200908294 九、發明說明： 【發明所屬之技術領域】 本發明關於一種記憶體，特別關於一種相變化記憶體。 【先前技術】 相變化記憶體具有高讀取速度、低功率、高容量、高可靠 度、高寫擦次數、低工作電壓/電流及低成本等特質，且非常 適合與CMOS製程結合，可用來作為較高密度的獨立式或爭 ‘ 入式的記憶體應用，是目前十分被看好的下一世代新記憶體。 由於相變化記憶體技術的獨特優勢，也使得其被認為非常有可 能取代目前商業化極具競爭性的SRAM與DRAM揮發性記憶 體與Flash非揮發性記憶體技術，可望成為未來極有潛力的^ 世代半導體記憶體。 發生在電流密度最高的區域。 相變化記憶體元件架構極為簡單，主要是在相變化材料的 上下之間分別製作電極材料來作為電流流通的路徑，目前最普 遍被採用的架構為T型架構。此架構的作法是在相變化材料之 i下加入加熱金屬的拾塞填充層，其好處是可降低加熱金屬盘相 變化材料之間的接觸面積，可增進加熱電極的加熱效率並降低 相變化記憶體元件的操作電流。在這樣的架構下，非晶區將會 ，可以明顯的發現主要200908294 IX. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a memory, and more particularly to a phase change memory. [Prior Art] Phase change memory has high read speed, low power, high capacity, high reliability, high number of erase and erase, low operating voltage / current and low cost, and is very suitable for combination with CMOS process. As a higher-density stand-alone or contiguous memory application, it is currently a very promising next generation of new memory. Due to the unique advantages of phase change memory technology, it is considered to be very likely to replace the currently commercialized SRAM and DRAM volatile memory and Flash non-volatile memory technology, which is expected to become a potential in the future. ^ Generation of semiconductor memory. Occurs in the area with the highest current density. The structure of the phase change memory component is extremely simple, and the electrode material is separately formed between the upper and lower sides of the phase change material as a path for current circulation. Currently, the most commonly adopted architecture is a T-type architecture. The structure of the structure is to add a plug filling layer of heated metal under the phase change material, which has the advantages of reducing the contact area between the materials of the heated metal disk phase change, improving the heating efficiency of the heating electrode and reducing the phase change memory. The operating current of the body element. Under such a structure, the amorphous region will be able to clearly identify the main
觸面積來達 0949-A22087TWF(N2)；P51960009TW；ph〇elip 綜觀目前相變化記憶體的發展趨勢， 的瓶頸乃在於元件的操作電流過大，因 6 200908294 成 且啕刊於CMOS元件的始, 鉍小以及記憶體密度的提升。麸 地突破。 知犯力的限制，較不易獲得有效 為解決上述問題’美國專利 相變化記,it體的製造方法。首先，」9,758/中提出—種形成 =上^ 開口之圖形化之介電層於該電極層與該基 板之上。接者，形成一相變化芦The touch area is up to 0949-A22087TWF(N2); P51960009TW; ph〇elip Looking at the current development trend of phase change memory, the bottleneck is that the operating current of the component is too large, because 6200908294 and published in the beginning of CMOS components, 铋Small and increased memory density. Break through the bran. Knowing the limitations of the offense is less likely to be effective. To solve the above problems, the US patent phase change, the manufacturing method of the body. First, a patterned dielectric layer forming an upper opening is formed on the electrode layer and the substrate. Receiver, forming a phase change
