【摘要】 在(0001)面的蓝宝石衬底上用低压MOCVD法生长p型GaN外延层。对p型GaN薄膜用180keV的Mn+离子注入进行磁性粒子掺杂,注入时GaN薄膜处于300℃,注入剂量分别为5.0×1015、1.0×1016和5.0×1016cm-2。对注入的样品在N2气流中进行快速热退火处理,温度为850℃,时间为30s。用超导量子干涉仪(SQUID)对样品的磁性进行了分析,在5.0×1015cm-2的注入样品中发现了较强的铁磁性;而1.0×1016和5.0×1016cm-2的Mn+离子注入样品中铁磁响应有所减弱。结合用X射线衍射(XRD)和扫描电子显微镜(SEM)对在不同剂量下Mn+注入GaN薄膜的结构、形貌和成分的分析,揭示了不同剂量磁性离子注入给GaN薄膜带来的结构、形貌和相应的铁磁性变化规律,发现只有适当的注入剂量(5.0×1015cm-2)才有利于在300℃下用180keV的Mn+注入对p型GaN薄膜进行磁性离子掺杂。更多还原

【Abstract】 Wurtzite p-type GaN epilayer,which has a thickness of 0.5mm,is prepared by MOCVD on GaN buffer with sapphire substrate.Magnetic doping of the p-type GaN film is achieved by 180keV Mn⁺ ions implantation.During the implantation,the GaN films are all kept at 300℃.The implanting dosages are 5.0×10¹⁵,1.0×10¹⁶ and（5.0）×10¹⁶cm^-2,respectively.After an annealing step at 850℃ for 30s in flowing N₂,the magnetism of the Mn⁺ implanted GaN films is investigated by superconducting quantum interference device（SQUID）.In the p-GaN film with 5.0×10¹⁵cm^-2 Mn⁺-implantation,obvious ferromagnetism is found with hysteresis loop.While with the increase of implanting doses,the ferromagnetism weakens for the samples with 1.0×10¹⁶ and（5.0）×10¹⁶cm^-2 Mn⁺-implantation.Combined with the structural characteristics studied by X-ray diffraction（XRD） and the morphology and constituent information revealed by scanning electron microscopy（SEM）,one discloses the relations between the implanting doses and the structure and magnetism of Mn⁺ implanted p-GaN films.Only suitable implanting dose(5.0×10¹⁵cm^-2) is beneficial to the recovery of implanting defects and the generation of ferromagnetism in the 180keV Mn⁺ implanted p-GaN films at 300℃.更多还原