Impedance matching network and method
First Claim
1. An impedance matching network comprising:
- an RF input configured to operably couple to a radio frequency (RF) source, the RF source configured to provide at least two repeating, non-zero pulse levels, the at least two pulse levels comprising a first pulse level and a second pulse level;
an RF output configured to operably couple to a plasma chamber having a variable impedance;
at least one electronically variable capacitor (EVC) configured to switch between a plurality of match configurations for reducing a reflected power at an output of the RF source as the variable impedance of the plasma chamber changes; and
a control circuit configured to carry out the operations of;
determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and
sending a control signal to alter the at least one EVC to provide the new match configuration, wherein the control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations.
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Accused Products
Abstract
In one embodiment, the present disclosure is directed to a method for impedance matching including a) positioning a matching network between a radio frequency (RF) source and a plasma chamber; b) determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and c) sending a control signal to alter the at least one EVC to provide the new match configuration. The control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations.
187 Citations
20 Claims
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1. An impedance matching network comprising:
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an RF input configured to operably couple to a radio frequency (RF) source, the RF source configured to provide at least two repeating, non-zero pulse levels, the at least two pulse levels comprising a first pulse level and a second pulse level; an RF output configured to operably couple to a plasma chamber having a variable impedance; at least one electronically variable capacitor (EVC) configured to switch between a plurality of match configurations for reducing a reflected power at an output of the RF source as the variable impedance of the plasma chamber changes; and a control circuit configured to carry out the operations of; determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and sending a control signal to alter the at least one EVC to provide the new match configuration, wherein the control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A semiconductor processing tool comprising:
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a plasma chamber having a variable impedance and configured to deposit a material onto a substrate or etch a material from a substrate; and an impedance matching network operably coupled to the plasma chamber, the matching network comprising; an RF input configured to operably couple to a radio frequency (RF) source, the RF source configured to provide at least two repeating, non-zero pulse levels, the at least two pulse levels comprising a first pulse level and a second pulse level; an RF output configured to operably couple to the plasma chamber; at least one electronically variable capacitor (EVC) configured to switch between a plurality of match configurations for reducing a reflected power at an output of the RF source as the variable impedance of the plasma chamber changes; and a control circuit configured to carry out the operations of; determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and sending a control signal to alter the at least one EVC to provide the new match configuration, wherein the control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations.
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9. A method for impedance matching comprising:
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a) positioning a matching network between a radio frequency (RF) source and a plasma chamber, wherein; the RF source is configured to provide at least two repeating, non-zero pulse levels, the at least two pulse levels comprising a first pulse level and a second pulse level; the plasma chamber has a variable impedance; and the matching network comprises at least one electronically variable capacitor (EVC) configured to switch between a plurality of match configurations for reducing a reflected power at an output of the RF source as the variable impedance of the plasma chamber changes; b) determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and c) sending a control signal to alter the at least one EVC to provide the new match configuration, wherein the control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations. - View Dependent Claims (10, 11, 12, 13, 14, 15, 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; coupling an impedance matching network between an RF source and the plasma chamber, wherein; the RF source is configured to provide at least two repeating, non-zero pulse levels, the at least two pulse levels comprising a first pulse level and a second pulse level; the plasma chamber has a variable impedance; and the matching network comprises at least one electronically variable capacitor (EVC) configured to switch between a plurality of match configurations for reducing a reflected power at an output of the RF source as the variable impedance of the plasma chamber changes; and performing impedance matching by; determining, from among the plurality of match configurations, a new match configuration to be used when there is an expected pulse level change from a first of the pulse levels to a second of the pulse levels; and sending a control signal to alter the at least one EVC to provide the new match configuration, wherein the control signal is sent a predetermined time period before a time for the expected pulse level change, the predetermined time period being substantially similar to a time period for the EVC to switch between two match configurations of the plurality of match configurations.
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Specification