【摘要】 研究并对比了Ti/Al/Ni/Au和Ti/Al/Pt/Au多层金属膜与未掺杂的Al0 .2 2 Ga0 .78N/GaN(i AlGaN/GaN)异质结构之间的欧姆接触性质。在退火温度低于 70 0℃时 ,两种接触样品上都不能得到欧姆接触。随着退火温度的升高 ,85 0℃快速退火后 ,在Ti/Al/Ni/Au接触上获得了 1.2 6×10 - 6 Ω·cm2 的比接触电阻率 ,在Ti/Al/Pt/Au接触上获得了 1.97× 10 - 5Ω·cm2 的比接触电阻率。研究结果表明 ,金属与半导体接触界面和Al0 .2 2 Ga0 .78N异质结构界面载流子沟道之间适当的势垒的存在对高质量欧姆接触的形成起重要作用 ,势垒的宽度取决于退火温度以及退火的具体进程。对Ti/Al/Ni/Au和Ti/Al/Pt/Au欧姆接触比接触电阻率的差异进行了解释。更多还原

【Abstract】 The ohmic contacts of Ti/Al/Ni/Au and Ti/Al/Pt/Au multi-layer on unintentionally-doped Al_0.22Ga_0.78N/GaN heterostructures were investigated. The specific contact resistivities of 1.26×10^-6 Ω·cm² for Ti/Al/Ni/Au contact and 1.97×10^-5 Ω·cm² for Ti/Al/Pt/Au contact were obtained. It is found that the formation of excellent ohmic contact on the Al_0.22Ga_0.78N/GaN heterostructures is attributed to the exsiting of a compatible barrier between the metal electrode and the carrier channel at the Al_0.22Ga_0.78N/GaN heterointerface. Several different reason are proposed to interpreate the different between the ohmic contact resistivity of Au/Ni/Al/Ti/i-AlGaN and that of Au/Pt/Al/Ti/i-AlGaN.更多还原