System and method for achieving uniformity in substrate processing using a transformer

Abstract

Systems and methods for achieving uniformity in substrate processing using transformers are described. One of the systems includes a primary winding having a first end and a second end. The first end is coupled to an output of an impedance matching circuit, and the second end is coupled to a capacitor. The system also includes a secondary winding associated with the primary winding, and the secondary winding is coupled to a first end and a second end of a transformer coupled plasma (TCP) coil of a plasma chamber. The primary winding receives a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux, thereby inducing a voltage in the secondary winding. The RF signal generated by the voltage is transmitted from the secondary winding to the TCP coil.

Description

Technical Field

[0001] Embodiments described in the present disclosure relate to systems and methods for using transformers to achieve uniformity in substrate processing. Background Art

[0002] The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently designated inventors is neither explicitly nor implicitly admitted to be prior art against the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed.

[0003] In a plasma tool, one or more radio frequency (RF) generators are coupled to an impedance matching network. The impedance matching network is coupled to a plasma chamber. An RF signal is supplied from the RF generator to the impedance matching network. The impedance matching network outputs an RF signal after receiving the RF signal. The RF signal is supplied from the impedance matching circuit to a plasma chamber for processing a wafer in the plasma chamber.

[0004] Due to the various structures used in the plasma tool, the efficiency of processing wafers and additional wafers is further reduced. For example, multiple wafers are not processed in a consistent manner. In addition, the uniformity of the processing rate across each wafer is reduced.

[0005] It is against this background that the embodiments described in this disclosure are presented. Summary of the invention

[0006] Embodiments of the present disclosure provide devices, systems, methods and computer programs for using transformers to achieve uniformity in processing substrates. It should be understood that embodiments herein can be implemented in a variety of ways, such as processes, devices, systems, parts of hardware, or methods on computer-readable media. Several embodiments are described below.

[0007] The processing rate for processing a substrate, such as an etching rate or a deposition rate, is increased in various ways. For example, increasing the RF power supplied by a radio frequency (RF) generator increases the processing rate. As another example, for the same power level, the ratio of voltage to current is an important factor in determining the processing rate. The ratio of voltage to current can be modified by inserting a series capacitor or by using an interlaced dual coil antenna system. In this article, the series capacitor is sometimes referred to as a coil terminal capacitor. The end of the series capacitor is coupled in series with a single antenna coil, and the other end of the series capacitor is grounded.

[0008] However, the series capacitors may create a resonance or resonance-like condition, thereby generating a high voltage across the single antenna coil. This high voltage may reduce uniformity in substrate processing. In addition, when the ends of the series capacitors are grounded, there is a large drop in the voltage across the coil antenna. This large drop may tilt the voltage across the coil antenna and reduce uniformity.

[0009] In the case of the interleaved dual coil antenna system, a plurality of series capacitors are inserted. Each series capacitor is connected in series with a corresponding antenna coil of the interleaved dual coil antenna system. Also, due to the series capacitors, the same problems as described above exist in the case of the interleaved dual coil antenna system.

[0010] In one embodiment, a transformer coupled inductively coupled plasma (ICP) system is used to increase the processing rate, and to significantly improve uniformity. The transformer is used to change the ratio of voltage to current for a given amount of power. The ratio of voltage to current changes as the ratio of the primary winding to the secondary winding changes. The ratio of the primary winding to the secondary winding is the ratio of the number of turns in the primary winding of the transformer to the number of turns in the secondary winding of the transformer. As the ratio of the primary winding to the secondary winding changes, the ratio of voltage to current changes and uniformity is improved. The transformer can be used for both single antenna coils and interleaved dual antenna coils.

[0011] In one embodiment, a transformer that operates efficiently at high frequencies is described.

[0012] In one embodiment, a system for achieving uniformity in substrate processing using a transformer is described. The system includes a primary winding having a first end and a second end. The first end is coupled to an output of an impedance matching circuit, and the second end is coupled to a capacitor. The system also includes a secondary winding associated with the primary winding, and the secondary winding is coupled to a first end and a second end of a transformer coupled plasma (TCP) coil of a plasma chamber. The primary winding receives a modified RF signal from the impedance matching circuit to generate a magnetic flux, thereby inducing a voltage in the secondary winding. The RF signal generated by the voltage is transmitted from the secondary winding to the TCP coil.

[0013] In one embodiment, a transformer device is described. The transformer device includes a primary winding having a first end and a second end. The first end is coupled to an output of an impedance matching circuit, and the second end is coupled to a capacitor. The transformer device also includes a first secondary winding associated with the primary winding, and the first secondary winding is coupled to a first end and a second end of a first TCP coil of a plasma chamber. The primary winding receives a modified RF signal from the impedance matching circuit to generate a magnetic flux, thereby inducing a voltage in the first secondary winding. The RF signal generated by the voltage induced in the first secondary winding is transmitted to the first TCP coil via the first secondary winding. The transformer device includes a second secondary winding associated with the primary winding, and the second secondary winding is coupled to a first end and a second end of a second TCP coil of a plasma chamber. The magnetic field is configured to induce a voltage in the second secondary winding. The RF signal generated by the voltage induced in the second secondary winding is transmitted from the second secondary winding to the second TCP coil.

[0014] In one embodiment, a method is described. The method includes receiving a modified RF signal from an output of an impedance matching circuit through a primary winding of a transformer. The primary winding is coupled to a capacitor. After receiving the modified RF signal, the method includes generating a magnetic flux through the primary winding to induce a voltage across a secondary winding of the transformer. The method includes transmitting an RF signal generated by the voltage from the secondary winding to a TCP coil of a plasma chamber.

[0015] Some advantages of the systems and methods described herein include the removal of coil terminal capacitors. As described above, coil terminal capacitors can reduce the uniformity of the processing rate across the surface of the substrate. By removing the coil terminal capacitors, the uniformity of the processing rate is improved.

[0016] Additional advantages of the systems and methods described herein include reducing voltage deviations between the endpoints of the antenna coil. The voltage deviations may cause bias in the processing rate across the substrate surface. The voltage deviations are reduced by connecting a transformer at each of its endpoints to a variable capacitor to control the voltage across the transformer. In addition, the voltage deviations are reduced by changing the ratio of the primary winding to the secondary winding. The secondary winding is coupled in series to the antenna coil. Changing the ratio of the primary winding to the secondary winding changes the voltage across the antenna coil to reduce the voltage deviation between the endpoints of the antenna coil. Reducing the voltage deviations improves substrate processing uniformity across the radius of the substrate.

