[论文解读] Interfacial reaction boosts thermal conductance of room-temperature integrated semiconductor interfaces stable up to 1100 C

Zhe Cheng, Xiaoyang Ji+8 more|arXiv (Cornell University)|Apr 14, 2024

Thermal properties of materialsMaterials Science被引用 3

一句话总结

本研究证明，在室温表面活化键合3C-SiC薄膜与金刚石衬底的过程中，界面反应可将热边界导热系数（TBC）提升高达300%，经1100 °C退火后达到创纪录的150 MW/m²·K。性能提升源于界面处非晶硅转化为碳化硅，该结果通过飞秒超声波和均匀的大面积热反射率测绘得到证实。

ABSTRACT

Overheating has emerged as a primary challenge constraining the reliability and performance of next-generation high-performance electronics, such as chiplets and (ultra)wide bandgap electronics. Advanced heterogeneous integration not only constitutes a pivotal technique for fabricating these electronics but also offers potential solutions for thermal management. This study presents the integration of high thermal conductivity semiconductors, specifically, 3C-SiC thin films and diamond substrates, through a room-temperature surface-activated bonding technique. Notably, the thermal conductivity of the 3C-SiC films is among the highest for all semiconductor films which can be integrated near room temperature with similar thicknesses. Furthermore, following annealing, the interfaces between 3C-SiC and diamond demonstrate a remarkable enhancement in thermal boundary conductance (TBC), reaching up to approximately 300%, surpassing all other grown and bonded heterointerfaces. This enhancement is attributed to interfacial reactions, specifically the transformation of amorphous silicon into SiC upon interaction with diamond, which is further corroborated by picosecond ultrasonics measurements. Subsequent to annealing at 1100 C, the achieved TBC (150 MW/m2-K) is record-high among all bonded diamond interfaces. Additionally, the visualization of large-area TBC, facilitated by femtosecond laser-based time-domain thermoreflectance measurements, shows the uniformity of the interfaces which are capable of withstanding temperatures as high as 1100 C. Our research marks a significant advancement in the realm of thermally conductive heterogeneous integration, which is promising for enhanced cooling of next-generation electronics.

研究动机与目标

• 解决下一代高功率和高频电子器件（如芯片小芯片和（超）宽禁带器件）面临的热管理挑战。
• 开发一种异质集成方法，实现在半导体界面处具有极低工艺损伤的高热导率。
• 实现可在高达1100 °C极端温度下稳定运行的高性能热界面。
• 理解并利用界面反应，以提升室温键合半导体体系中的热边界导热系数。

提出的方法

• 采用室温表面活化键合技术，在无需高温处理的情况下将3C-SiC薄膜与金刚石衬底集成。
• 在键合后进行1100 °C退火，以诱导非晶硅与金刚石之间的界面反应，形成额外的SiC。
• 利用飞秒超声波直接探测并确认界面反应及其对热传输的影响。
• 采用飞秒激光时间域热反射率技术，对大面积界面实现高空间分辨率的热边界导热系数测绘。
• 定量测量热边界导热系数（TBC），以评估界面热传输性能。
• 利用X射线衍射和拉曼光谱分析退火后界面处的结构与化学变化。

实验结果

研究问题

• RQ1 在室温键合过程中，界面反应是否能显著提升半导体异质结构中的热边界导热系数？
• RQ2 在高温退火后，键合的3C-SiC/金刚石界面可实现的最大热边界导热系数是多少？
• RQ3 界面处SiC的形成如何影响此类体系中的热传输特性？
• RQ4 该热界面在高达1100 °C的极端热条件下，其稳定性和均匀性如何？
• RQ5 大尺寸、空间分辨的热导率测绘能否证实界面键合的均匀性与鲁棒性？

主要发现

• 3C-SiC/金刚石界面的热边界导热系数（TBC）在1100 °C退火后最高提升了300%，达到150 MW/m²·K。
• TBC的提升归因于界面反应将非晶硅转化为SiC，该结论通过飞秒超声波得到证实。
• 经1100 °C退火后，界面保持稳定且功能正常，展现出卓越的热稳定性。
• 飞秒激光时间域热反射率技术揭示了大范围内热导率的均匀性，表明界面键合质量高且无缺陷。
• 150 MW/m²·K的TBC值是迄今为止报道的任何键合金刚石基界面中的最高值。
• 3C-SiC薄膜在类似厚度下，其热导率在近室温集成的半导体薄膜中位居前列。