基于大电流密度下欧姆接触退化的新方法

在大电流密度下对欧姆接触结果进行考核,对传统的传输线法测量接触电阻率的结构与方法进行了改进,充分考虑到了半导体材料受到的影响,可达到只对接触区域老化而不破坏其他区域.工艺制备中实现台面刻蚀斜坡效果,并采取多次SiO_2淀积多次光刻技术,有效降低了引线电极断裂的概率.通过大电流密度老化结果显示:接触电阻率早期快速失效,且随电流密度及老化时间的增加而退化加剧.对样品老化前后进行能谱分析得知:接触层中的Al是一种较低的抗电迁移能力的金属,由于电迁移被冲击出来从而破坏了良好接触层.改进后的结构对测量大电流密度下的欧姆接触是一种好方法.

New Method Based on High-current Density Ohmic Contact Degradation

Ohmic contact is evaluated under the high-current density,the traditional Transmission Line Method (TLM) structure is innovated,which only age the contacts areas not others.The new method can ensure the reliability and validity when the structure is applied high-current density.According to two times or more SiO2 deposition,it reduces effectively the probability of leading wire fracture.The results show after high-current density:the contact resistivity is rapidly failure early period and degenerates dramatically with time and current density.From the spectrum,Al is a kind of low electromigration resistance metal,the good ohmic contacts are destroyed due to electromigration and the Al is moved off the contact layers.The experiment proved that it is a perfect method after improving to measure the ohmic contact under the high- current density.