Method and composite for decreasing charge leakage
AssigneeMicron Technology, Inc.
InventorsMichael Nuttall, Garry A. Mercaldi
Life of this patent
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Abstract
A dielectric insulating composite for insulating a floating gate from a control gate in a non-volatile memory is described. A material, such as an undoped polysilicon, amorphous silicon, or amorphous polysilicon or a silicon rich nitride, is inserted in the gate structure. The oxide film that results from the oxidation of these films is relatively free from impurities. As a result, charge leakage between the floating gate and control gate is reduced.
Claims18
A process for forming a dielectric composite for insulating a floating gate from a control gate, the process comprising:
- depositing a layer of undoped polysilicon on the floating gate;
- forming a layer of silicon dioxide by oxidizing the layer of undoped polysilicon;
- depositing a layer of silicon nitride on the layer of silicon dioxide;
- depositing a layer of silicon rich nitride on the layer of silicon nitride;
- and
- forming a second layer of silicon dioxide by oxidizing the layer of silicon rich nitride, the control gate formed on the second layer of silicon dioxide.
A process for forming a dielectric composite for insulating a floating gate from a control gate, the process comprising:
- depositing a layer of undoped polysilicon on the floating gate;
- forming a layer of silicon dioxide by oxidizing the layer of undoped polysilicon;
- depositing two nitride layers on the layer of silicon dioxide;
- and
- forming a second layer of silicon dioxide by oxidizing one of the two nitride layers, the control gate formed on the second layer of silicon dioxide.
A process for forming a dielectric composite for insulating a floating gate from a control gate, the process comprising:
- depositing a layer of undoped polysilicon on the floating gate;
- forming a layer of silicon dioxide by oxidizing the layer of undoped polysilicon;
- depositing two nitride layers on the layer of silicon dioxide;
- and
- forming a second layer of silicon dioxide by oxidizing one of the two nitride layers, the control gate formed on the second layer of silicon dioxide, wherein after forming the floating gate by flowing silane and phosphine, the deposition of the layer of undoped polysilicon is accomplished by reducing the flow of phosphine.
Dependencies are inferred from the claim text.