(上海交通大學 材料科學與工程學院;教育部高溫材料及測試重點實驗室，上海 200240)
摘 要: 利用簡易合金靶在Si(100)襯底磁控濺射制備Cu、Cu-1.19%Cr和Cu-2.18%Cr薄膜，研究Cr對Cu薄膜在300~500 ℃真空退火前后的結(jié)構(gòu)和電阻率的影響。X射線衍射分析表明：Cu及Cu(Cr)薄膜均呈現(xiàn)Cu(111) 和Cu(200)衍射峰，并且Cu(Cr)薄膜一直保持較強的(111)織構(gòu)。原子力顯微分析表明：Cu薄膜在500 ℃退火時，薄膜與硅基底發(fā)生明顯的互擴散，薄膜表面的致密度及平整度下降；而Cu(Cr)薄膜在退火時保持較高的致密度，Cr顯著提高Cu/Si薄膜體系的熱穩(wěn)定性。Cu(Cr)薄膜的電阻率隨溫度升高先減小而后增加，在400 ℃及500 ℃退火30 min后分別達到最小值2.76 μΩ∙cm和2.97 μΩ∙cm，與純Cu膜相近(2.55 μΩ∙cm)。Cu(Cr)薄膜退火電阻率的大幅度減小與薄膜晶粒尺寸的增加以及Cr的擴散有關(guān)。適量的Cr摻雜和合理的退火工藝使得Cu(Cr)合金薄膜在高溫互連材料方面具有很大的應用前景。
關(guān)鍵字: Cu(Cr)薄膜；織構(gòu)；熱穩(wěn)定性；電阻率
（Key Laboratory for High Temperature Materials andTesting of Ministry of Education,School of Materials Science and Engineering,Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:Thin films of pure Cu and Cu with 1.19%Cr and 2.18%Cr were deposited by magnetron sputtering on Si(100) substrates. Samples were annealed at 300−500 ℃ in vacuum to investigate effects of Cr on the microstructure and resistivity characteristics of Cu/Si systems. X-ray diffraction reveals Cu(111) and Cu(200) peaks for Cu and Cu(Cr) films. However, Cu(Cr) films are textured in (111) orientation. Cr enhances the thermal stability of Cu/Si systems markedly. Resistivities of Cu(Cr) films after annealed at 400 ℃ and 500 ℃ are about 2.76 μΩ∙cm and 2.97 μΩ∙cm which approach to those of Cu films. The decrease of resistivity of annealed Cu(Cr) film can be attributed to the change of microstructure and microscopy of films and the diffusion of Cr. Once optimal amount of Cr and annealing procedures are determined, Cu(Cr) films can be applied as an electronic material resistant to high temperature.
Key words: Cu(Cr) films; texture; thermal stability; resistivity
