Method for fabricating semiconductor device
First Claim
1. A method for fabricating a semiconductor memory device, comprising:
- forming a trench in a portion of a substrate, defined as a cell region;
forming a gate oxide layer over the substrate including the trench;
forming a first polysilicon layer doped with N-type impurities on regions where N-type metal-oxide-semiconductor (MOS) transistors are to be formed in the cell region and the periphery region such that the first polysilicon layer fills the trench;
forming a second polysilicon layer doped with P-type impurities on an area where a P-type MOS transistor is to be formed;
forming a gate metal layer over the first polysilicon layer and the second polysilicon layer;
forming a gate hard mask layer on the gate metal layer; and
patterning the gate hard mask layer, the gate metal layer, and the first and the second polysilicon layers to form gate patterns for the N-type MOS transistors in the cell region and the periphery region, and the P-type MOS transistor in the periphery region.
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Abstract
A method for fabricating a semiconductor memory device is provided. The method includes: forming a trench in a portion of a substrate, defined as a cell region; forming a first polysilicon layer doped with N-type impurities on regions where N-type metal-oxide-semiconductor (MOS) transistors are to be formed in the cell region and the periphery region; forming a second polysilicon layer doped with P-type impurities on an area where a P-type MOS transistor is to be formed; forming a gate metal layer over the first and the second polysilicon layers; forming a gate hard mask layer on the gate metal layer; and patterning the gate hard mask layer, the gate metal layer, and the first and the second polysilicon layers to form gate patterns for the N-type MOS transistors in the cell region and the periphery region, and the P-type MOS transistor in the periphery region.
18 Citations
10 Claims
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1. A method for fabricating a semiconductor memory device, comprising:
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forming a trench in a portion of a substrate, defined as a cell region;
forming a gate oxide layer over the substrate including the trench;
forming a first polysilicon layer doped with N-type impurities on regions where N-type metal-oxide-semiconductor (MOS) transistors are to be formed in the cell region and the periphery region such that the first polysilicon layer fills the trench;
forming a second polysilicon layer doped with P-type impurities on an area where a P-type MOS transistor is to be formed;
forming a gate metal layer over the first polysilicon layer and the second polysilicon layer;
forming a gate hard mask layer on the gate metal layer; and
patterning the gate hard mask layer, the gate metal layer, and the first and the second polysilicon layers to form gate patterns for the N-type MOS transistors in the cell region and the periphery region, and the P-type MOS transistor in the periphery region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification