Alpha particle induced charge collection measurements and the effectiveness of reflecting barriers on VLSI memories

This paper presents experimental results of analog charge collection measurement of alpha particle induced carriers in memory arrays. Measurements with high intensity foils and variable angle collimated sources on various memory arrays with different reflecting structures are reported. A P-well reflecting barrier is shown to reduce charge collection by a factor 2 and SER by about two orders of magnitude. The effectiveness of the P-well barrier is demonstrated on a 64K DRAM of 154 mils □ with extremely low SER (.001%/1KHr at 1µsec cycle time).