 There are also many research reports on the use of ferric acid to make memory devices. For example, U.S. Patent Publication No. 17269 Ai discloses a ferroelectric memory device. Yanhai iron f memory t ^ & contains a smc〇n oxide film, formed on the tantalum oxide film and made of perovskite (perovskite, general structure AB〇3) material An electrode, and a ferric acid ferroelectric layer formed on the electrode and having a tetragonal (10) ag〇nal structure, wherein the termite material is selected from the group consisting of SrRU〇3, Nb-SrTi〇3, La_SrTi〇3, (Na Sr)c〇〇3 or a combination of these and the position of each iron atom in the ferroelectric ferroelectric layer can be replaced by at least one magnetic metal atom. It is selected from the group consisting of: Ru, Co, and Ni. In the specific example of the patent, the ferroelectric memory device is sequentially disposed from bottom to top. A stone substrate, a buffer layer (four), a lower electrode, an iron (four) ferroelectric layer, and an upper electrode. The buffer layer is such as - from 0 〆 0. ^1, Ln is selected from the group consisting of γ, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, H〇, parts, Tm, Yb, and Lu). The upper and lower electrodes are made of SrRu〇3, wherein the clever pole can also be made of Pt, IK)x and other materials, and the patent has a higher valence than the iron atom. The magnetic metal atom replaces the iron source:: the barium ferrite crystal can be maintained at neutral while avoiding leakage, but the above method tends to lower the ferroelectricity of the ferrite wire and cause the performance of the memory device to deteriorate. . ~ It can be seen that in the ferroelectric memory device, the properties of the ferroelectric layer of ferrite can affect the performance of the entire skirt, and generally the maintenance method is used to maintain or increase the polarity of iron (4). . At present, the methods commonly used for preparing ferrite 12916162 films are mainly pulsed laser deposition, RF magnetron sputtering and chemical solution deposition, in which chemical solution deposition is used. It is a hot topic for the current research and development in the industry. For example, Uchida et al. used isopentane oxidized [Bi(0-b C5Hn)3] and iron bismuth acetylacetonate, Bi(CH3COCHCOCH3)3 and 2-methoxyethanol as pioneers. Then, the precursor is coated on a substrate, and then annealed at a temperature of 500 ° C to obtain a barium ferrite layer (H. Uchida et al., Jpn. J. ApplPhys. f part 2, 44? L561 (2005)). However, in the above documents, the precursor has a good chemical activity, is very sensitive to moisture, is extremely difficult to handle during preparation, and affects the reproducibility of film preparation. According to the above literature, the barium ferrite film needs to be annealed at a temperature of 500 to 650 ° C or higher. Therefore, in order to prepare a barium ferrite film by chemical solution deposition, the industry still needs to find a better precursor and effective Improve production reproducibility and reduce annealing temperature. From the above, it is known that there is still a demand in the industry for a capacitor having a barium ferrite ferroelectric layer having high stability and low leakage properties, and a capacitor having high reproducibility. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a capacitor having a high stability and low leakage property of a ferroelectric layer of barium ferrite, and having high fabrication reproducibility and being prepared at a lower annealing temperature. The method of making capacitors. The capacitor having a ferric acid ferroelectric layer of the present invention comprises a substrate, a stack of electrodes disposed on the lower electrode of the substrate, and a conductive layer 8 1296162 formed on the lower electrode, and a conductive oxide layer is formed on the conductive oxide A ferroelectric layer of ferrite on the layer and a stack of electrodes on the ferroelectric layer of ferrite. The conductive oxide layer is made of a perovskite structural material, which is nickel (= lanthamm nickelate, (4) called) or lead strontium (4) (tetra) metaplumbate, BaPb03). The method for preparing a capacitor having a ferroelectric layer of ferric lanthanum ferrite comprises a step T column on the substrate, a lower electrode and a conductive oxide layer made of a perovskite structure, and the conductive layer A ferroelectric layer of ferrite and a lower electrode are sequentially formed on the oxide layer, wherein the perovskite structure material is selected from the group consisting of nickel acid and strontium lead. The capacitor of the invention has the conductive oxide layer, in particular, the conductive oxide layer is made of a -about titanium ore structure material (barium nickelate or lead acid lock). This material is also calcium as barium ferrite. Titanium ore structure, so the compatibility is higher: and = help to improve the crystal of iron (four), plus the bismuth citrate or the wrong acid, the lattice constant is similar to the ferric acid, making the ferric acid rendezvous Between the growth direction of the titanium ore structural material, the σ曰曰I·I and the stability of the ferric ferroelectric layer are higher, and the capacitor of the present invention is used for subsequent use, for example, in memory, etc. When installed, the leakage can be reduced. Further, the method of manufacturing the capacitor of the present invention also improves the reproducibility of the subsequent ferrite ferroelectric layer due to the presence of the conductive oxide layer. [Embodiment] The above-mentioned and other technical contents of the present invention 'features and effects are clearly shown in a preferred embodiment of the method, and a detailed description of the six specific examples. . Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals. Referring to FIG. 1, a preferred embodiment of a capacitor having a ferroelectric layer of barium ferrite ferrite comprises a substrate 1, a lower electrode disposed on the substrate 1, and a conductive oxide formed on the lower electrode 2. Layer 3, a ferroelectric ferroelectric layer 4 formed on the conductive oxide layer 3, and an electrode 5 stacked on the ferroelectric layer*. In the present invention, the conductive oxide layer 3 is made of a perovskite structure material selected from the group consisting of strontium nickelate and barium strontium titanate. The substrate 1 has a base layer 11, a diffusion barrier layer 12 stacked on the base layer 11, and an adhesion layer stacked on the diffusion barrier layer 12 ( Adhesi〇n layer)13. It should be noted that the structure of the substrate 1 is not limited to the combination of the above three layers, and may be changed according to actual needs or directly selected from commercially available products. The car prince, the base layer π is made by Shi Xi. The diffusion barrier layer 12 is disposed to prevent the base layer U from being formed because the heat is diffused. Preferably, the diffusion barrier layer is made of a material selected from the group consisting of the following: · · Dioxite, aluminum nitride, titanium nitride and nitride button. The purpose of the adhesion layer 13 is to bond the lower electrode 2 and the diffusion barrier layer 12. Preferably, the adhesion layer 13 is made of a material selected from the group consisting of titanium dioxide and titanium. And 钽. Preferably, the lower electrode 2 and the upper electrode 5 are respectively composed of a conductive metal 10 1296162. The conductive metal is selected from the group consisting of: the beginning, the silver, and the shu. According to the invention, Zhongcai, the conductive metal is Ming. It should also be noted that the thickness of each layer of the capacitor can be adjusted according to actual needs. / Preferably, the capacitor further comprises an oxide electrode layer (not shown in the drawing) disposed between the upper electrode 5 of the ferrite ferroelectric layer 4 ”. The oxide electrode layer is set for the purpose of To improve the properties of the entire capacitor, and preferably made of the same material as the material reduction layer 3 (made of acid recording or lead strontium). The capacitor of the present invention has a ferric acid (four) electrical layer. The preparation of the preferred embodiment comprises the steps of: forming a lower electrode 2 on the substrate 1 and a conductive oxide layer 3 made of a perovskite structure material, and a V oxide layer. Forming a ferric acid iron layer 4 and a power-on °, and the medium-yield titanium ore structure material is selected from the group consisting of strontium nickelate and barium lead. The materials which can be used for the respective layers of the capacitor are as described above, and are not described here. The lower electrode 2 and the upper electrode 5 can be formed by, for example, sputtering or electron gun evaporation, and in one embodiment of the present invention, The lower electrode 2 and the upper electrode 5 are each formed of platinum as a target and formed by sputtering. The electro-oxide layer 3 can be prepared by referring to the following documents: c·c. Yailg? Μ· S* Chen^ Τ· J. Hong? CM Wu5 JM Wu and TB WU? ApPl Phys· Lett., 66, 2643 (1995) ^ MS Chen5 TB Wu5 and JM Wu5 AppL Phys, Lett.. 685 1430(1996) ^ YR Luo 1296162 Coffee JM Wu, Liu /. ~· Ze",79, 3669(2〇〇ι), and c & Liang , JM Wu, and MC Chang, Appl. Phys. Letu> 81j 3624 (2002). In the specific example of the present invention, the conductive oxide layer 3 is made of bismuth citrate or a wrong acid, and Preferably, the ferrite ferroelectric layer 4 is formed by radio frequency sputtering or chemical solution deposition. S is prepared by the RF clock method. When the acid ferroelectric layer 4 is used, the Bi2Q3&Fe2〇3 powder of a specific ratio (1··1~2:丨) is firstly prepared, and then the barium ferrite target (BixFe〇3, and finally the second ceramic) is prepared by a conventional ceramic method. Using the RF sputtering method, the background pressure of the machine used is controlled to 1 (r5 t〇rr, the oxygen and argon are introduced, and the working pressure of 20 to 40 mtorr is maintained. And heating the substrate 1 to 350. (: sputtering, the ferric strontium ferrite layer 4 is formed after a period of time. When the ferric strontium ferrite layer 4 is prepared by chemical solution deposition, Preparing a precursor, applying the precursor to the conductive oxide layer 3 and annealing at a suitable temperature to form the ferroelectric ferroelectric layer 4, the precursor having an iron Acid-radicai salt 〇f Fe, an acid salt and a solvent. Preferably, the iron acid salt is selected from the group consisting of iron ferric nitrate, ferric nitrate (Fe(N〇3)3), ferric acetate (Fe) (C2H302) 3] and one of these combinations. Preferably, the acid salt of the bismuth is selected from the group consisting of bismuth acetylacetonate, 12 1296162
Bi(CH3COCHCOCH3)3]、石肖酸絲[[bismuth nitrate，Bi(N〇3)3] 、醋酸鉍[bismuth acetate，Bi(C2H302)3]及此等之一組合。 由於M原子於熱處理過程中可能會損失，而為了使鐵 酸鉍維持為鈣鈦礦結構，通常會藉由添加較多莫耳比例的 鉍之酸鹽來預防損失，較佳地，該鉍之酸鹽與該鐵之酸鹽 的添加莫耳比例範圍係介於1 ·· 1與2 ·· 1之間。更佳地， 該鉍之酸鹽與該鐵之酸鹽的添加莫耳比例範圍係介於丨·· i 與1.2 ·· 1之間。 較佳地，該先驅物所具有之溶劑係為一碳數範圍在1〜4 之有機酸與-醇類之組合 更佳地，該有機酸為丙酸或醋 酸，該醇類為2-甲氧基乙醇或2_乙氧基乙醇。而於本發明 之一具體例中，該溶劑為丙酸與2•甲氧基乙醇之一組合。 較佳地’該溶劑中之有機酸與該醇類之比例係介於】： 1至5 : 1之間。更佳地’該有機酸與該醇類之比例係介於 3 : 1至4 : 1之間。Bi(CH3COCHCOCH3)3], bismuth nitrate (Bi(N〇3)3], bismuth acetate, Bi(C2H302)3, and a combination thereof. Since the M atom may be lost during the heat treatment, in order to maintain the barium ferrite structure as a perovskite structure, the loss is usually prevented by adding a more molar ratio of the bismuth citrate, preferably, The molar ratio of the acid salt to the iron acid salt is between 1··1 and 2··1. More preferably, the molar ratio of the acid salt of the bismuth and the iron salt is between 丨·· i and 1.2··1. Preferably, the solvent of the precursor is preferably a combination of an organic acid and an alcohol having a carbon number ranging from 1 to 4, and the organic acid is propionic acid or acetic acid, and the alcohol is 2-A. Oxyethanol or 2-ethoxyethanol. In one embodiment of the invention, the solvent is one of propionic acid and methoxyethanol. Preferably, the ratio of the organic acid to the alcohol in the solvent is between: 1 and 5:1. More preferably, the ratio of the organic acid to the alcohol is between 3:1 and 4:1.