[0017] When the secondary winding is coupled in series with the antenna coil and no other components are coupled to the secondary winding or the antenna coil, the voltage across the antenna coil is the same as the voltage across the secondary winding. By changing the ratio of the primary winding to the secondary winding, or by coupling a variable capacitor to the primary winding, the voltage at the ends of the antenna coil can be controlled. The voltages at the ends of the antenna coil can be controlled to be substantially the same or the same. For example, the voltages at the ends of the antenna coil can be controlled to be within a predetermined range of the same voltage. Such substantially the same or the same voltages improve uniformity in substrate processing.

[0018] Further advantages of the systems and methods described herein include eliminating or mitigating issues with plasma beat frequency when the same RF frequency is applied to both the antenna coil and the pedestal. The beat frequency can undesirably adjust the plasma within the plasma chamber. The transformer acts as an isolation transformer to eliminate or mitigate issues with plasma beat frequency.

[0019] Other aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The embodiments are understood by referring to the following description in conjunction with the accompanying drawings.

[0021] 1A is a schematic diagram of an embodiment of a system used to illustrate the use of a transformer-based system for an internal coil of a transformer coupled plasma (TCP) chamber.

[0022] 1B is a schematic diagram of an embodiment of a system used to illustrate the use of a transformer based system for the external coil of a TCP chamber.

[0023] 2 is a schematic diagram of an embodiment of a system used to illustrate the use of a transformer based system for both the inner and outer coils of a TCP chamber.

[0024] 3 is a schematic diagram of an embodiment of a system illustrating transformers used to interleave inner TCP coils and interleave outer TCP coils.

[0025] 4A is a schematic diagram of an embodiment of a transformer having a primary winding and multiple secondary windings.

[0026] 4B is a schematic diagram of an embodiment of a transformer.

[0027] Figure 4C is a schematic diagram of an embodiment of a transformer illustrating multiple taps on the secondary winding.

[0028] Figure 4Dis a schematic diagram of an embodiment of a transformer, which is used to illustrate that the primary winding and the secondary winding of the transformer are twisted around each other.

[0029] Figure 4E is a schematic diagram of an implementation scheme of a transformer.

[0030] 5 is a schematic diagram of an embodiment of a transformer for illustrating the use of coaxial cable to fabricate the transformer.

[0031] 6A is a schematic diagram of an embodiment of a system illustrating the use of variable capacitors rather than the fixed capacitors of the system of FIG. 1A .

[0032] 6B is a schematic diagram of an embodiment of a system illustrating the use of variable capacitors rather than the fixed capacitors of the system of FIG. 1B .

[0033] 7 is a schematic diagram of an embodiment of a system for illustrating the use of the variable capacitor depicted in FIGS. 6A and 6B and the system of FIG. 2 .

[0034] 8 is a schematic diagram of an embodiment of a system for illustrating the use of the variable capacitor depicted in FIGS. 6A and 6B and the system of FIG. 3 .

[0035] 9 is a schematic diagram of an embodiment of a system for illustrating a plasma tool in which a transformer based system is used.

[0036] Fig.10 is a schematic diagram of an embodiment of a transformer, which is used to illustrate the principle of the transformer. DETAILED DESCRIPTION

[0037] The following embodiments describe systems and methods for achieving uniformity in processing substrates using transformers. It will be apparent that the embodiments herein may be implemented without some or all of these specific details. In other cases, well-known processing operations are not described in detail to avoid unnecessarily obscuring the embodiments herein.

[0038] FIG. 1A is a schematic diagram of an embodiment of a system 100 for illustrating the use of a transformer-based system (TBS) 102 for an internal coil of a transformer-coupled plasma (TCP) chamber 118. The TBS is sometimes referred to herein as a transformer device. The system 100 includes a host computer, a radio frequency generator (RFG), an impedance matching circuit (IMC) 110, a driver 1, a motor 1, a driver 2, a motor 2, a connection mechanism 160, and a connection mechanism 162. The system 100 also includes the TBS 102 and the plasma chamber 118. The system 100 also includes a variable capacitor 108 and another variable capacitor 128.

[0039] Examples of host computers include desktop computers, laptop computers, controllers, tablet computers, and smart phones. For example, the host computer includes a processor and a memory device, and the processor is coupled to the memory device. Examples of the processor include a microprocessor, an application specific integrated circuit (ASIC), a programmable logic device (PLD), a microcontroller, and a central processing unit (CPU). Examples of the memory device include a read-only memory (ROM), a random access memory (RAM), a flash memory, a storage disk array, a hard disk, etc.

[0040] The RF generator has an operating frequency. For example, the RF generator is a 400 kilohertz (kHz), or 2 megahertz (MHz), or 27 MHz, or 60 MHz RF generator. For example, the RF generator includes an RF power source such as an RF oscillator, which oscillates to generate an RF signal having a frequency such as 2 MHz or 27 MHz. The RF oscillator operates at an operating frequency such as 2 MHz or 27 MHz to generate the RF signal.

[0041] Examples of impedance matching circuit 110 include a network of one or more series circuits and one or more shunt circuits, wherein the series circuits and shunt circuits are coupled to each other to facilitate conversion of the RF signal received from the RF generator to output a modified RF signal. Examples of series circuits include capacitors, inductors, and resistors. Similarly, examples of shunt circuits include capacitors, inductors, and resistors.

[0042] Examples of motors as used herein include electric motors. Examples of electric motors include alternating current (AC) motors and direct current (DC) motors. By way of example, the electric motor includes a stator and a rotor, and the rotor rotates relative to the stator. An electric motor is an electrical machine that converts electrical energy into mechanical energy and operates to generate force in the form of rotation of a shaft attached to the rotor through interaction between the magnetic field of the electric motor and current in the wire windings of the stator.

[0043] An example of a driver as used herein includes one or more transistors coupled to each other to output a current signal when a voltage is applied to input terminals of the one or more transistors.

[0044] An example of a connection mechanism as used herein includes one or more shafts. Another example of a connection mechanism includes multiple shafts coupled to each other via one or more gears.

