TW201123570A - Tunnel magnetic resistance effect element and random access memory using same - Google Patents
Tunnel magnetic resistance effect element and random access memory using same Download PDFInfo
- Publication number
- TW201123570A TW201123570A TW099118380A TW99118380A TW201123570A TW 201123570 A TW201123570 A TW 201123570A TW 099118380 A TW099118380 A TW 099118380A TW 99118380 A TW99118380 A TW 99118380A TW 201123570 A TW201123570 A TW 201123570A
- Authority
- TW
- Taiwan
- Prior art keywords
- recording layer
- region
- layer
- magnetic
- magnetization
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y25/00—Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
- G11C11/161—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
- G11C11/165—Auxiliary circuits
- G11C11/1659—Cell access
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
- H01F10/3254—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
- H01F10/3268—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
- H01F10/3286—Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
- H01F10/329—Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/10—Magnetoresistive devices
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B61/00—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
- H10B61/20—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices comprising components having three or more electrodes, e.g. transistors
- H10B61/22—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices comprising components having three or more electrodes, e.g. transistors of the field-effect transistor [FET] type
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Power Engineering (AREA)
- Computer Hardware Design (AREA)
- Nanotechnology (AREA)
- Mram Or Spin Memory Techniques (AREA)
- Hall/Mr Elements (AREA)
Abstract
Description
201123570 及 件 元 應 效 阻 磁 隧 穿 之。 料} 材體 化憶 磁記 1直取 域垂存 領用機 術使隨 :技於{ ㈣之關AM] 說屬明RA® 明 所發之 技 #明本其 前 、、發 用 先 六 ί 使 Γ 近年來,MRAM ( Magnetic Random Access Memory ) 被開發作爲使用磁性體之記憶體。mram係以利用穿隧磁 阻(TMR: Tunneling Magnetoresistive )效應之 MTJ ( Magnetic Tunneling Junction)作爲要素元件,藉由控制 包含於MTJ元件之磁性體之磁化方向來記錄資訊。即使切 斷電源磁性體之磁化方向亦不會變化,可以實現記錄資訊 被保持之非揮發性動作。變化MTJ元件之磁化方向(資訊 之改寫)時除由外部施加磁場之方式以外,近年來被提出 者有對MTJ元件直接流入直流電流反轉其磁化之自旋傳輸 力矩(Spin Transfer Torque )磁化反轉(自旋注入磁化反 轉)方式。例如專利文獻1揭示:使用面內磁化材料作爲 記錄層,利用自旋注入磁化反轉之MT】元件以及將其集積 而成的記憶體:SPRAM ( Spin-transfer torque Magnetic Random Access Memory)。 SPRAM之集積度提升需要MTJ元件之微細化,但此時 MTJ元件中之磁化資訊之熱穩定性成爲問題。相對於反轉 MTJ元件之記錄層之磁化方向時必要之磁能,當環境溫度 引起之熱能變高時,即使未施加外部磁場或電流之情況下 -5- 201123570 議會引起磁化之反轉。伴隨尺寸之縮小MTJ元件之磁能亦 隨之減少,因此伴隨元件尺寸之微細化,該熱穩定性亦降 低。欲在微細區域維持熱穩定性,實現高信賴性之動作時 ,提高MTJ元件之記錄層材料之結晶磁氣異方性乃有效者 。目前爲止,使用結晶磁氣異方性較面內磁化材料爲高的 垂直磁化材料之MTJ元件已經被揭示(專利文獻2 )。另外 ,在適用垂直磁化材料之MTJ元件中,施加於記錄層內之 反磁場之影響係和面內磁化MTJ元件不同,對於減低磁化 反轉所要之電流密度(寫入電流密度)有所幫助。因此, 和面內磁化MTJ元件比較,具有可以減低寫入電流密度, 可以抑制消費電力之優點。 欲達成適用垂直磁化MTJ元件的SPRAM之更低消費電 力化時需要更加減低寫入電流密度。垂直磁化薄膜形成爲 多磁區構造時,基於電流之注入首先一部分磁區之磁化會 反轉,其周圍之磁壁之傳播會導致磁性薄膜全體之磁化反 轉現象乃習知者。和強磁性薄膜之磁化在全部區域同時反 轉之磁化反轉機構比較,該磁化反轉機構之磁化反轉所要 電流密度較少。但是,隨著MTJ元件之微細化進展,記錄 層使用之垂直磁化薄膜係採用不包含磁壁之單一磁區構造 ,磁化反轉成爲同時磁化反轉機構,因此寫入電流密度增 大。 另外,關於非電流注入方式,而是藉由外部磁場使 MTJ元件之記錄層之磁化反轉的方式,被揭示者有降低寫 入磁場之構成。例如專利文獻3揭示,在記錄層外周部設 -6- 201123570 置保持力小於中央部的區域,外部磁場施加時首先反轉外 周部之磁化,藉由洩漏磁場來促進中央部之磁化反轉的方 式。 專利文獻1 :特開2002 — 3 05 3 3 7號公報 專利文獻2:特開2003 — 142364號公報 專利文獻3:特開2002 — 299727號公報 【發明內容】 (發明所欲解決之課題) 本發明有鑑於上述問題,目的在於提供和習知技術比 較更能減低寫入電流密度的垂直磁化MTJ元件。另外,提 供即使記錄層成爲單一磁區構造之極微細區域之情況下, 亦可以減低寫入電流的垂直磁化Μ T J元件。 (用以解決課題的手段) 利用自旋注入磁化反轉方式時,相較於記錄層之外周 部使中央部之磁化先行反轉時更容易進行上述磁壁之傳輸 ,因此磁化反轉之效率較佳。另外,如此則,專利文獻3 所示’欲使外周部之磁化最先反轉時,需要使外周部之電 阻相較於中央部更降低’但是通常MTJ元件之形狀加工時 ’外周部曝曬於離子射束而成爲高電阻。因此,欲藉由電 流注入使外周部之磁化較中央部先行反轉乃困難者。 本發明係適用於’作爲MTJ元件之記錄層使用的磁性 體薄膜之一部分,相較於其周圍構成爲更薄之構造。或者 201123570 ,適用於作爲記錄層使用的磁性體薄膜之一部分區域之單 位面積之磁矩(Magnetic Moment),相較於其周圍被減 低之構造。 具體言之爲,本發明之穿隧磁阻效應元件係具備:記 錄層,由垂直磁化膜形成;固定層,由垂直磁化膜形成; 非磁性層,被配置於上述記錄層與上述固定層之間;及一 對電極層,分別相接於上述記錄層以及上述固定層被形成 ,用於使反轉上述記錄層之磁化方向用的電流朝元件膜厚 方向流入。記錄層係包含第1區域與第2區域之其中至少之 一,第1區域中之單位面積之磁矩,係低於第2區域中之單 位面積之磁矩:於記錄層之外周部分,第2區域之佔比係 大於第1區域之佔比。 【實施方式】 依據圖面詳細說明本發明之實施形態。又,本發明之 實施形態所述之MTJ元件,係利用自旋注入磁化反轉之機 構來使記錄層之磁化反轉者。亦即,於元件中流入電流, 自旋極化之電流之自旋對於磁性體記錄層之磁矩( magnetic moment)提供力矩(torque),據此而使記錄層 之磁化反轉。 (第1實施形態) 圖1表示第1實施形態之MTJ元件之模式圖,圖1 ( a ) 爲斷面模式圖,圖1 ( B )爲上面模式圖。元件,係於基板 201123570 2 0上積層下部電極層2 1、強磁性體之固定層Η、非磁性層 23、強磁性體之記錄層1〇、上部電極層22而構成。元件由 上面看時係呈直徑W之圓形。記錄層1〇及固定層11之磁化 ,係對於膜面呈垂直方向。流入自旋極化之電流時’記錄 層10與固定層11之材料及膜厚係設定成爲’使記錄層10之 磁化較固定層1 1之磁化先行被磁化反轉。本實施形態中’ 記錄層1 〇與固定層11之材料係使用同一強磁性體’記錄層 10之膜厚較固定層11爲薄。另外’於記錄層10之中央部, 被形成膜厚較周邊爲薄的凹型區域(區域丨)。亦即’凹 型形狀之區域1,和其以外之區域2比較’其之單位面積之 磁矩係較少(m〇 = Ms· t’ Ms:飽和磁化’ t:膜厚)。 又,雖未圖示,於上部電極層22及下部電極層21分別連接 配線用於對元件流入電流。 於第1實施形態中,固定層1 1及記錄層1 0之材料係使 用Ll〇型之Co5QPt5()規則合金。另外’下部電極層21係使用 Ta、Ru、Pt構成之積層膜,上部電極層22係使用Ta、Ru構 成之積層膜。另外,非磁性層2 3係使用氧化鎂(M g0 )。 記錄層10之膜厚tQ爲3nm,固定層11之膜厚非 磁性層23之膜厚爲lnm。元件之直徑W設爲30nm,設於記 錄層10中央之凹型部之直徑D設爲lOnm。 說明第1實施形態之MTJ元件之製作方法。圖2表示元 件之製作工程。以下依據圖2 ( A )〜圖2 ( Η )之工程順 序說明。首先,於基板20之上形成依下部電極層21、固定 層1 1、非磁性層2 3 '記錄層1 0、上部電極層2 2之順序積層 201123570 而成的積層膜2 5 (圖2 ( A ))。薄膜之形成係使用濺鍍法 ,全部之層於in-situ (現場)形成。之後,使用電子射束 (EB )微影成像或離子射束蝕刻將積層膜25加工成爲柱部 形狀(圖2 ( B ))。之後,於柱部表面在阻劑圖案5 1殘留 狀態下形成Al2〇3作爲層間絕緣膜52 (圖2 ( C ))。之後 ,藉由剝離除去柱部表面之阻劑,使柱部之表面露出(圖 2(D))。 之後,由露出之柱部之上塗布阻劑,藉由EB微影成像 形成柱部中央上部被開口之阻劑圖案(圖2 ( E ))。於此 狀態下,藉由離子射束直至上部電極層21、記錄層10之中 途爲止實施蝕刻予以除去(圖2(F))。蝕刻記錄層10之 中央部之深度h被設爲1 nm。蝕刻後,於現場藉由濺鍍法沈 積成爲追加之上部電極層26的Ru及Ta,覆蓋柱部之上部( 圖2(G))。之後,使用EB微影成像及離子射束蝕刻使 上部電極層2 1僅殘留柱部之上部而實施圖案化,完成MTJ 元件(圖2(H))。最後,於300°C溫度對實施元件之退 火。另外,阻劑圖案51之形成亦可使用EB微影成像以外之 技術,例如奈米印刷技術。 以下說明第1實施形態之MTJ元件之記錄層之改寫動作 。以固定層1 1之磁化被固定於元件之上部方向爲前提。記 錄層1 〇之磁化成爲和固定層1 1之磁化逆向之反平行配列時 ’由MTJ元件之上部朝下部流通電流時,自旋極化電子由 固定層1 1流入記錄層1 0,藉由自旋注入磁化反轉使記錄層 10之磁化被反轉。亦即,固定層11之磁化與記錄層10之磁 -10- 201123570 化成爲平行配列,Μ T J元件之電阻由高電阻狀態切換爲低 電阻狀態。另外,記錄層1 〇之磁化與固定層1 1之磁化成爲 朝向同一方向之平行配列時,由MTJ元件之下部朝上部流 通電流時,自旋極化電子會通過記錄層10而流入固定層11 。此時,僅持有和固定層11之自旋爲同一方向自旋之電子 會流入固定層11,持有逆向自旋之電子會於絕緣體23之表 面被反射。反射之電子會對記錄層10之磁化發揮作用,藉 由自旋注入磁化反轉而使記錄層1 〇之磁化被反轉。亦即, 固定層1 1之磁化與記錄層1 〇之磁化成爲反平行配列,MTJ 元件之電阻由低電阻狀態切換爲高電阻狀態。 於第1實施形態中,係設定記錄層10之中央部之膜厚 爲較薄。因此,記錄層1 0之磁化反轉進展如下。首先,考 慮記錄層之磁化朝膜面上側之狀態(圖3 ( A ))。自旋極 化電子由元件之上側流入下側時,首先膜厚薄的中央部區 域引起磁化反轉(圖3 ( B ))。亦即,磁化反轉之核被形 成。此時,於記錄層10內在磁化被反轉之中央部周圍形成 磁壁35。形成之磁壁35朝元件外周部傳輸(圖3 ( C )), 最後記錄層全體之磁化被反轉(圖3(D))。於習知MTJ 元件,記錄層1 〇之膜厚爲同樣,當和第1實施形態同一程 度之尺寸時成爲單一磁區構造,磁化會於記錄層1〇之全區 域被一起旋轉。相對於此種一起旋轉機構,於第1實施形 態之MTJ元件中,係在磁化反轉容易之區域設置中央部, 此處產生磁化反轉後藉由磁壁之傳輸使全體之磁化被反轉 。亦即,於第1實施形態之MTJ元件中,相較於在記錄層未 -11 - 201123570 設置凹型區域之習知構造,可以減少磁化反轉開始之電流 密度() ’可以減低消費電流。針對試作之第1實施形 態之MTJ元件評估結果發現,相較於在記錄層未設置凹型 區域之習知構造之垂直磁化M TJ元件,寫入電流可以減少 至約5 0 %。 磁壁之寬度5係和磁性體之結晶異方性能量Ku有關, 和1 / 成比例。具有約1 07 erg / cm2之高結晶異方性能 量Ku之CoPt規則合金等之情況下,磁壁之寬度5成爲約5 〜lOnm。藉由電流注入而欲於記錄層10中形成磁壁時,凹 型區域之直徑D ( 1 Onm )較好是和磁壁之寬度6爲同等以 上之大小。於第1實施形態雖設定記錄層之凹型區域之直 徑D爲1 〇nm,但爲獲得和本實施形態同樣效果時最小爲 5nm以上爲較好。另外,利用磁化反轉之核形成以及磁壁 之傳輸來進行改寫時,記錄層之直徑W,基於凹型區域之 直徑D與強磁性材料之磁壁之寬度δ,較好是爲评>〇+2 <5。本實施形態中設定記錄層之直徑W爲30nm,凹型區域 之直徑D爲1 Onm,磁壁之寬度5爲約5〜1 Onm,因此滿足 此一關係® 垂直磁化MTJ元件之寫入電流密度係以Jco 00 ( MsHk -4 π Ms2 ) · t表示(Ms:記錄層材料之飽和磁化,Hk:記 錄層材料之異方性磁場,t :記錄層之膜厚)。亦即,磁 化反轉所要之電流密度係和記錄層之膜厚成比例。於第1 實施形態,相對於記錄層1〇之膜厚“ =3 nm,中央之凹型區 域之膜厚雖設爲2nm,但其以外之尺寸亦可獲得同樣效果 -12- 201123570 。但是考慮寫入電流密度之基於各元件之不均勻分布,相 對於在記錄層未設置凹型區域之習知構成之MTJ元件,欲 獲得良好之JeG減低效果時,記錄層1〇之凹型區域之膜厚較 好是設爲至少周圍之8成以下程度。 於第1實施形態中,作爲記錄層10與固定層11之垂直 磁化材料雖使用LU型之C〇5CPt5()規則合金,但使用其以外 之垂直磁化材料亦可獲得和第1實施形態同樣之效果。具 體之材料例如可使用:L1,型之CoPt規則合金、m — 〇019型 之C〇75Pt35規則合金、Fe5〇Pt5()等之Ll〇型規則合金、或者 CoCrPt — Si02、FePt — Si02等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料,或者包含Fe、Co、Ni之其中 任一或1個以上的合金,與Ru、Pt、Rh、Pd、Cr等之非磁 性金屬被交互積層而成的積層膜,或者在TbFeCo、 GdFeCo等、Gd、Dy、Tb等之稀土類金屬中包含有遷移金 屬的非晶質合金。 又’於第1實施形態中,係於圓形記錄層形成圓形之 凹型區域’但是凹型區域之形狀可爲圓形以外之例如四角 形狀等。 又’於第〗實施形態中雖說明記錄層1 0爲單一磁區構 造之區域之極微細尺寸之元件,但本發明亦適用於更大尺 寸之元件。例如由上部看時直徑爲lOOnm之MTJ元件中, 即使於記錄層未設置凹型區域之習知構造在藉由電流注入 產生磁化反轉時,於記錄層中被形成磁區藉由磁壁之傳輸 使記錄層全體之磁化反轉。即使此種元件尺寸之情況下, -13- 201123570 適用本發明之記錄層中央部之膜厚爲較薄之MTJ元件中, 亦可以引起磁化反轉核之生成,相較於在記錄層未凹型區 域之習知元件更能減低寫入電流密度。 (第2實施形態) 第2實施形態係說明四角形狀之垂直磁化MTJ元件。圖 4表示第2實施形態之MTJ元件之斷面模式圖及上面圖。元 件之基本構造、積層膜之構成及材料,各層之膜厚係和第 1實施形態同樣。第2實施形態之元件由上面看爲正方形, 如圖4所示,於記錄層10(膜厚t〇 = 3nm)之中央部設置膜 厚較周圍薄的區域。元件之一邊A設爲30nm,設於記錄層 10之中央部的凹型部之一邊B設爲]Onm,凹型部之溝之深 度h設爲lnm。又,雖未圖示,於上部電極層22及下部電極 層2 1分別連接對元件流入電流用的配線。 第2實施形態之MTJ元件之改寫動作及磁化反轉機構係 和第1實施形態同樣。於記錄層1 〇係由膜厚薄的中央部先 產生磁化反轉,藉由磁壁之移動使記錄層10全體之磁化反 轉。如此則,和在記錄層未凹型區域之習知構造之垂直磁 化MTJ元件比較,可減低寫入電流密度。 藉由電流注入而欲於記錄層10中形成磁壁時,凹型區 域之一邊B較好是和磁壁之寬度<5爲同等以上之大小。於 第2實施形態雖設定記錄層之凹型區域之一邊B爲1 Onm, 但爲獲得和本實施形態同樣效果時最小爲5nm以上爲較好 。另外,利用磁化反轉之核形成以及磁壁之傳輸來進行改 14- 201123570 寫時,記錄層之一邊A,基於使用凹型區域之一邊B與強磁 性材料之磁壁之寬度<5,較好是爲A > B + 2 5。本實施形 態中設定記錄層之一邊A爲30nm,凹型區域之一邊B爲 10nm’磁壁之寬度5爲約5〜10nm,因此滿足此一關係。 又,垂直磁化MTJ元件之寫入電流密度係以Je()cx ( MsHk - 4 7Γ Ms2 ) . t表示(Ms :記錄層材料之飽和磁化, H k :記錄層材料之異方性磁場,t :記錄層之膜厚)。亦 即,磁化反轉所要之電流密度係和記錄層之膜厚成比例。 於第2實施形態,相對於記錄層10之膜厚t〇 = 3nm,中央之 凹型區域之膜厚雖設爲2nm,但其以外之尺寸亦可獲得同 樣效果。但是考慮寫入電流密度之基於各元件之不均勻分 布,相對於在記錄層未設置凹型區域之習知構成之MTJ元 件,欲獲得良好之:Uo減低效果時,記錄層10之凹型區域之 膜厚較好是設爲至少周圍之8成以下程度。 於第2實施形態中,作爲記錄層1 0與固定層1 1之垂直 磁化材料雖使用Ll〇型之Co5QPt5Q規則合金,但使用其以外 之垂直磁化材料亦可獲得和第2實施形態同樣之效果。具 體之材料例如可使用:L1,型之CoPt規則合金、m— 〇019型 之Co75Pt35規則合金、Fe5QPt5()等之LU型規則合金、或者 CoCrPt — Si02、FePt — Si02等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料,或者包含Fe、Co、Ni之其中 任一或1個以上的合金’以及Ru、Pt、Rh、Pd、Cr等之非 磁性金屬交互積層之積層膜’或者在TbFeCo、GdFeCo等 、Gd、Dy、Tb等之稀土類金屬中包含有遷移金屬的非晶 -15- 201123570 質合金。 又,於第2實施形態中,係於四角形狀記錄層形成四 角形狀之凹型區域,但是凹型區域之形狀可爲四角形狀以 外之例如圓形等。 (第3實施形態) 第3實施形態係和第2實施形態同樣,說明四角形狀之 垂直磁化MTJ元件。圖5表示第3實施形態之MTJ元件之斷 面模式圖及上面圖。元件之基本構造、積層膜之構成及材 料,各層之膜厚係和第1實施形態及第2實施形態同樣。第 3實施形態之元件由上面看爲具有四角形狀。如圖5所示, 於記錄層1〇之中央設置膜厚較周圍薄的區域。凹型部之區 域如圖5(B)之上面圖所示,由元件外周之一邊至對向一 邊爲止予以連接。元件之—邊A設爲3 Onm ’設於記錄層1 0 之中央的凹型部之寬度B設爲l〇nm。又,雖未圖示,於上 部電極層22及下部電極層21分別連接對元件流入電流用的 配線》 第3實施形態之MTJ元件之改寫動作及磁化反轉機構係 和第1實施形態同樣。於記錄層1 0係由膜厚薄的中央部先 產生磁化反轉’藉由磁壁之移動使記錄層10全體之磁化反 轉。如此則,和在記錄層未凹型區域之習知構造之垂直磁 化Μ T J元件比較,可減低寫入電流密度。 藉由電流注入而欲於記錄層1〇中形成磁壁時,凹型區 域之寬度Β較好是和磁壁之寬度5爲同等以上之大小。於 -16- 201123570 第3實施形態雖設定記錄層之凹型區域之寬度B爲1 Onm, 但爲獲得和本實施形態同樣效果時最小爲5nm以上爲較好 。另外’利用磁化反轉之核形成以及磁壁之傳輸來進行改 寫時’記錄層之一邊A,基於使用凹型區域之—邊b與強磁 性材料之磁壁之寬度6,較好是爲六>8+2(5。本實施形 態中設定記錄層之一邊A爲30nm,凹型區域之一邊B爲 1 Onm,磁壁之寬度<5爲約5〜1 Onm,因此滿足此一關係。 