Yu Chieh Hsu1,Yan Yu Chen1,Jia-Min Shieh2,Wen-Hsien Huang2,Chang-Hong Shen2,Yu-Lun Chueh1
National Tsing Hua University1,Taiwan Semiconductor Research Institute2
Yu Chieh Hsu1,Yan Yu Chen1,Jia-Min Shieh2,Wen-Hsien Huang2,Chang-Hong Shen2,Yu-Lun Chueh1
National Tsing Hua University1,Taiwan Semiconductor Research Institute2
With the proper selection of metal silicide, contact resistance can be effectively reduced between the source/drain (S/D) and connected metal. The addition of metal silicide at any connection region can also raise the on/off ratio and improve the performance of electric devices. In this work, we applied the pulsed laser annealing (PLA) method to form nickel silicide (NiSi) between S/D metal and the top connecting metal. Three different kinds of laser wavelengths, including 355 nm (ultraviolet laser), 532 nm (green laser) and 1064 nm (infrared laser), were used to compare the results of NiSi formation in these laser annealing processes. NiSi phase with low sheet resistance was formed by an ultraviolet laser annealing process without damaging the polyimide (PI) substrate. After integrating the PLA NiSi onto the S/D region, the on/off ratio increased at least 3 times and the field effect mobility increased by 50%. The contact resistance was lowered from 21 kΩ to 8.5 kΩ after integration. Furthermore, the voltage gain of the CMOS inverter was also improved by 30%, making it have a faster switching speed. For the 6T-SRAM part, the static noise margin (SNM) of 6T-SRAM is elevated from 0.82V to 1V at V<sub>dd</sub> = 4V. This work shows the achievability of using the PLA process to synthesize low thermal budget NiSi on the flexible substrate and the successful integration provides a new route to improve the performance of flexible 6T-SRAM devices. Better performance of the devices can ameliorate the application and function of wearable electronics, which will be an important part of the IoTs generation in the future.