| 摘要 |
PURPOSE:To lower the operating voltage and to secure a sufficient signal quantity by laminating a plurality of ferroelectric thin films, and causing each thin film to have different coercive electric field and remanence. CONSTITUTION:A thermal oxide film 8, a Ti film 9, and a Pt film 10 are formed on the surface of an n-type silicon substrate 7. Next, a plurality of ferroelectric thin films composed of a PZT film 11 and a PLZT film 12 are formed on the Pt film 10 by Sol Gel process. Here, the remanence and the coercive electric field of the lower one 12 out of the ferroelectric thin films 11 and 12 adjoining each other at the upside or downside and constituting the ferroelectric thin film, are made larger than those of the upper one 11. Consequently, it becomes possible to make the coercive electric field smaller and lower operating voltage. Besides, the remanence becomes sufficiently larger, and it becomes possible to obtain a sufficient signal quantity. |
