Memory retention and switching speed of ferroelectric field effect in (Pb,La)(Ti,Zr)O-3/La2CuO4:Sr heterostructure

We report long period memory retention characteristics and switching speed of (Pb, La)(Ti, Zr)O-3/La2CuO4 field effect devices previously proposed by one of the authors. Most of the devices retained one-half of their initial conductance modulations induced by the ferroelectric field effect for about two weeks. Some retained memory for over 10 months, which markedly surpasses previously reported performances for the memory retention of ferroelectric field effect devices. The switching time of devices having effectively a 200-mu m-long and 40-mu m-wide gate area reduced to 10 mu s, as the conductance between the source and drain increased. Such a short switching time is favorable for interpretation of the conductance modulation based on the Geld effect. Approaches to high density integration are discussed.