Method for fabricating semiconductor device and plasma doping system
View Patent ↗An impurity is introduced into a fin-type semiconductor region ( 102 ) formed on a substrate ( 100 ) using a plasma doping process, thereby forming an impurity-introduced layer ( 105 ). Carbon is introduced into the fin-type semiconductor region ( 102 ) using a plasma doping process to overlap at least a part of the impurity-introduced layer ( 105 ), thereby forming a carbon-introduced layer.
1. A method for fabricating a semiconductor device, the method comprising:
introducing an impurity into a fin-type semiconductor formed on a substrate using a plasma doping process, thereby forming an impurity-introduced layer; and
introducing carbon into the fin-type semiconductor using a plasma doping process, thereby forming a carbon-introduced layer to overlap at least a part of the impurity-introduced layer.
2. The method of claim 1 , wherein
the forming the impurity-introduced layer and the forming the carbon-introduced layer are performed in a same chamber.
3. The method of claim 2 , wherein
the forming the impurity-introduced layer and the forming the carbon-introduced layer are simultaneously performed using a mixture of a gas containing the impurity and a gas containing carbon.
4. The method of claim 1 , wherein
the forming the impurity-introduced layer includes forming an amorphous layer by impingement of ions contained in a plasma to overlap at least a part of the impurity-introduced layer while allowing a crystal layer to remain inside the fin-type semiconductor.
5. The method of claim 4 further comprising
after the forming the impurity-introduced layer and the forming the carbon-introduced layer, subjecting the amorphous layer to a heat treatment to recover crystallinity of the amorphous layer.
6. The method of claim 1 , wherein
the forming the impurity-introduced layer and the forming the carbon-introduced layer are each performed at a pressure of equal to or less than 0.35 Pa.
7. The method of claim 6 , wherein
the forming the impurity-introduced layer and the forming the carbon-introduced layer are each performed at a bias voltage of equal to or less than 250 V.
8. The method of claim 7 , wherein
a total plasma treatment time in the forming the impurity-introduced layer and the forming the carbon-introduced layer is equal to or less than 72 seconds.
9. The method of claim 1 , wherein
a total plasma treatment time in the forming the impurity-introduced layer and the forming the carbon-introduced layer is equal to or less than a maximum total plasma treatment time previously set based on the pressures and bias voltages in both of the forming the impurity-introduced layer and the forming the carbon-introduced layer.
10. The method of claim 1 , wherein
the forming the impurity-introduced layer is performed using a first gas containing at least one element selected from boron, arsenic, and phosphorus, and
the forming the carbon-introduced layer is performed using a second gas containing carbon.
11. The method of claim 10 , wherein
the first gas and the second gas are used while being diluted with helium.
12. The method of claim 10 , wherein
the second gas is a gas containing carbon and hydrogen.
13. The method of claim 10 , wherein
the first gas is a gas containing boron and hydrogen, a gas containing arsenic and hydrogen, or a gas containing phosphorus and hydrogen, and
the second gas contains carbon and hydrogen and has a lower molecular weight than the first gas.
14. The method of claim 13 , wherein
the first gas is B 2 H 6 , and
the second gas is CH 4 (methane).
15. The method of claim 13 , wherein
the first gas is AsH 3 , and
the second gas is CH 4 (methane), C 2 H 6 (ethane), C 3 H 6 (cyclopropane), C 2 H 8 (propane), C 4 H 10 (butane), or C 4 H 10 (isobutane).
16. The method of claim 13 , wherein
the first gas is PH 3 , and
the second gas is CH 4 (methane) or C 2 H 6 (ethane).
17. A plasma doping system for use in the method of claim 1 , the system comprising:
a chamber in which the substrate is placed;
a first gas supply unit for supplying a gas containing the impurity into the chamber; and
a second gas supply unit for supplying a gas containing carbon into the chamber.
18. The system of claim 17 further comprising a third gas supply unit for supplying a diluent gas into the chamber.
19. The method of claim 1 , wherein in the step of introducing carbon, carbon is introduced into upper and side portions of the fin-type semiconductor.