1377582 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種導 定性佳的導電材料。 電材料，特別是指__ 種高溫穩 【先前技術】 由於銅本身具備有極佳的導電性及抗電荷遷移性質 (electromigration resistance);因此，使得使用有銅導線的半1377582 IX. Description of the Invention: [Technical Field to Which the Invention Is Ascribed] The present invention relates to a conductive material which is excellent in conductivity. Electrical materials, especially __ kinds of high temperature stability [Prior Art] Since copper itself has excellent electrical conductivity and resistance to electromigration resistance; therefore, the use of copper wire half
導體元件之使用壽命及穩定性得以獲得改善，並進而成為 取代鋁導線的導電層。 … 然而，由於銅、銅合金等導電材料在高溫狀態下的機 械性質較差且高溫穩定性不足，以致於此等導電材料在使 用上受到許多限制。因此，半導體元件之銅導線在製程上 則面臨到許多因製程溫度所致的問題，諸如：附著性不足 易與石夕產生反應形成銅矽化物因而增加電阻係數 (resistivity)與漏電流等問題。 冶金術（metallurgy)相關領域者皆知，雖然於Cu内添加 與Cu互溶之金屬元素以形成固溶體（s〇iid s〇iuti〇n)可增加 a合金的高溫穩定性；然而，卻造成冑阻係數增加等^題 。因此，為解決銅導線在半導體製程上所面臨的高溫穩定 性不足等問題，可透過濺鐘（sputtedng)的製程在Cu鑛膜内 均勻散佈不互溶的元素，以使得此等不互溶元素得以呈過 飽=的形式m溶於Cu晶體（erystal)内以細化日日日粒^藉由此 等晶粒細化（grain refinement)之抑制再結晶的現象、且可降 低Cu原子的擴散速率，並抑制&與石夕基板在高溫的製程 5 1377582 環境下產生反應，進而降低電阻係數、漏電流問題並增加 銅導線的1¾溫穩定性。The service life and stability of the conductor elements are improved and, in turn, become a conductive layer that replaces the aluminum wires. ... However, since conductive materials such as copper and copper alloys have poor mechanical properties at high temperatures and insufficient high temperature stability, such conductive materials are subject to many limitations in use. Therefore, the copper wire of the semiconductor element faces many problems due to the process temperature in the process, such as insufficient adhesion, and it is easy to react with the stone to form a copper bismuth compound, thereby increasing the resistivity and leakage current. It is well known in the related art of metallurgy, although the addition of a metal element which is mutually soluble with Cu to form a solid solution (s〇iid s〇iuti〇n) in Cu can increase the high temperature stability of the a alloy; however, it causes Increase the coefficient of drag and so on. Therefore, in order to solve the problem of insufficient high temperature stability of the copper wire in the semiconductor process, the immiscible element can be evenly dispersed in the Cu film through a sputtering process, so that the immiscible elements can be presented. The form m of the fullness = is dissolved in the Cu crystal (erystal) to refine the phenomenon of recrystallization of the grain refinement by the daily grain, and the diffusion rate of the Cu atom can be lowered. It also inhibits & reacts with the Shixi substrate in a high temperature process 5 1377582, which reduces the resistivity and leakage current problems and increases the temperature stability of the copper wire.
此等添加不互溶元素於Cu晶體内來增加Cu的高溫穩 定性之相關技術手段，可見發明人於Metallurgical and Materials Transactions A，Vol. 29A，ρ· 647-658, (1998)、 Journal of Applied Physics, 85, p.6462-6469 (1999) ' Journal of Materials Research, Vol. 18, No. 6, p. 1429-1434 (2003) ' Applied Physics Letters, Vol. 87，No. 21，p. 211902 (2005)等 期刊上所發表之 Microstructure and Properties of Cu-C Pseudoalloy Films Prepared by Sputter Deposition 、 Microstructure and Properties of Sputtered Copper Films Containing Insoluble Molybdenum、Thermal Stability of Sputtered Copper Films Containing Dilute Insoluble Tungsten :A Thermal Annealing Study、Formation of A Reacted Layer at The Barrierless Cu(WN)/Si Interface 等文章中。另，相關 技術亦可見 S· L. Zhang 等人於 Journal of Electronic Materials, Vol. 30，p. Ll，（2001)所發表之 High conductivity copper-boron alloys obtained by low temperature annealing 的 文章。又，中華民國專利證書編號第TWI237328號發明專 利，亦揭露有銅薄膜内添加有不互溶氮化物（如WNt)以細化 晶粒等技術。 前揭技術手段中所添加的不互溶元素或氮化物，雖然 可增加銅導線的高溫穩定性；然而，此等不互溶元素或氮 化物對於晶粒細化的貢獻度有限，在400°C〜530°C的退火 6 1377582 (annealing)溫度下，Cu原子亦將因晶粒細化之抑制再結晶 能力不足而擴散到矽基材並與矽產生反應；因此，仍無法 有效地改善電阻係數、漏電流等問題。 