US2012248066A1PendingUtilityA1
Plasma processing apparatus and plasma processing method
Est. expiryMar 29, 2031(~4.7 yrs left)· nominal 20-yr term from priority
Inventors:Yohei Yamazawa
H01J 37/321H01J 37/32174H01J 37/3211H01J 37/3244H01J 37/32119H01J 37/32697H01J 37/32137H01J 2237/327H01J 2237/3341H01J 37/02
55
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Claims
Abstract
An inductively coupled plasma process can effectively and properly control plasma density distribution within donut-shaped plasma in a processing chamber is provided. In an inductively coupled plasma processing apparatus, a RF antenna 54 disposed above a dielectric window 52 is segmented in a diametrical direction into an inner coil 58 , an intermediate coil 60 , and an outer coil 62 in order to generate inductively coupled plasma. Between a first node N A and a second node N B provided in high frequency transmission lines of the high frequency power supply unit 66 , a variable intermediate capacitor 86 and a variable outer capacitor 88 are electrically connected in series to the intermediate coil 60 and the outer coil 62 , respectively, and no reactance device is connected to the inner coil 58.
Claims
exact text as granted — not AI-modified1 . A plasma processing apparatus, comprising:
a processing chamber having a dielectric window; a substrate holding unit for holding thereon a processing target substrate within the processing chamber; a processing gas supply unit configured to supply a processing gas into the processing chamber in order to perform a plasma process on the processing target substrate; an RF antenna provided outside the dielectric window in order to generate plasma of the processing gas within the processing chamber by inductive coupling; and a high frequency power supply unit configured to supply a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas in the RF antenna, wherein the RF antenna includes an inner coil, an intermediate coil, and an outer coil with gaps therebetween in a radial direction, respectively, and the inner coil, the intermediate coil and the outer coil are electrically connected to one another in parallel between a first node and a second node provided in high frequency transmission lines of the high frequency power supply unit, a variable intermediate capacitor and a variable outer capacitor are provided between the first node and the second node, and the variable intermediate capacitor is electrically connected in series to the intermediate coil, and the variable outer capacitor is electrically connected in series to the outer coil, and no reactance device is connected to the inner coil between the first node and the second node.
2 . The plasma processing apparatus of claim 1 ,
wherein if the number of windings of the inner coil and the number of windings of the outer coil are N i and N o , respectively, an impedance of the inner coil is Z i , and a maximum value and a minimum value of a combined impedance of the outer coil and the outer capacitor obtained by varying an electrostatic capacitance of the outer capacitor are Z o ( max ) and Z o ( min ), respectively, the following inequation is established:
| N o /Z o(max) |<|N i /Z i |<|N o /Z o(min) |
3 . The plasma processing apparatus of claim 2 ,
wherein each of the inner coil and the outer coil has a circular ring shape, and if radiuses of the inner coil and the outer coil are represented as “r i ” and “r o ”, respectively, a radius of a wire thickness of each of the coils is represented as “a”, a vacuum permeability is represented as “μ o ”, and when the combined impedance of the outer coil and the outer capacitor becomes the maximum value Z o ( max ) and the minimum value Z o ( min ), an electrostatic capacitance of the outer capacitor is represented as “C o ( max )” and “C o ( min )”, respectively, the following inequation is established:
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4 . The plasma processing apparatus of claim 1 ,
wherein directions of currents flowing in the inner coil, the intermediate coil, and the outer coil are identical to one another in a circumferential direction.
5 . The plasma processing apparatus of claim 1 ,
wherein a direction of the current flowing in the intermediate coil is opposite to a direction of the current flowing in the inner coil in the circumferential direction.
6 . The plasma processing apparatus of claim 5 ,
wherein the intermediate capacitor has a value of electrostatic capacitance smaller than a value when the intermediate capacitor and the intermediate coil generate a series resonance.
7 . The plasma processing apparatus of claim 1 ,
wherein a direction of the current flowing in the outer coil is identical to a direction of the current flowing in the inner coil in the circumferential direction.
8 . The plasma processing apparatus of claim 7 ,
wherein the outer capacitor has a value of electrostatic capacitance larger than a value when the outer capacitor and the outer coil generate a series resonance.
9 . The plasma processing apparatus of claim 1 ,
wherein a direction of the current flowing in the outer coil is opposite to a direction of a current flowing in the inner coil in the circumferential direction.
10 . The plasma processing apparatus of claim 9 ,
wherein the outer capacitor has a value of electrostatic capacitance smaller than a value when the outer capacitor and the outer coil generate a series resonance.
11 . A plasma processing apparatus, comprising:
a processing chamber having a dielectric window; a substrate holding unit for holding thereon a processing target substrate within the processing chamber; a processing gas supply unit configured to supply a processing gas into the processing chamber in order to perform a plasma process on the processing target substrate; an RF antenna provided outside the dielectric window in order to generate plasma of the processing gas within the processing chamber by inductive coupling; and a high frequency power supply unit configured to supply a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas in the RF antenna, wherein the RF antenna includes an inner coil, an intermediate coil, and an outer coil with gaps therebetween in a radial direction, respectively, and the inner coil, the intermediate coil and the outer coil are electrically connected to one another in parallel between a first node and a second node provided in high frequency transmission lines of the high frequency power supply unit, and a fixed or semi-fixed inner capacitor, a variable intermediate capacitor, and a variable outer capacitor are provided between the first node and the second node, and the fixed or semi-fixed inner capacitor is electrically connected to the inner coil, the variable intermediate capacitor is electrically connected in series to the intermediate coil, and the variable outer capacitor is electrically connected in series to the outer coil.
12 . The plasma processing apparatus of claim 11 ,
wherein if the number of windings of the inner coil and the number of windings of the outer coil are N i and N o , respectively, an impedance of the inner coil is Z i , and a maximum value and a minimum value of a combined impedance of the outer coil and the outer capacitor obtained by varying an electrostatic capacitance of the outer capacitor are Z o ( max ) and Z o ( min ), respectively, the following inequation is established:
| N o /Z o(max) |<|N i /Z i |<|N o /Z o(min) |
13 . The plasma processing apparatus of claim 12 ,
wherein each of the inner coil and the outer coil has a circular ring shape, and if radiuses of the inner coil and the outer coil are represented as “r i ” and “r o ”, respectively, a radius of a wire thickness of each of the coils is represented as “a”, a vacuum permeability is represented as “μ o ”, and when the combined impedance of the outer coil and the outer capacitor becomes the maximum value Z o ( max ) and the minimum value Z o ( min ), an electrostatic capacitance of the outer capacitor is represented as “C o ( max )” and “C o ( min )”, respectively, the following inequation is established:
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2
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0
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8
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a
-
2
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2
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max
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14 . A plasma processing apparatus, comprising:
a processing chamber having a dielectric window; a substrate holding unit for holding thereon a processing target substrate within the processing chamber; a processing gas supply unit configured to supply a processing gas into the processing chamber in order to perform a plasma process on the processing target substrate; an RF antenna provided outside the dielectric window in order to generate plasma of the processing gas within the processing chamber by inductive coupling; and a high frequency power supply unit configured to supply a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas in the RF antenna, wherein the RF antenna include an inner coil, an intermediate coil, and an outer coil with gaps therebetween in a radial direction, respectively, and the inner coil, the intermediate coil and the outer coil are electrically connected to one another in parallel between a first node and a second node provided in high frequency transmission lines of the high frequency power supply unit, and a fixed or semi-fixed inner inductor, a variable intermediate capacitor, and a variable outer capacitor are provided between the first node and the second node, and the fixed or semi-fixed inner inductor is electrically connected to the inner coil, the variable intermediate capacitor is electrically connected in series to the intermediate coil, and the variable outer capacitor is electrically connected in series to the outer coil.
15 . A plasma processing apparatus comprising:
a processing chamber having a dielectric window; a substrate holding unit for holding thereon a processing target substrate within the processing chamber; a processing gas supply unit configured to supply a processing gas into the processing chamber in order to perform a plasma process on the processing target substrate; an RF antenna provided outside the dielectric window in order to generate plasma of the processing gas within the processing chamber by inductive coupling; and a high frequency power supply unit configured to supply a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas in the RF antenna, wherein the RF antenna includes an inner coil, an intermediate coil and an outer coil with gaps therebetween in a radial direction, respectively, and the inner coil, the intermediate coil and the outer coil are electrically connected to one another in parallel between a first node and a second node provided in high frequency transmission lines of the high frequency power supply unit, and a variable inner capacitor, a variable intermediate capacitor, and a fixed or semi-fixed outer capacitor are provided between the first node and the second node, and the variable inner capacitor is electrically connected to the inner coil, the variable intermediate capacitor is electrically connected in series to the intermediate coil, and the fixed or semi-fixed outer capacitor is electrically connected in series to the outer coil.
