Qian Fengsong, Deng Jun, Ma Xiaochen, Fu Guosheng, Xu Chen
Key Laboratory of Optoelectronics Technology, Ministry of Education, Beijing University of Technology, Beijing 100124, China.
Fert Beijing Institute, School of Microelectronics, Beihang University, Beijing 100191, China.
Nanomaterials (Basel). 2023 Mar 31;13(7):1242. doi: 10.3390/nano13071242.
Vertical graphene (VG) combines the excellent properties of conventional graphene with a unique vertical nanosheet structure, and has shown tremendous promise in the field of electronics and composites. However, its complex surface morphology brings great difficulties to micro-nano fabrication, especially regarding photolithography induced nanosheet collapse and remaining chemical residues. Here, we demonstrate an innovative method for directly growing patterned VG on a SiO/Si substrate. A patterned Cr film was deposited on the substrate as a barrier layer. The VG was synthesized by PECVD on both the patterned Cr film and the exposed SiO/Si substrate. During the cooling process, the patterned Cr film covered by VG naturally peeled off from the substrate due to the thermal stress mismatch, while the VG directly grown on the SiO/Si substrate was remained. The temperature-dependent thermal stress distribution in each layer was analyzed using finite element simulations, and the separation mechanism of the Cr film from the substrate was explained. This method avoids the contamination and damage caused by the VG photolithography process. Our work is expected to provide a convenient and reliable solution for the manufacture of VG-based electronic devices.
垂直石墨烯（VG）将传统石墨烯的优异性能与独特的垂直纳米片结构相结合，在电子学和复合材料领域展现出巨大的潜力。然而，其复杂的表面形态给微纳制造带来了极大困难，尤其是光刻诱导的纳米片塌陷和残留化学残留物问题。在此，我们展示了一种在SiO/Si衬底上直接生长图案化VG的创新方法。在衬底上沉积图案化的Cr膜作为阻挡层。通过PECVD在图案化的Cr膜和暴露的SiO/Si衬底上合成VG。在冷却过程中，由于热应力失配，被VG覆盖的图案化Cr膜自然地从衬底上剥离，而直接生长在SiO/Si衬底上的VG则保留下来。使用有限元模拟分析了各层中随温度变化的热应力分布，并解释了Cr膜与衬底的分离机制。该方法避免了VG光刻工艺造成的污染和损伤。我们的工作有望为基于VG的电子器件制造提供一种便捷可靠的解决方案。
