高k介质金属栅器件热载流子测试及其失效机理

Test and Failure Mechanism of Hot Carriers in High-k Dielectric Metal Gate Devices

高k介质金属栅工艺器件的热载流子注入(HCI)效应已经表现出与成熟工艺不同的退化现象和失效机理。对不同栅电压下n型和p型金属氧化物场效应晶体管(MOSFET)的饱和漏电流退化情况,以及器件的退化效应进行测试和分析。通过分析衬底电流和栅电流在不同栅电压下的变化趋势对失效机理进行探讨,分析其对饱和漏电流退化的影响。研究结果表明,在高k介质金属栅工艺器件的HCI测试中,器件退化不再是受单一的老化机理影响,而是HCI效应、偏置温度不稳定(BTI)效应综合作用的结果。HCI测试中,在不同测试条件下失效机理也不再唯一。研究结果可为高k介质金属栅工艺下器件可靠性测试中测试条件的选择以及准确的寿命评估提供参考。

The hot carrier injection(HCI) effect of high-k dielectric metal gate process devices has shown different degradation phenomena and failure mechanisms from that of the mature process. The degradation of the saturation leakage current of n-type and p-type MOSFETs at different gate voltages and the degradation effects of the device were tested and analyzed. By analyzing the change tendencies of the substrate current and the gate current under different gate voltages, the failure mechanism was discussed, and the effect on the degradation of the saturation leakage current was analyzed. The research results show that in the HCI test of high-k dielectric metal gate process devices, the device degradation is no longer affected by a single aging mechanism, and it is affected by the combination of HCI effects and bias tempe-rature instability(BTI) effects. In the HCI test, the failure mechanism is no longer unique under different test conditions. The research results provide reference for the selection of test conditions and accurate lifetime evaluation in device reliability testing under high-k dielectric metal gate process.