Ultrathin films and multilayers, with controlled thickness down to single atomic layers, are critical for advanced technologies ranging from nanoelectronics to spintronics to quantum devices. However, for thicknesses less than 10nm, surfaces and dopants contribute significantly to the film properties, which can differ dramatically from that of bulk materials. For amorphous films being developed as low dielectric constant interfaces for nanoelectronics, the presence of surfaces or dopants can soften films and degrade their mechanical performance. Here we use coherent short wavelength light to fully and nondestructively characterize the mechanical properties of individual films as thin as 5nm within a bilayer, for the first time. In general, we find that the mechanical properties depend both on the amount of doping and the presence of surfaces. In very thin (5nm) silicon carbide bilayers with low hydrogen doping, surface effects induce a substantial softening - by almost an order of magnitude - compared with the same doping in thicker (46nm) bilayers. These findings are important for informed design of ultrathin films for a host of nano and quantum technologies, and for improving the switching speed and efficiency of next generation electronics.

中文翻译：

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超薄5nm低K介电双层的完整表征：掺杂剂和表面对机械性能的影响

可控厚度低至单原子层的超薄薄膜和多层薄膜对于从纳米电子学到自旋电子学到量子器件的先进技术至关重要。但是，对于小于10nm的厚度，表面和掺杂剂会显着影响薄膜的性能，这可能与块状材料有很大的不同。对于被开发为纳米电子的低介电常数界面的非晶膜，表面或掺杂剂的存在会软化膜并降低其机械性能。在这里，我们首次使用相干短波长光来全面，无损地表征双层内单个薄膜的机械性能，如5nm。通常，我们发现机械性能取决于掺杂量和表面的存在。在具有低氢掺杂的非常薄的（5nm）碳化硅双层中，与在较厚的（46nm）双层中进行相同的掺杂相比，表面效应会引起明显的软化-几乎一个数量级。这些发现对于明智地设计用于多种纳米和量子技术的超薄膜，以及对于提高下一代电子产品的开关速度和效率非常重要。