Gate electrode silicidation process
AssigneeFreescale Semiconductor, Inc.
InventorsVidya Kaushik, Benoit Froment
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Abstract
A fully-silicided gate electrode is formed from silicon and a metal by depositing at least two layers of silicon with the metal layer therebetween. One of the silicon layers may be amorphous silicon whereas the other silicon layer may be polycrystalline silicon. The silicon between the metal layer and the gate dielectric may be deposited in two layers having different crystallinities. This process enables greater control to be exercised over the phase of the silicide resulting from this silicidation process.
Claims9
A method of fabricating a fully-silicided gate electrode layer comprising a predetermined silicide phase located at a first surface of the gate electrode layer, the method comprising:
- forming at least one first layer of silicon;
- forming a metal layer of a non-silicided metal;
- forming an additional layer of silicon such that the metal layer is between the first layer(s) of silicon and the additional layer of silicon;
- and
- simultaneously applying heat to the superposed first silicon layer(s), metal layer and additional silicon layer to convert said first silicon layer, said metal layer and said additional layer of silicon into a metal silicide having a predetermined metal silicide phase at a first surface thereof, said first surface being arranged for contacting a gate insulator.
Dependencies are inferred from the claim text.