One of the major challenges in β-Ga₂O₃-based high power and high frequency devices is anticipated to be related to the low thermal conductivity of the material which is on the order of 10–30 W/m K. The use of diamond (thermal conductivity ∼2000 W/m K) as a substrate can be one effective approach for achieving better thermal management in β-Ga₂O₃-based devices. In this work, low pressure chemical vapor deposition was used to grow β-Ga₂O₃ films on (100) oriented, single-crystalline diamond substrates. A two-step growth technique was employed to avoid the oxidation of the diamond surface at high temperatures. From x-ray diffraction measurements, the β-Ga₂O₃ films grew along the $⟨-201⟩$ crystalline axis with the β-Ga₂O₃ (002) planes rotated by ±24.3–27° with respect to the diamond (111) planes. High-magnification scanning transmission electron microscopy imaging revealed an abrupt β-Ga₂O₃/diamond interface without any voids which is essential for the high rate of heat transfer across the interface. N-type electrical conductivity was measured in a Si-doped β-Ga₂O₃ film with 1.4 × 10¹⁹ cm⁻³ electron concentration and ∼3 cm²/V s electron mobility. This work demonstrates the feasibility of heteroepitaxy of β-Ga₂O₃ films on diamond substrates for potential device design and device fabrication with efficient thermal management.

中文翻译：

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通过低压化学气相沉积在（100）金刚石上两步生长β-Ga2O3膜

一个在主要挑战的β-Ga ₂ ö ₃基高功率和高频器件，预期可能与这是10-30 W的顺序上的材料的低导热率/米K.使用的金刚石（热导率〜2000瓦/米K）作为底物可以是用于在的β-Ga实现更好的热管理一个有效的方法_2个ö ₃系装置。在这项工作中，低压化学汽相淀积被用来生长的β-Ga _2层ö ₃上（100）取向，单晶金刚石基材膜。采用了两步生长技术以避免高温下金刚石表面的氧化。从X射线衍射测量中，的β-Ga ₂ ö沿着这部电影成长了₃部电影$⟨-201⟩$与的β-Ga晶轴₂ ö ₃（002）面相对于所述金刚石（111）平面旋转了±24.3-27°。高倍率扫描透射电子显微镜成像显示急剧的β-Ga ₂ ö ₃ /金刚石界面，而无需其是用于跨越界面的热传递的高速率必需的任何空隙。N型导电率的掺杂Si的的β-Ga测量₂ ö ₃膜用1.4×10 ¹⁹ 厘米^-3的电子浓度和〜3厘米² / Vs的电子迁移率。这项工作表明的异质外延的可行性的β-Ga ₂ ö ₃ 金刚石基板上的薄膜用于潜在的器件设计和器件制造以及有效的热管理。