论文标题
N极基ALN上的分子束在散装ALN底物上的同型
Molecular Beam Homoepitaxy of N-polar AlN on bulk AlN substrates
论文作者
论文摘要
N极基ALN屈服者通过血浆辅助分子束外延（PA-MBE）在单晶体积ALN底物的N面上生长。在高温下的原位热脱氧和AL辅助的热解吸的结合有助于清除天然表面氧化物和从底物的N极性表面的杂质，从而实现成功的同型。随后在原位清洁的底物上Aln层的外延生长，以足够高的Al液滴状态生长，表现出平滑的表面形态，并具有清洁和宽的原子步骤。 KOH蚀刻研究证实了同型膜的N极性。次级离子质谱谱图显示Si和H杂质浓度低于噪声水平，而O和C杂质的浓度分别观察到〜8x10^{17}原子/cm^3和〜2x10^{17}原子/cm^3。尽管结构缺陷密度很低，但有趣的是，它们是不同维度的反转域。
N-polar AlN epilayers were grown on the N-face of single crystal bulk AlN substrates by plasma assisted molecular beam epitaxy (PA-MBE). A combination of in situ thermal deoxidation and Al-assisted thermal desorption at high temperature helped in removing native surface oxides and impurities from the N-polar surface of the substrate enabling successful homoepitaxy. Subsequent epitaxial growth of AlN layer on the in situ cleaned substrates, grown in sufficiently high Al droplet regime, exhibited smooth surface morphologies with clean and wide atomic steps. KOH etch studies confirmed the N-polarity of the homoepitaxial films. Secondary ion mass spectrometry profiles show Si and H impurity concentrations below the noise levels, whereas O and C impurities concentrations of ~ 8x10^{17} atoms/cm^3 and ~ 2x10^{17} atoms/cm^3 are observed respectively. Though the structural defect densities are low, they interestingly appear as inversion domains of different dimensionalities.