[0045] The TBS 102 includes a transformer 104 having a primary winding 104A and a secondary winding 104B. Examples of transformers as used herein include ferrite core transformers for low frequency applications. For example, when the RF generator has an operating frequency less than 1 MHz, the transformer is a ferrite core transformer. As another example, the transformer is a twisted-wire transformer as described below. The twisted-wire transformer is used for high frequency applications. For example, when the RF generator has an operating frequency greater than 1 MHz, the twisted-wire transformer is used. The TBS 102 also includes a capacitor 112, which is a fixed capacitor.

[0046] In addition, the plasma chamber 118 includes a TCP coil system (TCS) 150, a coil terminal capacitor 157, and another coil terminal capacitor 159. The TCP coil system 150 includes a TCP coil 116 and a plurality of TCP coils 152 and 154.

[0047] TCP coil 116 is an inner TCP coil, and TCP coils 152 and 154 are outer TCP coils. For example, the inner TCP coil has a diameter that is smaller than the diameter of any of the outer TCP coils. As another example, the outer TCP coil surrounds the inner TCP coil. The outer TCP coil may surround the inner TCP coil at the same horizontal plane as the inner TCP coil, or at a different horizontal plane than the inner TCP coil.

[0048] The RF transmission line 158 includes one or more RF rods, and each RF rod is surrounded by an RF channel. As an example, the RF transmission line 158 includes a plurality of RF rods, and any two of the RF rods are coupled to each other via RF strips. An insulating material is provided between each RF rod and a corresponding RF channel surrounding the RF rod to insulate the RF rod from the RF channel.

[0049] The host computer is coupled to the input terminal I1, the driver 1 and the driver 2 of the RF generator. For example, the host computer is coupled to the digital signal processor (DSP) of the RF generator via the input terminal I1 and a data transmission cable. The RF generator includes the DSP and an RF oscillator, and the DSP is coupled to the RF oscillator. Examples of the transmission cable include a serial transmission cable that transmits data in series between the DSP and the RF generator, a parallel transmission cable that transmits data in parallel, and a universal serial bus (USB) cable.

[0050] The output O1 of the RF generator is coupled to the input I2 of the IMC 110. For example, the output O1 of the RF oscillator is coupled to the input I2 of the IMC 110 via the RF cable 156. The output O2 of the IMC 110 is coupled to the variable capacitor 108 via a portion PRTN1 of the RF transmission line 158, and is coupled to the variable capacitor 128 via another portion PRTN2 of the RF transmission line 158. For example, the variable capacitor 108 is coupled to a point P1 on the RF rod of the RF transmission line 158, and the variable capacitor 128 is coupled to a point P2 on the RF rod of the RF transmission line 158.

[0051] Variable capacitor 108 is coupled to motor 1 via connection mechanism 160, and motor 1 is coupled to drive 1. An end of variable capacitor 108 is coupled to portion PRTN1 of RF transmission line 158 at point P1, and an opposite end of variable capacitor 108 is coupled to end 106A of primary winding 104A. An opposite end 106B of primary winding 104A is coupled to an end of capacitor 112. An opposite end of capacitor 112 is coupled to a ground connection at ground potential (e.g., zero potential).

[0052] The end of the secondary winding 104B is coupled to the end 114A of the TCP coil 116, and the opposite end of the secondary winding 104B is coupled to the opposite end 114B of the TCP coil 116. The TCP coil 116 and the secondary winding 104B are coupled to each other in series. For example, the end of the secondary winding 104B coupled to the end 114A has the same potential as the end 114A. Similarly, the opposite end of the secondary winding 104B coupled to the end 114B has the same potential as the end 114B. As another example, the voltage across the end of the secondary winding 104B is the same as the voltage across the ends 114A and 114B of the TCP coil 116. It should be noted that there is no coil terminal capacitor coupled in series with the TCP coil 116. For example, the coil terminal capacitor is not coupled to the end 114B of the TCP coil 116.

[0053] Variable capacitor 128 is coupled to motor 2 via connection mechanism 162, where motor 2 is coupled to drive 2. An end of variable capacitor 128 is coupled to portion PRTN2 of RF transmission line 158 at point P2, and an opposite end of variable capacitor 128 is coupled to ends of TCP coils 152 and 154 via point P3. An opposite end of TCP coil 152 is coupled to an end of coil terminal capacitor 156, and an opposite end of TCP coil 154 is coupled to an end of coil terminal capacitor 159. Opposite ends of coil terminal capacitors 156 and 159 are coupled to ground connections.

[0054] To operate the plasma system 100, the host computer generates a control signal and transmits the control signal to the RF generator via the input terminal I1. After receiving the control signal, the DSP of the RF generator controls the RF oscillator to generate an RF signal 164. The RF signal 164 is supplied to the IMC 110 via the output terminal O1 of the RF generator, the RF cable 156, and the input terminal I2 of the IMC 110. The IMC 110 receives the RF signal 164 and changes the impedance of the RF signal 164 to output a modified RF signal 166 at the output terminal O2 of the IMC 110. For example, the series circuit and the shunt circuit of the IMC 110 change the impedance of the RF signal 164 to reduce the RF power reflected from the plasma chamber 118 via the RF transmission line 158 toward the RF generator.

[0055] The modified RF signal 166 is transmitted from the output terminal O2 of the IMC 110 via the portion PRTN1 of the RF transmission line 158 to the point P1, and is separated into a portion 168 and another portion 170 at the point P1. The portion 168 of the modified RF signal 166 is provided from the point P1 to the variable capacitor 108, and the portion 170 of the modified RF signal 168 is provided from the point P1 to the variable capacitor 128 via the portion PRTN2 of the RF transmission line 158 and the point P2. The portion 168 is referred to herein as the modified RF signal 168, and the portion 170 is referred to herein as the modified RF signal 170.

[0056] The capacitance of the variable capacitor 128 changes the impedance of the modified RF signal 170 to output a modified RF signal 172. The modified RF signal 172 is separated into modified RF signals 172A and 172B at point P3. The modified RF signal 172A is provided to the TCP coil 152 from point P3, and the modified RF signal 172B is provided to the TCP coil 154 from point P3.

[0057] The capacitance of the variable capacitor 108 changes the impedance of the modified RF signal 168 to output the modified RF signal 120. The modified RF signal 120 is transmitted from the variable capacitor 108 and the end 106A of the primary winding 104A to the primary winding 104A. The modified RF signal 120 generates a voltage across the ends 106A and 106B of the primary winding 104A, and the modified RF signal 120 passes from the end 106A through the primary winding 104A to the end 106B to generate a magnetic field having a magnetic flux. The magnetic flux is the amount of magnetic field passing through a unit surface area in a plane perpendicular to the magnetic field.

