| 摘要 |
PURPOSE:To improve the effect of electron injection from an injector, and the integrity by making an SiO2 film sufficiently thicker than a control gate on a read transistor. CONSTITUTION:In the conventional method, SiO215 on a control gate and SiO216 on a read transistor are simultaneously formed films and the voltage transmitted to a floating gate 13 is lower than the voltage applied to the control gate and, consequently, a channel 14 is not sufficiently depleted which makes the electron injection by an injector less effective. The film 16, then, is formed as thick as other gate films in the order of 1,000Angstrom , which is sufficiently thicker than the film 15 to provide a large capacitance of the read transistor. No extra process is needed for this. In this construction, the voltage of the control gate is amply transmitted to the floating gate, improving the electron injection effect of the injector and the integration since the capacitance ratio is controlled by the thickness the SiO2 film and not by expanding the gate area. |
