Effects of ZnO buffer layers on the fabrication of GaN films using pulsed laser deposition
Effects of ZnO buffer layers on the fabrication of GaN films using pulsed laser deposition
复制标题
DOI：
10.1063/1.2730573
复制
发表时间：
2007-05-01
影响因子：
3.2
通讯作者：
Xue, C. S.
中科院分区：
文献类型：
--
作者：
Man, B. Y.;Yang, C.;Xue, C. S.
在氮气氛中，通过GaN靶的脉冲激光沉积，使用ZnO缓冲层在Si（111）衬底上沉积GaN薄膜。在NH3气氛中，在950 ℃下退火15分钟后，获得高质量的GaN薄膜。用X射线衍射、傅里叶变换红外光谱和原子力显微镜对薄膜的结晶质量、成分和表面形貌进行了表征。通过对测量结果的分析，得出ZnO缓冲层及其结晶质量影响GaN薄膜的结构特性（结晶质量、成分和表面形貌）的结论。晶体ZnO缓冲层改善了GaN薄膜的成核和生长。GaN薄膜在氨气（NH3）气氛中退火时，Zn-O键被破坏，少量O和Zn原子离开原位，N和Ga原子填充空位，形成特殊组分的六方结构。这种结构有利于GaN的外延生长，而原子的运动又使GaN晶粒有更多的机会运动，形成Ga-N键。退火时间对GaN薄膜的制备有显著影响，在本实验条件下，最小退火时间为15 min。(c)2007年，美国物理学会。
GaN thin films were deposited on Si (111) substrates using ZnO buffer layers by pulsed laser deposition of a GaN target in a nitrogen atmosphere. High-quality GaN thin films were obtained after annealing at 950 degrees C for 15 min in a NH3 atmosphere. The crystalline quality, composition, and surface morphology of the films were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, and atomic force microscopy. Through analysis of the measured results, a conclusion was drawn that ZnO buffer layers and their crystalline quality affected the structural properties (crystalline quality, composition, and surface morphology) of GaN films. Crystalline ZnO buffer layers improved nucleation and growth of GaN films. Zn-O bonds are destroyed when the GaN films are annealed in ammonia (NH3) ambience; a few O and Zn atoms depart from their positions, while N and Ga atoms fill in the empty positions and form a hexagonal structure of a special component. The structure is propitious to the epitaxial growth of GaN, while the motion of atoms gives the grains of GaN more chances to move and form Ga-N bonds. The annealing time markedly affects the preparation of GaN films and the least annealing time is 15 min under our experimental conditions. (c) 2007 American Institute of Physics.