[0058] The magnetic field induces a voltage across the end of the secondary winding 104B. The voltage induced across the end of the secondary winding 104B generates an RF signal 122 (e.g., an RF current signal) that flows from the end 114A of the TCP coil 116 to the end 114B of the TCP coil. When one or more processing gases (described below) are applied to the plasma chamber 118 in addition to applying the RF signal 122 to the TCP coil 116 and applying the modified RF signals 172A and 172B to the respective TCP coils 152 and 154, a plasma is generated or maintained within the plasma chamber 118 for substrate processing within the plasma chamber 118, as described below.

[0059] The inductance of the primary winding 104A modifies the impedance of the modified RF signal 120 received at the end 106A to output a modified RF signal 174 at the end 106B of the primary winding 104A. The capacitor 112 receives the modified RF signal 174. After receiving the modified RF signal 174, the capacitance of the capacitor 112 produces a voltage across the ends of the capacitor 112, and this voltage determines the voltage across the ends 106A and 106B of the primary winding 104A of the transformer 104.

[0060] Likewise, during operation of the plasma system 100, the host computer transmits a capacitance control signal to the driver 1. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 108, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 104A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 104B. The capacitance of the variable capacitor 108, and the voltage amounts to be achieved across the primary winding 104A and the secondary winding 104B are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 108 based on the corresponding relationship between the capacitance of the variable capacitor 108 and the voltage amount to be achieved across the primary winding 104A and the secondary winding 104B.

[0061] After receiving the capacitance control signal, the driver 1 generates a current signal, which is transmitted to the motor 1. The motor 1 rotates to rotate the plates of the variable capacitor 108 relative to the relatively positioned plates of the variable capacitor 108 via the connection mechanism 160 to achieve the capacitance within the capacitance control signal and further achieve the voltage across the primary winding 104A and the voltage across the secondary winding 104B.

[0062] In addition, during operation of the plasma system 100, the host computer transmits a capacitance control signal to the driver 2. The capacitance control signal is generated by the host computer to achieve the capacitance of the variable capacitor 128. After receiving the capacitance control signal, the driver 2 generates a current signal and transmits it to the motor 2. The motor 2 rotates to rotate the plate of the variable capacitor 128 relative to the oppositely positioned plate of the variable capacitor 128 via the connection mechanism 162 to achieve the capacitance within the capacitance control signal.

[0063] In one embodiment, the capacitance of the variable capacitor 108 is not controlled during operation of the plasma system 100. For example, during processing of a substrate, the capacitance of the variable capacitor 108 is fixed. As another example, a fixed capacitor is used instead of the variable capacitor 108. Similarly, in one embodiment, the capacitance of the variable capacitor 128 is not controlled during operation of the plasma system 100. For example, during processing of the substrate, the capacitance of the variable capacitor 128 is fixed. As another example, a fixed capacitor is used instead of the variable capacitor 128.

[0064] In one embodiment, one or more of the variable capacitors 108 and 128 are not used in the plasma system 100. For example, the primary winding 104A is coupled to a point P1 on the RF transmission line 158, but is not coupled to the variable capacitor 108. As another example, the TCP coils 152 and 154 are coupled to the RF transmission line 158 via points P2 and P3, but are not coupled to the variable capacitor 128.

[0065] FIG. 1B is a schematic diagram of an embodiment of a system 180 illustrating the use of a TBS 184 for an external coil of a transformer coupled plasma (TCP) chamber 182. The structure and function of system 180 are the same as system 100 ( FIG. 1A ), except for some differences between systems 180 and 100. The differences between systems 180 and 100 are described below.

[0066] The system 180 includes a host computer, an RF generator, an IMC 110, a driver 1, a motor 1, a driver 2, a motor 2, a connection mechanism 160, and a connection mechanism 162. The system 180 also includes a TBS 184 and a plasma chamber 182. The system 180 also includes variable capacitors 108 and 128.

[0067] The TBS 184 includes a transformer 124 having a primary winding 124A and a secondary winding 124B. The TBS 184 also includes a capacitor 130 as a fixed capacitor. In addition, the plasma chamber 182 includes a TCP coil system (TCS) 186, a coil terminal capacitor 188, and another coil terminal capacitor 190. The TCP coil system 186 includes TCP coils 116 and 152 and a TCP coil 192.

[0068] TCP coils 116 and 192 are inner TCP coils, while TCP coil 152 is an outer TCP coil. For example, the diameter of the inner TCP coil is smaller than the diameter of any of the outer TCP coils. As another example, the outer TCP coil surrounds the inner TCP coil. The outer TCP coil may surround the inner TCP coil at the same horizontal plane as the inner TCP coil, or at a different horizontal plane than the inner TCP coil.

[0069] One end of variable capacitor 108 is coupled to portion PRTN1 of RF transmission line 158 at point P1, and an opposite end of variable capacitor 108 is coupled to ends of TCP coils 192 and 116 via point P4. An opposite end of the TCP coil is coupled to an end of coil termination capacitor 188, and an opposite end of TCP coil 116 is coupled to an end of coil termination capacitor 190. Opposite ends of coil termination capacitors 188 and 190 are coupled to ground connections.

[0070] One end of variable capacitor 128 is coupled to portion PRTN2 of RF transmission line 158 at point P2, while an opposite end of variable capacitor 128 is coupled to end 126A of primary winding 124A. An opposite end 126B of primary winding 124A is coupled to an end of capacitor 130. An opposite end of capacitor 130 is coupled to a ground connection.

[0071] The end of the secondary winding 124B is coupled to the end 132A of the TCP coil 152, and the opposite end of the secondary winding 124B is coupled to the opposite end 132B of the TCP coil 152. The TCP coil 152 and the secondary winding 124B are coupled to each other in series. For example, the end of the secondary winding 124B coupled to the end 132A has the same potential as the end 132A. Similarly, the opposite end of the secondary winding 124B coupled to the end 132B has the same potential as the end 132B. As another example, the voltage across the end of the secondary winding 124B is the same as the voltage across the ends 132A and 132B of the TCP coil 152. It should be noted that there is no coil terminal capacitor coupled in series with the TCP coil 152. For example, the coil terminal capacitor is not coupled to the end 132B of the TCP coil 152.

