Heteroepitaxial growth of α-, β-, γ- and κ-Ga2O3 phases by metalorganic vapor phase epitaxy
Heteroepitaxial growth of α-, β-, γ- and κ-Ga2O3 phases by metalorganic vapor phase epitaxy
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DOI：
10.1016/j.jcrysgro.2019.01.018
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发表时间：
2019-03-15
影响因子：
1.8
通讯作者：
Krautscheid, Harald
中科院分区：
文献类型：
--
作者：
Gottschalch, Volker;Merker, Stefan;Krautscheid, Harald
报道了不同Ga2O3相的金属有机气相外延生长条件的改善。研究了衬底材料、生长条件和前驱体的变化对相形成的影响。三甲基镓（TMG）和N2O分别作为镓和氧的常见前驱体。此外，还为K-Ga2O3的生长提供了水分。讨论了添加三乙基硼（TEB）和二甲基肼（DMHy）对α相形成的影响。生长条件可以确定，其中α -， β -， γ -和kappa-Ga2O3外延沉积。kappa相外延生长在c面、a面和r面Al2O3、（1 11 1）MgO、（1 11 1）MgAl2O4和（0 0 0 1）Al2O3/(0 0 0 1) GaN异质结构上。在（0 0 01）Al2O3、（1 1 1）、（1 0 0）MgAl2O4、（1 0 0）MgO以及（0 0 01）Al2O3/(0 0 01) GaN上成功地生长了具有缺陷尖晶石结构的γ - ga2o3。硼的加入稳定了α相在c-、a-和r-面Al2O3上的MOVPE生长。通过x射线衍射（XRD）鉴定了不同的Ga2O3相。测定了Ga2O3相与不同衬底之间的外延关系。在200 ~ 2000 nm的光谱范围内测量的透射光谱显示，在c-平面蓝宝石上生长的β -、γ -和kappa-Ga2O3层有明确的吸收边，吸收边约为4.9 eV， α - ga2o3层为5.3 eV。
Improved MOVPE (metalorganic vapor phase epitaxy) growth conditions for the different Ga2O3 phases are reported. The influence of the substrate material, the growth conditions and the variation of precursors on the phase formation was investigated. Trimethylgallium (TMG) and N2O were used as common precursors for gallium and oxygen, respectively. In addition, water was supplied for the growth of K-Ga2O3. The influence of additional triethylboron (TEB) and dimethylhydrazin (DMHy) on the formation of the alpha-phase is discussed. Growth conditions could be determined, where alpha-, beta-,gamma- and kappa-Ga2O3 is epitaxially deposited. The kappa-phase was epitaxially grown on c-, a- and r-plane Al2O3, (1 1 1) MgO, (1 1 1) MgAl2O4 and on a (0 0 0 1) Al2O3/(0 0 0 1) GaN heterostructure. Successful MOVPE growth of gamma-Ga2O3 with defect spinel structure has been achieved on (0 0 01) Al2O3, (1 1 1) and (1 0 0) MgAl2O4, (1 0 0) MgO as well as on (0 0 01) Al2O3/(0 0 01) GaN. Boron addition stabilizes the MOVPE growth of the alpha-phase on c-, a- and r-plane Al2O3. The various Ga2O3 phases were identified by X-ray diffraction (XRD). The epitaxial relationships between the Ga2O3 phases and the different substrates were determined.Optical transmission spectra measured in the spectral range from 200 to 2000 nm show a well-defined absorption edge at about 4.9 eV for layers of beta-, gamma- and kappa-Ga2O3 and 5.3 eV for layers of alpha-Ga2O3 grown on c-plane sapphire.