較佳地，該退火處理之溫度範圍係介於35〇〇c與彻。C 之間。更佳地，該退火處理之溫度範圍係介於 550°C 之間。 u L /、 <實施例> 1.製備電容器時’利用射頻濺鍍法製備鐵酸 [具艘例！】該導電氧化物層由絲酸網所製成 鉍鐵電層 參閱圖2，該具體例1 板1、一由鉑（以下簡稱為 鎳酸鑭（以下簡稱為『Ln〇 之電容器由下至上依序包含一基 『Pt』）所製成之下電極2、一由 』）所製成之導電氧化物層3、一 13 1296162 鐵酸鉍（以下簡稱為『BF0』）鐵電層4及一由鉑所製成之上 電極5’其中該基板i由下至上依序具有一由矽所製成之基 底層11、一由二氧化矽所構成之擴散阻絕層12及一由二氧 化鈦所製成之附著層13(該具體例丨之電容器的結構由上至 下依序疊置為 Pt/BFO/LNO/Pt/Ti〇2/Si〇2/Si)。 • 該具體例丨之電容器的製法包含以下步驟：於該基板 U由台灣國家奈米實驗室NDL所製造）上，利用射頻磁控錢 .鍍（RF magnetron sputtering)機台，並於一具有低於 5χ1〇一5 torr之基礎壓力的高真空環境系統中，於一濺鍍搶上放置鉑 作為靶材，並在室溫下，於該基底層u上依序進行濺鍍， 以製得總厚度為100 mm之該基板丨及該下電極2(由上至下 依序疊置為Pt/Ti〇2/Si〇2/Si)。接著利用射頻濺鍍法及射頻 磁控濺鍍機台，於一具有低於丨χ丨〇-5 t〇rr之基礎壓力的高 真空環境系統中，於一濺鍍槍上放置鎳酸鑭作為靶材，並 將溫度控制在350〇C以及將工作壓力設為10χ1〇-3 t〇rr，以 _ 於该下電極2上形成一厚度為200 nm之導電氧化物層3(由 、上至下依序疊置為LNO/Pt/TiCVSiOVSi)。再利用添加莫耳 • 比例為1 · 1 : 1之Bi2〇3及Fe2〇3粉末，以傳統陶瓷製法製備 鐵酸Μ革巴材（Bi^FeO3)，接著同樣利用上述射頻濺鍍法，將 該鐵酸鉍靶材放置於該濺鍍搶上及控制操作壓力為4〇χ1(Γ3 torr’同時以熱電偶（therm0C0Upie)來監控該基板1之溫度， 再將基板加熱至300。(：，於該導電氧化物層3上進行濺鍍， 以形成厚度為200 nm之鐵酸鉍鐵電層4(由上至下依序疊置 為BFO/LNO/Pt/TiCVSiCVSi)。最後同樣利用濺鍍法及以鉑 14 1296162 作為靶材’於該鐵酸鉍鐵電層4上進行濺鍍，以形成厚度 為100 nm之上電極5,並製得該具體例i之電容器。 【具體例2】該導電氧化物層由鉛酸鋇所製成 孩具體例2之電谷器的結構同樣如圖2所示，除了該 導電氧化物層3是由鉛酸鋇(以下簡稱為『Bp〇』)所製成之 外’其餘製程條件及各層的組成及厚度皆與該具體例i相 同，取後亦製得該電容器。（該具體例2之電容器的結構由 上至下依序疊置為 pt/BF〇/Bp〇/pt/Ti〇2/Si〇2/si) [比較例1】未設置該導電氧化物層 該比較例1之電容器的結構如圖3所示，除了未設置 口亥導電氧化物| 3以及於製備該鐵酸絲鐵電㉟4時將該基 板狐度加熱至350°C之外，其餘製程條件及各層的組成及 厚度皆與該具體例1相同，最後亦製得該電容器。（該比較 例1之電容器的結構由上至下依序疊置為Preferably, the temperature range of the annealing treatment is between 35 〇〇c and 。. Between C. More preferably, the annealing treatment has a temperature range of between 550 °C. u L /, <Examples> 1. When preparing a capacitor 'Preparation of ferric acid by radio frequency sputtering [With a ship case! The conductive oxide layer is made of a silk firic acid grid. Referring to Fig. 2, the specific example 1 is a plate 1 and a platinum (hereinafter referred to as "nickel strontium hydride" (hereinafter referred to as "Ln 〇 capacitor from bottom to top" The conductive oxide layer 3 and the 13 132962 ferrite (hereinafter referred to as "BF0") ferroelectric layer 4 and the electrode 2, which is made of a base "Pt") An upper electrode 5' made of platinum, wherein the substrate i has a base layer 11 made of tantalum, a diffusion barrier layer 12 made of ruthenium dioxide and a titanium dioxide layer from bottom to top. The adhesion layer 13 is formed (the structure of the capacitor of this specific example is sequentially stacked from top to bottom to be Pt/BFO/LNO/Pt/Ti〇2/Si〇2/Si). • The capacitor of this specific example includes the following steps: on the substrate U manufactured by NDL, National Taiwan Laboratory, using RF magnetron sputtering machine, and having a low In a high vacuum environment system with a base pressure of 5χ1〇5 torr, platinum is used as a target on a sputtering plate, and sputtering is sequentially performed on the substrate layer u at room temperature to obtain a total The substrate 丨 and the lower electrode 2 having a thickness of 100 mm are sequentially stacked from top to bottom to be Pt/Ti〇2/Si〇2/Si. Then, using a radio frequency sputtering method and a radio frequency magnetron sputtering machine, a nickel strontium oxide is placed on a sputtering gun in a high vacuum environment system having a base pressure lower than 丨χ丨〇-5 t〇rr. a target, and the temperature is controlled at 350 ° C and the working pressure is set to 10 χ 1 〇 -3 t rr to form a conductive oxide layer 3 having a thickness of 200 nm on the lower electrode 2 (from, up to The next layer is sequentially stacked as LNO/Pt/TiCVSiOVSi). Then, using Bi2〇3 and Fe2〇3 powders with a molar ratio of 1·1:1, a barium ferrite leather material (Bi^FeO3) is prepared by a conventional ceramic method, and then the above RF sputtering method is also used. The barium ferrite target is placed on the sputtering and the control operating pressure is 4〇χ1 (Γ3 torr' while the temperature of the substrate 1 is monitored by a thermocouple (therm0C0Upie), and the substrate is heated to 300. (:, Sputtering is performed on the conductive oxide layer 3 to form a barium iron ferrite layer 4 having a thickness of 200 nm (stacked from top to bottom in order to BFO/LNO/Pt/TiCVSiCVSi). Finally, sputtering is also used. The method and the platinum 14 1296162 as a target 'sputtered on the ferroelectric ferroelectric layer 4 to form the electrode 5 having a thickness of 100 nm, and the capacitor of the specific example i was obtained. [Specific example 2] The conductive oxide layer is made of barium strontium hydride. The structure of the electric grid device of the specific example 2 is also shown in FIG. 2 except that the conductive oxide layer 3 is made of lead bismuth (hereinafter referred to as "Bp〇"). The remaining process conditions and the composition and thickness of each layer are the same as in the specific example i, and the capacitor is also obtained after taking it. (The structure of the capacitor of this specific example 2 is sequentially stacked from top to bottom to pt/BF〇/Bp〇/pt/Ti〇2/Si〇2/si) [Comparative Example 1] The conductive oxide layer is not provided. The structure of the capacitor of Comparative Example 1 is as shown in FIG. 3, except that the conductive oxide oxide is not provided, and the substrate is heated to 350 ° C when the ferric ferroelectric 354 is prepared. The conditions and the composition and thickness of each layer were the same as in the specific example 1, and the capacitor was finally produced. (The structure of the capacitor of Comparative Example 1 was sequentially superposed from top to bottom.
Pt/BFO/Pt/Ti〇2/Si〇2/Si) 2·製備電容器時’則化學沉積法製備鐵酸麵鐵電層 [具體例3】 邊具體例3之電容器的結構同樣如_ 2所示，除了使 用化學沉積法製備鐵酸鉍鐵電層4以及利用鈦（以下簡稱為 『Τι』）作為該附著層13的材料之外，其餘製程條件及各層 的組成及厚度皆與該具體例1相同，最後亦 。(該具體例3之電容器的結構由上至下依序叠電置二Pt/BFO/Pt/Ti〇2/Si〇2/Si) 2. When preparing a capacitor, a ferrite ferroelectric layer is prepared by a chemical deposition method [Specific Example 3] The structure of the capacitor of the specific example 3 is also the same as _ 2 As shown, in addition to the preparation of the barium ferrite ferroelectric layer 4 by chemical deposition and the use of titanium (hereinafter referred to as "Τι") as the material of the adhesion layer 13, the remaining process conditions and the composition and thickness of each layer are specific to the specific Example 1 is the same, and finally. (The structure of the capacitor of this specific example 3 is sequentially stacked from top to bottom.
