Herein, the growth and fabrication of BeMgZnO/ZnO heterostructure field‐effect transistors (HFETs) are reported on, as well as their direct current (DC) and radio frequency (RF) characterization. With a high 2D electron gas density of ≈8 × 10¹² cm⁻², made possible by BeO and MgO coalloying in the barrier, typical drain currents of 0.24 A mm⁻¹ are obtained in Zn‐polar BeMgZnO/ZnO HFETs with a Be content of 2–3% and a Mg content below 30%. Typical on/off current ratios above 10⁴, transconductance values of ≈50 mS mm⁻¹, and current‐gain cutoff frequencies f_T of 5.0 GHz, the highest among ZnO‐based FETs, are achieved in devices with a gate length of 1.5 μm using Al₂O₃ as the gate dielectric. An average electron velocity above 1 × 10⁷ cm s⁻¹, deduced from the bias‐dependent cutoff frequency and extraction of transit time under the gate, suggests that even with relatively long gate lengths the average electron velocity is near the theoretical limit (3.5 × 10⁷ cm s⁻¹) of the high peak velocity in ZnO.

中文翻译：

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高性能BeMgZnO / ZnO异质结构场效应晶体管

本文报道了BeMgZnO / ZnO异质结构场效应晶体管（HFET）的生长和制造，以及直流（DC）和射频（RF）的特性。由于势垒中BeO和MgO的结合使二维电子气密度高到≈8×10 ¹²  cm ^-2，在带有Be的Zn极性BeMgZnO / ZnO HFET中，典型的漏极电流为0.24 A mm ^-1。含量2-3％，镁含量低于30％。在栅长为1.5的器件中，可以实现典型的开/关电流比高于10 ⁴，跨导值≈50mS mm ^-1以及5.0 GHz的电流增益截止频率f _T，这是基于ZnO的FET中最高的。使用铝的微米₂ O ₃作为栅极电介质。由偏置相关的截止频率和栅极下的通过时间得出的平均电子速度高于1×10 ⁷  cm s ^-1，这表明即使栅极长度相对较长，平均电子速度也接近理论极限（3.5 ZnO的高峰值速度的××10 ⁷  cm s ^-1）。