Method for fabricating a memory device with a floating gate
AssigneeMacronix International Co., Ltd.
InventorsTso-Hung Fan, Tao-Cheng Lu, Wen-Jer Tsai, Samuel Pan
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Abstract
A fabrication method for a memory device with a floating gate is provided. A substrate is provided. A channel doping step is performed on the substrate, wherein the actual threshold voltage of the subsequently formed memory device becomes greater than the preset threshold voltage. A stack gate and source/drain regions are then sequentially formed on the substrate to complete the formation of the memory device. The drain-turn-on leakage is prevented by an increase of the actual threshold voltage.
Claims19
A method for fabricating a memory device with a floating gate, comprising:
- providing a substrate;
- performing a channel doping step that comprises at least three implantation steps on the substrate, wherein each implantation step is performed to implant a dosage of dopants with an implantation energy which are different from dosages and implantation energies of the two other implantation steps such that an actual threshold voltage of the memory device with the floating gate becomes greater than a preset threshold voltage of the memory device with the floating gate;
- forming a stack gate on the substrate;
- and
- forming a source/drain region in the substrate.
A method for reducing a drain-turn-on leakage for a memory device with a floating gate, comprising:
- providing a substrate;
- and
- performing a channel doping step that comprises a plurality of implantation steps on the substrate, wherein each implantation step is performed to implant a dosage of dopants with an implantation energy that are different from dosages and implantation energies of other implantation steps such that an actual threshold voltage of the memory device with the floating gate becomes greater than a preset threshold voltage of the memory device with the floating gate.
A method for fabricating a memory device with a floating gate, comprising:
- providing a substrate;
- performing a first implantation step, and second implantation step and a third implantation step on the substrate with the first implantation step implanting a first dosage of dopants into a first depth of the substrate, the second implantation step implanting a second dosage of dopants into a second depth of the substrate and the third implantation step implanting a third dosage of dopants into a third depth of the substrate such that an actual threshold voltage of the memory device with the floating gate becomes greater than a preset threshold voltage of the memory device with the floating gate.
Dependencies are inferred from the claim text.