(上海交通大学 材料科学与工程学院;教育部高温材料及测试重点实验室，上海 200240)
摘 要: 利用简易合金靶在Si(100)衬底磁控溅射制备Cu、Cu-1.19%Cr和Cu-2.18%Cr薄膜，研究Cr对Cu薄膜在300~500 ℃真空退火前后的结构和电阻率的影响。X射线衍射分析表明：Cu及Cu(Cr)薄膜均呈现Cu(111) 和Cu(200)衍射峰，并且Cu(Cr)薄膜一直保持较强的(111)织构。原子力显微分析表明：Cu薄膜在500 ℃退火时，薄膜与硅基底发生明显的互扩散，薄膜表面的致密度及平整度下降；而Cu(Cr)薄膜在退火时保持较高的致密度，Cr显著提高Cu/Si薄膜体系的热稳定性。Cu(Cr)薄膜的电阻率随温度升高先减小而后增加，在400 ℃及500 ℃退火30 min后分别达到最小值2.76 μΩ∙cm和2.97 μΩ∙cm，与纯Cu膜相近(2.55 μΩ∙cm)。Cu(Cr)薄膜退火电阻率的大幅度减小与薄膜晶粒尺寸的增加以及Cr的扩散有关。适量的Cr掺杂和合理的退火工艺使得Cu(Cr)合金薄膜在高温互连材料方面具有很大的应用前景。
关键字: Cu(Cr)薄膜；织构；热稳定性；电阻率
（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
