A Method for Improving the Reliability of Sonns Structured Devices Using Asymmetric Hierarchical Barriers

Abstract

The invention discloses a method for improving the reliability of a self organizing neural networks (SONNs) structure device by using an asymmetric layered potential barrier. The method comprises the following steps of: 1, providing a P-type substrate; 2, manufacturing a tunneling silicon nitride layer and a tunneling oxidation layer with equal electrical thickness; 3, manufacturing a memory silicon nitride layer on the surface of the tunneling oxidation layer; 4, manufacturing a blocking oxidation layer on the memory silicon nitride layer; and 5, manufacturing polycrystalline silicon on the blocking oxidation layer. The invention aims to provide the method for improving the reliability of the SONNs structure device by using the asymmetric layered potential barrier. The method is high in charge holding capacity, and a cavity in an erasure state can be prevented from entering an interface state in compiling and erasure cycles, so the durability of the device is improved.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a method for improving the reliability of a SONNS structure device by using an asymmetric layered potential barrier. Background technique [0002] Flash memory is a type of non-volatile memory device. Traditional flash memory uses polysilicon floating gates to store data. Since polysilicon is a conductor, the charges stored in the floating gates are continuously distributed. When there is a leakage channel, the charge stored in the entire floating gate will be lost through this leakage channel. The recently developed SONOS structure replaces the original polysilicon charge storage layer with a silicon nitride layer capable of trapping charges. Since it uses trap energy levels to store charges, the stored charges are discretely distributed. Such a leakage channel will not cause a large leakage current, so the reliability is greatly improved. [0003] The SONOS structure has becom...

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Problems solved by technology

[0007] However, for silicon nitride with a smaller potential barrier, the charge retention ability will be affected to a certain extent, and the height of the potential barrier does not decrease when a voltage is applied, such as figure 2 As shown in , where, when the gate voltage V is added to the SONOS structure device, although the energy band after the voltage is added (such as figure 2 Shown by the dotted line in the middle) relative to the energy band when no voltage is applied (such as figure 2 (shown by the solid line in the center) has shifted, but the height of the potential has not decreased

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