Pt/BF0/LN0/Pt/Ti/Si02/Si) 忒具體例3之電容器之鐵酸鉍鐵電層4的製法為：首 15 1296162 先以3 : 1的比例混合丙酸及2-曱氧基乙醇，而製得一溶劑 ’再將此溶劑於110。(：下加熱1小時，以去除水分。將50 毫升之溶劑冷卻至80°C，再於該溶劑中加入5.06克之醋酸 Μ及4.4克乙醯基丙酮酸鐵（醋酸鉍與乙醯基丙酮酸鐵之莫 耳比例為1.05 : 1 )，待醋酸祕及乙醯基丙酮酸鐵溶解後，即 製得一溶液。然後，將該溶液於8〇。(：下加熱迴流2小時， 即製得一先驅物（Bii^FeOO。利用旋塗機（spi n coater，由台 灣擎邦公司製造）將該先驅物旋塗於該導電氧化物層3上， 塗佈步驟係每次以2400轉/分之速度塗佈約3〇秒，且在每 -人塗佈後’將其放置在一加熱板上，於常壓及丨5〇〇c溫度 下加熱5分鐘，再於350°C溫度下熱解10分鐘。接著，重 複數次上述塗佈步驟後，於35〇cC溫度下退火1〇分鐘，便 於忒導電氧化物層3上形成該鐵酸鉍鐵電層4，且該鐵酸鉍 鐵電層4的厚度為200 nm。 [具體例4、5及6】 除了勿別將退火溫度改變為45〇°c、500°C及550°C之 外，其餘製程條件及各層的組成及厚度皆與該具體例3相 同，最後亦分別製得具體例4、5及6之電容器。 【比較例2】 名比較例2之電容器的結構與該比較例丨相同（如圖3 所示），除了未設置該導電氧化物層3之外，其餘製程條件 及各層的組成及厚度皆與該具體{列3相同，最後亦製得該 比較=2之電谷裔。（該比較例2之電容器的結構由上至下 依序疊置為 Pt/BFO/Pt/Ti/Si〇2/Si> 16 1296162 [比較例3、4及5] 除了分別將退火溫度改變為450°C、500°C及550。(：之 外，其餘製程條件及各層的組成及厚度皆與比較例2相同 ，最後亦分別製得比較例3、4及5之電容器。 〈測試〉將具體例1〜6及比較例1〜5分別進行以下測試： (1) 晶體結構分析•·上述具體例1〜6、比較例1及4分別於 形成鐵酸鉍鐵電層之步驟後，利用X射線繞射分析儀（ 曰本Rigaku公司所製造，型號為D/DAX-IIB)分析該鐵 酸鉍鐵電層的晶體結構。具體例1、2及比較例1之結 果分別如圖4中之（b)、（a)及（c)所示，具體例3〜6及比 較例4之結果如圖5及6所不。 (2) 表面形態分析：於形成鐵酸鉍鐵電層之步驟後，比較 例1及具體例1、2分別利用原子力顯微鏡（atomic force microscopy，由德國Veeco公司所製造，型號為 DI 3100)來觀察該鐵酸鉍鐵電層的表面形態，而比較例 2及具體例3〜6則分別使用掃描電子顯微鏡（scanning electron microscopy，由日本JEOL公司所製造，型號 為JSM 6500F)來觀察該鐵酸鉍鐵電層的表面形態，比 較例1及具體例1、2之結果分別如圖7中之（a)、（b)及 (c)所示，比較例2及具體例3〜6之結果如圖8所示。 (3) 微觀結構分析：比較例1及具體例1分別於形成鐵酸 鉍鐵電層之步驟後，利用掃描穿透式電子顯微鏡 (scanning transmission electron microscope(STEM)，由 曰本JEOL公司所製造，型號為JEM-3000F)，另串接 17 1296162 一高角度環形暗視野（high-angle annular dark-field， HAADF)偵測器及一能散X射線分光計（energy dispersion X-ray spectrometer，EDS)，於室溫、300KV 及約0.17 nm之解析度限制下，進行該鐵酸鉍鐵電層之 高解析 z-對比影像（high_resoluion z-contrast image)及組 成掃描剖面（compositional scanning profile)的分析，於 圖9中，比較例1之結果如（b)所示，具體例1之結果 則如（a)、（c)及（d)所示。 (4) 介電常數（dielectric constant)及散逸因子（loss tangent ，tanS)分析：將兩根探針分別點觸比較例1〜5及具體 例1〜6之電容器中的上電極5及下電極2，接著再利用 電阻、電容、電感量測儀（由美國HP公司製造，型號 為HP4284A)並於不同頻率下進行介電常數及散逸因子 的量測。比較例1及具體例1、2之結果如圖1 〇所示 ，具體例3〜6及比較例2〜5之結果分別如圖11、12、 13及14所示。 (5) 漏電性質分析：利用漏電流測試儀（pA meter/DC voltage source，由美國HP公司所製造，型號為HP 4140B)且於直流電源下觀測具體例1〜6及比較例1〜5 於不同電場（electric field)下之漏電密度（leakage current density)變化。具體例1、2與比較例1之結果如圖15 所示，具體例3及比較例2之結果分別如圖17之曲線 B及A所示，具體例4及比較例3之結果分別如圖18 之曲線B及A所示，具體例5及比較例4之結果分別 18 1296162 如圖19之曲線B及A所示，具體例6及比較例5之結 果分別如圖20之曲線B及A所示。 (6)鐵電性質分析：具體例1、2及比較例1是利用商用標 準鐵電量測機器（由美國Raduant Technologies公司所製 造，型號為RT6000)並於1 kHz之頻率、室溫及不同電 場下，進行電滯曲線（ferroelectric hysteresis loop)的分 析。具體例1、2及比較例1之結果分別如圖21中之 曲線B、C及A所示。 <結果> (1)晶體結構分析： I. 具體例1、2與比較例1之比較（利用射頻濺鍍法製備 鐵酸鉍鐵電層）：參閱圖4,（a)、（b)及（c)分別表示具 體例2、1及比較例1之結果。於圖4中，由（c)之 XRD圖看來，可發現比較例1之BFO層是以無規則 位向於下電極層2(Pt)上成長，而由（b)之XRD圖看 來，則可發現具體例1之BFO層為（100)位向，以及 由（a)之XRD圖看來，可發現具體例2之BFO層為 (111)位向，由上述比較可知，比較例1之BFO層為 不規則位向，結晶性質不佳；而相反地，具體例1、 2之BFO層的結晶方向較一致，且該BFO層之位向 與該下電極層2(具體例1為LNO，具體例2為BPO) 之位向相似。由此可知，具體例1及2之BFO層確 實具有較佳之結晶性質，顯見成長於LNO或BPO上 之BFO具有較佳之晶體結構。此外，具體例1及2 19 1296162 之BFO層的結晶溫度為300°C，而比較例1之結晶 溫度為350°C，可證明成長於LNO或BPO上之BFO 可於較低溫度下結晶。 II.具體例3〜6與比較例4之比較（利用化學沉積法製備 鐵酸鉍鐵電層）：參閱圖5，可發現由於LNO具有 (100)及（200)之優選位向，所以具體例3〜6之BFO層 的（100)及（200)位向皆被強化，如此證明具體例3〜6 之BFO層是沿著LNO之位向成長。再參閱圖6，曲 線a、b分別為退火溫度皆為500°C之具體例5及比 較例4的XRD結果，可發現具體例5之BFO層具有 (100)及（200)位向，而比較例4則未具有一定位向， 由此比較可知，具體例5具有較佳之結晶性質。因 此，具體例3〜6之BFO層確實具有較佳之結晶性質 ，顯見成長於LNO上之BFO具有較佳之晶體結構。 (2)表面形態分析： I. 具體例1、2與比較例1之比較（利用射頻濺鍍法製備 鐵酸鉍鐵電層）：參閱圖7，（a)、（b)及（c)分別為比較 例1、具體例1及具體例2之結果。於圖7中，可發 現比較例1、具體例1及具體例2之BFO層的方均 根表面粗糙度（root-mean-square surface roughness)分 別為7.2 nm、1.8 nm及4.2 nm，而晶粒尺寸分別估 計為180 nm、35 nm及70 nm，由此可見該具體例1 及2具有較小之晶粒尺寸，這可能是因為LNO及 BPO可提供較多數量之成核位置，使得BFO之晶粒 20 1296162 尺寸較小，並可讓BFO層具有均勻分布之晶粒，且 未具有多孔性及第二相。因此證明，具體例1及2 之BFO層由於分別成長於LNO及BPO上，故具有 較佳之表面形態。 II. 具艘例3〜6與比較例2之比較（利用化學沉積法製備 鐵酸鉍鐵電層）：參閱圖8，可發現比較例2之晶粒 大小遠大於具體例3〜6，顯見具體例3〜6之表面形態 較佳。此外，具體例3〜6之晶粒大小並無太大變化 ，可見退火溫度之增加並不會影響晶粒大小。因此 證明，具體例3〜6之BFO層由於成長於LNO上，故 具有較佳之表面形態。 (3)微觀結構分析： I. 具體例1、2與比較例1之比較（利用射頻濺鍍法製備 鐵酸鉍鐵電層）：參閱圖9,（a)及（b)分別顯示具體例 1及比較例1之STEM-HAADF圖及組成掃描剖面， 可發現該比較例1形成一界面層（interface layer)，此 界面層是由Bi、Fe及Pt所組成，由EDS鑑定其原 子比例分別為0.24、0·68及0.08，且該比較例1之 BFO層的表面粗糙，而反觀（a)，該具體例1之BFO 層的表面平滑，且該具體例1並未形成一明顯界面 層，因此證明成長於LNO上之BFO層具有較佳之化 學均質性（chemical homogeneity)。此外，圖 9 之（c) 顯示該具體例1之BFO層於LNO上之橫剖面圖，可 發現BFO層與LNO層之間的界面具有原子級的界面 21 1296162 粗糙度，料可證明該具體例i並未形成—明顯界 面。圖9之⑷顯示該具體例mF〇層的高解析 TEM圖以及其對應[〇〇1]晶帶軸（贿咖）繞射圖， 由此圖可看出具體例kBF〇層確實呈現結晶狀態 〇 (4)介電常數及散逸因子分析： I·具體例1、2舆比較例1之比較（利用射頻濺鍍法製備 鐵酸鉍鐵電層）：參閱圖10，⑷及（b)分別顯示介電 常數及散逸因子之結果。由（a)來看，隨著頻率的增 加，比較例1之介電常數會降低，而具體例丨及2 之介電常數則未有明顯的變化，此顯示具體例1及2 具有穩定的介電常數值。由（b)來看，隨著頻率的增 加，該比較例1之散逸因子會降低，而具體例1及2 之散逸因子則未有明顯的變化，顯示具體例1及2 具有穩定的散逸因子。因此證明，具體例1及2可 維持穩定之介電常數及散逸因子。 II·具體例3〜6與比較例2〜5之比較（利用化學沉積法製 備鐵酸鉍鐵電層）：圖11為具體例3及比較例2之介 電常數及散逸因子的比較，可發現具體例3之介電 常數較該比較例2之介電常數為高，而該具體例3 之散逸因子則與該比較例2之散逸因子相近。同樣 地，見圖12，具體例4與比較例3亦可發現相同之 結果，而圖13及圖14可看出，具體例5、6之介電 常數分別較該比較例4、5之介電常數為高，而具體 22 1296162 例5、6之散逸因子則較比較例4、5之散逸因子為 低。因此，相較於比較例2，具體例3〜6具有較低且 較一致的散逸因子數值，其介電常數也較高（此一現 象隨著退火溫度的增加而更為明顯），如此證明在 LNO層上的BFO層具有較佳的介電性質。 (5)漏電性質分析： I. 具體例1、2與比較例1之比較（利用射頻濺鍍法製備 鐵酸鉍鐵電層）：參閱圖15，可發現BFO/LNO(具體 例1)之電流密度小於該BFO/Pt(比較例1)之電流密度 ，以及在小於1〇2 KV/cm之電場下，BFO/BPO(具體 例2)之電流密度小於該比較例1之電流密度，因此 具體例1及2之電容器具有較低之漏電性質，同時 證明本發明之電容器藉由提供一導電氧化物層（LN〇 或BPO)，而可使BFO之漏電性降低。 II·具體例3〜6舆比較例2〜5之比較（利用化學沉積法製 備鐵酸鉍鐵電層）：參閱圖16,可發現隨著退火溫度 的降低，漏電流密度也會隨著降低，也就是漏電流 岔度大小為：350°C(具體例3)< 450°C(具體例4)< 500°C(具體例5)< 550°C(具體例6)，可見退火溫度 越低可獲得較低的漏電流密度。參閱圖17,隨著外 加電場的增加，亦可發現該具體例3之漏電流密度 較该比較例2之漏電流密度為低，但是於圖1 8〜2〇 中’則發現具體例4〜6之漏電流密度較比較例3〜5 之漏電流密度為高，如此證明當於LNO層上形成 23 1296162 BFO時，於較低退火溫度下可獲得較低之漏電流密 度，而於Pt上形成BF0時，則需要較高之退火溫度 才可獲得較低之漏電密度。 (6)鐵電性質分析： I·具想例1、2與比較例i之比較（利用射頻減链法製備 鐵酸鉍鐵電層）：參閱圖21，a、B及c分別表示比 杈例1、具體例1及具體例2之電滞曲線，可發現比 較例1並未具有飽和電滯曲線，而具體例丨、2則具 有飽和之電滞曲線，顯見具體例1、2可維持鐵電性 質。 ，，、不上所述，本發明之具有鐵酸鉍鐵電層之電容器由於 具有一導電氧化物層，特別是該導電氧化物層是由一鈣鈦 礦結構材料⑽關絲酸鋇）所製成，使得該㈣簡電層 的結晶性較佳以及穩定性較高，且本發明之電容器在後續 用於例如記憶體等裝置時，低漏電現象。此外，本發 明之電容器的製法亦因為該導電氧化物層之存在，而讓後 續鐵㈣鐵電層的製作再現性提高，且可使用射頻㈣法 或是化學溶液沉積法來製備鐵酸鉍鐵電層。 