异质结InP/InGaAs探测器欧姆接触温度特性研究

Temperature-dependent characteristics of ohmic contact in hetero-junction InP /InGaAs detector

为了研究异质结InP/InGaAs探测器帽层的欧姆接触特性,采用Au/p-InP传输线模型(TLM),对比不同退火温度下的接触特性,在480℃、30 s的退火条件下实现室温比接触电阻为3.84×10^(-4)Ω·cm^2,同时,对欧姆接触的温度特性进行了研究,发现随着温度降低比接触电阻增加,在240~353 K温度范围内界面电流传输主要为热电子-场发射机制(TFE);240 K以下,接触呈现肖特基特性.利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)分别对界面处的扩散程度和化学反应进行了分析,发现经过480℃、30 s退火后样品界面处存在剧烈的互扩散,反应产物Au_(10)In_3有利于改善Au/p-InP的接触性能.

The contact characteristics of Au / p-InP in hetero-junction InP /InGaAs detector were studied in this work. Under the annealing condition of 480℃ for 30 s,the ohmic contact was formed with the room-temperature special contact resistance 3. 84 × 10^（- 4）Ω·cm^2. Temperature-dependent characteristics of ohmic contact were investigated. The results indicate that the special contact resistance increases with decreasing temperature,the current transmission mechanism at the interface is thermion-field emission mechanism（ TFE） at the temperature of 243 K to 353 K; while below 240 K,the contact performance presents schottky property. By means of scanning electron microscope（ SEM） and X-ray diffractometer,the diffusion degree and metallurgical reaction at the Au /InP interface were investigated,and the penetration degree is very heavy at the interface of sample after annealed at 480℃for 30 s and the generation of Au_（10） In_3 produced by metallurgical reaction contributes to improve the contact performance of Au /p-InP.