又,垂直磁化MTJ元件之寫入電流密度係以jeG〇c ( MsHk -An Ms2 ) · t表示(Ms:記錄層材料之飽和磁化,201123570 and the element should be magnetically tunneled. Material} Materialized memory magnetic record 1 Straight-taken field storage machine with the use of technology: Technology in the { (four) of the off AM] said that the Ming RA ® Ming issued by the technology #明本前,,用用六六ί 使Γ In recent years, MRAM (Magnetic Random Access Memory) has been developed as a memory using magnetic materials. The mram uses MTJ (Magnetic Tunneling Junction) using the tunneling magnetoresistive effect (TMR) as an element to record information by controlling the magnetization direction of the magnetic body included in the MTJ element. Even if the magnetization direction of the magnetic body of the power supply is not changed, the non-volatile operation in which the recorded information is held can be realized. In addition to the manner in which the magnetic field is applied by changing the magnetization direction of the MTJ element (information rewriting), in recent years, it has been proposed that the spin transfer torque (Spin Transfer Torque) magnetization of the MTJ element directly flows into the DC current to reverse its magnetization. Turn (spin injection magnetization reversal) mode. For example, Patent Document 1 discloses an apparatus in which an in-plane magnetization material is used as a recording layer, and an MR-inverted magnetization inversion element is used and a memory (SPRAM (Spin-Transfer Torque Magnetic Random Access Memory)) is used. The increase in the degree of integration of the SPRAM requires the miniaturization of the MTJ element, but at this time, the thermal stability of the magnetization information in the MTJ element becomes a problem. The magnetic energy necessary to reverse the magnetization direction of the recording layer of the MTJ element, when the thermal energy caused by the ambient temperature becomes high, even if no external magnetic field or current is applied, the reversal of magnetization is caused by the council. As the size of the MTJ element is reduced, the magnetic energy is also reduced. Therefore, the thermal stability is also reduced as the size of the element is miniaturized. When it is desired to maintain thermal stability in a fine region and achieve high reliability, it is effective to increase the crystal magnetic anisotropy of the recording layer material of the MTJ element. Heretofore, an MTJ element using a crystal magnetic anisotropy and a high perpendicular magnetization material as an in-plane magnetization material has been disclosed (Patent Document 2). Further, in the MTJ element to which the perpendicular magnetization material is applied, the influence of the diamagnetic field applied to the recording layer is different from that of the in-plane magnetization MTJ element, which contributes to the reduction of the current density (write current density) required for magnetization reversal. Therefore, compared with the in-plane magnetized MTJ element, it has the advantage that the write current density can be reduced and the power consumption can be suppressed. It is necessary to further reduce the write current density in order to achieve a lower consumption power of the SPRAM to which the perpendicular magnetization MTJ element is applied. When the perpendicular magnetization film is formed into a multi-magnetic domain structure, the magnetization of a part of the magnetic domain is reversed based on the injection of current, and the propagation of the magnetic wall around it causes the magnetization reversal phenomenon of the entire magnetic film to be known. Compared with the magnetization reversal mechanism in which the magnetization of the ferromagnetic film is simultaneously reversed in all regions, the magnetization reversal mechanism of the magnetization reversal mechanism requires less current density. However, as the miniaturization of the MTJ element progresses, the perpendicular magnetization film used in the recording layer is a single magnetic domain structure which does not include a magnetic wall, and the magnetization reversal becomes a simultaneous magnetization reversal mechanism, so that the write current density is increased. Further, regarding the non-current injection method, the magnetization of the recording layer of the MTJ element is reversed by the external magnetic field, and the disclosed person has a configuration for reducing the writing magnetic field. For example, Patent Document 3 discloses that in the outer peripheral portion of the recording layer, -6-201123570 is provided with a holding force smaller than the central portion, and when the external magnetic field is applied, the magnetization of the outer peripheral portion is first reversed, and the magnetization reversal of the central portion is promoted by the leakage magnetic field. the way. Patent Document 1: Japanese Laid-Open Patent Publication No. JP-A-2002- No. PCT-A No. PCT Publication No. JP-A-2002 SUMMARY OF THE INVENTION In view of the above problems, it is an object of the invention to provide a perpendicular magnetization MTJ element which is more capable of reducing the write current density as compared with the prior art. Further, it is possible to provide a vertical magnetization Μ T J element in which the write current can be reduced even when the recording layer has a very fine region of a single magnetic domain structure. (Means for Solving the Problem) When the spin injection magnetization reversal method is used, it is easier to carry out the magnetic wall transfer when the magnetization of the central portion is reversed earlier than the peripheral portion of the recording layer, so that the efficiency of magnetization reversal is higher. good. In addition, as described in Patent Document 3, when the magnetization of the outer peripheral portion is first reversed, the resistance of the outer peripheral portion needs to be lower than that of the central portion. However, when the shape of the MTJ element is usually processed, the outer peripheral portion is exposed to sunlight. The ion beam becomes a high resistance. Therefore, it is difficult to invert the magnetization of the outer peripheral portion by the current injection before the center portion. The present invention is applied to a portion of a magnetic thin film used as a recording layer of an MTJ element, and is configured to be thinner than its periphery. Or 201123570, a magnetic moment suitable for a unit area of a partial region of a magnetic thin film used as a recording layer, compared to a structure in which the periphery thereof is reduced. Specifically, the tunneling magnetoresistive effect element of the present invention comprises: a recording layer formed of a perpendicular magnetization film; a fixed layer formed of a perpendicular magnetization film; and a non-magnetic layer disposed on the recording layer and the fixed layer And a pair of electrode layers respectively formed in contact with the recording layer and the fixed layer, for causing a current for reversing the magnetization direction of the recording layer to flow in the film thickness direction of the element. The recording layer includes at least one of the first region and the second region, and the magnetic moment per unit area in the first region is lower than the magnetic moment per unit area in the second region: in the outer portion of the recording layer, The proportion of the 2 regions is greater than the proportion of the first region. [Embodiment] Embodiments of the present invention will be described in detail with reference to the drawings. Further, in the MTJ element according to the embodiment of the present invention, the magnetization of the recording layer is reversed by a mechanism of spin injection magnetization reversal. That is, a current flows in the element, and the spin of the spin-polarized current provides a torque to the magnetic moment of the magnetic recording layer, whereby the magnetization of the recording layer is reversed. (First Embodiment) Fig. 1 is a schematic view showing an MTJ element according to a first embodiment, wherein Fig. 1(a) is a cross-sectional schematic view, and Fig. 1(B) is a top view. The element is formed by laminating a lower electrode layer 2 1 on a substrate 201123570, a fixed layer of ferromagnetic material, a non-magnetic layer 23, a recording layer 1 of a ferromagnetic material, and an upper electrode layer 22. The element is circular in diameter W when viewed from above. The magnetization of the recording layer 1 and the fixed layer 11 is perpendicular to the film surface. When the current of the spin polarization is flown, the material and film thickness of the recording layer 10 and the fixed layer 11 are set such that the magnetization of the recording layer 10 is magnetized in reverse with respect to the magnetization of the fixed layer 11. In the present embodiment, the material of the recording layer 1 and the fixed layer 11 is made of the same ferromagnetic material. The thickness of the recording layer 10 is thinner than that of the fixed layer 11. Further, in the central portion of the recording layer 10, a concave region (region 丨) having a film thickness thinner than the periphery is formed. That is, the area 1 of the 'concave shape' is smaller than the area 2 other than the area 2 (m〇 = Ms·t' Ms: saturation magnetization 't: film thickness). Further, although not shown, wiring is connected to the upper electrode layer 22 and the lower electrode layer 21, respectively, for injecting a current into the element. In the