[0072] During operation of the plasma system 180, the modified RF signals 120 and 172 are generated in the same manner as described above with reference to FIG. 1A. In addition, the modified RF signal 120 is split at point P4 into modified RF signals 194A and 194B. The modified RF signal 194A is provided to the TCP coil 192 from point P4, and the modified RF signal 194B is provided to the TCP coil 116 from point P4.

[0073] In addition, the modified RF signal 172 is transmitted to the primary winding 124A from the variable capacitor 128 and the end 126A of the primary winding 124A. The modified RF signal 172 generates a voltage across the ends 126A and 126B of the primary winding 124A, and the modified RF signal 172 passes from the end 126A through the primary winding 124A to the end 126B of the primary winding 124A to generate a magnetic field having a magnetic flux.

[0074] The magnetic field generated by the primary winding 124A induces a voltage across the end of the secondary winding 124B. The voltage induced across the end of the secondary winding 124B generates an RF signal 138 (e.g., an RF current signal) that flows from the end 132A of the TCP coil 152 to the end 132B of the TCP coil 152. When one or more processing gases are applied to the plasma chamber 182 in addition to applying the RF signal 138 to the TCP coil 152 and applying the modified RF signals 194A and 194B to the respective TCP coils 192 and 116, a plasma is generated or maintained in the plasma chamber 182 to perform substrate processing in the plasma chamber 182.

[0075] The inductance of the primary winding 124A modifies the impedance of the modified RF signal 172 received at the end 126A to output a modified RF signal 196 at the end 126B of the primary winding 124A. The capacitor 130 receives the modified RF signal 196. After receiving the modified RF signal 196, the capacitance of the capacitor 130 produces a voltage across the ends of the capacitor 130, and this voltage determines the voltage across the ends 126A and 126B of the primary winding 124A of the transformer 124.

[0076] Likewise, during operation of the plasma system 180, the host computer transmits a capacitance control signal to the driver 2. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 128, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 124A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 124B. The capacitance of the variable capacitor 128, and the voltage amounts to be achieved across the primary winding 124A and the secondary winding 124B are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 128 based on the corresponding relationship between the capacitance of the variable capacitor 128 and the voltage amount to be achieved across the primary winding 124A and the secondary winding 124B.

[0077] After receiving the capacitance control signal, driver 2 generates a current signal, which is transmitted to motor 2. Motor 2 rotates to rotate the plates of variable capacitor 128 relative to the relatively positioned plates of variable capacitor 128 to achieve the capacitance within the capacitance control signal, thereby achieving the voltage across primary winding 124A and the voltage across secondary winding 124B.

[0078] Additionally, during operation of the plasma system 180, the host computer transmits a capacitance control signal to the driver 1. The capacitance control signal is generated by the host computer to achieve the capacitance of the variable capacitor 108. After receiving the capacitance control signal, the driver 1 generates a current signal, which is transmitted to the motor 1. The motor 1 rotates to rotate the plates of the variable capacitor 108 relative to the oppositely positioned plates of the variable capacitor 108 to achieve the capacitance within the capacitance control signal.

[0079] In one embodiment, the capacitance of the variable capacitor 108 is not controlled during operation of the plasma system 180. For example, during processing of a substrate, the capacitance of the variable capacitor 108 is fixed. As another example, a fixed capacitor is used instead of the variable capacitor 108. Similarly, in one embodiment, the capacitance of the variable capacitor 128 is not controlled during operation of the plasma system 180. For example, during processing of a substrate, the capacitance of the variable capacitor 128 is fixed. As another example, a fixed capacitor is used instead of the variable capacitor 128.

[0080] In one embodiment, one or more of the variable capacitors 108 and 128 are not used in the plasma system 180. For example, the TCP coils 192 and 116 are coupled to the point P1 on the RF transmission line 158 via the point P4, but are not coupled to the variable capacitor 108. As another example, the primary winding 124A is coupled to the point P2 on the RF transmission line 158, but is not coupled to the variable capacitor 128.

[0081] FIG2 is a schematic diagram of an embodiment of a system 200 for illustrating the use of a TBS 202 for both the internal and external coils of a transformer coupled plasma (TCP) chamber 204. System 200 is a combination of a portion of system 100 and a portion of system 180 (FIGS. 1A and 1B). For example, except for the differences between systems 200 and 100 as described below, the structure and function of system 200 are the same as system 100 (FIG. 1A). Except for the differences between systems 200 and 100 as described below, the structure and function of system 200 are the same as system 180 (FIG. 1B).

[0082] The system 200 includes a host computer, an RF generator, an IMC 110, a driver 1, a motor 1, a driver 2, a motor 2, a connection mechanism 160, and a connection mechanism 162. The system 200 also includes a TBS 202 and a plasma chamber 204. The system 200 also includes variable capacitors 108 and 128.

[0083] The TBS 202 includes the transformer 104 and the capacitor 112. The TBS 202 also includes the transformer 124 and the capacitor 130. In addition, the plasma chamber 204 includes a TCP coil system (TCS) 206, which includes the TCP coils 116 and 152. The plasma chamber 204 does not include any coil terminal capacitors, such as the coil terminal capacitors 157, 159 (FIG. 1A), 188, and 190 (FIG. 1B).

[0084] TCP coil 116 is an inner TCP coil, and TCP coil 152 is an outer TCP coil. For example, the diameter of the inner TCP coil is smaller than the diameter of the outer TCP coil. As another example, the outer TCP coil surrounds the inner TCP coil. The outer TCP coil can surround the inner TCP coil at the same horizontal plane as the inner TCP coil, or at a different horizontal plane than the inner TCP coil.

[0085] One end of the variable capacitor 108 is coupled to the transformer 104 in the same manner as described above with reference to FIG. 1A, and the transformer 104 is coupled to the TCP coil 116 and the capacitor 112 in the same manner as described above with reference to FIG. 1A. In addition, one end of the variable capacitor 128 is coupled to the transformer 124 in the same manner as described above with reference to FIG. 1B, and the transformer 124 is coupled to the TCP coil 152 and the capacitor 130 in the same manner as described above with reference to FIG. 1B.

[0086] The operation of plasma system 200 is described above in part with reference to FIG1A and in part with reference to FIG1B. For example, the operation of transformer 104, variable capacitor 108, and capacitor 112 is described with reference to FIG1A. Similarly, the operation of transformer 124, variable capacitor 128, and capacitor 130 is described with reference to FIG1B.

