Conductive surface oxide on CrN(001) layers
Conductive surface oxide on CrN(001) layers
复制标题
DOI：
10.1063/1.5091034
复制
发表时间：
2019-04
影响因子：
4
通讯作者：
Mary E. McGahay;D. Gall
中科院分区：
文献类型：
--
作者：
Mary E. McGahay;D. Gall
暴露于含O2气氛的外延CrN（001）层表现出导电的2D表面氧化物，其薄层电导Gs，oxide = 5.9 × 10−5 [Ω/Ω]−1。这一点通过在90%Ar-10%O2混合物中使用原位输运测量来证明，其中压力从<10 - 6连续增加到240 Pa，显示电导增加与CrN厚度d = 10和300 nm无关，但对于在氧暴露之前用绝缘AlN覆盖的对照样品不存在。这表明半导体CrN的n型掺杂通过用O替代N表面原子。冷却到77 K导致Gs，oxide降低到3.9 × 10−5 [Ω/Ω]−1，表明传导电子没有完全离域。总体结果表明，在难熔过渡金属氮化物中，2D电子传输器件的路径，并可以解释先前报道的CrN传输特性的大变化。暴露于含O2气氛的CrN（001）外延层表现出导电的2D表面氧化物，其薄层电导Gs，氧化物= 5.9 × 10−5 [Ω/Ω]−1。这是使用在90%Ar-10%O2混合物中的原位输运测量来证明的，其中压力从<10 - 6连续增加到240 Pa，显示电导增加与CrN厚度d = 10和300 nm无关，但对于在氧暴露之前用绝缘AlN覆盖的对照样品不存在。这表明半导体CrN的n型掺杂通过用O替代N表面原子。冷却到77 K导致Gs，oxide降低到3.9 × 10−5 [Ω/Ω]−1，表明传导电子没有完全离域。整体结果表明，在难熔过渡金属氮化物的2D电子传输设备的路径，并可以解释以前报道的CrN的传输性能的大的变化。
Epitaxial CrN(001) layers that are exposed to an O2-containing atmosphere exhibit a conductive 2D surface oxide with a sheet conductance Gs,oxide = 5.9 × 10−5 [Ω/◻]−1. This is demonstrated using in situ transport measurements in a 90% Ar–10% O2 mixture with continuously increasing pressure from <10−6 to 240 Pa, showing a conductance increase that is independent of the CrN thickness d = 10 and 300 nm but is absent for control samples that are capped with insulating AlN prior to oxygen exposure. This suggests n-type doping of semiconducting CrN through substitutional replacement of N surface atoms with O. Cooling to 77 K leads to a decrease in Gs,oxide to 3.9 × 10−5 [Ω/◻]−1, indicating that the conduction electrons are not fully delocalized. The overall results indicate a path towards 2D electron transport devices in refractory transition metal nitrides and may explain the large variation in previously reported transport properties of CrN.Epitaxial CrN(001) layers that are exposed to an O2-containing atmosphere exhibit a conductive 2D surface oxide with a sheet conductance Gs,oxide = 5.9 × 10−5 [Ω/◻]−1. This is demonstrated using in situ transport measurements in a 90% Ar–10% O2 mixture with continuously increasing pressure from <10−6 to 240 Pa, showing a conductance increase that is independent of the CrN thickness d = 10 and 300 nm but is absent for control samples that are capped with insulating AlN prior to oxygen exposure. This suggests n-type doping of semiconducting CrN through substitutional replacement of N surface atoms with O. Cooling to 77 K leads to a decrease in Gs,oxide to 3.9 × 10−5 [Ω/◻]−1, indicating that the conduction electrons are not fully delocalized. The overall results indicate a path towards 2D electron transport devices in refractory transition metal nitrides and may explain the large variation in previously reported transport properties of CrN.