实现用于AlGaN功率电子器件的ScB2晶体环境压力生长
Enabling the Ambient Pressure Growth of ScB2 Crystals for AlGaN Power Electronics
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中文总结 AI 辅助
本文通过激光加热光学浮区助熔剂法在环境压力下生长出高质量ScB2单晶，验证其晶格匹配特性，为富Al AlGaN功率电子器件提供可规模化制造的衬底候选材料。
中文摘要 AI 辅助
本文报道了在激光加热光学浮区中，通过助熔剂法在环境压力下生长超高温陶瓷单晶ScB2。晶体分别从富Sc（55-65 at% Sc）和富B自助熔剂（80-83 at% B）中生长，生长速率范围为0.2-2 mm/hr。所生长晶体的结构与AlB2型层状六方相（空间群P6/mmm）高度一致，在富Sc（分别为富B）条件下生长的晶体的晶格常数a = 3.1423(2) Å（分别为3.1502(3) Å）和c = 3.5084(3) Å（分别为3.5041(3) Å）。晶体天然沿面内[100]方向生长。电子背散射衍射表明，Sc助熔剂生长产生包含多个含有Sc夹杂物的畴的晶锭，且这些畴高度取向一致。相比之下，B助熔剂晶锭在初始成核区之后为单畴。对B助熔剂晶体的(h000)和(000l)反射的摇摆曲线测量显示单峰，证明晶体无晶界；散射强度尾部的不对称性表明存在点缺陷。表面X射线光电子能谱显示，B助熔剂晶体的电子环境优于Sc助熔剂晶体，并产生高度分辨的B 1s和Sc 2p结合能峰。(11-20)面的功函数测量值约为5 eV，与ScB2的高导电性一致。这些结果证明了ScB2在环境压力下生长的可行性，将其确立为富Al AlGaN功率微电子器件的晶格匹配衬底候选材料，并表明该生长路线可实现ScB2衬底的可扩展制造。
英文摘要
Here we report the growth of single crystalline ScB2, an ultrahigh-temperature ceramic, at ambient pressure in a laser-heated Optical Floating Zone via the travelling solvent method. Crystals have been grown from both Sc-rich (55-65 at% Sc) and B-rich self-flux (80-83 at% B) at growth rates in the range of 0.2-2 mm/hr. The structure of grown crystals is in good agreement with an AlB2-type layered hexagonal phase, space group P6/mmm, with lattice constants a = 3.1423(2) Å (resp. 3.1502(3) Å) and c = 3.5084(3) Å (resp. 3.5041(3) Å) for crystals grown under Sc-rich (resp. B-rich) conditions. Crystals natively grow along the in-plane [100] direction. Electron backscattered diffraction shows that Sc-flux growth results in boules with multiple domains containing Sc inclusions, with the domains highly aligned. In contrast, B-flux boules are single domain after the initial nucleation region. Rocking-curve measurements of B-flux crystals for the (h000) and (000l) reflections show single peaks, establishing that the crystals are free from grain boundaries; the asymmetry in the scattered-intensity tails suggests the presence of point defects. Surface X-ray photoemission spectroscopy shows that the electronic environment in B-flux crystals is superior to that of Sc-flux crystals and produces highly resolved binding-energy peaks for B 1s and Sc 2p. Work-function measurements for the (11-20) plane give a value of approximately 5 eV, consistent with the highly electrically conductive nature of ScB2. These results demonstrate the viable ambient-pressure growth of ScB2, establish it as a lattice-matched substrate candidate for Al-rich AlGaN power microelectronics, and show that this growth route enables scalable manufacturing of ScB2 substrates.
发表机构
- Johns Hopkins University（约翰斯·霍普金斯大学）
- University of North Texas（北德克萨斯大学）
- Morgan State University（摩根州立大学）
- National Laboratories of the Rockies（落基山国家实验室）
- Colorado School of Mines（科罗拉多矿业学院）
- University of Colorado Boulder（科罗拉多大学博尔德分校）
- Towson University（陶森大学）
- Argonne National Laboratory（阿贡国家实验室）
- The University of Virginia（弗吉尼亚大学）
机构由 AI 辅助整理，请以论文原文为准。
