外加偏压对未退火Co/n-poly-SiGe肖特基接触特性的影响

Effect of external bias on Schottky contact characteristics of unannealed Co/n-poly-SiGe

采用直流离子束溅射法，在n型单晶硅衬底上淀积Si1-xGex薄膜。俄歇电子谱（AEs）测得Si1-xGex薄膜的Ge含量约为0．15。对薄膜进行高温磷扩散后，经XRD测试为多晶态，即得n—poly—Si0.85Ge0.15。在n—poly—Si0.85Ge0.15上溅射一层薄的Co膜，做成Co／n—poly—Si0.85Ge0.15肖特基结样品。在90～332K范围对未退火样品做I-V-T测试。研究发现，随着外加偏压增大，表观理想因子缓慢上升，肖特基势垒高度（SBH）下降。基于SBH的不均匀分布建模，得到了二者近似为线性负相关的结论。

On n-type monoerystalline Si substrates, the Si1-xGex films were deposited by DC ion beam sputtering technique. The Ge percentage of 15% in the as-deposited Si1-xGex film was determined approximately by AES spectra. The Si0.85Ge0.15 films were doped with phosphorus at high temperature through thermal diffusion to form n-type polycrystalline films, the n-poly-Si0.85Ge0.15, which is verified by XRD. And the Co/n-poly-Si0.85Ge0.15/n-Si Schottky junctions were made by sputtering Co. In the measuring temperature range of 90-332K, the variable temperature I-V test was done on the unannealed samples. It is found that, with the increase of external bias, the apparent ideality factor increases slowly, while the Schottky Barrier Height （SBH） decreases. Based on the modeling of inhomogeneous distribution of SBH, a conclusion was drawn that the two variables have an approximate negative linear correlation.