口。利用上述製程，雖然可達::之上’並填入該開 的目的，然而，由於在該結：===極之接觸面積 τ 形成電性連結通路的部分為 填洞‘程，該製程無論在加熱效率、以及接觸面電性均勾度都 有相當的限制。此外’大部份的介電材料之導熱係數係約為 0.7 W/m-K，然而進一步使用導熱係數低於〇1 w/m_K之材 料，則可大幅降低熱的散失。然而，該等材料容易受熱產生化 學或性質上的變化，不易整合至相變化記憶體的製程中。 此外，在美國專利 20060157689 (Forming a carb〇n layer between phase change layers of a phase change memory)揭露利 用一包含碳的膜層來加熱相變化層。然而，由於無法精確得知 在該含碳的膜層内，該低電阻導電路徑(fllament)係如何形成， 且該導電路徑的寬窄為何，因此非常難設計一利用該含碳膜層 作為加熱層的相變化記憶體。 有鑑於此’設計一嶄新的相變化記憶體元件之製程，來克 服習知技術的缺點，實為相變化記憶體製程技術極需研究之重 點。 【發明内容】 0949-A22087TWF(N2)；P51960009TW；phoe!ip 7 2UU^〇8294 本發明係提供-種相變化 、 兩相變化層間之導電通、首、°體及其製造方式，利用介於 降低操作電流及能量。j彳、’隹持熱不對外溢散的目的，有效 t電極;-第-相變:=_>第，及-隻化層與該第二電極電性Λ冑極電性連結，一第-相 及第二相變化層之間並與;j及：導電橋接形成於該第-結。 Λ 及第二相變化層分別電性連 明之=藉:崎施例及比較實施例，以更進-步說明本發 明之/μ 來關本發明之範圍，本發 月之辄圍應以所附之中請專利範圍為準。 【實施方式】 -般來部’導電金屬材料—般係為高導熱材質，因此常被 來作為加熱器。在該金屬導電屬的鄰近地區，金屬導電層與 週遭物質的溫度差甚至會高達_。〇。當與該金屬導電屬接 觸之相變化層受熱時，直接與金屬導電層相鄰的相變化區域才 ^產生相變化，離該金屬導電層較遠的相變化層並未產生相變 =，因此該相變化層並非均勻的受熱。所以，當加熱時間愈短 4，愈不容易產生完整的相變化，而利用具有比介電層低的導 熱係數的材料，來防止熱的散失，係為一重要的課題。 綜觀用於相變化記憶體的材料，如硫屬化合物 (chalCOgenide)(例如：GesSbzTe5)具有較低的導熱係數。硫屬 化合物的導熱係數一般係介於0.2至0.3 W/m-k之間。理想化 的狀態係，儘可能的利用相變化材料將加熱器（金屬導電層）給 覆蓋住。 0949-A22087TWF(N2)；P51960009TW；phoelip 8 200908294 以下，請配合圖式，來详細說明本發明之實施例所述之相 變化記憶體的製造方法。 首先，請參照第la圖，提供一具有一第一介電層12〇之 基板100 ’其中該介電層具有一開口 1〇1。接著，一第—電極 103作為一下電極係形成於該開口 1〇1，並露出該第一電極ι〇3 的上表面·其中，該基底〗〇〇可為一半導體製程所使用之基 板，例如為矽基板。該基底100可為一已完成CM0S前段製 程的基底，亦可能包含隔離結構、電容、二極體與其類似物， 為簡化圖示起見，圖中僅以一平整基底表示。該第一電極1〇3 係為導電材料，例如為AI、W、Mo、Ti、TiN、TiW或mouth. With the above process, although it is possible to: "above' and fill in the purpose of the opening, however, since the portion of the junction: === pole contact area τ forms an electrical connection path is a hole filling process, the process Both the heating efficiency and the electrical properties of the contact surface are quite limited. In addition, most of the dielectric materials have a thermal conductivity of about 0.7 W/m-K. However, further use of a material having a thermal conductivity lower than 〇1 w/m_K can greatly reduce heat loss. However, such materials are susceptible to chemical or chemical changes in heat and are not easily integrated into the process of phase change memory. Further, in Forming a carb〇n layer between phase change layers of a phase change memory, a layer containing carbon is used to heat the phase change layer. However, since it is impossible to accurately know how the low-resistance conductive path is formed in the carbon-containing film layer, and the width of the conductive path is narrow, it is very difficult to design a carbon-containing film layer as a heating layer. Phase change memory. In view of the process of designing a new phase change memory component to overcome the shortcomings of the conventional technology, it is extremely important to study the phase change memory system technology. SUMMARY OF THE INVENTION 0949-A22087TWF(N2); P51960009TW;phoe!ip 7 2UU^〇8294 The present invention provides a phase change, a two-phase change layer between the conductive, the first, the body and its manufacturing method, the use of Reduce operating current and energy. j彳, 'The purpose of holding the heat is not to overflow, the effective t electrode; - the first phase change: = _ > the first, and - only the layer and the second electrode are