[0087] In one embodiment, one or more of the variable capacitors 108 and 128 are not used in the plasma system 200. For example, the primary winding 104A is coupled to a point P1 on the RF transmission line 158, but not to the variable capacitor 108. As another example, the primary winding 124A is coupled to a point P2 on the RF transmission line 158, but not to the variable capacitor 128.

[0088] FIG3 is a schematic diagram of an embodiment of a system 300 for illustrating transformers used for interleaving inner TCP coils and interleaving outer TCP coils. The structure and function of system 300 are the same as system 200 ( FIG2 ), except for the differences between systems 300 and 200 as described below. System 300 includes a host computer, an RF generator, IMC 110, motor 1, drive 1, motor 2, and drive 2. System 300 also includes variable capacitors 108 and 128, a transformer-based system 302, a connection mechanism 160, a connection mechanism 162, and a plasma chamber 310.

[0089] The TBS 302 includes a transformer 332 having a primary winding 104A and a plurality of secondary windings 104B and 304. The TBS 302 also includes another transformer 334 having a primary winding 124A and a plurality of secondary windings 124B and 314.

[0090] The plasma chamber 310 includes a TCP coil 116, a TCP coil 192, another TCP coil 152, and a TCP coil 154. TCP coils 192 and 116 are inner TCP coils, and TCP coils 152 and 154 are outer TCP coils. For example, the diameter of any of the inner TCP coils is smaller than the diameter of any of the outer TCP coils. As another example, the outer TCP coil surrounds the inner TCP coil. The outer TCP coil may surround the inner TCP coil at the same horizontal plane as the inner TCP coil, or at a different horizontal plane than the inner TCP coil.

[0091] One end of the secondary winding 304 of the transformer 332 is coupled to the end 306A of the TCP coil 192, and the opposite end of the secondary winding 304 is coupled to the opposite end 306B of the TCP coil 192. The TCP coil 192 and the secondary winding 304 are coupled in series with each other. For example, the end of the secondary winding 304 coupled to the end 306A has the same potential as the end 306A. Similarly, the opposite end of the secondary winding 304 coupled to the end 306B has the same potential as the end 306B. As another example, the voltage across the end of the secondary winding 304 is the same as the voltage across the ends 306A and 306B of the TCP coil 192. It should be noted that there is no coil terminal capacitor coupled in series with the TCP coil 192. For example, the coil terminal capacitor is not coupled to the end 306B of the TCP coil 192.

[0092] Similarly, one end of the secondary winding 314 of the transformer 334 is coupled to the end 316A of the TCP coil 154, and the opposite end of the secondary winding 314 is coupled to the opposite end 316B of the TCP coil 154. For example, the end of the secondary winding 314 coupled to the end 316A has the same potential as the end 316A. Likewise, the opposite end of the secondary winding 314 coupled to the end 316B has the same potential as the end 316B. As another example, the voltage across the end of the secondary winding 314 is the same as the voltage across the ends 316A and 316B of the TCP coil 154. It should be noted that there is no coil terminal capacitor coupled in series with the TCP coil 154. For example, the coil terminal capacitor is not coupled to the end 316B of the TCP coil 154.

[0093] During operation of the system 300, the modified RF signal 120 is output from the variable capacitor 108 in the same manner as described above with reference to FIG. 1A. Similarly, the RF signal 122 is generated by the secondary winding 104B of the transformer 332 in the same manner as described above with reference to FIG. 1A. The modified RF signal 120 generates a voltage across the ends 106A and 106B of the primary winding 104A, and the modified RF signal 120 passes from the end 106A through the primary winding 104A to the end 106B of the primary winding 104A to generate a magnetic field having a magnetic flux. The magnetic field induces a voltage across the end of the secondary winding 304. The voltage induced across the end of the secondary winding 304 generates an RF signal 312 (e.g., an RF current signal) that flows from the end 306A of the TCP coil 192 to the end 306B of the TCP coil 192.

[0094] Furthermore, during operation of system 300, modified RF signal 172 is output from variable capacitor 128 in the same manner as described above with reference to FIG IB. Similarly, RF signal 138 is generated by secondary winding 124B of transformer 334 in the same manner as described above with reference to FIG IB.

[0095] The modified RF signal 172 generates a voltage across the ends 126A and 126B of the primary winding 124A, and the modified RF signal 172 passes from the end 126A through the primary winding 124A to the end 126B of the primary winding 124A to generate a magnetic field having a magnetic flux. The magnetic field induces a voltage across the end of the secondary winding 314. The voltage induced across the end of the secondary winding 314 generates an RF signal 320 (e.g., an RF current signal), which flows from the end 316A of the TCP coil 154 to the end 316B of the TCP coil 154.

[0096] When one or more process gases (described below) are applied to the plasma chamber 310 in addition to the RF signal 122 through the TCP coil 116, the RF signal 312 through the TCP coil 192, the RF signal 320 through the TCP coil 154, and the RF signal 138 through the TCP coil 152, a plasma is generated or maintained in the plasma chamber 310 for substrate processing in the plasma chamber 310.

[0097] Likewise, during operation of the plasma system 300, the host computer transmits a capacitance control signal to the driver 1. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 108, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 104A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 104B, and corresponds to another voltage amount to be achieved across the secondary winding 304. The capacitance of the variable capacitor 108, and the voltage amounts to be achieved across the primary winding 104A, the secondary winding 104B, and the secondary winding 304 are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 108 based on the corresponding relationship between the capacitance of the variable capacitor 108, and the voltage amounts to be achieved across the primary winding 104A, the secondary winding 104B, and the secondary winding 304.

[0098] After receiving the capacitance control signal, the driver 1 generates a current signal, which is transmitted to the motor 1. The motor 1 rotates to rotate the plates of the variable capacitor 108 relative to the relatively positioned plates of the variable capacitor 108 to achieve the capacitance within the capacitance control signal, thereby further achieving the voltage across the primary winding 104A, the voltage across the secondary winding 104B, and the voltage across the secondary winding 304.

[0099] In addition, during operation of the plasma system 300, the host computer transmits a capacitance control signal to the driver 2. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 128, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 124A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 124B, and corresponds to another voltage amount to be achieved across the secondary winding 314. The capacitance of the variable capacitor 128, and the voltage amounts to be achieved across the primary winding 124A, the secondary winding 124B, and the secondary winding 314 are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 128 based on the corresponding relationship between the capacitance of the variable capacitor 128 and the voltage amounts to be achieved across the primary winding 124A, the secondary winding 124B, and the secondary winding 314.