惟以上所述者，僅為本發明之較佳實施例而已，當不 月匕以此限疋本發明實施之範圍，即大凡依本發明申請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1疋一不思圖’說明本發明之具有鐵酸鉍鐵電層之 24 1296162 電容器之一較佳實施例的結構； 圖2是一示意圖，說明本發明之具有鐵酸絲鐵電層之 電容器之一具體例的結構； 圖3是一示意圖，說明本發明之具有鐵酸鉍鐵電層之 電容器之一比較例的結構； 圖4是XRD圖，（a)、（b)、（c)分別說明具體例2、具體 例1及比較例1之鐵酸叙層的晶體結構分析； 圖5疋xrd圖，說明具體例3〜6之鐵酸絲層的晶體結 構分析； 圖6是XRD圖，說明具體例5及比較例4之鐵義詹 的晶體結構分析比較，曲線a、b分別為具體例5及比較例 4的XRD結果； 圖7是-表面形態分析圖，說明具體例i、具體例2及 比較例1之鐵酸麵層的表面形態比較（比較们及具體例i 、2之結果分別如圖7中之（a)、（1))及（〇所示” 圖8是一表面形態分析圖，說明具體例3〜6及比較例2 之鐵酸鉍層的表面形態比較； 圖9是一微觀結構分析圖， | 口兄咧具體例1及比較例1 之微觀結構分析’其中（a)及彳公μ % - ϋ 較例1之STEM-HAADF圖及組成掃描剖 例1之橫剖面圖，以及（d)顯示該具體例 析TEM圖以及其對應[001]晶帶軸繞射圖 ⑻及⑼刀別顯不該具體例1及該比 面’（c)顯示該具體 1之BFO層的高解 〜^ 丁仰仙）與頻率之關 ，說明該具體例1、具體例2及比 平乂例1之介電常數及 25 1296162 因子於不同頻率下之變化； 圖11疋"電书數（εΓ)/散逸因子（tan5)與頻率之關係圖’ 說明該具體例3及比較例2之介電常數及散逸因子於不同 頻率下之變化； 圖12是介電常數（Sr)/散逸因子（tan§)與頻率之關係圖， 說明該具體例4及比較例3之介電常數及散逸因子於不同 頻率下之變化；Pt / BF0 / LN0 / Pt / Ti / Si02 / Si) 忒 The specific example 3 of the capacitor ferrite ferroelectric layer 4 is made: first 15 1296162 first mixed propionic acid and 2-oxo in a ratio of 3:1 Based on ethanol, a solvent was prepared and the solvent was again at 110. (: heating for 1 hour to remove moisture. Cool 50 ml of the solvent to 80 ° C, then add 5.06 g of barium acetate and 4.4 g of iron acetylacetonate (the solution of barium acetate and acetylpyruvate) to the solvent. The molar ratio of iron is 1.05 : 1 ), and after the acetic acid secret and iron acetyl ketoacetate are dissolved, a solution is prepared. Then, the solution is heated at reflux for 2 hours. A precursor (Bii^FeOO. The precursor was spin-coated on the conductive oxide layer 3 by a spin coater (manufactured by Taiwan Gyungon Co., Ltd.), and the coating step was 2400 rpm each time. The speed is applied for about 3 sec seconds, and after each person coating, it is placed on a hot plate, heated at atmospheric pressure and 丨5〇〇c for 5 minutes, and then heated at 350 °C. After 10 minutes of the coating step, the coating step is repeated several times, and then annealed at a temperature of 35 ° C C for 1 minute to facilitate formation of the barium ferrite ferroelectric layer 4 on the conductive oxide layer 3, and the barium iron ferrite The thickness of the electric layer 4 is 200 nm. [Specific Examples 4, 5, and 6] In addition to not changing the annealing temperature to 45 〇 ° C, 500 ° C, and 550 ° C The remaining process conditions and the composition and thickness of each layer were the same as in the specific example 3. Finally, the capacitors of the specific examples 4, 5 and 6 were separately prepared. [Comparative Example 2] The structure of the capacitor of Comparative Example 2 and the comparative example The same (as shown in Figure 3), except that the conductive oxide layer 3 is not provided, the other process conditions and the composition and thickness of each layer are the same as the specific {column 3, and finally the comparison = 2 electric valley is also obtained. (The structure of the capacitor of Comparative Example 2 is sequentially stacked from top to bottom as Pt/BFO/Pt/Ti/Si〇2/Si> 16 1296162 [Comparative Examples 3, 4 and 5] except that the annealing temperature is respectively obtained Changed to 450 ° C, 500 ° C and 550. (:, the other process conditions and the composition and thickness of each layer are the same as in Comparative Example 2, and finally the capacitors of Comparative Examples 3, 4 and 5 were separately prepared. 〉 Specific examples 1 to 6 and comparative examples 1 to 5 were each subjected to the following tests: (1) Crystal structure analysis • The above specific examples 1 to 6 and comparative examples 1 and 4 were respectively after the step of forming a barium ferrite ferroelectric layer The iron was analyzed by an X-ray diffraction analyzer (manufactured by Sakamoto Rigaku, model D/DAX-IIB) The crystal structure of the ruthenium ferroelectric layer. The results of Specific Examples 1, 2 and Comparative Example 1 are shown in (b), (a) and (c) of Figure 4, and the results of Specific Examples 3 to 6 and Comparative Example 4, respectively. 5 and 6 (2) Surface morphology analysis: After the step of forming a ferroelectric layer of ferrite ferrite, Comparative Example 1 and Specific Examples 1 and 2 were respectively subjected to atomic force microscopy (by Veeco, Germany). Manufactured, model DI 3100) to observe the surface morphology of the barium ferrite ferroelectric layer, and Comparative Example 2 and Specific Examples 3 to 6 respectively used scanning electron microscopy (manufactured by Japan JEOL Co., Ltd., model number is JSM 6500F) to observe the surface morphology of the ferroelectric layer of ferrite ferrite, the results of Comparative Example 1 and Specific Examples 1 and 2 are shown in (a), (b) and (c) of Figure 7, respectively, and Comparative Example 2 The results of Specific Examples 3 to 6 are shown in Fig. 8. (3) Microstructural analysis: Comparative Example 1 and Specific Example 1 were respectively produced by Sakamoto JEOL after a step of forming a ferroelectric layer of ferrite ferrite, using a scanning transmission electron microscope (STEM). , model number JEM-3000F), another series connected to 17 1296162 a high-angle annular dark-field (HAADF) detector and an energy dispersion X-ray spectrometer (EDS) The analysis of the high-resoluion z-contrast image and the compositional scanning profile of the barium ferrite ferroelectric layer at room temperature, 300 KV and a resolution limit of about 0.17 nm In Fig. 9, the results of Comparative Example 1 are shown in (b), and the results of Specific Example 1 are as shown in (a), (c), and (d). (4) Dielectric constant and loss tangent (tanS) analysis: the two probes are respectively touched to the upper electrode 5 and the lower electrode of the capacitors of Comparative Examples 1 to 5 and Specific Examples 1 to 6, respectively. 2. Then, the resistance, capacitance, and inductance measuring instruments (manufactured by HP, USA, model HP4284A) were used and the dielectric constant and the dissipation factor were measured at different frequencies. The results of Comparative Example 1 and Specific Examples 1 and 2 are shown in FIG. 1A, and the results of Specific Examples 3 to 6 and Comparative Examples 2 to 5 are shown in FIGS. 11, 12, 13, and 14, respectively. (5) Analysis of leakage properties: using a leakage current tester (pA meter/DC voltage source, manufactured by HP, USA, model HP 4140B) and observing specific examples 1 to 6 and comparative examples 1 to 5 under DC power supply The change in leakage current density under different electric fields. The results of Specific Examples 1, 2 and Comparative Example 1 are shown in Fig. 15. The results of Specific Example 3 and Comparative Example 2 are shown in curves B and A of Fig. 17, respectively, and the results of Specific Example 4 and Comparative Example 3 are as shown in the figure. The curves