Method of generating plasma in remote plasma source and method of fabricating semiconductor device using the same method
Provided are a method of generating plasma and a method of fabricating a semiconductor device including the method, which may improve selectivity in an etching process and minimize damage to layers. The method of generating plasma includes generating first plasma by supplying at least one first process gas into a first remote plasma source (RPS) and applying first energy having a first power at a first duty ratio, and generating second plasma by supplying at least one second process gas into a second RPS and applying second energy having a second power at a second duty ratio.
1. A method of fabricating a semiconductor device, the method comprising:
placing an etching target on a stage in a process chamber;
generating a first plasma by supplying at least one first process gas into a first plasma chamber spaced from and outside the process chamber and applying a first energy having a first power and a first frequency at a first duty ratio to the first plasma chamber;
generating a second plasma by supplying at least one second process gas into a second plasma chamber spaced from and outside the process chamber and applying a second energy having a second power and a second frequency at a second duty ratio to the second plasma chamber;
supplying the first plasma and the second plasma into the process chamber, wherein the first plasma and the second plasma are independently supplied into the process chamber; and
etching the etching target using the first plasma and the second plasma,
the first energy is applied during an on-off time period of the first energy comprising an on time period during which the first power is turned on and an off time period during which the first power is turned off, the second energy is applied during an on-off time period of the second energy comprising an on time period during which the second power is turned on and an off time period during which the second power is turned off, and the on-off time period of the first energy is equal in duration to the on-off time period of the second energy,
the first duty ratio is equal to the second duty ratio, and the on time period of the first energy is concurrent with the off time period of the second energy,
the first energy is applied as a continuous wave during the on time period of the first energy or the second energy is applied as a continuous wave during the on time period of the second energy.
2. The method of claim 1 , wherein the supplying of the at least one first process gas into the first plasma chamber and the applying of the first energy to the first plasma chamber are performed independent of the supplying of the at least one second process gas into the second plasma chamber and the applying of the second energy to the second plasma chamber, and
the first power is less than the second power.
3. The method of claim 1 , wherein the first energy is applied during a plurality of on-off time periods of the first energy each comprising an on time period during which the first power is turned on and an off time period during which the first power is turned off, the first energy is pulsed at a first pulse frequency during at least one on time period, and the first pulse frequency is less than the first frequency of the first energy, and
the second energy is applied during a plurality of on-off time periods of the second energy each comprising an on time period during which the second power is turned on and an off time period during which the second power is turned off, the second energy is pulsed at a second pulse frequency during at least one on time period, and the second pulse frequency is less than the second frequency of the second energy.
4. The method of claim 1 , wherein a showerhead unit configured to supply the first plasma and the second plasma into the process chamber is disposed in the process chamber,
the showerhead unit includes a first channel fluidly connected to the first plasma chamber and configured to supply the first plasma into the process chamber and a second channel fluidly connected to the second plasma chamber and configured to supply the second plasma into the process chamber, and
the supplying of the first plasma and the supplying of the second plasma into the process chamber comprises discretely supplying the first plasma and the second plasma through the first and second channels into the process chamber without mixing the first plasma and the second plasma.
5. The method of claim 4 , wherein the showerhead unit includes a first showerhead having a plurality of first holes fluidly connected to the first channel, and a second showerhead having a plurality of second holes fluidly connected to the second channel,
the first holes are configured to allow at least one first type of element used to process the etching target, from among a plurality of types of elements contained in the first plasma, to pass therethrough, and
the second holes are configured to allow at least one second type of element used to process the etching target, from among a plurality of types of elements contained in the second plasma, to pass therethrough.
6. The method of claim 4 , wherein the discretely supplying of the first plasma and the second plasma through the first and second channels comprises sequentially, simultaneously, or alternately supplying the first plasma and the second plasma into the process chamber.
7. The method of claim 4 , wherein the generating of the first plasma comprises controlling types and amounts of elements contained in the first plasma by controlling at least one of the at least one first process gas, the first power, the first frequency, and the first duty ratio,
the generating of the second plasma comprises controlling types and amounts of elements contained in the second plasma by controlling at least one of the at least one second process gas, the second power, the second frequency, and the second duty ratio, and
the supplying of the first plasma and the second plasma into the process chamber comprises supplying at least one first type of element used to process the etching target, from among a plurality of types of elements contained in the first plasma, through the first channel and supplying at least one second type of element used to process the etching target, from among a plurality of types of elements contained in the second plasma, through the second channel.
