Cheng Qilong, Rajauria Sukumar, Schreck Erhard, Smith Robert, Wang Na, Reiner Jim, Dai Qing, Bogy David
Department of Mechanical Engineering, UC Berkeley, California, 94720, USA.
Western Digital Corporation, Recording Sub System Staging and Research, San Jose, CA, 95135, USA.
Sci Rep. 2020 Nov 18;10(1):20087. doi: 10.1038/s41598-020-77021-1.
The microelectronics industry is pushing the fundamental limit on the physical size of individual elements to produce faster and more powerful integrated chips. These chips have nanoscale features that dissipate power resulting in nanoscale hotspots leading to device failures. To understand the reliability impact of the hotspots, the device needs to be tested under the actual operating conditions. Therefore, the development of high-resolution thermometry techniques is required to understand the heat dissipation processes during the device operation. Recently, several thermometry techniques have been proposed, such as radiation thermometry, thermocouple based contact thermometry, scanning thermal microscopy, scanning transmission electron microscopy and transition based threshold thermometers. However, most of these techniques have limitations including the need for extensive calibration, perturbation of the actual device temperature, low throughput, and the use of ultra-high vacuum. Here, we present a facile technique, which uses a thin film contact thermometer based on the phase change material [Formula: see text], to precisely map thermal contours from the nanoscale to the microscale. [Formula: see text] undergoes a crystalline transition at [Formula: see text] with large changes in its electric conductivity, optical reflectivity and density. Using this approach, we map the surface temperature of a nanowire and an embedded micro-heater on the same chip where the scales of the temperature contours differ by three orders of magnitude. The spatial resolution can be as high as 20 nanometers thanks to the continuous nature of the thin film.
微电子行业正在突破单个元件物理尺寸的基本限制，以生产速度更快、功能更强的集成芯片。这些芯片具有纳米级特征，会耗散功率，导致出现纳米级热点，进而引发器件故障。为了解热点对可靠性的影响，需要在实际工作条件下对器件进行测试。因此，需要开发高分辨率测温技术，以了解器件运行过程中的散热过程。最近，已经提出了几种测温技术，如辐射测温法、基于热电偶的接触测温法、扫描热显微镜、扫描透射电子显微镜和基于转变的阈值温度计。然而，这些技术大多存在局限性，包括需要大量校准、会干扰实际器件温度、通量低以及需要使用超高真空。在此，我们提出一种简便的技术，该技术使用基于相变材料[公式：见原文]的薄膜接触温度计，能够精确绘制从纳米尺度到微米尺度的热轮廓。[公式：见原文]在[公式：见原文]时会发生晶体转变，其电导率、光学反射率和密度会发生很大变化。利用这种方法，我们绘制了同一芯片上纳米线和嵌入式微加热器的表面温度，其中温度轮廓的尺度相差三个数量级。由于薄膜的连续性，空间分辨率可高达20纳米。