first embodiment, the material of the fixed layer 1 1 and the recording layer 10 is a Co5QPt5 () regular alloy of the L1 type. Further, the lower electrode layer 21 is a laminate film composed of Ta, Ru, and Pt, and the upper electrode layer 22 is a laminate film composed of Ta or Ru. Further, the nonmagnetic layer 23 is made of magnesium oxide (M g0 ). The film thickness tQ of the recording layer 10 was 3 nm, and the film thickness of the film thickness of the pinned layer 11 of the pinned layer 11 was 1 nm. The diameter W of the element was set to 30 nm, and the diameter D of the concave portion provided at the center of the recording layer 10 was set to lOnm. A method of manufacturing the MTJ element of the first embodiment will be described. Figure 2 shows the fabrication of the components. The following is a description of the engineering sequence according to Fig. 2 (A) to Fig. 2 ( Η ). First, a laminated film 2 5 in which the lower electrode layer 21, the fixed layer 1 1 , the non-magnetic layer 2 3 'the recording layer 10 and the upper electrode layer 2 2 are laminated on the substrate 20 is formed on the substrate 20 (Fig. 2 (Fig. 2 (Fig. 2 A)). The formation of the film was carried out by sputtering, and all layers were formed in in-situ (on-site). Thereafter, the laminated film 25 is processed into a pillar shape by electron beam (EB) lithography or ion beam etching (Fig. 2(B)). Thereafter, Al2〇3 is formed as an interlayer insulating film 52 on the surface of the pillar portion in a state where the resist pattern 51 remains (Fig. 2(C)). Thereafter, the surface of the column portion was exposed by peeling off the resist on the surface of the column portion (Fig. 2(D)). Thereafter, a resist is applied from the exposed pillar portion, and a resist pattern which is opened at the center of the center portion of the pillar portion is formed by EB lithography (Fig. 2(E)). In this state, etching is performed by ion beam irradiation until the upper electrode layer 21 and the recording layer 10 (Fig. 2(F)). The depth h of the central portion of the etching recording layer 10 was set to 1 nm. After the etching, Ru and Ta which are added to the upper electrode layer 26 are deposited by sputtering on the spot, and the upper portion of the pillar portion is covered (Fig. 2(G)). Thereafter, EB lithography and ion beam etching were used to pattern the upper electrode layer 21 with only the upper portion of the pillar portion, and the MTJ device was completed (Fig. 2(H)). Finally, the component is annealed at a temperature of 300 °C. Alternatively, the formation of the resist pattern 51 may be performed using techniques other than EB lithography, such as nano printing. The rewriting operation of the recording layer of the MTJ element of the first embodiment will be described below. It is assumed that the magnetization of the fixed layer 11 is fixed to the upper portion of the element. When the magnetization of the recording layer 1 is reversely aligned with the magnetization of the fixed layer 11, when the current flows from the upper portion of the MTJ element to the lower portion, the spin-polarized electrons flow from the fixed layer 1 1 into the recording layer 10, by The spin injection magnetization reversal causes the magnetization of the recording layer 10 to be reversed. That is, the magnetization of the pinned layer 11 and the magnetic -10- 201123570 of the recording layer 10 are parallelized, and the resistance of the Μ T J element is switched from the high resistance state to the low resistance state. Further, when the magnetization of the recording layer 1 and the magnetization of the fixed layer 11 are arranged in parallel in the same direction, when a current flows from the lower portion of the MTJ element toward the upper portion, the spin-polarized electrons flow into the fixed layer 11 through the recording layer 10. . At this time, only electrons which are spin in the same direction as the spin of the pinned layer 11 flow into the pinned layer 11, and electrons having a reverse spin are reflected on the surface of the insulator 23. The reflected electrons act on the magnetization of the recording layer 10, and the magnetization of the recording layer 1 is reversed by the spin injection magnetization reversal. That is, the magnetization of the fixed layer 11 and the magnetization of the recording layer 1 are antiparallel, and the resistance of the MTJ element is switched from the low resistance state to the high resistance state. In the first embodiment, the film thickness at the central portion of the recording layer 10 is set to be thin. Therefore, the magnetization reversal of the recording layer 10 progresses as follows. First, the state of magnetization of the recording layer toward the surface side of the film is considered (Fig. 3 (A)). When the spin-polarized electrons flow from the upper side of the element to the lower side, first, the central portion of the thin film thickness causes magnetization reversal (Fig. 3(B)). That is, the core of magnetization reversal is formed. At this time, the magnetic wall 35 is formed in the recording layer 10 around the central portion where the magnetization is reversed. The formed magnetic wall 35 is transported toward the outer peripheral portion of the element (Fig. 3(C)), and finally the magnetization of the entire recording layer is reversed (Fig. 3(D)). In the conventional MTJ device, the film thickness of the recording layer 1 is the same, and when it is the same size as in the first embodiment, it has a single magnetic domain structure, and the magnetization is rotated together in the entire area of the recording layer 1〇. In the MTJ element of the first embodiment, the center portion is provided in the region where the magnetization reversal is easy, and the magnetization is reversed after the magnetization is reversed, whereby the entire magnetization is reversed. In other words, in the MTJ element of the first embodiment, the current density () at which the magnetization inversion starts can be reduced as compared with the conventional structure in which the concave portion is provided in the recording layer -11 - 201123570. As a result of evaluation of the MTJ element of the first embodiment of the test, it was found that the write current can be reduced to about 50% compared to the conventionally structured perpendicular magnetization M TJ element in which the concave portion is not provided in the recording layer. The width 5 of the magnetic wall is related to the crystal anisotropy energy Ku of the magnetic body, and is proportional to 1 / . In the case of a CoPt regular alloy having a high crystal anisotropy performance of about 1 07 erg / cm 2 , the width 5 of the magnetic wall is about 5 to 1 nm. When a magnetic wall is to be formed in the recording layer 10 by current injection, the diameter D ( 1 Onm ) of the concave portion is preferably equal to or larger than the width 6 of the magnetic wall. In the first embodiment, the diameter D of the concave region of the recording layer is set to be 1 〇 nm, but it is preferable to obtain a minimum of 5 nm or more in order to obtain the same effect as in the present embodiment. Further, when the core is formed by magnetization reversal and the magnetic wall is rewritten, the diameter W of the recording layer is preferably based on the diameter D of the concave region and the width δ of the magnetic wall of the ferromagnetic material. <5. In the present embodiment, the diameter W of the recording layer is set to 30 nm, the diameter D of the concave region is 1 Onm, and the width 5 of the magnetic wall is about 5 to 1 Onm, so that the relationship of the write current density of the perpendicular magnetization MTJ element is satisfied. Jco 00 ( MsHk -4 π Ms2 ) · t represents (Ms: saturation magnetization of the recording layer material, Hk: anisotropic magnetic field of the recording layer material, t: film thickness of the recording layer). That is, the current density required for magnetization reversal is proportional to the film thickness of the recording layer. In the first embodiment, the film thickness of the recording layer 1 is "=3 nm, and the film thickness of the central concave region is 2 nm. However, the same effect can be obtained for the other dimensions -12-201123570. But consider writing The in-current density is based on the uneven distribution of the respective elements, and the film thickness of the concave portion of the recording layer 1 is better than that of the conventionally constructed MTJ element in which the concave portion is not provided in the recording layer. In the first embodiment, as the perpendicular magnetization material of the recording layer 10 and the fixed layer 11, a LU type C〇5CPt5() regular alloy is used, but a perpendicular magnetization other than the same is used. The material can also obtain the same effects as those of the first embodiment. For the specific material, for example, a L1, a CoPt regular alloy, a C〇75Pt35 regular alloy of the m-〇019 type, and an L1〇 type of Fe5〇Pt5() can be used. a regular alloy or a material having a granular structure in which a granular magnetic body such as CoCrPt — SiO 2 , FePt — SiO 2 is dispersed in a non-magnetic parent phase, or an alloy containing one or more of Fe, Co, and Ni, and Ru, Pt, Rh A laminated film in which non-magnetic metals such as Pd and Cr are alternately laminated, or an amorphous alloy containing a transition metal in a rare earth metal such as TbFeCo, GdFeCo, or the like, Gd, Dy, or Tb. In the embodiment, a circular