8. The method of claim 1 , further comprising generating ions from the first plasma and the second plasma by applying a bias voltage to the process chamber.
9. The method of claim 1 , wherein the etching target comprises a substrate or substrate structure including a material layer formed on the substrate or the substrate structure.
10. The method of claim 3 , wherein the first pulse frequency is greater than a first on-off time frequency which has an inverse relationship with the on-off time period of the first energy, and the second pulse frequency is greater than a second on-off time frequency which has an inverse relationship with the on-off time period of the second energy.
11. The method of claim 1 , wherein the first energy is pulsed at a first pulse frequency during the on time period of the first energy, and the first pulse frequency is less than the first frequency of the first energy.
12. The method of claim 1 , wherein the second energy is pulsed at a second pulse frequency during the on time period of the second energy, and the second pulse frequency is less than the second frequency of the second energy.
13. The method of claim 12 , wherein the second pulse frequency is greater than a second on-off time frequency which has an inverse relationship with the on-off time period of the second energy.
14. A method of fabricating a semiconductor device, the method comprising:
placing an etching target on a stage in a process chamber;
generating a first plasma by supplying at least one first process gas into a first plasma chamber spaced from and outside the process chamber and applying a first energy having a first power and a first frequency at a first duty ratio to the first plasma chamber;
generating a second plasma by supplying at least one second process gas into a second plasma chamber spaced from and outside the process chamber and applying a second energy having a second power and a second frequency at a second duty ratio to the second plasma chamber;
supplying the first plasma and the second plasma into the process chamber, wherein the first plasma and the second plasma are independently supplied into the process chamber; and
etching the etching target using the first plasma and the second plasma,
the first energy is applied during an on-off time period of the first energy comprising an on time period during which the first power is turned on and an off time period during which the first power is turned off, the second energy is applied during an on-off time period of the second energy comprising an on time period during which the second power is turned on and an off time period during which the second power is turned off, and the on-off time period of the first energy is equal in duration to the on-off time period of the second energy,
the first duty ratio is equal to the second duty ratio, and the on time period of the first energy partially overlaps the on time period of the second energy,
the first energy is applied as a continuous wave during the on time period of the first energy or the second energy is applied as a continuous wave during the on time period of the second energy.
15. The method of claim 14 , wherein the first energy is applied during a plurality of on-off time periods of the first energy each comprising an on time period during which the first power is turned on and an off time period during which the first power is turned off, the first energy is pulsed at a first pulse frequency during at least one on time period, and the first pulse frequency is less than the first frequency of the first energy, and
the second energy is applied during a plurality of on-off time periods of the second energy each comprising an on time period during which the second power is turned on and an off time period during which the second power is turned off, the second energy is pulsed at a second pulse frequency during at least one on time period, and the second pulse frequency is less than the second frequency of the second energy.
16. The method of claim 15 , wherein the first pulse frequency is greater than a first on-off time frequency which has an inverse relationship with the on-off time period of the first energy, and the second pulse frequency is greater than a second on-off time frequency which has an inverse relationship with the on-off time period of the second energy.
17. The method of claim 14 , wherein a showerhead unit configured to supply the first plasma and the second plasma into the process chamber is disposed in the process chamber,
the showerhead unit includes a first channel fluidly connected to the first plasma chamber and configured to supply the first plasma into the process chamber and a second channel fluidly connected to the second plasma chamber and configured to supply the second plasma into the process chamber, and
the supplying of the first plasma and the supplying of the second plasma into the process chamber comprises discretely supplying the first plasma and the second plasma through the first and second channels into the process chamber without mixing the first plasma and the second plasma.
18. The method of claim 17 , wherein the at least one first process gas supplied into the first plasma chamber is a fluorine-based gas,
the at least one second process gas supplied into the second plasma chamber is an oxide-based gas, and
the supplying of the first plasma and the second plasma into the process chamber comprises supplying a fluorine radical into the process chamber through the first channel and supplying a nitric oxide (NO) radical into the process chamber through the second channel.
19. The method of claim 18 , wherein the etching target comprises a substrate or substrate structure including a material layer formed on the substrate or the substrate structure, and the etching target is isotropically etched by controlling an inner temperature and pressure of the process chamber and amounts of the fluorine radical and the NO radical.