Title :
A technique for measuring threshold mismatch in DRAM sense amplifier devices
Author :
Sprogis, Edmund J.
Author_Institution :
IBM, Essex Junction, VT, USA
Abstract :
The magnitude of the threshold difference between cross-coupled FET pairs of a DRAM (dynamic random-access memory) sense amplifier directly detracts from the amount of signal developed. A static testing technique is described that quickly and accurately measures the threshold difference between every N-channel device pair in an entire sense amplifier bank on an array-like test structure. The static measurement results are correlated with a dynamic sense amplifier signal margin test. High volume data provided by the technique are useful for characterizing and correcting process- or mas-induced threshold mismatch, in order to maximize signal margin and minimize retention-time losses in VLSI DRAMs
Keywords :
DRAM chips; VLSI; field effect integrated circuits; integrated circuit testing; DRAM sense amplifier devices; N-channel device pair; VLSI; array-like test structure; cross-coupled FET pairs; dynamic sense amplifier signal margin test; retention-time losses; signal margin; static testing technique; threshold mismatch; Capacitance; Circuit noise; Doping; FETs; Laser beam cutting; Random access memory; Semiconductor device measurement; Signal processing; Signal to noise ratio; Testing;
Conference_Titel :
Microelectronic Test Structures, 1991. ICMTS 1991. Proceedings of the 1991 International Conference on
Conference_Location :
Kyoto
Print_ISBN :
0-87942-588-1
DOI :
10.1109/ICMTS.1990.161721