concave portion is formed in the circular recording layer, but the shape of the concave portion may be a quadrangular shape or the like other than a circular shape. Further, in the first embodiment, the recording layer 10 is a single magnetic body. An extremely fine-sized component of the region of the region structure, but the present invention is also applicable to a larger-sized component. For example, in an MTJ device having a diameter of 100 nm when viewed from the upper portion, even a conventional structure in which a concave region is not provided in the recording layer is borrowed. When magnetization reversal occurs by current injection, the magnetic domain formed in the recording layer is reversed by the magnetic wall by the magnetic wall. Even in the case of such a component size, the recording layer of the present invention is applied to -13-201123570. In the MTJ element in which the film thickness of the central portion is thin, the formation of the magnetization reversal core can also be caused, and the write current density can be reduced as compared with the conventional element in the non-recessed region of the recording layer. In the second embodiment, a quadrilateral perpendicular magnetization MTJ element will be described. Fig. 4 is a cross-sectional schematic view and a top view of the MTJ element of the second embodiment. The basic structure of the element, the structure and material of the laminated film, and the layers are The film thickness is the same as that of the first embodiment. The element of the second embodiment is square as viewed from above, and as shown in Fig. 4, the film thickness is thinner than the periphery in the central portion of the recording layer 10 (thickness t 〇 = 3 nm). In the region, one side A of the element is set to 30 nm, and one side B of the concave portion provided at the central portion of the recording layer 10 is set to ]Onm, and the depth h of the groove of the concave portion is set to 1 nm. Further, although not shown, wiring for inflow current to the element is connected to the upper electrode layer 22 and the lower electrode layer 21, respectively. The rewriting operation and the magnetization reversal mechanism of the MTJ element of the second embodiment are the same as those of the first embodiment. In the recording layer 1, the magnetization reversal is first caused by the central portion of the film thickness, and the magnetization of the entire recording layer 10 is reversed by the movement of the magnetic wall. Thus, the write current density can be reduced as compared with the conventionally structured perpendicular magnetization MTJ element of the unconcave region of the recording layer. When a magnetic wall is to be formed in the recording layer 10 by current injection, one side B of the concave portion is preferably equal to or larger than the width <5 of the magnetic wall. In the second embodiment, the side B of one of the concave regions of the recording layer is set to be 1 Onm, but it is preferable to obtain a minimum of 5 nm or more in order to obtain the same effect as in the present embodiment. In addition, when the core formation by magnetization reversal and the transmission of the magnetic wall are performed, the edge A of the recording layer is based on the width B of the magnetic wall of one of the concave regions and the magnetic wall of the ferromagnetic material. For A > B + 2 5. In the present embodiment, one side of the recording layer A is set to 30 nm, and one side B of the concave portion is 10 nm. The width 5 of the magnetic wall is about 5 to 10 nm, so that this relationship is satisfied. Further, the write current density of the perpendicular magnetization MTJ element is represented by Je()cx ( MsHk - 4 7 Γ Ms2 ) . t (Ms : saturation magnetization of the recording layer material, H k : anisotropic magnetic field of the recording layer material, t : film thickness of the recording layer). That is, the current density required for magnetization reversal is proportional to the film thickness of the recording layer. In the second embodiment, the film thickness t 〇 = 3 nm with respect to the recording layer 10 and the film thickness of the central concave region are set to 2 nm, but the same effects can be obtained in other dimensions. However, considering the uneven distribution of the writing current density based on the respective elements, the film of the concave portion of the recording layer 10 is preferably obtained with respect to the conventionally constructed MTJ element in which the concave portion is not provided in the recording layer. The thickness is preferably set to be at least about 80% of the circumference. In the second embodiment, the L5〇-type Co5QPt5Q regular alloy is used as the perpendicular magnetization material of the recording layer 10 and the fixed layer 1 1 , but the same effect as in the second embodiment can be obtained by using the perpendicular magnetization material other than the above. . Specific materials may be, for example, L1, a CoPt regular alloy of the type, a Co75Pt35 regular alloy of the m-〇019 type, a LU type regular alloy such as Fe5QPt5(), or a granular magnetic body such as CoCrPt-SiO2, FePt-SiO2 or the like. A material of a granular structure in a non-magnetic parent phase, or an alloy comprising one or more of Fe, Co, and Ni, and a layer of a non-magnetic metal interfacial layer of Ru, Pt, Rh, Pd, Cr, or the like. The film 'or an amorphous -15-201123570 alloy containing a migration metal in a rare earth metal such as TbFeCo, GdFeCo, or the like, Gd, Dy, or Tb. Further, in the second embodiment, the quadrangular shape recording layer is formed in a rectangular shape in a rectangular shape, but the shape of the concave portion may be, for example, a square shape or the like. (Third Embodiment) In the third embodiment, a quadrilateral perpendicular magnetization MTJ element will be described in the same manner as in the second embodiment. Fig. 5 is a cross-sectional view showing the MTJ element of the third embodiment and a top view thereof. The basic structure of the element, the structure of the laminated film, and the material thickness of each layer are the same as those of the first embodiment and the second embodiment. The element of the third embodiment has a quadrangular shape as viewed from above. As shown in FIG. 5, a region where the film thickness is thinner than the periphery is provided in the center of the recording layer 1A. The area of the concave portion is connected from one side of the outer circumference of the element to the opposite side as shown in the upper view of Fig. 5(B). The edge A of the element is set to 3 Onm The width B of the concave portion provided at the center of the recording layer 10 is set to 10 nm. Further, although not shown, the wiring for inflow current to the element is connected to the upper electrode layer 22 and the lower electrode layer 21, respectively. The rewriting operation and the magnetization reversal mechanism of the MTJ element of the third embodiment are the same as those of the first embodiment. In the recording layer 10, magnetization reversal occurs first in the central portion of the thin film thickness, and the magnetization of the entire recording layer 10 is reversed by the movement of the magnetic wall. In this way, the write current density can be reduced as compared with the conventional magnetization Μ T J element of the conventional structure in the non-recessed region of the recording layer. When a magnetic wall is to be formed in the recording layer 1 by current injection, the width Β of the concave region is preferably equal to or larger than the width 5 of the magnetic wall. In the third embodiment, the width B of the concave region of the recording layer is set to 1 Onm, but it is preferable to obtain a minimum effect of 5 nm or more in order to obtain the same effect as in the present embodiment. Further, when the core formation by magnetization reversal and the transmission of the magnetic wall are used for rewriting, the side A of the recording layer is based on the width of the magnetic wall of the edge b and the ferromagnetic material using the concave region, preferably six > 8 +2 (5. In the present embodiment, one side of the recording layer A is set to 30 nm, one side of the concave area B is 1 Onm, and the width of the magnetic wall < 5 is about 5 to 1 Onm, so that the relationship is satisfied. The write current density of the MTJ element is expressed by jeG〇c ( MsHk -An Ms2 ) · t (Ms: saturation magnetization of the recording layer material,
