Method of suppressing junction capacitance of source/drain regions
AssigneeUnited Microelectronics Corp.
InventorsTony Lin, Wen-Kuan Yeh, Jih-Wen Chou
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Abstract
A method of suppressing junction capacitance of the source/drain regions is disclosed in this invention. The source/drain regions are formed by double implantation of phosphorus ions and arsenic ions. The phosphorus ion implantation lowers the energy needed in the implantation of arsenic ions, and reduces dislocations in the source/drain regions formed during implanting arsenic ions. Further, the double implantation suppresses the junction profile of arsenic ions, and enhances the width of depletion regions. So, the junction capacitance is reduced, thereby accelerate the function of semiconductor devices.
Claims17
A method of suppressing junction capacitance of source/drain regions, comprising:
- forming a gate structure on a substrate;
- forming an LDD structure in the substrate;
- forming spacers on a sidewall of the gate structure subsequent to the formation of the LDD structure;
- performing a phosphorus ion implanting step to form a heavily doped portion of a source/drain region in the substrate using the spacer and the gate structure as masks;
- and
- performing an arsenic ion implanting step to complete forming the heavily doped portion of the source/drain region in the substrate.
A method of suppressing junction capacitance of source/drain regions in NMOS, comprising:
- forming a LDD structure in a P-type substrate;
- performing one N-type ion implanting step to form a heavily doped portion of a source/drain region in the substrate subsequent to the formation of the LDD structure;
- performing the other N-type ion implanting step to complete forming the heavily doped portion of the source/drain region on the substrate.
A method of suppressing junction capacitance of source/drain regions in PMOS, comprising:
- forming a LDD structure in a N-type substrate;
- performing one P-type ion implanting step to form a heavily doped portion of a source/drain region structure in the substrate subsequent to the formation of the LDD structure;
- Performing the other P-type ion implanting step to complete forming the heavily doped portion of the source/drain structure in the substrate.
Dependencies are inferred from the claim text.