离子注入制备Ga2O3 n-沟道场效应晶体管

β-Ga2O3 is a new, wide and direct band gap (4.9 eV) semiconductor. Compared to SiC and GaN, β-Ga2O3 has a larger band gap and a higher electric breakdown field, and thus, is more suitable for n-channel MOSFETs. In this study, single crystalline Ga2O3 thin films are prepared by atomic layer deposition followed by thermal annealing at high temperatures in pure oxygen atmosphere. Fe and Cr ion implantation into Ga2O3 are performed to prepare insulating or semi-insulating layers as the substrates of the MOSFETs. Selective area ion implantation of Si and Sn are carried out to dope the active regions, such as source, drain and n-type channel under the gate. The gate oxide layers can be optimized from Al2O3, HfO2, ZrO2 by using ALD. Finally we are going to fabricate 3 prototypes of Ga2O3 MOSFETs including both enhancement type and depletion mode. During the study, it is expected for us to publish more than 10 high-quality papers and applied for 3 national invention patents as well as give invited talks at international conferences.

β-Ga2O3是一种新的III-VI族宽禁带（4.9eV）直接带隙半导体材料，与SiC或GaN相比，Ga2O3具有更大的禁带宽度和更高的临界击穿电场强度，更适合制备n-沟道MOSFETs。本课题拟用原子层沉积法（ALD）在晶格匹配的衬底（Al2O3和GaN）上生长Ga2O3薄膜，通过高纯氧气氛下高温热退火处理，制备Ga2O3外延单晶薄膜。采用多能量和多剂量的过渡金属Fe和Cr离子注入制备Ga2O3绝缘衬底，用Si和Sn离子选区注入制备n-沟道MOSFET的源极、漏极和栅极下的导电沟道。在此基础上，用ALD方法生长栅极绝缘层（选择Al2O3、HfO2或ZrO2），蒸镀Ti/Au作为源极和漏极接触电极，Ti/Pt/Au作为栅极接触电极，制备Ga2O3 n-沟道MOSFETs（包括增强型和耗尽型等3种结构）原型器件。发表高水平论文10篇以上，申请国家发明专利3项，部分结果在国际会议作邀请报告。

本课题在蓝宝石衬底上沉积Ga2O3薄膜，并通过优化薄膜制备工艺和热退火条件，提高了Ga2O3薄膜质量，利用ALD方法精确控制Ga2O3薄膜掺杂工艺制备出导电和不导电的Ga2O3薄膜。在此基础上，制备了存储窗口大、保持特性好的Ga2O3阻变存储器；制备了Ga2O3 MSM 型紫外探测器和Ga2O3/p-GaN自供电型紫外探测器；制备了Ga2O3掺In2O3高性能薄膜晶体管。并利用SRIM软件模拟Si离子在Ga2O3中注入分布和能量的关系，还使用Silvaco TCAD软件对垂直型PN二极管及肖特基势垒二极管的不同台面在反向偏压下的电场分布特性进行了模拟计算，制备的n-沟道场效应晶体管正在分析和测试中。本课题最终成果可望直接应用于工业生产，申请8项国家发明专利（其中四项获批），发表了21篇标注有本基金的SCI号论文。