of B and A of 18 show that the results of specific example 5 and comparative example are respectively 18 1296162 as shown by curves B and A of FIG. 19, and the results of specific example 6 and comparative example 5 are respectively shown by curves B and A of FIG. Shown. (6) Analysis of ferroelectric properties: Specific examples 1, 2 and 1 are commercial standard iron electric measuring machines (manufactured by Radanant Technologies, USA, model RT6000) and are at a frequency of 1 kHz, room temperature and different Under the electric field, an analysis of the ferroelectric hysteresis loop was performed. The results of Specific Examples 1, 2 and Comparative Example 1 are shown as curves B, C and A in Fig. 21, respectively. <Results> (1) Crystal structure analysis: I. Comparison of specific examples 1, 2 and comparative example 1 (Preparation of barium ferrite ferric oxide layer by radio frequency sputtering): Refer to Fig. 4, (a), (b) And (c) show the results of Specific Examples 2, 1 and Comparative Example 1, respectively. In Fig. 4, it can be seen from the XRD pattern of (c) that the BFO layer of Comparative Example 1 is grown on the lower electrode layer 2 (Pt) in a random position, and the XRD pattern of (b) appears. It can be found that the BFO layer of the specific example 1 has a (100) orientation, and from the XRD pattern of (a), it can be found that the BFO layer of the specific example 2 has a (111) orientation, and the above comparison shows that the comparative example The BFO layer of 1 is in an irregular orientation, and the crystallinity is not good; on the contrary, the crystal orientation of the BFO layer of the specific examples 1 and 2 is relatively uniform, and the orientation of the BFO layer is opposite to the lower electrode layer 2 (Specific Example 1) The position of LNO, and the specific example 2 is BPO) is similar. From this, it is understood that the BFO layers of Specific Examples 1 and 2 have a good crystallinity, and it is apparent that BFO grown on LNO or BPO has a preferable crystal structure. Further, the crystallization temperature of the BFO layer of Specific Examples 1 and 2 19 1296162 was 300 ° C, and the crystallization temperature of Comparative Example 1 was 350 ° C, and it was confirmed that BFO grown on LNO or BPO can be crystallized at a lower temperature. II. Comparison of Specific Examples 3 to 6 and Comparative Example 4 (Preparation of ferroelectric layer of barium ferrite by chemical deposition method): Referring to FIG. 5, it can be found that since LNO has a preferred orientation of (100) and (200), it is specifically The (100) and (200) orientations of the BFO layers of Examples 3 to 6 were all strengthened, and it was confirmed that the BFO layers of Specific Examples 3 to 6 grew toward the position of LNO. Referring to Fig. 6, the curves a and b are the XRD results of the specific example 5 and the comparative example 4 in which the annealing temperatures are all 500 ° C, respectively, and it can be found that the BFO layer of the specific example 5 has the (100) and (200) orientations. Comparative Example 4 did not have a positioning direction, and as a result, it was found that Specific Example 5 had preferable crystal properties. Therefore, the BFO layers of Specific Examples 3 to 6 do have preferable crystal properties, and it is apparent that BFO grown on LNO has a preferable crystal structure. (2) Surface morphology analysis: I. Comparison of specific examples 1, 2 and comparative example 1 (preparation of ferroelectric ferroelectric layer by radio frequency sputtering): See Figure 7, (a), (b) and (c) The results of Comparative Example 1, Specific Example 1, and Specific Example 2, respectively. In FIG. 7, the root-mean-square surface roughness of the BFO layers of Comparative Example 1, Specific Example 1, and Concrete Example 2 was found to be 7.2 nm, 1.8 nm, and 4.2 nm, respectively, and the grain size. Estimated to be 180 nm, 35 nm, and 70 nm, respectively, which shows that the specific examples 1 and 2 have smaller grain sizes, which may be because LNO and BPO can provide a larger number of nucleation sites, making BFO crystal The granule 20 1296162 is small in size and allows the BFO layer to have uniformly distributed grains without porosity and a second phase. Therefore, it has been confirmed that the BFO layers of Specific Examples 1 and 2 have a preferred surface morphology since they are grown on LNO and BPO, respectively. II. Comparison of Ships 3 to 6 and Comparative Example 2 (Preparation of barium ferrite ferric oxide layer by chemical deposition method): Referring to FIG. 8, it can be found that the grain size of Comparative Example 2 is much larger than that of Concrete Examples 3 to 6. The surface morphology of Specific Examples 3 to 6 is preferred. Further, the grain sizes of the specific examples 3 to 6 did not change much, and it was found that the increase in the annealing temperature did not affect the grain size. Therefore, it has been confirmed that the BFO layers of Specific Examples 3 to 6 have a preferable surface morphology since they grow on the LNO. (3) Microstructure analysis: I. Comparison of specific examples 1, 2 and comparative example 1 (Preparation of barium ferrite ferric oxide layer by radio frequency sputtering): Referring to Fig. 9, (a) and (b) respectively show specific examples. 