[0100] After receiving the capacitance control signal, the driver 2 generates a current signal, which is transmitted to the motor 2. The motor 2 rotates to rotate the plates of the variable capacitor 128 relative to the relatively positioned plates of the variable capacitor 128 to achieve the capacitance within the capacitance control signal and further achieve the voltage across the primary winding 124A, the voltage across the secondary winding 124B, and the voltage across the secondary winding 314.

[0101] In one embodiment, one or more of the variable capacitors 108 and 128 are not used in the plasma system 300 , in the same manner as described above with reference to the plasma system 200 of FIG. 2 .

[0102] Likewise, in one embodiment, as described above with reference to the plasma system 200 of FIG. 2 , one or more of the variable capacitors 108 and 128 are fixed.

[0103] 4A is a schematic diagram of an embodiment of a transformer 400 having a primary winding and a plurality of secondary windings. Transformer 400 includes a primary winding 402 and a plurality of secondary windings 404A, 404B, 404C, and 404D. Transformer 400 is an example of a stranded wire transformer.

[0104] Primary winding 402 is an example of any one of primary windings 104A (FIGS. 1A and 2) and 124A (FIGS. 1B and 2). Any one of secondary windings 404A-404D is an example of any one of secondary windings 104B (FIG. 1A), 124B (FIG. 1B), 304 (FIG. 3), and 314 (FIG. 3).

[0105] The primary winding 402 and the secondary windings 404A-404D are twisted together to manufacture the transformer 400. An example of the primary winding 402 is a metal wire with an insulating coating on the metal wire. For example, the primary winding 402 is a copper wire or a magnetic wire coated with polyurethane. Similarly, an example of each of the secondary windings 404A-404D is a metal wire. For example, each of the secondary windings 404A-404D is a copper wire with a polyurethane coating.

[0106] In one embodiment, transformer 400 includes more or less than four secondary windings. For example, transformer 400 includes two secondary windings, or five secondary windings. If transformer 400 includes both of secondary windings 404A-404D and primary winding 402, transformer 400 is an example of transformer 332 or transformer 334 (FIG. 3). If transformer 400 includes one of secondary windings 404A-404D and primary winding 402, transformer 400 is an example of transformer 104 (FIG. 1A) or transformer 124 (FIG. 1B).

[0107] In one embodiment, the primary winding 402 and the secondary windings 404A- 404D are twisted around each other to form a braided structure.

[0108] 4B is a schematic diagram of an embodiment of a transformer 410. Transformer 410 is another example of a twisted wire transformer. Transformer 410 includes a primary winding 402 and secondary windings 404A, 404B, and 404C. Primary winding 402 and secondary windings 404A-404C are twisted with each other to manufacture transformer 410.

[0109] It should be noted that there is no core material used to make transformer 410. Transformer 410 is an air core transformer. This facilitates the use of transformer 410 in high frequency applications, as described below. The high frequencies include microwave frequencies.

[0110] In one embodiment, the primary winding 402 and the secondary windings 404A, 404B, and 404C are twisted around each other to form a braided structure.

[0111] Figure 4C 4 is a schematic diagram of an embodiment of a transformer 420 for illustrating a plurality of taps on a secondary winding. Transformer 420 is yet another example of a stranded wire transformer. Transformer 420 includes a primary winding 402 and a secondary winding 404A. As an example, primary winding 402 and secondary winding 404A are twisted around each other to manufacture transformer 420. Secondary winding 404A has a plurality of taps, including tap 0, tap 1, tap 2, tap 3, tap 4, and tap 5. As an example, the taps of the secondary winding are contacts, such as wire connections, formed at locations along the secondary winding.

[0112] As an example, end 114A of TCP coil 116 ( FIGS. 1A , 2 , and 3 ) is coupled to tap 5, while end 114B of TCP coil 116 is coupled to tap 0. As another example, end 114A of TCP coil 116 is coupled to tap 4, while end 114B of TCP coil 116 is coupled to tap 0. As yet another example, end 114A of TCP coil 116 is coupled to tap 4, while end 114B of TCP coil 116 is coupled to tap 1. As yet another example, end 114A of TCP coil 116 is coupled to tap 3, while end 114B of TCP coil 116 is coupled to tap 1.

[0113] As another example, end 306A of TCP coil 192 ( FIG. 3 ) is coupled to tap 5, while end 306B of TCP coil 192 is coupled to tap 0. As another example, end 306A of TCP coil 192 is coupled to tap 4, while end 306B of TCP coil 192 is coupled to tap 0. As yet another example, end 306A of TCP coil 192 is coupled to tap 4, while end 306B of TCP coil 192 is coupled to tap 1. As yet another example, end 306A of TCP coil 192 is coupled to tap 3, while end 306B of TCP coil 192 is coupled to tap 1.

[0114] As yet another example, end 316A of TCP coil 154 ( FIG. 3 ) is coupled to tap 5, while end 316B of TCP coil 154 is coupled to tap 0. As another example, end 316A of TCP coil 154 is coupled to tap 4, while end 316B of TCP coil 154 is coupled to tap 0. As yet another example, end 316A of TCP coil 154 is coupled to tap 4, while end 316B of TCP coil 154 is coupled to tap 1. As yet another example, end 316A of TCP coil 154 is coupled to tap 3, while end 316B of TCP coil 154 is coupled to tap 1.

[0115] As yet another example, end 132A of TCP coil 152 ( FIGS. 1B , 2 , and 3 ) is coupled to tap 5, while end 132B of TCP coil 152 is coupled to tap 0. As another example, end 132A of TCP coil 152 is coupled to tap 4, while end 132B of TCP coil 152 is coupled to tap 0. As yet another example, end 132A of TCP coil 152 is coupled to tap 4, while end 132B of TCP coil 152 is coupled to tap 1. As yet another example, end 132A of TCP coil 152 is coupled to tap 3, while end 132B of TCP coil 152 is coupled to tap 1.