16 . The plasma processing apparatus of claim 15 ,
wherein if the number of windings of the inner coil and the number of windings of the outer coil are N i and N o , respectively, an impedance of the outer coil is Z o , and a maximum value and a minimum value of a combined impedance of the inner coil and the inner capacitor obtained by varying an electrostatic capacitance of the inner capacitor are Z i ( max ) and Z i ( min ) respectively, the following inequation is established:
| N i /Z i(max) <|N 0 /Z o |<|N i /Z i(min) |
17 . The plasma processing apparatus of claim 16 ,
wherein each of the inner coil and the outer coil has a circular ring shape, and if radiuses of the inner coil and the outer coil are represented as “r i ” and “r o ”, respectively, a radius of a wire thickness of each of the coils is represented as “a”, a vacuum permeability is represented as “μ o ”, and when the combined impedance of the inner coil and the inner capacitor becomes the maximum value Z i ( max ) and the minimum value Z i ( min ), an electrostatic capacitance of the inner capacitor is represented as C i ( max ) and C i ( min ), respectively, the following inequation is established:
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8
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18 . The plasma processing apparatus of claim 1 , further comprising:
an output common capacitor connected between the second node and a ground potential at an output side.
19 . A plasma processing method for performing a plasma process on a processing target substrate by using a plasma processing apparatus having a processing chamber having a dielectric window; a substrate holding unit for holding thereon a processing target substrate within the processing chamber; a processing gas supply unit configured to supply a processing gas into the processing chamber in order to perform a plasma process on the processing target substrate; an RF antenna provided outside the dielectric window in order to generate plasma of the processing gas within the processing chamber by inductive coupling; and a high frequency power supply unit configured to supply a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas in the RF antenna, the plasma processing method comprising:
segmenting the RF antenna into an inner coil, an intermediate coil, and an outer coil with gaps therebetween in a radial direction, respectively, the inner coil, the intermediate coil and the outer coil being electrically connected to one another in parallel between a first node and a second node provided in high frequency transmission lines of the high frequency power supply unit; providing a variable intermediate capacitor and a variable outer capacitor between the first node and the second node, the variable intermediate capacitor being electrically connected in series to the intermediate coil, the variable outer capacitor being electrically connected in series to the outer coil, no reactance device being connected to the inner coil; and controlling plasma density distribution on the processing target substrate by selecting or variably adjusting electrostatic capacitances of the intermediate capacitor and the outer capacitor.
20 . The plasma processing method of claim 19 ,
wherein the current flowing in the inner coil is reduced by making at least one of electrostatic capacitances of the intermediate capacitor and the outer capacitor close to a value when a series resonance is generated.
21 . The plasma processing method of claim 19 ,
wherein the current flowing in the inner coil is increased by making at least one of electrostatic capacitances of the intermediate capacitor and the outer capacitor apart from a value when a series resonance is generated.
22 . The plasma processing method of claim 19 ,
wherein electrostatic capacitances of the intermediate capacitor and the outer capacitor are adjusted to enable plasma density on the processing target substrate to be uniformized in a diametrical direction.
23 . The plasma processing method of claim 19 ,
wherein the plasma density on the processing target substrate is adjusted so as to be uniformized in the diametrical direction by conforming multiplication of the number of turns of each of the intermediate coil and the outer coil and an amount of a coil current thereof to multiplication of the number of turns of the inner coil and an amount of a coil current thereof.
24 . The plasma processing method of claim 19 ,
wherein a direction of the current flowing in the intermediate coil is opposite to a direction of the current flowing in the inner coil in the circumferential direction by variably adjusting the electrostatic capacitance of the intermediate capacitor in a range smaller than a value when the intermediate capacitor and the intermediate coil generate a series resonance.
25 . The plasma processing method of claim 19 ,
wherein a direction of the current flowing in the intermediate coil is identical to a direction of the current flowing in the inner coil in the circumferential direction by variably adjusting the electrostatic capacitance of the intermediate capacitor in a range larger than a value when the intermediate capacitor and the intermediate coil generate a series resonance.
26 . The plasma processing method of claim 19 ,
wherein a direction of the current flowing in the outer coil is opposite to a direction of the current flowing in the inner coil in the circumferential direction by variably adjusting the electrostatic capacitance of the outer capacitor in a range smaller than a value when the outer capacitor and the outer coil generate a series resonance.
27 . The plasma processing method of claim 19 ,
wherein a direction of the current flowing in the outer coil is identical to a direction of the current flowing in the inner coil in the circumferential direction by variably adjusting the electrostatic capacitance of the outer capacitor in a range larger than a value when the outer capacitor and the outer coil generate a series resonance.Cited by (0)
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