1 and the STEM-HAADF pattern of Comparative Example 1 and the composition scan profile, it can be found that the comparative example 1 forms an interface layer composed of Bi, Fe and Pt, and the atomic ratios thereof are identified by EDS. 0.24, 0·68, and 0.08, and the surface of the BFO layer of Comparative Example 1 was rough, and in contrast, (a), the surface of the BFO layer of the specific example 1 was smooth, and the specific example 1 did not form a distinct interface layer. Therefore, it is proved that the BFO layer grown on the LNO has better chemical homogeneity. In addition, (c) of FIG. 9 shows a cross-sectional view of the BFO layer of the specific example 1 on the LNO, and it can be found that the interface between the BFO layer and the LNO layer has an atomic interface interface 21 1296162 roughness, which can prove the specific Example i did not form - a distinct interface. Fig. 9(4) shows a high-resolution TEM image of the mF layer of this specific example and its corresponding [〇〇1] crystal ribbon axis (bribe) diffraction pattern. From this figure, it can be seen that the specific example kBF layer actually exhibits a crystalline state. (4) Analysis of dielectric constant and dissipation factor: I. Specific example 1, 2 舆 Comparison of Comparative Example 1 (Preparation of bismuth ferrite ferric oxide layer by RF sputtering): Refer to Figure 10, (4) and (b) respectively. The result of the dielectric constant and the dissipation factor. From (a), as the frequency increases, the dielectric constant of Comparative Example 1 decreases, and the dielectric constants of the specific examples and 2 do not change significantly. This shows that the specific examples 1 and 2 have stable Dielectric constant value. From (b), as the frequency increases, the dissipation factor of Comparative Example 1 decreases, while the dissipation factors of Specific Examples 1 and 2 show no significant change, indicating that Specific Examples 1 and 2 have stable dissipation factors. . Therefore, it was confirmed that the specific examples 1 and 2 can maintain a stable dielectric constant and a dissipation factor. II. Comparison of Specific Examples 3 to 6 with Comparative Examples 2 to 5 (Preparation of Ferric Barium Ferrate Ferroelectric Layer by Chemical Deposition): FIG. 11 is a comparison of dielectric constant and dissipation factor of Specific Example 3 and Comparative Example 2, The dielectric constant of Specific Example 3 was found to be higher than that of Comparative Example 2, and the dissipation factor of this Specific Example 3 was similar to the dissipation factor of Comparative Example 2. Similarly, as shown in FIG. 12, the specific results can be found in the specific example 4 and the comparative example 3. However, as shown in FIG. 13 and FIG. 14, the dielectric constants of the specific examples 5 and 6 are respectively compared with the comparative examples 4 and 5. The electrical constant is high, and the dissipation factor of the specific 22 1296162 cases 5 and 6 is lower than the dissipation factor of the comparative examples 4 and 5. Therefore, compared with Comparative Example 2, the specific examples 3 to 6 have lower and more consistent values of the dissipation factor, and the dielectric constant is also higher (this phenomenon is more pronounced as the annealing temperature increases), thus The BFO layer on the LNO layer has better dielectric properties. (5) Analysis of leakage properties: I. Comparison of specific examples 1, 2 and comparative example 1 (preparation of ferroelectric layer of barium ferrite by radio frequency sputtering): Referring to Fig. 15, BFO/LNO (specific example 1) can be found The current density is less than the current density of the BFO/Pt (Comparative Example 1), and the electric current density of the BFO/BPO (Specific Example 2) is less than the current density of the Comparative Example 1 under an electric field of less than 1〇2 KV/cm, The capacitors of Concrete Examples 1 and 2 have lower leakage properties, and it is also demonstrated that the capacitor of the present invention can reduce the leakage of BFO by providing a conductive oxide layer (LN〇 or BPO). II. Specific Examples 3 to 6 舆 Comparison of Comparative Examples 2 to 5 (Preparation of bismuth ferrite ferrite layer by chemical deposition method): Referring to FIG. 16, it can be found that as the annealing temperature is lowered, the leakage current density is also lowered. That is, the leakage current intensity is: 350 ° C (specific example 3) < 450 ° C (specific example 4) < 500 ° C (specific example 5) < 550 ° C (specific example 6), visible The lower the annealing temperature, the lower the leakage current density. Referring to FIG. 17, the leakage current density of the specific example 3 is lower than that of the comparative example 2 as the applied electric field increases, but in the case of FIG. 18 to 2, the specific example 4 is found. The leakage current density of 6 is higher than that of Comparative Examples 3 to 5, which proves that when 23 1296162 BFO is formed on the LNO layer, a lower leakage current density can be obtained at a lower annealing temperature, and on Pt. When BF0 is formed, a higher annealing temperature is required to obtain a lower leakage density. (6) Analysis of ferroelectric properties: I·Comparative with comparison example 1 and comparison with comparative example i (Preparation of ferroelectric ferroelectric layer by radio frequency chain reduction method): Referring to Fig. 21, a, B and c respectively represent comparison The hysteresis curves of Example 1, Specific Example 1 and Specific Example 2 show that Comparative Example 1 does not have a saturated hysteresis curve, while the specific examples 2 and 2 have a saturated hysteresis curve. It is apparent that the specific examples 1 and 2 can be maintained. Ferroelectric properties. The capacitor having the ferroelectric ferrite layer of the present invention has a conductive oxide layer, in particular, the conductive oxide layer is composed of a perovskite structural material (10). It is made such that the (four) simple electrical layer has better crystallinity and higher stability, and the capacitor of the present invention has a low leakage phenomenon when it is subsequently used in a device such as a memory. In addition, the capacitor of the present invention is also prepared by the presence of the conductive oxide layer to improve the reproducibility of the subsequent ferroelectric layer, and the radio frequency (tetra) method or chemical solution deposition method can be used to prepare the ferrite strontium ferrite. Electrical layer. However, the above is only the preferred embodiment of the present invention, and is not limited to the scope of the present invention, that is, the simple equivalent change made according to the scope of the invention and the description of the invention. And modifications are still within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the structure of a preferred embodiment of a 24 1296162 capacitor having a ferroelectric ferroelectric layer of the present invention; FIG. 2 is a schematic view showing the iron of the present invention. FIG. 3 is a schematic view showing the structure of a comparative example of a capacitor having a ferroelectric layer of ferric strontium ferrite according to the present invention; FIG. 4 is an XRD pattern, (a), (b) and (c) respectively, the crystal structure analysis of the ferrite layer of the specific example 2, the specific example 1 and the comparative example 1 is shown; FIG. 5 is a diagram showing the crystal structure of the ferrite layer of the specific examples 3 to 6. 