Study Of Hot Carrier Injection Effect Based On 0.18um And 65nm Commercial CMOS Technology

Complementary Metal Oxide Semiconductor(CMOS)integrated circuits are the cornerstones of IC,and the reliability issues of CMOS have always been the focus of attention in the industry.After the CMOS process comes to deep sub-micron process,the thickness of the gate oxide and the channel length are greatly scaling down,however,the operating voltage of the device is not reduced in proportion,so that the lateral and horizontal electric fields in the channel region become higher,and hot carrier injection occurs.Hot carrier injection effect of NMOS devices is more serious than that of PMOS devices.Based on the background,this article focuses on the hot carrier injection effect of NMOS devices.Based on the 0.18?m process and 65 nm process used on a large scale in the industry,a hot carrier injection effect test structure was designed.The test structure was tested for electrical functionality.Based on test structures and test conditions,a hot carrier injection test procedure was set up based on the I-V characteristic test method.Through the test and verification,the test platform is stable and reliable,and it can completely complete the experimental research of NMOS device hot carrier degradation.For 0.18-?m NMOS devices,the effect of hot carrier injection on the Id-Vg curve,threshold voltage,saturation drain current,and transconductance was investigated.The NMOS device hot carrier lifetime prediction was carried out to prove that the lifetime of the device can reach the requirement of 10 years under the condition of DC stress.By comparing the degradation of hot carrier injection of the annular-gate device and the straight-gate device,the results show that the hot-carrier degradation of the gate-gate device is weaker than that of the direct-gate device in the case of the source in the ring.At the 65 nm node,the worst-case bias for hot carrier injection is different from the long-channel device.The results show that the worst bias at the 65 nm node has been changed from the DAHC bias to the CHC bias.The mechanism of hot carrier injection changes as the size of the device changes,and the effect of temperature on hot carrier degradation in MOS devices also changes.In the 65 nm process,the hot carrier degradation under high temperature conditions is more serious.The effects of total dose irradiation and hot carrier injection on the MOS devices are similar.The chips that operate for a long time in an irradiation environment will be affected by these two kinds of reliability issues.The total dose radiation is studied for hot carrier injection.The impact of this becomes meaningful.The effect of total dose radiation on 65 nm NMOS was studied.The results show that due to the device's gate oxide thickness is sufficiently thin,the device's performance degradation due to total dose radiation is limited.However,hot-carrier degradation of the irradiated device was significantly higher than that of the un-irradiated device,indicating that the total dose irradiation accelerated the degradation of hot carriers.The hot carrier degradation after total dose radiation was compared between the direct gate device and the gated gate device.The results show that after the total dose radiation,the ring gate device is less degraded.Compared with the effect of different irradiation bias on the thermal carrier degradation of NMOS devices,the results show that the worst open irradiation bias can cause the device to drift more seriously when the hot carrier is injected.