In this talk I will introduce two related topics. The first part is the fabrication and study on 2D boron sheets, namely borophene. Borophene possesses enormous polymorphs arising from periodic hole patterns in a triangular lattice. We found that the structure of 2D boron sheets can be tuned by the interaction and charge transfer between the film and the substrate. And even a honeycomb 2D boron sheet can be achieved by using Al(111) as the substrate. The novel electronic and vibrational properties of 2D boron sheets will be discussed. In the second part I introduce our efforts in building a tip-enhanced Raman spectroscopy based on our low-temperature (4K) scanning tunneling microscopy (STM). Combing with an MBE for in-situ growth of 2D materials, this system has demonstrated to be very powerful in studying atomic scale vibrational properties of 2D materials.