Current status of FET-type ferroelectric memories

摘要

Current status of FET-type ferroelectric memories is reviewed. It is shown that improvement of the data retention characteristics is most important to commercialize the FET-type ferroelectric memories. Then, recent results on fabrication of MFIS-FETs are reviewed, in which usefulness of a Si{sub}3N{sub}4 buffer layer and a (Bi,La){sub}4Ti{sub}3O{sub}12 ferroelectric film is shown. Finally, the features and basic operation of a 1T2C-type ferroelectric memory are discussed and it is experimentally demonstrated that the stored data are non-destructively read out and the data retention time is much longer than that of a conventional ferroelectric-gate FET.