Hk :記錄層材料之異方性磁場,t :記錄層之膜厚)。亦 即,磁化反轉所要之電流密度係和記錄層之膜厚成比例。 於第3實施形態,相對於記錄層10之膜厚U = 3nm,中央之 凹型區域之膜厚雖設爲2ηπι,但其以外之尺寸亦可獲得同 樣效果。但是考慮寫入電流密度之基於各元件之不均勻分 布,相對於在記錄層未設置凹型區域之習知構成之MTJ元 件,欲獲得良好之:Uo減低效果時,記錄層10之凹型區域之 膜厚較好是設爲至少周圍之8成以下程度。 於第3實施形態中,作爲記錄層1 0與固定層1 1之垂直 磁化材料雖使用Llo型之Co5GPt5()規則合金’但使用其以外 之垂直磁化材料亦可獲得和第3實施形態同樣之效果。具 體之材料例如可使用:L1,型之CoPt規則合金、m— 〇019型 之C〇75Pt35規則合金、Fe5〇Pt5Q等之Ll〇型規則合金、或者 C 〇 C r P t - S i Ο 2、F e P t - S i Ο 2等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料’或者包含Fe、Co、Ni之其中 -17- 201123570 任一或1個以上的合金,以及Ru、Pt、Rh、Pd、Cr等之非 磁性金屬交互積層之積層膜,或者在TbFeCo、GdFeCo等 、Gd、Dy、Tb等之稀土類金屬中包含有遷移金屬的非晶 質合金。 (第4實施形態) 第4實施形態係說明具備複數個凹型部之垂直磁化MTJ 元件。圖6表示第4實施形態之MTJ元件之斷面模式圖及上 面圖。元件之基本構造、積層膜之構成及材料,各層之膜 厚係和第3實施形態同樣,但於第4實施形態形成複數個凹 型部。元件之一邊A設爲lOOnm,設於記錄層10之凹型區 域之寬度B設爲l〇nm。又,雖未圖示,於上部電極層22及 下部電極層2 1分別連接對元件流入電流用的配線。 第4實施形態之MTJ元件之改寫動作及磁化反轉機構基 本上係和第1實施形態同樣。由設於記錄層1 0之2處之膜厚 薄的部分產生磁化反轉,藉由磁壁之移動使記錄層10全體 之磁化反轉。如此則,和在記錄層未凹型區域之習知構造 之垂直磁化Μ T J元件比較,可減低寫入電流密度。 藉由電流注入而欲於記錄層1 0中形成磁壁時,凹型區 域之寬度Β較好是和磁壁之寬度<5爲同等以上之大小。於 第4實施形態雖設定記錄層之凹型區域之寬度Β爲1 〇nm, 但爲獲得和本實施形態同樣效果時最小爲5 nm以上爲較好 〇 又,垂直磁化MTJ兀件之寫入電流密度係以je()〇c ( -18- 201123570Hk : an anisotropic magnetic field of the recording layer material, t : film thickness of the recording layer). That is, the current density required for magnetization reversal is proportional to the film thickness of the recording layer. In the third embodiment, the film thickness U = 3 nm with respect to the recording layer 10, and the film thickness of the central concave region is 2 η πι, but the same effects can be obtained in other dimensions. However, considering the uneven distribution of the writing current density based on the respective elements, the film of the concave portion of the recording layer 10 is preferably obtained with respect to the conventionally constructed MTJ element in which the concave portion is not provided in the recording layer. The thickness is preferably set to be at least about 80% of the circumference. In the third embodiment, the L5-type Co5GPt5() regular alloy is used as the perpendicular magnetization material of the recording layer 10 and the fixed layer 1 1 but the perpendicular magnetization material other than the same can be used as in the third embodiment. effect. Specific materials can be used, for example, L1, a CoPt regular alloy of the type, a C〇75Pt35 regular alloy of the m—〇019 type, a L1〇 type regular alloy of Fe5〇Pt5Q, or the like, or C 〇C r P t - S i Ο 2 a material of a granular structure in which a granular magnetic body such as F e P t - S i Ο 2 is dispersed in a non-magnetic parent phase or one or more of -17-201123570 including Fe, Co, and Ni. Alloy, and a laminated film of a non-magnetic metal intercalation layer of Ru, Pt, Rh, Pd, Cr, or the like, or an amorphous alloy containing a migration metal in a rare earth metal such as TbFeCo, GdFeCo, Gd, Dy, Tb or the like . (Fourth Embodiment) In the fourth embodiment, a perpendicular magnetization MTJ element including a plurality of concave portions will be described. Fig. 6 is a cross-sectional schematic view and a top view showing the MTJ element of the fourth embodiment. The basic structure of the element, the structure and material of the laminated film, and the film thickness of each layer are the same as those of the third embodiment. However, in the fourth embodiment, a plurality of concave portions are formed. One side A of the element is set to 100 nm, and the width B of the concave area provided in the recording layer 10 is set to 10 nm. Further, although not shown, wiring for inflow current to the element is connected to the upper electrode layer 22 and the lower electrode layer 21, respectively. The rewriting operation and the magnetization reversing mechanism of the MTJ element of the fourth embodiment are basically the same as those of the first embodiment. Magnetization reversal occurs in a portion of the recording layer 10 which is thin, and the magnetization of the entire recording layer 10 is reversed by the movement of the magnetic wall. Thus, the write current density can be reduced as compared with the conventional magnetization Μ T J element of the conventional configuration in the non-recessed region of the recording layer. When a magnetic wall is to be formed in the recording layer 10 by current injection, the width Β of the concave region is preferably equal to or larger than the width <5 of the magnetic wall. In the fourth embodiment, the width Β of the concave region of the recording layer is set to 1 〇 nm. However, in order to obtain the same effect as in the embodiment, the minimum is 5 nm or more, and the write current of the perpendicular magnetization MTJ element is obtained. Density is je()〇c ( -18- 201123570
MsHk - 4 π Ms2 ) · t表示(Ms :記錄層材料之飽和磁化,MsHk - 4 π Ms2 ) · t denotes (Ms : saturation magnetization of the recording layer material,
Hk :記錄層材料之異方性磁場,t :記錄層之膜厚)。亦 即,磁化反轉所要之電流密度係和記錄層之膜厚成比例。 於第4實施形態,相對於記錄層1〇之膜厚t() = 3nm,中央之 凹型區域之膜厚雖設爲2nm,但其以外之尺寸亦可獲得同 樣效果。但是考慮寫入電流密度之基於各元件之不均勻分 布,相對於在記錄層未設置凹型區域之習知構成之MTJ元 件,欲獲得良好之減低效果時,記錄層10之凹型區域之 膜厚較好是設爲至少周圍之8成以下程度。 於第4實施形態中,作爲記錄層10與固定層1 1之垂直 磁化材料雖使用Ll〇型之Co5cPt5Q規則合金,但使用其以外 之垂直磁化材料亦可獲得和第4實施形態同樣之效果。具 體之材料例如可使用:Lh型之CoPt規則合金、m— 〇019型 之Co75Pt35規則合金、Fe5〇Pt5〇等之Ll〇型規則合金、或者 CoCrPt - Si02、FePt - Si02等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料,或者包含Fe、Co、Ni之其中 任一或1個以上的合金,以及Ru、Pt、Rh ' Pd ' Cr等之非 磁性金屬交互積層之積層膜,或者在TbFeCo、GdFeCo等 、Gd、Dy、Tb等之稀土類金屬中包含有遷移金屬的非晶 質合金。 (第5實施形態) 第5實施形態係說明記錄層中之磁化反轉之核形成、 並非藉由記錄層之形狀’而是藉由物性之控制來實現之 -19" 201123570 MTJ元件。圖7表示第5實施形態之MTJ元件之斷面模式圖 。元件之基本構造係和第1實施形態同樣。記錄層1 0及固 定層1 1係使用垂直磁化之強磁性體之c〇5〇Pt5G合金’非磁 性層23係使用MgO。於第5實施形態’係如圖7所示,上部 電極層22係由第1帽蓋層41及第2帽蓋層42構成。第1帽蓋 層41係配置於記錄層10之大略中央,於其周圍被配置第2 帽蓋層42,第1帽蓋層41係使用Ti (鈦),第2帽蓋層42係 使用Pt (鉑)。於記錄層10內,藉由和第1帽蓋層41之反 應而形成反應區域43。 記錄層10之膜厚tG爲3nm,固定層11之膜厚 ,非磁性層23之膜厚爲lnm。元件之直徑W設爲30nm,第1 帽蓋層41之直徑D設爲lOnm。又,雖未圖示,於上部電極 層22及下部電極層2 1分別連接對元件流入電流用的配線》 說明第5實施形態之MTJ元件之製作方法。圖8表示元 件之製作工程。以下依據圖8 ( A )〜圖8 ( I )之工程順序 說明。首先,於基板20之上形成依下部電極層21、固定層 1 1、非磁性層23、記錄層1 0、第1帽蓋層4 1之順序積層而 成的積層膜25 (圖8 ( A ))。薄膜之形成係使用濺鍍法, 全部之層於in_situ (現場)形成。之後,使用電子射束( EB )微影成像或離子射束蝕刻將積層膜25加工成爲柱部形 狀(圖8 ( B ))。之後,於柱部表面在阻劑圖案5 1殘留狀 態下形成Al2〇3作爲層間絕緣層52 (圖8 ( C ))。之後, 藉由剝離除去柱部表面之阻劑,使柱部之表面露出(圖8 (D))。之後,由露出之柱部之上塗布阻劑,藉由EB微 -20- 201123570 形束 分射 部子 一 離 之由 央藉 中, 部下 柱態 於狀 像此 成於 影。Hk : an anisotropic magnetic field of the recording layer material, t : film thickness of the recording layer). That is, the current density required for magnetization reversal is proportional to the film thickness of the recording layer. In the fourth embodiment, the film thickness t() = 3 nm of the recording layer 1 is 2 nm, and the film thickness of the central concave region is 2 nm, but the same effects can be obtained. However, considering the uneven distribution of the writing current density based on the respective elements, the film thickness of the concave portion of the recording layer 10 is higher than that of the conventionally constructed MTJ element in which the concave portion is not provided in the recording layer. It is good to set it to at least 80% of the surrounding area. In the fourth embodiment, the L5〇-type Co5cPt5Q regular alloy is used as the perpendicular magnetization material of the recording layer 10 and the fixed layer 1 1. However, the same effect as in the fourth embodiment can be obtained by using the perpendicular magnetization material other than the above. Specific materials can be used, for example, a CoPt regular alloy of the Lh type, a Co75Pt35 regular alloy of the m-〇019 type, a L1〇 regular alloy of Fe5〇Pt5〇, or a granular magnetic dispersion of CoCrPt-SiO2, FePt-SiO2 or the like. a material having a granular structure in a non-magnetic parent phase, or an alloy containing one or more of Fe, Co, and Ni, and a non-magnetic metal cross-layer of Ru, Pt, Rh ' Pd ' Cr, or the like The laminated film or an amorphous alloy containing a transition metal in a rare earth metal such as TbFeCo, GdFeCo, or the like, Gd, Dy, or Tb. (Fifth Embodiment) The fifth embodiment describes the formation of a nucleus of magnetization reversal in the recording layer, and is realized by the control of physical properties not by the shape of the recording layer -19 " 201123570 MTJ element. Fig. 7 is a cross-sectional view showing the MTJ element of the fifth embodiment. The basic structure of the element is the same as that of the first embodiment. The recording layer 10 and the fixed layer 1 1 are made of a ferromagnetic material of a perpendicular magnetization, and a non-magnetic layer 23 is made of MgO. In the fifth embodiment, as shown in Fig. 7, the upper electrode layer 22 is composed of a first cap layer 41 and a second cap layer 42. The first cap layer 41 is disposed substantially at the center of the recording layer 10, and the second cap layer 42 is disposed around the first cap layer 41. Ti (titanium) is used for the first cap layer 41, and Pt is used for the second cap layer 42. (platinum). In the recording layer 10, a reaction region 43 is formed by reaction with the first cap layer 41. The film thickness tG of the recording layer 10 was 3 nm, the film thickness of the pinned layer 11, and the film thickness of the non-magnetic layer 23 was 1 nm. The diameter W of the element was set to 30 nm, and the diameter D of the first cap layer 41 was set to 10 nm. Further, although not shown, a wiring for inflow current to the element is connected to the upper electrode layer 22 and the lower electrode layer 21, respectively. A method of manufacturing the MTJ element according to the fifth embodiment will be described. Figure 8 shows the fabrication of the components. The following is based on the engineering sequence of Figure 8 (A) to Figure 8 (I). First, a laminated film 25 formed by laminating the lower electrode layer 21, the fixed layer 11, the nonmagnetic layer 23, the recording layer 10, and the first cap layer 4 1 is formed on the substrate 20 (FIG. 8 (A) )). The formation of the film was carried out by sputtering, and the entire layer was formed in insitu (in situ). Thereafter, the laminated film 25 is processed into a columnar shape by electron beam (EB) lithography or ion beam etching (Fig. 8(B)). Thereafter, Al2〇3 is formed as an interlayer insulating layer 52 on the surface of the pillar portion in a state where the resist pattern 51 remains (Fig. 8(C)). Thereafter, the surface of the column portion is exposed by peeling off the resist on the surface of the column portion (Fig. 8(D)). After that, the resist is coated on the exposed pillar portion, and the EB micro-20-201123570 beam splitting portion is separated from the central portion, and the lower column state is formed in the image.
