Holden Konner E K, Dezelah Charles L, Conley John F
School of Electrical Engineering and Computer Science , Oregon State University , Corvallis , Oregon 97331 , United States.
EMD Performance Materials , Haverhill , Massachusetts 01832 , United States.
ACS Appl Mater Interfaces. 2019 Aug 21;11(33):30437-30445. doi: 10.1021/acsami.9b08926. Epub 2019 Aug 8.
A novel atomic layer deposition (ALD) process for nickel oxide (NiO) is developed using a recently reported diazadienyl complex, Ni(DAD), and ozone. A window of constant growth per cycle is found between 185 and 200 °C at 0.12 nm/cycle, among the highest reported for ALD NiO. For films deposited at 200 °C, grazing-incidence X-ray diffraction indicates a randomly oriented polycrystalline cubic NiO phase. X-ray photoelectron spectroscopy shows good agreement with bulk NiO reference spectra and no detectable impurities. Atomic force microscopy reveals low root mean square roughness of 0.6 nm for an 18 nm thick film. The refractive index of 2.36 and an electronic bandgap of 3.78 eV, as determined by variable angle spectroscopic ellipsometry, are close to reported values for bulk and thin film NiO. Finally, fabricated Ag/NiO/n-Si/In heterojunction diodes show a current-voltage asymmetry of 1.27 × 10 at 2.3 V and an ideality factor of 3.5, confirming the intrinsic p-type semiconducting behavior of transparent NiO.
利用最近报道的二氮二烯基配合物Ni(DAD)和臭氧，开发了一种用于氧化镍(NiO)的新型原子层沉积(ALD)工艺。在185至200°C之间，每循环的恒定生长窗口为0.12 nm/循环，这是ALD NiO报道的最高值之一。对于在200°C下沉积的薄膜，掠入射X射线衍射表明为随机取向的多晶立方NiO相。X射线光电子能谱与块状NiO参考光谱显示出良好的一致性，且未检测到杂质。原子力显微镜显示，18 nm厚的薄膜的均方根粗糙度低至0.6 nm。通过可变角度光谱椭偏仪测定的2.36的折射率和3.78 eV的电子带隙，与块状和薄膜NiO的报道值接近。最后，制备的Ag/NiO/n-Si/In异质结二极管在2.3 V时的电流-电压不对称性为1.27×10，理想因子为3.5，证实了透明NiO的本征p型半导体行为。