electrically connected, the first - And the second phase change layer and the; j and: a conductive bridge formed on the first junction. Λ and the second phase change layer are electrically connected to each other, and the second embodiment of the present invention is used to further illustrate the scope of the present invention. The scope of the patent is subject to the attachment. [Embodiment] - The general conductive material is generally made of a highly conductive material, and therefore is often used as a heater. In the vicinity of the metal conductive genus, the temperature difference between the metal conductive layer and the surrounding material may even be as high as _. Hey. When the phase change layer in contact with the metal conductive genus is heated, the phase change region directly adjacent to the metal conductive layer generates a phase change, and the phase change layer farther from the metal conductive layer does not undergo a phase change = The phase change layer is not uniformly heated. Therefore, the shorter the heating time 4, the less likely it is to produce a complete phase change, and the use of a material having a lower thermal conductivity than the dielectric layer to prevent heat loss is an important issue. Looking at materials used for phase change memory, such as chalCOgenide (eg, GesSbzTe5) has a lower thermal conductivity. The thermal conductivity of the chalcogenide is generally between 0.2 and 0.3 W/m-k. The idealized state is to cover the heater (metal conductive layer) with phase change material as much as possible. 0949-A22087TWF(N2); P51960009TW;phoelip 8 200908294 Hereinafter, a method of manufacturing the phase change memory according to the embodiment of the present invention will be described in detail with reference to the drawings. First, referring to the first drawing, a substrate 100' having a first dielectric layer 12' is provided, wherein the dielectric layer has an opening 1?. Next, a first electrode 103 is formed as a lower electrode system in the opening 1〇1, and exposes an upper surface of the first electrode ι〇3. The substrate 〇〇 can be a substrate used in a semiconductor process, for example, It is a substrate. The substrate 100 can be a substrate that has completed the CM0S front-end process, and may also include isolation structures, capacitors, diodes, and the like. For simplicity of illustration, the figure is represented by only a flat substrate. The first electrode 1〇3 is made of a conductive material, such as AI, W, Mo, Ti, TiN, TiW or
TaN。第一介電層102可為習知所使用之任何介電材質。 接著，請參照第lb圖，一第一相變化層1〇4係形成於該 第一電極103之上並與之形成電性連結。其中，該第一相變化 層104可由硫屬化合物所構成，例如含Ge、％、Te或其混人 之材料’舉例而言可為GeTe、GeSb' SbTe、GeSbTe或 InGeSbTe。 接著，請參照第lc圖，一第二介電層1〇5係形成該第一 介電層102之上，該第二介電層1〇5具有一開口 1〇6 ,貫穿該 第二介電層105，並露出該第一相變化層1〇4之上表面。第— 介電層1〇5可為習知所使用之任何介電材質。值得注意的是該 開口 106具有-寬度W’該寬度％係可小於微影製程的曝光 極限。 接著’請參照第Id圖’形成—導電橋接1G7填入該開口 106中’並與該第-相變化層⑽紐連結。