A Study on High Density Gate-Oxide Anti-Fuse PROM Memory Cell Program Features

摘要

The program consistency of high density gate-oxide anti-fuse PROM (programmable read only memory) memory cell is considered in this paper. To solve this problem, we do research on the mechanism and models of gate-oxide break down. A test chip based on 2T memory cell is also designed for the experiment. During the test, we have found that the program consistency of 2T cell is really pessimistic. What’s more, the program voltage has effect on the consistency. Through research and test, we have got the optimal program voltage-6.5V for 2T memory cell in 180nm technology. To further improve the consistency, we modify the 2T memory cell and propose a 3T memory cell. It consumes 18% more area, but the standard deviation of equivalent resistance decreases 15.3% in the worst situation. The deviation can decrease 80.3% at most. The program consistency is greatly improved.