Semiconductor memory device and manufacturing method thereof
AssigneeFujitsu Limited
InventorYoshihiro Sugiyama
Life of this patent
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Abstract
A semiconductor memory device which more reliably retains electrons trapped in its charge-trapping regions. A high-dielectric gate insulating film is grown on a semiconductor substrate. This gate insulating film is composed of first and second oxides, where the second oxide has a smaller bandgap than that of the first oxide and is scattered in dot-like form, surrounded by the first oxide. The memory cell is programmed by injecting electrons into a local potential minimum that is produced due to the bandgap difference between the phase-separated first and second oxides.
Claims7
A method of manufacturing a non-volatile semiconductor memory device which uses a high-dielectric material for gate insulation, the method comprising the steps of:
- forming a gate insulating film by depositing a mixture of a first oxide and a second oxide, the second oxide having a smaller bandgap than that of the first oxide;
- and
- applying a heat treatment to the gate insulating film to produce a phase separated state of the first and second oxides deposited.
Dependencies are inferred from the claim text.