Method of manufacturing buried contact in SRAM
AssigneeUnited Microelectronics Corp.
InventorMing I Chen
Life of this patent
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Abstract
A method of manufacturing buried contact window in SRAM includes implanting oxygen ions into a substrate inside a buried contact window region adjacent to the location for forming a source/drain region, and then carrying out oxidative reaction in the implanted region to form an silicon oxide layer using the heat generated by a subsequent polysilicon deposition process or a laser beam. The silicon oxide layer protects the substrate by acting as a buffer, thus preventing the substrate from being over-etched to form a deep trench. Consequently, contact resistance between the buried contact window and the source/drain region is lowered, and leakage current at the junction is prevented.
Claims19
A method of manufacturing a buried contact window of an SRAM, comprising the steps of:
- providing a substrate, wherein the substrate has a device isolation structure;
- forming an oxide layer and a first conductive layer over the substrate;
- patterning the first conductive layer to form a first opening in a buried contact window region, wherein the first opening exposes the substrate in the buried contact window region;
- patterning an area within the buried contact window region adjacent to one side of a desired source/drain region, and then performing a first ion implantation in that area;
- forming a second conductive layer, wherein the second conductive layer connects electrically with the substrate through the first opening;
- patterning the second conductive layer to form a conductive line and a gate together with a second opening between the conductive line and the gate such that the second opening exposes the desired source/drain region and a portion of the buried ion-doped contact window region;
- and
- performing a second ion implantation implanting ions into the substrate through the second opening to form a buried contact window and a source/drain region.
A method of manufacturing a buried contact window of an SRAM, comprising the steps of:
- providing a substrate, wherein the substrate has a device isolation structure;
- forming an oxide layer and a first conductive layer over the substrate;
- patterning the first conductive layer to form a first opening in a buried contact window region, wherein the first opening exposes the substrate in the buried contact window region;
- patterning an area within the buried contact window region located to one side of a desired source/drain region, and then performing a first ion implantation in that area;
- forming a second conductive layer, wherein the second conductive layer connects electrically with the substrate through the first opening;
- patterning the second conductive layer to form a conductive line and a gate together with a second opening located between the conductive line and the gate such that the second opening exposes the desired source/drain region and a portion of the buried ion-doped contact window region.
Dependencies are inferred from the claim text.