Restricted capacitor switching
First Claim
1. An impedance matching network, the network comprising:
- a radio frequency (RF) input configured to operably couple to an RF source;
an RF output configured to operably couple to a plasma chamber;
a first electronically variable capacitor (EVC) comprising discrete capacitors configured to be switched in and out to alter a first capacitance of the first EVC;
a second EVC comprising discrete capacitors configured to be switched in and out to alter a second capacitance of the second EVC; and
a control circuit operably coupled to the first and second EVCs, the control circuit configured to;
determine or receive a reflection parameter value at the RF input or the RF output;
stop the altering of the first capacitance and the second capacitance when the reflection parameter value is at or below a first reflection value;
cause a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is (a) at or above a second reflection value and (b) at or below the third reflection value, the limited altering allowing only a predetermined number of predetermined discrete capacitors to switch in or out; and
cause an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value, the unlimited altering allowing any discrete capacitor of the first or second EVC to switch in or out.
3 Assignments
0 Petitions
Accused Products
Abstract
In one embodiment, the present disclosure is directed to a method for matching an impedance. The method can include determining or receiving a reflection parameter value at an RF input or output; stopping the altering of a first capacitance and a second capacitance when the reflection parameter value is at or below a first reflection value; causing a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a second reflection value and at or below the third reflection value; and causing an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value.
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Citations
20 Claims
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1. An impedance matching network, the network comprising:
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a radio frequency (RF) input configured to operably couple to an RF source; an RF output configured to operably couple to a plasma chamber; a first electronically variable capacitor (EVC) comprising discrete capacitors configured to be switched in and out to alter a first capacitance of the first EVC; a second EVC comprising discrete capacitors configured to be switched in and out to alter a second capacitance of the second EVC; and a control circuit operably coupled to the first and second EVCs, the control circuit configured to; determine or receive a reflection parameter value at the RF input or the RF output; stop the altering of the first capacitance and the second capacitance when the reflection parameter value is at or below a first reflection value; cause a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is (a) at or above a second reflection value and (b) at or below the third reflection value, the limited altering allowing only a predetermined number of predetermined discrete capacitors to switch in or out; and cause an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value, the unlimited altering allowing any discrete capacitor of the first or second EVC to switch in or out. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A semiconductor processing tool comprising:
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a plasma chamber configured to deposit a material onto a substrate or etch a material from the substrate; and an impedance matching network operably coupled to the plasma chamber, the matching network comprising; a radio frequency (RF) input configured to operably couple to an RF source; an RF output configured to operably couple to the plasma chamber; a first electronically variable capacitor (EVC) comprising discrete capacitors configured to be switched in and out to alter a first capacitance of the first EVC; a second EVC comprising discrete capacitors configured to be switched in and out to alter a second capacitance of the second EVC; and a control circuit operably coupled to the first and second EVCs, the control circuit configured to; determine or receive a reflection parameter value at the RF input or the RF output; stop the altering of the first capacitance and the second capacitance when the reflection parameter value is at or below a first reflection value; cause a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is (a) at or above a second reflection value and (b) at or below the third reflection value, the limited altering allowing only a predetermined number of predetermined discrete capacitors to switch in or out; and cause an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value, the unlimited altering allowing any discrete capacitor of the first or second EVC to switch in or out. - View Dependent Claims (11, 12, 13, 14)
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15. A method of matching an impedance comprising:
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operably coupling a radio frequency (RF) input of a matching network to an RF source; operably coupling an RF output of the matching network to a plasma chamber, the plasma chamber comprising (a) a first electronically variable capacitor (EVC) comprising discrete capacitors configured to be switched in and out to alter a first capacitance of the first EVC, and (b) a second EVC comprising discrete capacitors configured to be switched in and out to alter a second capacitance of the second EVC; and determining or receiving a reflection parameter value at the RF input or the RF output; stopping the altering of the first capacitance and the second capacitance when the reflection parameter value is at or below a first reflection value; causing a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is (a) at or above a second reflection value and (b) at or below the third reflection value, the limited altering allowing only a predetermined number of predetermined discrete capacitors to switch in or out; and causing an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value, the unlimited altering allowing any discrete capacitor of the first or second EVC to switch in or out. - View Dependent Claims (16, 17, 18, 19)
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20. A method of manufacturing a semiconductor, the method comprising:
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placing a substrate in a plasma chamber configured to deposit a material layer onto the substrate or etch a material layer from the substrate; and coupling an impedance matching circuit between a radio frequency (RF) source and the plasma chamber, the impedance matching circuit comprising; a radio frequency (RF) input configured to operably couple to an RF source; an RF output configured to operably couple to a plasma chamber; a first electronically variable capacitor (EVC) comprising discrete capacitors configured to be switched in and out to alter a first capacitance of the first EVC; a second EVC comprising discrete capacitors configured to be switched in and out to alter a second capacitance of the second EVC; and a control circuit operably coupled to the first and second EVCs, the control circuit configured to; determine or receive a reflection parameter value at the RF input or the RF output; stop the altering of the first capacitance and the second capacitance when the reflection parameter value is at or below a first reflection value; cause a limited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is (a) at or above a second reflection value and (b) at or below the third reflection value, the limited altering allowing only a predetermined number of predetermined discrete capacitors to switch in or out; and cause an unlimited altering of the first capacitance and the second capacitance to pursue an impedance match when the reflection parameter value is at or above a third reflection value, the unlimited altering allowing any discrete capacitor of the first or second EVC to switch in or out.
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Specification