Department of Mechanical Engineering, University of Michigan, Ann Arbor, 48109, USA.
ACS Nano. 2012 May 22;6(5):4248-57. doi: 10.1021/nn300774n. Epub 2012 May 2.
Understanding energy dissipation at the nanoscale requires the ability to probe temperature fields with nanometer resolution. Here, we describe an ultra-high vacuum (UHV)-based scanning thermal microscope (SThM) technique that is capable of quantitatively mapping temperature fields with ∼15 mK temperature resolution and ∼10 nm spatial resolution. In this technique, a custom fabricated atomic force microscope (AFM) cantilever, with a nanoscale Au-Cr thermocouple integrated into the tip of the probe, is used to measure temperature fields of surfaces. Operation in an UHV environment eliminates parasitic heat transport between the tip and the sample enabling quantitative measurement of temperature fields on metal and dielectric surfaces with nanoscale resolution. We demonstrate the capabilities of this technique by directly imaging thermal fields in the vicinity of a 200 nm wide, self-heated, Pt line. Our measurements are in excellent agreement with computational results-unambiguously demonstrating the quantitative capabilities of the technique. UHV-SThM techniques will play an important role in the study of energy dissipation in nanometer-sized electronic and photonic devices and the study of phonon and electron transport at the nanoscale.
要了解纳米尺度的能量耗散，就需要能够用纳米级分辨率探测温度场。在这里，我们描述了一种基于超高真空（UHV）的扫描热显微镜（SThM）技术，该技术能够以约 15 mK 的温度分辨率和约 10 nm 的空间分辨率定量绘制温度场。在该技术中，使用定制的原子力显微镜（AFM）悬臂，其探针的尖端集成了纳米级的 Au-Cr 热电偶，来测量表面的温度场。在 UHV 环境中操作可消除针尖和样品之间的寄生热传输，从而能够以纳米级分辨率定量测量金属和介电表面上的温度场。我们通过直接对 200nm 宽的自加热 Pt 线附近的热场进行成像，展示了该技术的功能。我们的测量结果与计算结果非常吻合，明确地证明了该技术的定量能力。UHV-SThM 技术将在研究纳米级电子和光子器件中的能量耗散以及研究纳米尺度的声子和电子输运方面发挥重要作用。