6 is an XRD pattern illustrating the crystal structure analysis comparison of the specific example 5 and the iron sample of the comparative example 4. The curves a and b are the XRD results of the specific example 5 and the comparative example 4, respectively. FIG. 7 is a surface morphology analysis. The surface morphology of the ferrite coating layer of the specific example i, the specific example 2, and the comparative example 1 is compared (the results of the comparison and the specific examples i and 2 are respectively shown in (a), (1) of FIG. 7) and 〇"" Fig. 8 is a surface morphology analysis chart showing the tables of the barium ferrite layers of Specific Examples 3 to 6 and Comparative Example 2. Morphological comparison; Figure 9 is a microstructural analysis diagram, | Microstructure analysis of specific example 1 and Comparative Example 1 '(a) and 彳公μ % - S STEM-HAADF diagram and composition scan of Comparative Example 1 The cross-sectional view of the first embodiment, and (d) show the specific example TEM image and the corresponding [001] crystal ribbon axis diffraction pattern (8) and (9), the specific example 1 and the specific surface '(c) Displaying the high solution of the BFO layer of the specific 1 and the frequency, the dielectric constant of the specific example 1, the specific example 2, and the specific example 1 and the variation of the 25 1296162 factor at different frequencies are shown; 11疋"Number of books (εΓ)/Dissipation factor (tan5) versus frequencyFig. 'Describe the dielectric constant and dissipation factor of the specific example 3 and the comparative example 2 at different frequencies; Fig. 12 is a dielectric A graph showing the relationship between the constant (Sr)/dissipation factor (tan§) and the frequency, and the dielectric constant and the dissipation factor of the specific example 4 and the comparative example 3 at different frequencies;
圖13是介電常數⑹/散逸因子（tanS)與頻率之關係圖， 說明該具體例5及比較例4之介電常數及散逸因子於不同 頻率下之變化； 圖14疋介電常數（Sr)/散逸因子（tan§)與頻率之關係圖， 說明該具體例6及比較例5之介電常數及散逸因子於不同 頻率下之變化； 圖15是一電流密度與電場之關係圖，說明該具體例工 、具體例2及比較Μ !之電流密度於不同電場下之變化·， 圖16是-電流密度與電場之關係圖，說明該具體例 3〜6之電流密度於不同電場下之變化； 圖Π是-電流密度與電場之關係圖，說明該具體例3 及比較例2之電流密度於不同電場 、 兒勿r心交化，其中，曲線a 為比較例2之結果，曲線b為具體例2之結果· 圖18是一電流密度與電場之關係圖，說明該具體例4 及比較例3之電流密度於不同電場下之變化，Figure 13 is a graph showing the dielectric constant (6) / dissipation factor (tanS) versus frequency, showing the dielectric constant and the dissipation factor of the specific example 5 and the comparative example 4 at different frequencies; Fig. 14 疋 dielectric constant (Sr ) / dissipation factor (tan §) versus frequency, illustrating the dielectric constant and dissipation factor of the specific example 6 and comparative example 5 at different frequencies; Figure 15 is a relationship between current density and electric field, illustrating The current density of the specific example, the specific example 2, and the comparison are different under different electric fields. FIG. 16 is a graph showing the relationship between the current density and the electric field, and the current densities of the specific examples 3 to 6 are under different electric fields. The graph is a graph of current density versus electric field, indicating that the current densities of the specific example 3 and the comparative example 2 are different in the electric field, and the curve a is the result of the comparative example 2, and the curve b The result of the specific example 2 is a graph showing the relationship between the current density and the electric field, and the variation of the current density of the specific example 4 and the comparative example 3 under different electric fields.
再中，曲線A 為比較例3之結果，曲線b為具體例4之結果· 說明該具體例5 圖19是一電流密度與電場之關係圖 26 1296162 及比較例4之電流密度於不同電場下之變化，其中，曲線A 為比較例4之結果，曲線B為具體例5之結果； 圖20是一電流畨度與電場之關係圖，說明該具體例6 及比較例5之電流密度於不同電場下之變化，其中，曲線a 為比較例5之結果，曲線B為具體例6之結果；及 圖21是一電滯曲線圖，說明該具體例1、具體例2及 比較例1之極化率於不同電場下之變化，曲線A、B及C分 別為比較例1、具體例1及具體例2之結果。 27 1296162 【主要元件符號說明】 1…… .....基板 2 ····· ……下電極 11 ••… .....基底層 3 ••… ••…導電氧化物層 12····. ••…擴散阻絕層 4 ••… ••…鐵酸鉍鐵電層 13····， …··附著層 5 ••… .....上電極Further, the curve A is the result of the comparative example 3, the curve b is the result of the specific example 4, and the specific example 5 is shown in Fig. 19 is a relationship between the current density and the electric field. The current density of the graph 1 1296162 and the comparative example 4 is under different electric fields. The change of the curve A is the result of the comparative example 4, the curve B is the result of the specific example 5; FIG. 20 is a relationship diagram of the current mobility and the electric field, indicating that the current densities of the specific example 6 and the comparative example 5 are different. The change under the electric field, wherein the curve a is the result of the comparative example 5, the curve B is the result of the specific example 6; and FIG. 21 is a hysteresis curve diagram illustrating the specific example 1, the specific example 2 and the comparative example 1 The conversion rate was changed under different electric fields, and the curves A, B, and C were the results of Comparative Example 1, Specific Example 1, and Specific Example 2, respectively. 27 1296162 [Description of main component symbols] 1...... ..... Substrate 2 ····· ...... Lower electrode 11 ••... ..... Base layer 3 ••... ••... Conductive oxide layer 12 ····.••...Diffusion barrier layer 4••... ••... Ferric sulphide ferritic layer 13····, ...·· adhesion layer 5 ••...
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