\1/ F 案 圖 劑 阻 去 除 後 之\1/ F case agent is removed after removal
案 圖第 G JHJ HJ /1\ f豸8 阻触圖 成53C 8 圖 層 蓋 帽 圖 8 5 2 膜 層 積 於 之柱部上設爲積層有第2帽盖層42之Pt的狀態(圖8 ( Η) )。接著,使用ΕΒ微影成像及離子射束蝕刻將第2帽蓋層 42加工成爲上部電極層之形狀(圖8(1))。最後,於 400°C溫度下實施元件之退火,形成反應區域43完成MTJ元 件(圖8 ( J ))。又,本實施形態中,阻劑圖案之形成雖 使用E B微影成像,但亦可使用其以外之圖案化技術例如奈 米印刷技術。 記錄層1 0內之反應區域43係不作爲強磁性體,因此記 錄層1〇實質上和第1實施形態同樣,和中央部之膜厚變薄 者等效。因此,欲對元件流入電流反轉其磁化時,和第1 實施形態之元件同樣之機構可以發揮作用。亦即,首先, 中央部之磁化被反轉,於其周圍被形成之磁壁會朝外周部 傳輸,而使記錄層10全體之磁化被反轉。藉由該磁化反轉 機構,和第1實施形態同樣,相較於在記錄層未設置凹型 區域之習知MTJ元件,可以減少磁性資訊之改寫必要之電 流密度。 藉由電流注入而欲於記錄層1 0中形成磁壁時,第1帽 蓋層41之直徑D較好是和磁壁之寬度(5爲同等以上之大小 。於第5實施形態雖設定第1帽蓋層41之直徑D爲l〇nm,但 爲獲得和本實施形態同樣效果時最小爲Snm以上爲較好。 又,垂直磁化Μ T J元件之寫入電流密度係以J G OC ( -21 - 201123570Figure G JHJ HJ /1\ f豸8 The contact diagram is 53C 8 The layer cap is shown in Fig. 8 5 2 The film is laminated on the column to form the Pt of the second cap layer 42 (Fig. 8 ( Η)). Next, the second cap layer 42 is processed into the shape of the upper electrode layer by ruthenium lithography and ion beam etching (Fig. 8 (1)). Finally, the annealing of the device was carried out at a temperature of 400 ° C to form a reaction region 43 to complete the MTJ element (Fig. 8 (J)). Further, in the present embodiment, the formation of the resist pattern is performed by E B lithography, but other patterning techniques such as a nano-printing technique may be used. Since the reaction region 43 in the recording layer 10 is not a ferromagnetic material, the recording layer 1 is substantially equivalent to the thickness of the central portion as in the first embodiment. Therefore, when the magnetization of the element inflow current is reversed, the mechanism similar to that of the element of the first embodiment can function. That is, first, the magnetization of the central portion is reversed, and the magnetic wall formed around it is transmitted toward the outer peripheral portion, and the magnetization of the entire recording layer 10 is reversed. According to the magnetization reversing mechanism, as in the first embodiment, the current density required for the rewriting of the magnetic information can be reduced as compared with the conventional MTJ element in which the concave portion is not provided in the recording layer. When a magnetic wall is to be formed in the recording layer 10 by current injection, the diameter D of the first cap layer 41 is preferably equal to or larger than the width of the magnetic wall (5 is equal to or greater than the size of the fifth embodiment. The diameter D of the cap layer 41 is 10 nm, but it is preferably at least Snm or more in order to obtain the same effect as in the embodiment. Further, the write current density of the perpendicular magnetization Μ TJ element is JG OC (-21 - 201123570)
MsHk- 4 π Ms2 ) · t表示(Ms :記錄層材料之飽和磁化,MsHk-4 π Ms2 ) · t denotes (Ms : saturation magnetization of the recording layer material,
Hk :記錄層材料之異方性磁場,t :記錄層之膜厚)。亦 即,磁化反轉所要之電流密度係和記錄層之膜厚成比例。 於第5實施形態,相對於記錄層10之膜厚t〇 = 3nm,中央之 反應區域43之深度h雖設爲lnm,但其以外之尺寸亦可獲得 同樣效果。但是考慮寫入電流密度之基於各元件之不均勻 分布,相對於在記錄層未設置凹型區域之習知構成之MTJ 元件,欲獲得良好之】。〇減低效果時,於記錄層10之中央部 ,不包含反應區域4 3之膜厚(tG-h)較好是設爲至少周圍 之膜厚t〇之8成以下程度。 於第5實施形態中,作爲記錄層10與固定層11之垂直 磁化材料雖使用Ll〇型之C〇5QPt5Q規則合金,但使用其以外 之垂直磁化材料亦可獲得和第5實施形態同樣之效果。具 體之材料例如可使用:L1 ,型之CoPt規則合金、m- 〇019型 之C〇75Pt35規則合金、Fe5()Pt5〇等之Ll〇型規則合金、或者 CoCrPt — Si02、FePt — 3丨02等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料,或者包含Fe、Co、Ni之其中 任一或1個以上的合金,以及Ru、Pt、Rh、Pd、Cr等之非 磁性金屬交互積層之積層膜,或者在TbFeCo、GdFeCo等 、Gd、Dy、Tb等之稀土類金屬中包含有遷移金屬的非晶 質合金。 又,於第5實施形態,第1帽蓋層41與第2帽蓋層42之 材料組合雖使用Ti與Pt,但亦可使用其他材料。例如第2 帽蓋層42亦可使用Ta與Ru等。 -22- 201123570 又,於第5實施形態,係於四角形狀之記錄層形成四 角形狀之反應區域43,但反應區域43之形狀可爲四角形狀 以外之例如圓形等。 (第6實施形態) 第6實施形態係說明記錄層中之磁化反轉之核形成、 並非藉由記錄層之形狀,而是藉由結晶性之控制來實現之 MTJ元件。圖9表示第6實施形態之MTJ元件之斷面模式圖 。元件之基本構造係和第1實施形態同樣。記錄層1 0及固 定層11係使用垂直磁化之強磁性體之C〇5〇Pt5Q合金’非磁 性層23係使用MgO。於第6實施形態,係如圖9所示’於記 錄層1 0內包含改質區域44。改質區域44爲非晶質化之區域 。記錄層10之膜厚tQ爲3nm,固定層11之膜厚^爲ΙΟηηι, 非磁性層23之膜厚爲lnm。元件之直徑W設爲3〇nm ’改質 區域44之直徑D設爲10nm。又,雖未圖示,於上部電極層 22及下部電極層2 1分別連接對元件流入電流用的配線。 說明第6實施形態之元件之製作方法。製作方法基本 上和圖2所示第1實施形態之元件同樣。但是,形成積層膜 2 5之柱部,藉由剝離除去柱部表面之阻劑圖案5 1之後爲不 同。於第6實施形態,係在露出柱部表面之製程狀態(圖2 (D ))下,由記錄層1 〇之中央上部照射收束離子射束, 使記錄層1 〇中央部之結晶構造改質。之後,藉由EB微影成 像及離子射束蝕刻、加工上部電極層22而完成MTJ元件。 最後於3 00°C進行熱處理。 -23- 201123570 記錄層1 0內之改質區域44係和其以外之區域之結晶構 造不同,結晶構造成爲非晶質。非晶質之區域不會產生垂 直磁化,因此,實質上和第1實施形態同樣,和記錄層1 0 之中央部之膜厚變薄爲等效。因此,對元件流入電流使磁 化反轉時,係由和第1實施形態之元件同樣之機構發揮作 用。亦即,首先,中央部之磁化被反轉,於其周圍被形成 之磁壁會朝外周部傳輸,而使記錄層10全體之磁化被反轉 。藉由該磁化反轉機構,和第1實施形態同樣,相較於在 記錄層未設置凹型區域之習知MTJ元件,可以減少磁性資 訊之改寫必要之電流密度。 藉由電流注入而欲於記錄層10中形成磁壁時,改質區 域44之直徑D較好是和磁壁之寬度5爲同等以上之大小。 於第6實施形態雖設定改質區域44之直徑D爲1 Onm,但爲 獲得和本實施形態同樣效果時最小爲5nm以上爲較好。 又,垂直磁化MTJ元件之寫入電流密度係以JeQ〇c ( MsHk — 4 7Γ Ms2 ) · t表示(Ms :記錄層材料之飽和磁化,Hk : an anisotropic magnetic field of the recording layer material, t : film thickness of the recording layer). That is, the current density required for magnetization reversal is proportional to the film thickness of the recording layer. In the fifth embodiment, the film thickness t 〇 = 3 nm with respect to the recording layer 10 and the depth h of the central reaction region 43 are set to 1 nm, but the same effects can be obtained in other dimensions. However, considering the uneven distribution of the writing current density based on each element, it is desirable to obtain an MTJ element having a conventional configuration in which a concave region is not provided in the recording layer. When the effect of the reduction is small, the film thickness (tG-h) which does not include the reaction region 43 in the central portion of the recording layer 10 is preferably set to be at least about 80% of the surrounding film thickness t〇. In the fifth embodiment, the L1〇-type C〇5QPt5Q regular alloy is used as the perpendicular magnetization material of the recording layer 10 and the fixed layer 11, but the same effect as in the fifth embodiment can be obtained by using the perpendicular magnetization material other than the above. . Specific materials can be used, for example, L1, type CoPt regular alloy, m-〇019 type C〇75Pt35 regular alloy, Fe5()Pt5〇, etc. Ll〇 type regular alloy, or CoCrPt — Si02, FePt — 3丨02 a material having a granular structure in which a granular magnetic body is dispersed in a non-magnetic parent phase, or an alloy containing one or more of Fe, Co, and Ni, and Ru, Pt, Rh, Pd, Cr, or the like. A laminated film of a non-magnetic metal cross-layer, or an amorphous alloy containing a transition metal in a rare earth metal such as TbFeCo, GdFeCo, or the like, Gd, Dy, or Tb. Further, in the fifth embodiment, Ti and Pt are used for the material combination of the first cap layer 41 and the second cap layer 42, but other materials may be used. For example, Ta, Ru, or the like can be used for the second cap layer 42. Further, in the fifth embodiment, the reaction layer 43 having a quadrangular shape is formed on the recording layer having a quadrangular shape, but the shape of the reaction region 43 may be, for example, a circle other than the square shape. (Sixth embodiment) The sixth embodiment describes the formation of a nucleus in which the magnetization is reversed in the recording layer, and the MTJ element which is realized not by the shape of the recording layer but by the control of crystallinity. Fig. 9 is a cross-sectional view showing the MTJ element of the sixth embodiment. The basic structure of the element is the same as that of the first embodiment. The recording layer 10 and the fixed layer 11 are made of a C 5 〇 Pt 5 Q alloy using a perpendicular magnetized ferromagnetic material. The non-magnetic layer 23 is made of MgO. In the sixth embodiment, as shown in Fig. 9, the modified region 44 is included in the recording layer 10. The modified region 44 is an amorphous region. The film thickness tQ of the recording layer 10 was 3 nm, the film thickness of the pinned layer 11 was ΙΟηηι, and the film thickness of the non-magnetic layer 23 was 1 nm. The diameter W of the element was set to 3 〇 nm. The diameter D of the modified region 44 was set to 10 nm. Further, although not shown, wirings for inflow current to the element are connected to the upper electrode layer 22 and the lower electrode layer 21, respectively. A method of manufacturing the element of the sixth embodiment will be described. The manufacturing method is basically the same as that of the first embodiment shown in Fig. 2. However, the pillar portion of the build-up film 25 is formed to be different after peeling off the resist pattern 5 1 on the surface of the pillar portion. In the sixth embodiment, in the process state in which the surface of the column portion is exposed (Fig. 2 (D)), the concentrated ion beam is irradiated from the center of the upper portion of the recording layer 1 to change the crystal structure of the central portion of the recording layer 1 quality. Thereafter, the MTJ element is completed by EB lithography and ion beam etching