MOCVD growth and characterization of conductive homoepitaxial Si-doped Ga2O3
MOCVD growth and characterization of conductive homoepitaxial Si-doped Ga2O3
复制标题
DOI：
10.1016/j.rinp.2021.104167
复制
发表时间：
2021-05-10
影响因子：
5.3
通讯作者：
Selim, F. A.
中科院分区：
文献类型：
--
作者：
Hernandez, Armando;Islam, Md Minhazul;Selim, F. A.
通过金属有机化学气相沉积 (MOCVD) 在天然衬底上以 1 μm/小时的生长速率生长外延 Ga2O3 薄膜。在沉积过程中通过硅掺杂将电子电导率引入薄膜中，并优化生长和掺杂参数以控制电传输特性。薄膜的结构、表面形貌、电传输性能、掺杂剂浓度和捕获缺陷方面进行了表征。研究发现，电子密度不仅仅取决于掺杂剂浓度，并且金属有机前体的使用似乎会诱导额外的碳供体。该工作表明，MOCVD Ga2O3 薄膜的电子密度和电导率主要由掺杂剂浓度、C 浓度和薄膜中存在的俘获缺陷之间的相互作用决定，这很可能适用于通过 MOCVD 生长的其他氧化物薄膜。成功生长了电阻率约为0.07Ω·cm的Ga2O3导电薄膜。大多数这些薄膜的电子密度在1019 cm(-3)范围内，但迁移率仅限于1.5 cm(2)/V.s。通过降低 Si 掺杂水平，在一些薄膜中以载流子浓度为代价获得了 30 cm(2)/V.s 的较高迁移率，导致电阻率达到 0.3 Omega.cm 量级。这种电导率和迁移率范围与场效应晶体管 (FET) 以及 Ga2O3 作为透明 FET 在深紫外 (DUV) 技术中的应用相关。
Epitaxial Ga2O3 films were grown by Metal Organic Chemical Vapor Deposition (MOCVD) on native substrates at growth rate of 1 mu m/hour. The electron conductivity was introduced in the films through Si doping during deposition and the growth and doping parameters were optimized to control the electrical transport properties. The films were characterized in terms of structure, surface morphology, electrical transport properties, dopant concentrations and trapping defects. It was found that electron densities are not solely dependent on dopant concentrations and the use of metal organic precursor seems to induce additional donors of carbon. The work shows that the electron density and conductivity of MOCVD Ga2O3 films are mainly governed by the interplay between dopant concentration, C concentration and the presence of trapping defects in the films, which is most likely applicable for other oxide films grown by MOCVD. Conductive films of Ga2O3 with resistivity in the order of 0.07 Omega.cm were successfully grown. The electron density in most of these films was in the range of 1019 cm(-3) but the mobility was limited to 1.5 cm(2)/V.s. Higher mobility of 30 cm(2)/V.s was obtained in some films at the expense of carrier concentration by reducing Si doping level resulting in resistivity in the order of 0.3 Omega.cm. This range of conductivity and mobility is relevant for field-effect transistors (FET) and the applications of Ga2O3 as transparent FET in Deep Ultra-Violet (DUV) technology.