該導電橋接1〇7 0949-A22087TWF(N2)；P5l960009TW；phoelip 200908294 係為導電材料，例如為A1、W、MoTaN. The first dielectric layer 102 can be any dielectric material conventionally used. Next, referring to FIG. 1b, a first phase change layer 1〇4 is formed on the first electrode 103 and electrically connected thereto. Wherein, the first phase change layer 104 may be composed of a chalcogen compound, for example, a material containing Ge, %, Te or a mixture thereof may be, for example, GeTe, GeSb'SbTe, GeSbTe or InGeSbTe. Next, referring to FIG. 1c, a second dielectric layer 1〇5 is formed on the first dielectric layer 102, and the second dielectric layer 1〇5 has an opening 1〇6 extending through the second dielectric layer. The electric layer 105 exposes the upper surface of the first phase change layer 1〇4. The first dielectric layer 1〇5 can be any dielectric material conventionally used. It is noted that the opening 106 has a width W' which may be less than the exposure limit of the lithography process. Next, please refer to the "Id diagram" to form a conductive bridge 1G7 filled in the opening 106 and connected to the first phase change layer (10). The conductive bridge is 1〇7 0949-A22087TWF(N2); P5l960009TW; phoelip 200908294 is a conductive material, such as A1, W, Mo
Ti、TiN、TiW 或 1 1、 111N、 11Ti, TiN, TiW or 1 1, 111N, 11
TaN，且具有—厚度介於μ。。·，或可介於n. 第-Ϊί/^第U圖，—第二相變化層⑽係形成於兮 = 該導電橋接1〇7之上，並與該導電橋接二 :入、、、° ’其中该弟二相變化層108可由硫屬化合物所構戍， 列士 3 Ge、Sb、Te或其混合之材料，舉例而言可為⑽。、TaN, and has a thickness of μ. . Or, may be between n. - Ϊ ί / ^ U, - the second phase change layer (10) is formed on 兮 = the conductive bridge 1 〇 7 and bridged with the conductive two: into,,, ° Wherein the two-phase change layer 108 may be constructed of a chalcogen compound, a material of Lishi 3 Ge, Sb, Te or a mixture thereof, for example, (10). ,
GeSb、SbTe、GeSbTe 或 InGeSbTe。 、 取後’請參照第If圖’形成—第二電極·作為上 於該第二相變化層1〇8之上’並與該第二相變化層舰電性連 接。接著，形成-第三介電層11G圍繞該第二電極膨該第 一電極109係為導電材料，例如為入卜w、M〇、Ti、、 TW，TaN。在本實施例中，料電橋接1〇7係形成於該第 -及第二相變化層1()4及⑽之間。且該開口應具有一較窄 截面，以降低與該相變層之接觸面積。由於該開口腿係由導 電金屬層所填滿而非由相變化材料層所填滿，因此導電金屬廣 在該開口之壓降4乎可以忽略。此外，由於利用導電金屬作為 導電橋接而非加熱器，有助於在其兩端維持相等的溫度。再 者，產生相變化的區域係被相變化材質所包覆，因此該相變化 層亦可視為一熱阻隔層。 如第If圖所示，一第一截面區域112係由該第一相變化 層104及該導電橋接1〇7彼此相接處之截面所構成；以及一第 二截面區域111係由該第二相變化層1〇8及該導電橋接1〇7彼 此相接觸之截面所構成。在此實施例，該第一截面區域112及 该第一截面區域111具有相同之尺寸。在其他實施例中，該第 0949-A22087TWF(N2)；P51960009TW；ph〇elip 10 200908294 =區域ii2及韻二截面區域η〗亦可具有不同之尺寸。 料電橋接1G7可具有傾斜的剖面、或為杯型、τ型、或倒τ I如第2圖及第3圖所示。在該等實施例中，由於相變化層 與導電橋接的躺面齡影_電綠度社,卜使得接觸面 積小的#之電流拔度大於接觸面積大的一端之電流密度，因 此相、艾化％生只會選擇在接觸面積小的—端。因此未發生相變 化的相化變層則是用來料熱的阻隔層 。如果沒有同時在導電 金屬層的兩端同時配置相變化層，_導電金屬層會作用為一 加熱器’而非-導電橋接’無法有效的維持住熱，導致熱散失。 雖然本發明已以實施例揭露如上，然其並非用以限定本發 明，任何熟習此技藝者，衫脫離本發明之精神和 可作些許之更動與㈣，本發明之贿 ; 請專利範_敎者為準。 附之申 0949-A22087TWF(N2)；P51960009TW:phoelip 200908294 【圖式簡單說明】 第la至第If係顯示本發明一實施例所述之相變化記憶體 的製作流程剖面圖。 第2圖及第3圖係顯示本發明所述之相變化記憶體之其他 實施例。 【主要元件符號說明】 101〜開口， 120〜第一介電層； 103〜第一電極； 104〜第一相變化層； 105〜第二介電層； 106〜開口； 107〜導電橋接； 108〜第二相變化層； 109〜第二電極； 110〜第三介電層； 111〜第二截面區域； 112〜第一截面區域； W〜剖面寬度。 