Improved Data Retention of Single Gate PMOS OTP Cell by Dielectric Film Process Optimization

A dielectric film process optimization is proposed in this paper to improve data retention for high efficiency P channel OTP (One time programmable memory) cell. P-channel OTP data retention is quite challenging during OTP process development, probably due to floating gate electric charge. The data retention of PMOS OTP cell can be improved from less than one year to 30 years at high temperature 85°C by plasma density adjustment during dielectric film deposition. The mechanism is investigated in this paper, probably due to floating poly stress released, and defect repaired.