and processing of the upper electrode layer 22. Finally, heat treatment was carried out at 300 °C. -23- 201123570 The modified region 44 in the recording layer 10 is different from the crystal structure in the region other than the region, and the crystal structure is amorphous. Since the amorphous region does not have a vertical magnetization, it is substantially equivalent to the thin film thickness at the central portion of the recording layer 10 as in the first embodiment. Therefore, when the element inflow current reverses the magnetization, the mechanism similar to that of the element of the first embodiment functions. That is, first, the magnetization of the central portion is reversed, and the magnetic wall formed around it is transmitted toward the outer peripheral portion, and the magnetization of the entire recording layer 10 is reversed. According to the magnetization reversing mechanism, as in the first embodiment, the current density necessary for the rewriting of the magnetic information can be reduced as compared with the conventional MTJ element in which the concave portion is not provided in the recording layer. When a magnetic wall is to be formed in the recording layer 10 by current injection, the diameter D of the modified region 44 is preferably equal to or larger than the width 5 of the magnetic wall. In the sixth embodiment, the diameter D of the modified region 44 is set to be 1 Onm, but it is preferable to obtain a minimum effect of 5 nm or more in order to obtain the same effect as in the present embodiment. Further, the write current density of the perpendicular magnetization MTJ element is represented by JeQ〇c ( MsHk - 4 7 Γ Ms2 ) · t (Ms : saturation magnetization of the recording layer material,
Hk :記錄層材料之異方性磁場,t :記錄層之膜厚)。亦 即’磁化反轉所要之電流密度係和記錄層之膜厚成比例。 於第6實施形態,相對於記錄層1〇之膜厚tQ = 3nm,中央之 改質區域44之厚度h雖設爲lnm,但其以外之尺寸亦可獲得 同樣效果。但是考慮寫入電流密度之基於各元件之不均勻 分布,相對於在記錄層未設置凹型區域之習知構成之MTJ 元件,欲獲得良好之Jeo減低效果時,於記錄層1 0之中央部 ’不包含改質區域44之膜厚(tG - h )較好是設爲至少周圍 -24- 201123570 之膜厚(to)之8成以下程度。 於第6實施形態中,作爲記錄層10與固定層11之垂直 磁化材料雖使用L1Q型之c〇5QPt5。規則合金,但使用其以外 之垂直磁化材料亦可獲得和第6實施形態同樣之效果。具 體之材料例如可使用:L1 ,型之CoPt規則合金、m— D019型 之Co75Pt35規則合金' Fe5GPt5()等之Ll〇型規則合金、或者 CoCrPt - Si02、FePt - 3丨〇2等粒狀磁性體分散於非磁性體 母相中的顆粒狀構造之材料,或者包含Fe、Co、Ni之其中 任一或1個以上的合金,以及Ru、Pt、Rh、Pd、Cr等之非 磁性金屬交互積層之積層膜,或者在TbFeCo、GdFeCo等 、Gd、Dy、Tb等之稀土類金屬中包含有遷移金屬的非晶 質合金。 又,於第6實施形態,係於四角形狀之記錄層形成四 角形狀之改質區域44,但改質區域44之形狀可爲四角形狀 以外之例如圓形等。 (第7實施形態) 第7實施形態係說明適用本發明之MTJ元件的隨機存取 記憶體者。圖1 〇表示本發明之磁性記憶格之構成例之斷面 模式圖。該磁性記憶格1 〇〇係搭載有第1〜第6實施形態之 Μ T J 元件 1 1 0。 C— MOS111係由2個η型半導體112、113及1個ρ型半導 體11 4構成。於η型半導體U2被電連接成爲汲極之電極121 ,介由電極141及電極147被接地。於η型半導體113被電連 -25- 201123570 接成爲源極之電極122。123爲閘極,藉由該閘極12 3之〇N / OFF來控制源極電極122與汲極電極121間之電流之ON/ OFF。於上述電極122被積層電極145、電極144、電極143 、電極142、電極146,介由電極146連接MTJ元件11〇之下 部電極1 1。 位元線222係連接於MTJ元件1 10之上部電極22。本實 施形態之磁性記憶格中,係藉由流入MTJ元件1 1 0之電流、 亦即自旋傳輸力矩來旋轉MTJ元件1 10之記錄層之磁化方向 而記錄磁性資訊。自旋傳輸力矩並非空間上之外部磁場, 主要是由流通於MTJ元件中之自旋極化電流之自旋,對 MTJ元件之強磁性自由層之磁矩提供力矩(torque)的原 理。因此,於MTJ元件具備由外部供給電流之手段,使用 該手段流入電流而可以實現自旋傳輸力矩磁化反轉。本實 施形態中,在位元線222與電極1 46之間流入電流,可以控 制1 1 〇中之記錄層之磁化之方向。 圖1 1表示配置有上述磁性記憶格1 00之磁性隨機存取 記憶體之構成例。於閘極電極1 2 3所連接之字元線2 2 3及位 元線2 2 2,係電連接於記憶格1 〇 〇。藉由配置具有第1〜第6 實施形態之MTJ元件的磁性記憶格1 〇〇,如此則,相較於磁 性記憶體係使用面內磁化MTJf元件或使用在記錄層未設置 凹型區域之垂直磁化MTJ元件的習知記憶體,該磁性記億 體可以更低消費電力動作,可實現GB(109位元)等級之 高密度磁性記憶體。 本構成時之寫入,首先,係對欲流入電流之位元線 •26- 201123570 2 22所連接之寫入驅動器發送寫入致能信號使其升壓,於 位元線222流通特定電流。對應於電流之方向使寫入驅動 器23 0乃至寫入驅動器231之任一降爲接地,調節電位差’ 控制電流方向。之後,經過特定時間後,對字元線223所 連接之寫入驅動器232發送寫入致能信號使寫入驅動器232 升壓,使欲寫入之MTJ元件所連接之電晶體設爲ON。如此 則,電流流入MTJ元件,進行自旋力矩磁化反轉。使電晶 體設爲特定時間之ON之後,切斷對寫入驅動器232之信號 ,使電晶體設爲OFF。讀出時,僅使欲讀出之MTJ元件所 連接之位元線222升壓至讀出電壓V,僅設定選擇電晶體 成爲ON流通電流,進行讀出。該構造爲最單純之1電晶體 + 1記憶格之配置,因此單位格之佔有面積爲2Fx4F = 8F2, 可設爲高度集積者。 (發明效果) 藉由適用本發明之元件構造,相較於習知技術,可以 減低垂直磁化MTJ元件中之寫入電流密度。另外,即使是 記錄層之磁性體薄膜爲單一磁區構造的極微細元件,亦可 以抑制寫入電流密度之增大。 【圖式簡單說明】 圖1表示第1實施形態之MTJ元件之模式圖,(A)爲 斷面模式圖,(B)爲上面模式圖。 圖2表示第1實施形態之MTJ元件之製作工程圖。 -27- 201123570 圖3表示第1實施形態之MTJ元件之磁化反轉機構之模 式圖" 圖4表示第2實施形態之MTJ元件之模式圖,(A)爲 斷面模式圖,(B)爲上面模式圖。 圖5表示第3實施形態之MTJ元件之模式圖,(A )爲 斷面模式圖,(B)爲上面模式圖。 圖6表示第4實施形態之MTJ元件之模式圖,(A)爲 斷面模式圖,(B)爲上面模式圖。 圖7表示第5實施形態之MTJ元件之斷面模式圖。 圖8表示第5實施形態之MTJ元件之製作工程圖。 圖9表示第6實施形態之MTJ元件之斷面模式圖。 圖1 〇表示磁性記憶格之構成例之斷面模式圖。 圖11表示隨機存取記憶體之構成例之模式圖。 【主要元件符號說明】 1 〇 :記錄層 11 :固定層 20 :基板 2 1 :下部電極層 22 :上部電極層 23 :非磁性層 25 :積層膜 26 :追加之上部電極層 35 :磁壁 -28- 201123570 4 1 :第1帽蓋層 42 :第2帽蓋層 4 3 :反應區域 44 :改質區域 5 1 :阻劑圖案 52 :層間絕緣膜 5 3 :離子射束 100 :記憶格 1 1 0 : Μ T J 元件 111: C - MOS 1 1 2、1 1 3 : η型半導體 1 14 : ρ型半導體 1 2 1 :源極電極 1 2 2 :源極電極 1 2 3 :閘極電極 1 4 1〜1 47 :電極 1 5 0 :寫入線 2 2 2 :位元線 2 2 3 :字元線 230、231、232:寫入驅動器 -29Hk : an anisotropic magnetic field of the recording layer material, t : film thickness of the recording layer). That is, the current density required for the magnetization reversal is proportional to the film thickness of the recording layer. In the sixth embodiment, the film thickness tQ of the recording layer 1 is 3 nm, and the thickness h of the central modified region 44 is set to 1 nm, but the same effect can be obtained in other dimensions. However, considering the uneven distribution of the writing current density based on the respective elements, the MTJ element of the conventional configuration in which the concave region is not provided in the recording layer is required to obtain a good Jeo reduction effect at the central portion of the recording layer 10 The film thickness (tG - h ) not including the modified region 44 is preferably set to be at least 80% of the film thickness (to) of the surrounding -24 to 201123570. In the sixth embodiment, as the perpendicular magnetization material of the recording layer 10 and the fixed layer 11, the L1Q type c〇5QPt5 is used. In the case of a regular alloy, the same effect as in the sixth embodiment can be obtained by using a perpendicular magnetization material other than the above. Specific materials such as: L1, type CoPt regular alloy, m-D019 type Co75Pt35 regular alloy 'Fe5GPt5(), etc. Ll〇 type regular alloy, or CoCrPt-SiO2, FePt-3丨〇2, etc. a material having a granular structure dispersed in a non-magnetic parent phase, or an alloy containing one or more of Fe, Co, and Ni, and a non-magnetic metal interaction of Ru, Pt, Rh, Pd, Cr, or the like The laminated film is laminated or an amorphous alloy containing a transition metal in a rare earth metal such as TbFeCo, GdFeCo, or the like, Gd, Dy, or Tb. Further, in the sixth embodiment, the modified region 44 having a rectangular shape is formed on the recording layer having a quadrangular shape, but the shape of the modified region 44 may be, for example, a circle other than the square shape. (Seventh Embodiment) The seventh embodiment describes a random access memory to which the MTJ element of the present invention is applied. Fig. 1 is a cross-sectional schematic view showing a configuration example of a magnetic memory cell of the present invention. The magnetic memory cell 1 is equipped with the Μ T J element 1 1 0 of the first to sixth embodiments. The C-MOS 111 is composed of two n-type semiconductors 112 and 113 and one p-type semiconductor 11 4 . The n-type semiconductor U2 is electrically connected to the electrode 121 of the drain, and is grounded via the electrode 141 and the electrode 147. The n-type semiconductor 113 is connected to the electrode 122 of the source by the electrical connection -25-201123570. 123 is the gate, and the source electrode 122 and the drain electrode 121 are controlled by the 〇N /OFF of the gate 12 3 Current ON/OFF. The electrode 122 is laminated with the electrode 145, the electrode 144, the electrode 143, the electrode 142, and the electrode 146, and the electrode 146 is connected to the lower electrode 11 of the MTJ element 11 via the electrode 146. The bit line 222 is connected to the upper electrode 22 of the MTJ element 1 10 . In the magnetic memory cell of the present embodiment, the magnetic information is recorded by rotating the magnetization direction of the recording layer of the MTJ element 1 10 by the current flowing into the MTJ element 110, i.e., the spin transmission torque. The spin transfer torque is not a spatial external magnetic field, mainly due to the spin of the spin-polarized current flowing through the MTJ element, which provides the principle of torque to the magnetic moment of the strong magnetic free layer of the MTJ element. Therefore, the MTJ element is provided with means for supplying current from the outside, and current is applied by the means to realize magnetization reversal of the spin transmission torque. In this embodiment, a current flows between the bit line 222 and the electrode 1 46, and the direction of magnetization of the recording layer in the 1 〇 can be controlled. Fig. 11 shows a configuration example of a magnetic random access memory in which the magnetic memory cell 100 described above is arranged. The word line 2 2 3 and the bit line 2 2 2 connected to the gate electrode 