0949-A22087TWF(N2)；P51960009TW；phoelip 12GeSb, SbTe, GeSbTe or InGeSbTe. Then, the second electrode is formed as the upper surface of the second phase change layer 1〇8 and is electrically connected to the second phase change layer. Next, the third dielectric layer 11G is formed as a conductive material around the second electrode, for example, w, M, Ti, TW, TaN. In the present embodiment, a material bridge 1-7 is formed between the first and second phase change layers 1 () 4 and (10). And the opening should have a narrower cross section to reduce the contact area with the phase change layer. Since the open leg is filled with a conductive metal layer and not filled with a phase change material layer, the voltage drop across the opening of the conductive metal is negligible. In addition, the use of conductive metals as conductive bridges rather than heaters helps maintain equal temperatures across their ends. Further, the phase change phase is covered by the phase change material, so the phase change layer can also be regarded as a thermal barrier layer. As shown in FIG. If a first cross-sectional area 112 is formed by a cross section of the first phase change layer 104 and the conductive bridge 1〇7, and a second cross-sectional area 111 is composed of the second The phase change layer 1〇8 and the cross section of the conductive bridge 1〇7 are in contact with each other. In this embodiment, the first cross-sectional area 112 and the first cross-sectional area 111 have the same dimensions. In other embodiments, the 0949-A22087TWF(N2); P51960009TW; ph〇elip 10 200908294=area ii2 and the rhyme cross-sectional area η may also have different sizes. The material bridge 1G7 can have a sloping profile, or a cup shape, a τ type, or an inverted τ I as shown in Figs. 2 and 3. In these embodiments, due to the phase change layer of the phase change layer and the conductive bridge, the current pull of the contact area is smaller than the current density of the end of the contact area, so the phase, Ai %% will only choose to have a small contact area. Therefore, the phase change layer which has not undergone phase change is a barrier layer for heat. If the phase change layer is not simultaneously disposed at both ends of the conductive metal layer, the _ conductive metal layer acts as a heater instead of the conductive bridge, which does not effectively maintain heat, resulting in heat loss. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone skilled in the art can shed the spirit of the present invention and make some changes and (4), the bribe of the present invention; Subject to it. Attachment 0949-A22087TWF(N2); P51960009TW: phoelip 200908294 [Simplified Schematic Description] The first to the IF are sectional views showing the manufacturing process of the phase change memory according to an embodiment of the present invention. Figures 2 and 3 show other embodiments of the phase change memory of the present invention. [Major component symbol description] 101~opening, 120~first dielectric layer; 103~first electrode; 104~first phase change layer; 105~second dielectric layer; 106~opening; 107~conductive bridging; ~ second phase change layer; 109 to second electrode; 110 to third dielectric layer; 111 to second cross-sectional area; 112 to first cross-sectional area; W to cross-sectional width. 0949-A22087TWF(N2);P51960009TW;phoelip 12