40 nm Dual-port and two-port SRAMs for automotive MCU applications under the wide temperature range of −40 to 170°C with test screening against write disturb issues

A 2-read/write dual-port SRAM and 1-read/1-write two-port SRAM with stable operation at temperatures of −40 to 170°C are implemented in 40 nm embedded flash CMOS technology for automotive microcontroller applications. To reduce the leakage current and to ensure the read/write operating margin at over 125°C, a new 8T SRAM bitcell with the optimized process and sizing is proposed. A test circuit for screening disturb failures for dual-port and two-port SRAMs is also proposed. Designed and fabricated test chips showed that measured V min is achieved under 0.7 V with good distribution. Results show that the proposed test circuits can screen the disturb failures effectively.