Manufacturable embedded CMOS 6T-SRAM technology with high-k gate dielectric device for system-on-chip applications

Abstract

Manufacturable embedded CMOS 6T-SRAM with the HfO/sub 2/-Al/sub 2/O/sub 3/ dielectric for system-on-chip (SoC) applications is successfully demonstrated for the first time in the semiconductor industry. The possibility of the high-k gate dielectric in low power SoC applications is suggested. 0.11/spl mu/m NFET and PFET devices with thin high-k gate dielectric have 470 and 150/spl mu/A//spl mu/m at Ioff=0.1nA/um and Vdd=1.2V, respectively. Inversion thickness of NFET and PFET are 2.4nm and 2.7nm, respectively. Gate leakage current of the high-k is 1000 times lower than that of the oxynitride at the accumulation region. Static noise margin of 2.14/spl mu/m/sup 2/ 6T-SRAM bit cell is about 300mV at Vdd=1.2V. 6T-SRAM chip yield of the high-k is comparable to that of the oxynitride. The post nitridation after high-k film deposition is very important to the yield of the SRAM chips due to the suppression of the PFET boron penetration. Stand-by current of the SRAM chips with the high-k is shown to be a decreases of 60% compared with the oxynitride.