Refractory metal silicide deposition process
AssigneeTexas Instruments Incorporated
InventorRobert H. Havemann
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Abstract
A method for forming a refractory metal silicide on a semiconductor device is disclosed. The method comprises the steps of depositing a layer of refractory metal on the device and reacting the layer with nitrogen. The reaction is accomplished at a partial pressure of nitrogen greater than one atmosphere. The disclosed process allows thin layers of low resistance silicide to be formed for use as an ohmic contact while also forming a nitride layer for use as a device-to-device interconnection.
Claims11
A method for forming a refractory metal silicide layer on a semiconductor device, the method comprising the steps of:
- exposing at least one region of elemental silicon of the device;
- depositing a layer of refractory metal on the device to cover the exposed region;
- and
- reacting nitrogen with the metal layer to form a layer of silicide having a first thickness adjacent said at least one exposed region of elemental silicon and a layer of nitride having a second thickness, the partial pressure of the nitrogen being greater than one atmosphere such that said second thickness is greater than said first thickness.
A method for forming a local interconnect in conjunction with a silicide process comprising the steps of:
- forming a layer of refractory metal on a surface of a silicon substrate;
- and
- reacting the metal layer with nitrogen at a partial pressure greater than one atmosphere to form a layer of silicide upon said silicon substrate and a layer of nitride.
A method for forming a silicide/nitride bilayer on a silicon substrate comprising the steps of:
- depositing approximately 1,000 Angstroms of titanium onto the substrate, and
- forming a silicide/nitride bilayer under a partial pressure of nitrogen greater than one atmosphere, said silicide/nitride bilayer comprising approximately 500 Angstroms of TiSi.sub.2 and 1,000 Angstroms of TiN.
Dependencies are inferred from the claim text.