1 2 3 are electrically connected to the memory cell 1 〇 . By arranging the magnetic memory cell 1 具有 having the MTJ elements of the first to sixth embodiments, the in-plane magnetization MTJf element is used as compared with the magnetic memory system or the perpendicular magnetization MTJ in which the concave region is not provided in the recording layer is used. The conventional memory of the component, the magnetic memory can operate at a lower power consumption, and can realize a high-density magnetic memory of a GB (109-bit) level. In the case of writing in this configuration, first, a write enable signal is applied to the write driver connected to the bit line 26 to 201123570 2 22 of the current to be boosted, and a specific current flows through the bit line 222. Corresponding to the direction of the current, either the write driver 203 or the write driver 231 is lowered to ground, and the potential difference is adjusted to control the current direction. Thereafter, after a lapse of a certain period of time, the write driver 232 connected to the word line 223 transmits a write enable signal to boost the write driver 232, and turns on the transistor to which the MTJ element to be written is connected. In this way, current flows into the MTJ element to perform magnetization reversal of the spin torque. After the transistor is turned ON for a specific time, the signal to the write driver 232 is turned off to turn off the transistor. At the time of reading, only the bit line 222 to which the MTJ element to be read is connected is boosted to the read voltage V, and only the selected transistor is turned ON, and read. This configuration is the simplest configuration of the transistor + 1 memory cell, so the occupied area of the unit cell is 2Fx4F = 8F2, which can be set as the height collector. (Effect of the Invention) By applying the element structure of the present invention, the write current density in the perpendicular magnetization MTJ element can be reduced as compared with the prior art. Further, even if the magnetic thin film of the recording layer is an extremely fine element having a single magnetic domain structure, the increase in the write current density can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an MTJ element according to a first embodiment, wherein (A) is a sectional view and (B) is a top view. Fig. 2 is a view showing the construction of the MTJ element of the first embodiment. -27-201123570 Fig. 3 is a schematic view showing a magnetization reversing mechanism of the MTJ element according to the first embodiment. Fig. 4 is a schematic view showing an MTJ element according to the second embodiment, and (A) is a sectional view, and (B) For the above pattern. Fig. 5 is a schematic view showing the MTJ element of the third embodiment, wherein (A) is a sectional view and (B) is a top view. Fig. 6 is a schematic view showing the MTJ element of the fourth embodiment, wherein (A) is a sectional view and (B) is a top view. Fig. 7 is a cross-sectional schematic view showing the MTJ element of the fifth embodiment. Fig. 8 is a view showing the construction of the MTJ element of the fifth embodiment. Fig. 9 is a cross-sectional schematic view showing the MTJ element of the sixth embodiment. Fig. 1 is a cross-sectional schematic view showing a configuration example of a magnetic memory cell. Fig. 11 is a schematic view showing a configuration example of a random access memory. [Description of main component symbols] 1 〇: recording layer 11: fixed layer 20: substrate 2 1 : lower electrode layer 22: upper electrode layer 23: non-magnetic layer 25: laminated film 26: additional upper electrode layer 35: magnetic wall -28 - 201123570 4 1 : 1st cap layer 42 : 2nd cap layer 4 3 : Reaction zone 44 : Modification zone 5 1 : Resistive pattern 52 : Interlayer insulating film 5 3 : Ion beam 100 : Memory cell 1 1 0 : Μ TJ element 111 : C - MOS 1 1 2 , 1 1 3 : n-type semiconductor 1 14 : p-type semiconductor 1 2 1 : source electrode 1 2 2 : source electrode 1 2 3 : gate electrode 1 4 1 to 1 47 : Electrode 1 5 0 : Write line 2 2 2 : Bit line 2 2 3 : Word line 230, 231, 232: Write driver -29
Claims (1)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2009/060432 WO2010143248A1 (en) | 2009-06-08 | 2009-06-08 | Tunnel magnetic resistance effect element and random access memory using same |
Publications (2)
Publication Number | Publication Date |
---|---|
TW201123570A true TW201123570A (en) | 2011-07-01 |
TWI430485B TWI430485B (en) | 2014-03-11 |
Family
ID=43308518
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
TW099118380A TWI430485B (en) | 2009-06-08 | 2010-06-07 | Tunneling magnetoresistive element using the same, and a RAM (Random Access Memory) |
Country Status (3)
Country | Link |
---|---|
JP (1) | JP5456035B2 (en) |
TW (1) | TWI430485B (en) |
WO (1) | WO2010143248A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102017623B1 (en) * | 2012-08-30 | 2019-09-03 | 삼성전자주식회사 | Magnetic Memory Device |
JP6948229B2 (en) * | 2017-11-09 | 2021-10-13 | 株式会社日立製作所 | Thermoelectric converter and heat transport system |
JP2021150364A (en) * | 2020-03-17 | 2021-09-27 | ソニーセミコンダクタソリューションズ株式会社 | Semiconductor device and manufacturing method thereof |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005079508A (en) * | 2003-09-03 | 2005-03-24 | Canon Inc | Magnetic film, multilayered magnetic film, method and mechanism for inverting magnetization of magnetic film, and magnetic random access memory |
JP4384183B2 (en) * | 2007-01-26 | 2009-12-16 | 株式会社東芝 | Magnetoresistive element and magnetic memory |
JP2008211058A (en) * | 2007-02-27 | 2008-09-11 | Toshiba Corp | Magnetic random access memory and writing method thereof |
JP4649457B2 (en) * | 2007-09-26 | 2011-03-09 | 株式会社東芝 | Magnetoresistive element and magnetic memory |
JP5191717B2 (en) * | 2007-10-05 | 2013-05-08 | 株式会社東芝 | Magnetic recording element, manufacturing method thereof, and magnetic memory |
-
2009
- 2009-06-08 WO PCT/JP2009/060432 patent/WO2010143248A1/en active Application Filing
- 2009-06-08 JP JP2011518149A patent/JP5456035B2/en not_active Expired - Fee Related
-
2010
- 2010-06-07 TW TW099118380A patent/TWI430485B/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
WO2010143248A1 (en) | 2010-12-16 |
JP5456035B2 (en) | 2014-03-26 |
JPWO2010143248A1 (en) | 2012-11-22 |
TWI430485B (en) | 2014-03-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4903277B2 (en) | Magnetoresistive element, magnetic memory cell using the same, and random access memory | |
US7981697B2 (en) | Current-confined effect of magnetic nano-current-channel (NCC) for magnetic random access memory (MRAM) | |
JP5579175B2 (en) | Magnetoresistive element and random access memory using the same | |
US7486551B1 (en) | Method and system for providing domain wall assisted switching of magnetic elements and magnetic memories using such magnetic elements | |
JP5321991B2 (en) | Magnetic memory device and driving method thereof | |
KR101497863B1 (en) | High speed low power magnetic devices based on current induced spin-momentum transfer | |
JP5191717B2 (en) | Magnetic recording element, manufacturing method thereof, and magnetic memory | |
WO2011111473A1 (en) | Magnetoresistive element and magnetic memory | |
US9917248B2 (en) | Memory element, memory apparatus | |
TW200414497A (en) | Magnetic memory device having yoke layer and its manufacturing method | |
JP2009194160A (en) | Magnetic memory | |
WO2012004883A1 (en) | Magnetoresistive effect element and random access memory using same | |
JP2007080952A (en) | Multi-level recording spin injection inverted magnetization element and device using the same | |
JP2012059906A (en) | Storage element and memory unit | |
KR20120048482A (en) | Method and system for providing hybrid magnetic tunneling junction elements with improved switching | |
US20150255134A1 (en) | Storage cell, storage device, and magnetic head | |
US20150249207A1 (en) | Storage cell, storage device, and magnetic head | |
JP4840041B2 (en) | Electric field applied magnetic recording system and recording / reproducing apparatus | |
JP2012064623A (en) | Storage element and memory unit | |
TW200408151A (en) | Ferromagnetic layer for magnetoresistive element | |
TWI324770B (en) | ||
JP2004119641A (en) | Magnetic storage medium and magnetic memory device utilizing the same | |
TW201123570A (en) | Tunnel magnetic resistance effect element and random access memory using same | |
JP2004087870A (en) | Magnetoresistive effect element and magnetic memory device | |
JP2004023015A (en) | Magnetoresistive effect element and method of manufacturing the same, and magnetic memory device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
MM4A | Annulment or lapse of patent due to non-payment of fees |