Anharmonic Phonon Decay Effect of Single Crystal Diamond
随着金刚石作为散热材料在大功率半导体器件、激光器、微波器件和大规模集成电路等领域中的应用愈加广泛, 通过对金刚石局部进行精确测温以评价其散热性能是一个重要的研究课题。本文使用拉曼光谱仪对不同掺杂类型的高温高压(HTHP)样品和化学气相沉积(CVD)样品在228~678 K进行检测, 得到了金刚石样品TO模拉曼峰位、半峰全宽等与温度的一一对应关系, 并通过理论计算模型明确了热膨胀、三声子、四声子随温度变化对拉曼峰位、半峰全宽的贡献。理论和实验测试结果发现: 不同掺杂以及不同类型样品的拉曼光谱峰位无明显区别; 随温度升高, 半峰全宽宽化, 主要影响因素为声子衰减导致的非简谐效应, 同时受载流子的电离率、浓度、类型, 以及缺陷和杂质影响; 声子寿命主要受到声子的非简谐衰减作用影响, 基本不受杂质散射的影响。本研究为金刚石材料的温度检测提供了一种无损、非接触、高空间分辨率的方法。
As a promising heat dissipation material, diamond is wildly used in high power semiconductor devices, lasers, microwave devices and large-scale integrated circuit fields. The accurate local temperature measurement of diamond to evaluate its heat dissipation performance has become an important research topic. In this paper, Raman spectroscopy was employed to investigate the Raman spectra (TO mode) characteristics of diamond in the temperature range of 228 to 678 K. The one-to-one correspondence between Raman peak position, full width at half maximum (FWHM) and temperature of different doped diamond samples was established. The contributions of thermal expansion, three phonons and four phonons to Raman peak position at variable temperatures were analyzed by theoretical model calculation. The results show that there is no significant difference among the Raman spectra of different doped samples of HTHP and CVD. With the increase of temperature, the FWHM broadens. It is considered that the anharmonic effect caused by phonon attenuation is the determining factor, while the ionization rate, concentration and type of carriers, defects and impurities contribute partial influence. Meanwhile, the phonon lifetime is mainly affected by the anharmonic attenuation of phonons, and appears largely unaffected by impurity scattering. This study shed light on a non-destructive, non-contact, high spatial resolution method to the temperature measurement for diamond materials.
李斌, 胡秀飞, 杨旖秋, 王英楠, 谢雪健, 彭燕, 杨祥龙, 王希玮, 胡小波, 徐现刚, 冯志红. 单晶金刚石声子非简谐衰减效应研究[J]. 人工晶体学报, 2023, 52(3): 442. 李斌, 胡秀飞, 杨旖秋, 王英楠, 谢雪健, 彭燕, 杨祥龙, 王希玮, 胡小波, 徐现刚, 冯志红. Anharmonic Phonon Decay Effect of Single Crystal Diamond[J]. Journal of Synthetic Crystals, 2023, 52(3): 442.