基于低频噪声的薄膜电阻器可靠性表征方法

Thin-film Resistor Reliability Characterization Based on Low Frequency Noise

薄膜电阻的低频噪声同器件的损伤程度密切相关。文中采用两级低噪声放大器和高速高精度PCI数据采集卡构建的测试系统测量了一组1.5 kΩ镍铬薄膜电阻老化试验前后的低频噪声,结合显微分析发现电迁移是薄膜电阻可靠性退化的主导机制,电迁移损伤发生前后低频噪声的幅值、频率指数和转折频率等参量均会发生异常波动。分析表明,低频噪声能更敏感地反映薄膜电阻的损伤程度,可作为此类器件可靠性无损的筛选依据。

The low-frequency noise of thin-film resistor and its inner defects are closely related. In this paper, the low-frequency noises of a batch of 1.5 kfl NiCr thin-film resistors both before and after ageing are measured by a testing setup comprised of two-stage low-noise amplifiers and a high speed and high accuracy PCI data acquisition card. Electro-migration inside the thin-film resistor is identified to be the dominant degradation mechanism by a com- bination analysis of both low-frequency noise and microscopy. The parameters of low-frequency noise such as ampli- tude, frequency index and turning frequency exhibit unusual fluctuations right before the occurrence of electro-migra- tion. It is concluded that the low-frequency noise of thin-film resistor can sensitively manifest the damages inside the component, and as a result, low-frequency noise can be used as an indicator for non-destructive screening.