Begeza Viktor, Mehner Erik, Stöcker Hartmut, Xie Yufang, García Alejandro, Hübner Rene, Erb Denise, Zhou Shengqiang, Rebohle Lars
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstrasse 400, 01328 Dresden, Germany.
TU Dresden, faculty of physics, 01062 Dresden, Germany.
Nanomaterials (Basel). 2020 Mar 31;10(4):648. doi: 10.3390/nano10040648.
The nickel monogermanide (NiGe) phase is known for its electrical properties such as low ohmic and low contact resistance in group-IV-based electronics. In this work, thin films of nickel germanides (Ni-Ge) were formed by magnetron sputtering followed by flash lamp annealing (FLA). The formation of NiGe was investigated on three types of substrates: on amorphous (a-Ge) as well as polycrystalline Ge (poly-Ge) and on monocrystalline (100)-Ge (c-Ge) wafers. Substrate and NiGe structure characterization was performed by Raman, TEM, and XRD analyses. Hall Effect and four-point-probe measurements were used to characterize the films electrically. NiGe layers were successfully formed on different Ge substrates using 3-ms FLA. Electrical as well as XRD and TEM measurements are revealing the formation of Ni-rich hexagonal and cubic phases at lower temperatures accompanied by the formation of the low-resistivity orthorhombic NiGe phase. At higher annealing temperatures, Ni-rich phases are transforming into NiGe, as long as the supply of Ge is ensured. NiGe layer formation on a-Ge is accompanied by metal-induced crystallization and its elevated electrical resistivity compared with that of poly-Ge and c-Ge substrates. Specific resistivities for 30 nm Ni on Ge were determined to be 13.5 μΩ·cm for poly-Ge, 14.6 μΩ·cm for c-Ge, and 20.1 μΩ·cm for a-Ge.
一锗化镍（NiGe）相因其电学性质而闻名，比如在基于IV族的电子器件中具有低欧姆电阻和低接触电阻。在本工作中，通过磁控溅射然后进行闪光灯退火（FLA）形成了锗化镍（Ni-Ge）薄膜。在三种类型的衬底上研究了NiGe的形成：非晶锗（a-Ge）、多晶锗（poly-Ge）以及单晶（100）-锗（c-Ge）晶圆。通过拉曼光谱、透射电子显微镜（TEM）和X射线衍射（XRD）分析对衬底和NiGe结构进行了表征。利用霍尔效应和四点探针测量对薄膜进行电学表征。使用3毫秒的闪光灯退火在不同的锗衬底上成功形成了NiGe层。电学以及XRD和TEM测量结果表明，在较低温度下形成了富镍的六方相和立方相，同时形成了低电阻率的正交晶系NiGe相。在较高的退火温度下，只要确保锗的供应，富镍相就会转变成NiGe。在a-Ge上形成NiGe层伴随着金属诱导结晶，并且与poly-Ge和c-Ge衬底相比其电阻率升高。对于在锗上的30纳米镍，poly-Ge的比电阻率测定为13.5μΩ·cm，c-Ge为14.6μΩ·cm，a-Ge为20.1μΩ·cm。