由上述說明可知’使得有效量的不互溶元素得以呈過 飽和的形式固溶於銅晶體中，並降低銅晶體整體的電阻係 數與漏電流以增加其在半導體元件之高溫製程上的適用性Such a technique for adding an immiscible element to a Cu crystal to increase the high temperature stability of Cu can be seen by the inventors in Metallurgical and Materials A, Vol. 29A, ρ·647-658, (1998), Journal of Applied Physics , 85, p.6462-6469 (1999) 'Journal of Materials Research, Vol. 18, No. 6, p. 1429-1434 (2003) ' Applied Physics Letters, Vol. 87, No. 21, p. 211902 ( 2005) Microstructure and Properties of Cu-C Pseudoalloy Films Prepared by Sputter Deposition, Microstructure and Properties of Sputtered Copper Films Containing Insoluble Molybdenum, Thermal Stability of Sputtered Copper Films Containing Dilute Insoluble Tungsten : A Thermal Annealing Study, Formation Of A Reacted Layer at The Barrierless Cu (WN)/Si Interface and other articles. Further, related art can also be found in the article by S. L. Zhang et al., Journal of Electronic Materials, Vol. 30, p. Ll, (2001), High conductivity copper-boron alloys obtained by low temperature annealing. Further, the invention patent of the Republic of China Patent No. TWI237328 discloses a technique in which an immiscible nitride (e.g., WNt) is added to a copper film to refine grains. The immiscible elements or nitrides added in the prior art techniques can increase the high temperature stability of the copper wires; however, the contribution of such immiscible elements or nitrides to grain refinement is limited at 400 ° C. At an annealing temperature of 530 ° C at 6 1377582 (annealing) temperature, Cu atoms will also diffuse into the ruthenium substrate due to insufficient recrystallization ability of the grain refinement and react with ruthenium; therefore, the resistivity cannot be effectively improved. Leakage current and other issues. It can be seen from the above description that the effective amount of the immiscible element is dissolved in the copper crystal in a supersaturated form, and the overall resistance coefficient and leakage current of the copper crystal are lowered to increase the applicability of the high temperature process of the semiconductor element.
，是當前開發高溫穩定性佳的導電材料相關領域者所待解 決的課題。 【發明内容】 <發明概要>It is a problem to be solved in the field of developing conductive materials with high temperature stability. SUMMARY OF THE INVENTION <Summary of the Invention>
與C、W、WNt、Mo、B、Ta等不溶於Cu晶體中的元 素或氮化物相比較之下，Ru、Re ' Ho等不與Cu互溶的元 素，更可有效地呈過飽和的形式固溶於Cu晶體中；因此， 在高溫的退火處理過程中，部分Ru、Re、H〇等元素可自 Cu晶格位置（lattice site)中析出於Cu晶粒的晶界如伽 boundary)處’如此，更可有效地抑制Cu晶粒的再結晶 (recrystamzati〇n)行為，對晶粒細化之抑制再結晶能力= 獻度亦相對比先前技術所提的元素高。 Μ以形成一含有 Re、Ho，或此等 因此，本發明主要是在鋼晶體内引入 Cu10〇-x_yMxNy之組成物，且μ是選自ru 之一組合。值得一提的是，當^ 田x值或y值過大時，將影響 該組成物的導電度（electrical conductivity);因此，以原子 百分比計，〇·〇<χ$ 10.0，0 OgyS 1〇 〇。 <發明目的〉 7Compared with elements such as C, W, WNt, Mo, B, Ta, etc., which are insoluble in Cu crystals, elements such as Ru, Re 'Ho, etc. which are not mutually soluble with Cu are more effectively supersaturated. Soluble in Cu crystal; therefore, in the high temperature annealing process, some elements such as Ru, Re, H〇 can be precipitated from the lattice site of Cu crystal grain boundary such as gamma boundary In this way, the recrystallization behavior of the Cu crystal grains can be effectively suppressed, and the recrystallization resistance of the grain refinement = the contribution is also higher than that of the elements mentioned in the prior art. Μ to form a composition containing Re, Ho, or the like. Therefore, the present invention mainly introduces a composition of Cu10〇-x_yMxNy in a steel crystal, and μ is a combination selected from ru. It is worth mentioning that when the value of x or y is too large, it will affect the electrical conductivity of the composition; therefore, in atomic percentage, 〇·〇<χ$ 10.0,0 OgyS 1〇 Hey. <Objectives of the Invention> 7