摘要:
A method for forming shallow trench isolation wherein oxide divots at the edge of the isolation and active regions are reduced or eliminated is described. A trench is etched into a semiconductor substrate. An oxide layer is deposited overlying the semiconductor substrate and filling the trench. Nitrogen atoms are implanted into the oxide layer overlying the trench. The substrate is annealed whereby a layer of nitrogen-rich oxide is formed at the surface of the oxide layer overlying the trench. The oxide layer is planarized to the semiconductor substrate wherein the nitrogen-rich oxide layer is planarized more slowly than the oxide layer resulting in a portion of the oxide layer remaining overlying the trench after the oxide layer overlying the semiconductor substrate has been removed wherein the portion of the oxide layer remaining provides a smooth transition between the shallow trench isolation and the active areas completing the formation of shallow trench isolation in the fabrication of an integrated circuit device.
摘要:
A method of manufacturing conductive lines that are thicker (not wider) in the critical paths areas. We form a plurality of first level conductive lines over a first dielectric layer. The first conductive lines run in a first direction. The first level conductive lines are comprised of a first level first conductive line and a second first level conductive line. We form a second dielectric layer over the first level conductive lines and the first dielectric layer. Next, we form a via opening in the second dielectric layer over a portion of the first level first conductive line. A plug is formed filling the via opening. We form a trench pattern in the second dielectric layer. The trench pattern is comprised of trenches that are approximately orthogonal to the first level conductive lines. We fill the trenches with a conductive material to form supplemental second lines. We form second level conductive lines over the supplemental second lines and the plug. The second level conductive lines are aligned parallel to the supplemental second lines. The supplemental second lines are formed under the critical path areas of the second level conductive lines. The second level conductive lines are not formed to contact the first level conductive lines where a contact is not desired. In the critical path areas of the second level conductive lines, the supplemental second lines underlie the second level conductive lines thereby increasing the effective overall wiring thickness in the critical path area thereby improving performance.
摘要:
A method of fabricating first and second gates comprising the following steps. A substrate having a gate dielectric layer formed thereover is provided. The substrate having a first gate region and a second gate region. A thin first gate layer is formed over the gate dielectric layer. The thin first gate layer within the second gate region is masked to expose a portion of the thin first gate layer within the first gate region. The exposed portion of the thin first gate layer is converted to a thin third gate layer portion. A second gate layer is formed over the thin first and third gate layer portions. The second gate layer and the first and third gate layer portions are patterned to form a first gate within first gate region and a second gate within second gate region.
摘要:
A method for forming a single gate having a dual work-function is described. A gate electrode is formed overlying a gate dielectric layer on a substrate. Sidewalls of the gate electrode are selectively doped whereby the doped sidewalls have a first work-function and whereby a central portion of the gate electrode not doped has a second work-function to complete formation of a single gate having multiple work-functions in the fabrication of integrated circuits.
摘要:
A method of fabricating a dual gate electrode CMOS device having dual gate electrodes. An N+ poly gate is used for the nMOSFET and a metal gate is used for the pMOSFET. The N+ nMOSFET poly gate may be capped with a highly conductive metal to reduce its gate resistance. A sacrificial cap is used for the N+ poly gate to eliminate a mask level for the dual gate electrodes.
摘要:
Low current leakage DRAM structures are achieved using a selective silicon epitaxial growth over an insulating layer on memory cell (device) areas. An insulating layer, that also serves as a stress-release layer, and a Si3N4 hard mask are patterned to leave portions over the memory cell areas. Shallow trenches are etched in the substrate and filled with a CVD oxide which is polished back to the hard mask to form shallow trench isolation (STI) around the memory cell areas. The hard mask is selectively removed to form recesses in the STI aligned over the memory cell areas exposing the underlying insulating layer. Openings are etched in the insulating layer to provide a silicon-seed surface from which is grown a selective epitaxial layer extending over the insulating layer within the recesses. After growing a gate oxide on the epitaxial layer, FETs and DRAM capacitors can be formed on the epitaxial layer. The insulating layer under the epitaxial layer drastically reduces the capacitor leakage current and improves DRAM device performance. This self-aligning method also increases memory cell density, and is integratable into current DRAM processes to reduce cost.
摘要:
A method for siliciding source/drain junctions is described wherein compressive stress of the underlying silicon is avoided by the insertion of a buffer layer between the silicide and the silicon. A gate electrode and associated source/drain extensions are provided in and on a semiconductor substrate. A buffer oxide layer is deposited overlying the semiconductor substrate and the gate electrode. A polysilicon layer is deposited overlying the buffer oxide layer. The polysilicon layer will form the source/drain junctions and silicon source. The source/drain junctions are silicided whereby the buffer oxide layer provides compressive stress relief during the siliciding.
摘要:
A process for forming metal structures, encapsulated in silicon rich oxide, (SRO), shapes and layers, needed to protect the metal structures from the corrosive effects of fluorine radicals, present in low k, fluorinated silica glass, (FSG), which in turn is formed in the spaces between metal structures, has been developed. The process features initial formation of the metal structures, capped with an overlying SRO shape. This is followed by the formation of SRO spacers on the sides of the SRO capped, metal structures. Another thin, conformal SRO layer is then deposited to insure encapsulation of the metal structures, however still leaving adequate space between the SRO encapsulated metal structures for the low k FSG layer, needed to limit capacitance and improve device performance.
摘要:
Low current leakage DRAM structures are achieved using a selective silicon epitaxial growth over an insulating layer on memory cell (device) areas. An insulating layer, that also serves as a stress-release layer, and a Si3N4 hard mask are patterned to leave portions over the memory cell areas. Shallow trenches are etched in the substrate and filled with a CVD oxide which is polished back to the hard mask to form shallow trench isolation (STI) around the memory cell areas. The hard mask is selectively removed to form recesses in the STI aligned over the memory cell areas exposing the underlying insulating layer. Openings are etched in the insulating layer to provide a silicon-seed surface from which is grown a selective epitaxial layer extending over the insulating layer within the recesses. After growing a gate oxide on the epitaxial layer, FETs and DRAM capacitors can be formed on the epitaxial layer. The insulating layer under the epitaxial layer drastically reduces the capacitor leakage current and improves DRAM device performance. This self-aligning method also increases memory cell density, and is integratable into current DRAM processes to reduce cost.
摘要:
A method for forming a MOSFET having an elevated source/drain structure is described. A sacrificial oxide layer is provided on a substrate. A polish stop layer is deposited overlying the sacrificial oxide layer. An oxide layer is deposited overlying the polish stop layer. An opening is formed through the oxide layer and the polish stop layer to the sacrificial oxide layer. First polysilicon spacers are formed on sidewalls of the opening wherein the first polysilicon spacers form an elevated source/drain structure. Second polysilicon spacers are formed on the first polysilicon spacers. The oxide layer and sacrificial oxide layer exposed within the opening are removed. An epitaxial silicon layer is grown within the opening. A gate dielectric layer is formed within the opening overlying the second polysilicon spacers and the epitaxial silicon layer. A gate material layer is deposited within the opening. The gate material layer, first polysilicon spacers and second polysilicon spacers are polished back to the polish stop layer thereby completing formation of a MOSFET having an elevated source/drain structure in the fabrication of an integrated circuit device.