Methods of forming halo regions in NMOS transistors
View Patent ↗Disclosed are methods of forming a halo region in n-channel type MOS (NMOS) transistors. In one example, the method includes forming, on a channel region of a semiconductor substrate, a structure having a gate insulation film pattern and a gate conductive film pattern stacked sequentially; forming an ion implantation buffer film on an exposed surface of the semiconductor substrate and the gate conductive film pattern; performing a first ion implantation process for injecting fluorine ions into the semiconductor substrate; performing a second ion implantation process for implanting p-type halo ions into the semiconductor substrate; performing a third ion implantation process for implanting n-type impurity ions into the semiconductor substrate; and diffusing the p-type halo ions and the n-type impurity ions using a thermal process.
1. A method for forming a halo region in an NMOS transistor, comprising the steps of:
forming, on a channel region of a semiconductor substrate, a structure having a gate insulation film pattern and a gate conductive film pattern stacked sequentially;
forming an ion implantation buffer film comprising an oxide on an exposed surface of the semiconductor substrate and the gate conductive film pattern;
performing a first ion implantation process for injecting fluorine ions through the ion implantation buffer film into the semiconductor substrate;
performing a second ion implantation process for implanting p-type halo ions through the ion implantation buffer film into the semiconductor substrate;
performing a third ion implantation process for implanting n-type impurity ions through the ion implantation buffer film into the semiconductor substrate; and
diffusing the p-type halo ions and the n-type impurity ions using a thermal process.
2. The method of claim 1 , first ion implantation process comprises implanting fluorine ions with an ion implantation energy of 5 to 50 keV a concentration of 5×10 14 to 5×10 15 ions/cm 2 , and an implantation gradient of 20° to 30°.
3. The method of claim 1 , wherein, the second ion implantation process comprises implanting the BF 2 ions with an ion implantation energy of 10 to 40 keV, a concentration of 1×10 14 to 1×10 15 ions/cm 2 , and an implantation gradient of 20° to 30°.
4. The method of claim 1 , wherein the thermal process includes a rapid thermal process performed at a temperature of 800 to 1000° for 10 to 30 seconds in an atmosphere of N 2 .
5. The method of claim 1 , wherein said fluorine ions are implanted with an energy of 5 to 50 keV.
6. The method of claim 1 , wherein said fluorine ions are implanted at a concentration of 5×10 14 to 5×10 15 ions/cm 2 .
7. The method of claim 1 , wherein said fluorine ions arc implanted at a gradient of 20° to 30°.
8. The method of claim 1 , wherein said p-type halo ions comprise BF 2 ions.
9. The method said p-type halo ions are implanted with an ion implantation energy of 10 to 40 keV.
10. The method of claim 1 , wherein said p-type halo ions are implanted at a concentration of 1×10 14 to 1×10 15 ions/cm 2 .
11. The method of claim 1 , wherein said p-type halo ions are implanted at a gradient of 20° to 30°.
12. The method of claim 1 , wherein said thermal process is performed at a temperature of 800 to 1000° C.
13. The method of claim 1 , wherein said thermal process comprises a rapid thermal process, performed for 10 to 30 seconds.
14. The method of claim 1 , wherein said n-type impurity ions comprise As ions.
15. The method of claim 14 , wherein said As ions arc implanted with an ion implantation energy of 5 to 50 keV.
16. The method of claim 14 , wherein said As ions arc implanted at a concentration of 1×10 15 to 5×10 15 ions/cm 2 .
17. The method of claim 1 , wherein said n-type impurity ions are implanted with an ion implantation energy of 5 to 50 keV.
18. The method of claim 1 , wherein said n-type impurity ions are implanted at a concentration of 1×10 15 to 5×10 15 ions/cm 2 .