Choolakkal Arun Haridas, Niiranen Pentti, Dorri Samira, Birch Jens, Pedersen Henrik
Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.
Nat Commun. 2024 Dec 11;15(1):10667. doi: 10.1038/s41467-024-55007-1.
Semiconductor devices are constructed from stacks of materials with different electrical properties, making deposition of thin layers central in producing semiconductor chips. The shrinking of electronics has resulted in complex device architectures which require deposition into holes and recessed features. A key parameter for such deposition is the step coverage (SC), which is the ratio of the thickness of material at the bottom and at the top. Here, we show that adding a co-flow of a heavy inert gas affords a higher SC for deposition by chemical vapor deposition (CVD). By adding a co-flow of Xe to a CVD process for boron carbide using a single source precursor with a lower molecular mass than the atomic mass of Xe, the SC increased from 0.71 to 0.97 in a 10:1 aspect ratio feature. The concept was further validated by a longer deposition depth in lateral high aspect ratio structures. We suggest that competitive co-diffusion is a general route to conformal CVD.
半导体器件由具有不同电学性质的材料堆叠而成，这使得薄层沉积成为生产半导体芯片的核心环节。电子产品的小型化导致了复杂的器件架构，需要将材料沉积到孔洞和凹陷特征中。这种沉积的一个关键参数是台阶覆盖度（SC），它是底部和顶部材料厚度的比值。在此，我们表明添加重惰性气体的共流可通过化学气相沉积（CVD）实现更高的台阶覆盖度。在使用分子量低于Xe原子量的单源前驱体进行碳化硼化学气相沉积过程中，通过添加Xe共流，在纵横比为10:1的特征结构中，台阶覆盖度从0.71提高到了0.97。通过横向高深宽比结构中更长的沉积深度，该概念得到了进一步验证。我们认为竞争性共扩散是实现保形化学气相沉积的一般途径。
