光电耦合器件低频噪声特性与可靠性老化研究

Research on Low-Frequency Noise Characteristic and Reliability Aging of Optoelectronic Coupled Devices

摘要:

在宽的输入偏置电流范围条件下,开展了光电耦合器件低频噪声特性测试与功率老化和高温老化的可靠性试验研究。结果表明,光电耦合器件的低频噪声主要是内部光敏晶体管1/f噪声,并随输入偏置电流的增大呈现先增大后减小的规律,这与器件的工作状态密切相关。功率老化试验后,高输入偏置电流条件下的低频噪声有所增大,这归因于电应力诱发的有源区缺陷。高温老化试验后,整个器件线性工作区条件下的低频噪声都明显增大,说明温度应力能够更多地激发器件内部的缺陷。相对于1/f噪声幅度参量,低频噪声宽带噪声电压参量可以更灵敏准确地进行器件可靠性表征。

Abstract:

The low-frequency noise (LFN) characteristics of optoelectronic coupled devices (OCDs) were tested over a wide range of input current with special emphasis on the influence of power aging and high temperature aging. Experimental results demonstrate that 1/f noise of internal photosensitive transistor is the main type of LFN in OCDs, and it increases first and then decreases with increasing input bias current, which is due to the defects of active region. After power aging, the LFN under high input bias current increases slightly, which is attributed to active region traps induced by electrical stress. After high temperature aging, the magnitude of LFN increases evidently in the whole linear operating area, which illustrates that high temperature stress can stimulate more internal traps in the devices. Compared with 1/f noise magnitude, low-freauencey wideband noise voltage is more sensitive and accurate in indicating the reliability of OCDs.