[0116] Transitioning between these taps (e.g., from tap 1 to tap 2, or from tap 2 to tap 3) changes the voltage applied by the secondary winding 404A to the TCP coil, which is coupled in series with the secondary winding 404A. For example, when the TCP coil is coupled to the secondary winding 404A via taps 0 and 5, a different amount of voltage is applied to the TCP coil than when the TCP coil is coupled to the secondary winding 404A via taps 1 and 3. As another example, when the TCP coil is coupled to the secondary winding 404A via taps 1 and 2, a different amount of voltage is applied to the TCP coil than when the TCP coil is coupled to the secondary winding 404A via taps 2 and 4.

[0117] In one embodiment, the secondary winding 404A has a greater or lesser number of taps (eg, three or seven) instead of six taps.

[0118] In one embodiment, one or more of the secondary windings 404A-404D (FIG. 4A) have taps. For example, the secondary winding 404A has three taps, the secondary winding 404B has three taps, and the secondary winding 404C has three taps. As another example, instead of connecting taps 0 to 6 to the secondary winding 404A or as a supplement to connecting taps 0 to 6 to the secondary winding 404A, taps 0 to 6 are connected to the secondary winding 404B. As another example, instead of connecting taps 0 to 6 to the secondary winding 404A or as a supplement to connecting taps 0 to 6 to the secondary winding 404A, taps 0 to 6 are connected to any one of the secondary windings 404C, 404D, and 404E.

[0119] In one embodiment, one or more of the secondary windings 404A-404D has a different number of taps than the other one or more of the secondary windings 404A-404D. For example, each of the secondary windings 404A and 404B has three taps, while each of the secondary windings 404C and 404D has four taps.

[0120] Figure 4D 4 is a schematic diagram of an embodiment of a transformer 450, which is used to illustrate that the transformer has a primary winding and a secondary winding twisted around each other. The transformer 450 includes a primary winding 402 and a secondary winding 404A. The primary winding 402 is twisted around the secondary winding 404A, and the secondary winding 404A is twisted around the primary winding 402 to manufacture the transformer 450.

[0121] Figure 4E4 is a schematic diagram of an embodiment of a transformer 460. The transformer 460 includes a primary winding 452 and a secondary winding 454. Each of the primary winding 452 and the secondary winding 454 is a metal tube covered by an insulator. For example, the metal tube is made of copper. As another example, the metal tube is hollow, and the space passes through the shell of the tube. The primary winding 452 and the secondary winding 454 are wound in a manner interlaced with each other. For example, the primary winding 452 is wound on the top of the secondary winding 454, and the secondary winding 454 is wound on the top of the primary winding 452, so that the primary winding 452 and the secondary winding 454 are alternately arranged to manufacture the transformer. When the primary winding 452 and the secondary winding 454 are wound in an interlaced manner, a cylindrical portion 462 including the primary winding 452 and the secondary winding 454 is formed.

[0122] 5 is a schematic diagram of an embodiment of a transformer 500, which is used to illustrate the use of coaxial cable to make the transformer 500. The transformer 500 is used for high frequency applications. For example, when the RF generator has an operating frequency greater than 1 MHZ, the transformer 500 is used.

[0123] Transformer 500 includes a primary winding 502 and a secondary winding 504. Primary winding 502 is an example of any one of primary windings 104A (FIG. 1A) and 124A (FIG. 2). Secondary winding 504 is an example of any one of secondary windings 104B (FIG. 1A), 124B (FIG. 1B), 304 (FIG. 3), and 314 (FIG. 3).

[0124] The primary winding 502 has an outer shield 502A and an inner conductor 502B. The outer shield 502B is made of an insulator, while the inner conductor 502A is made of a metal (eg, copper). The outer shield 502A covers (eg, surrounds) the inner conductor 502B along its length.

[0125] Similarly, the secondary winding 504 has an outer shield 504A and an inner conductor 504B. The outer shield 504B is made of an insulator, while the inner conductor 504A is made of a metal (e.g., copper). Examples of insulators described herein include plastic, polyvinyl chloride, polyethylene, and polypropylene. The outer shield 504A covers (e.g., surrounds) the inner conductor 504B along its length.

[0126] The primary winding 502 and the secondary winding 504 are connected to each other via a connection portion 506. For example, the primary winding 502 and the secondary winding 504 are disposed adjacent to each other, and an insulator connects the primary winding 502 and the secondary winding 504.

[0127] The length of inner conductor 504B is twice the length of inner conductor 502A to achieve a 1:2 ratio between primary winding 502 and secondary winding 504. The double length of inner conductor 504B is depicted as a dashed line between point 506A on inner conductor 502B and point 506B on inner conductor 504B. The dashed line is used to illustrate that the length of inner conductor 504B is twice the length of inner conductor 502B. As another example, inner conductor 504B has another length, such as three or four times the length of inner conductor 502A.

[0128] As an example, the length of the secondary winding 504 is one quarter of a wavelength, which is denoted as λ / 4. Other examples of the length of the secondary winding 504 include 1 / 2 wavelength or 1 / 5 th The length of the wavelength.

[0129] In one embodiment, the coaxial cable has a center metal conductor. The center conductor is covered by a dielectric along the length of the center conductor, and the dielectric is covered by an outer metal conductor along the length of the dielectric. The outer metal conductor is covered by an insulator along the length of the outer metal conductor. An example of the center conductor is a copper wire. As an example, the dielectric is plastic, or polyvinyl chloride. An example of the outer metal conductor is a metal mesh made of copper, and an example of the insulator is plastic, or polyvinyl chloride, or polyethylene, or polypropylene.

[0130] 6A is a schematic diagram of an embodiment of a system 600 that illustrates the use of a variable capacitor 602 instead of capacitor 112 (FIG. 1A). The structure and function of system 600 are the same as system 100 (FIG. 1A), except that system 600 has a variable capacitor 602 instead of capacitor 112. For example, system 600 includes a transformer-based system 603 that is the same as transformer-based system 102 (FIG. 1A), except that transformer-based system 603 includes a variable capacitor 602 instead of capacitor 112 (which is fixed).

[0131] The system 600 further includes a driver 3, a motor 3, and a connection mechanism 604. The host computer is coupled to the driver 3, and the driver 3 is coupled to the motor 3. The motor 3 is coupled to the variable capacitor 602 via the connection mechanism 604.

[0132] During operation of the system 600, the host computer transmits a capacitance control signal to the driver 3. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 602, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 104A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 104B. The capacitance of the variable capacitor 602, and the voltage amounts to be achieved across the primary winding 104A and the secondary winding 104B are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 602 based on the corresponding relationship between the capacitance of the variable capacitor 602 and the voltage amounts to be achieved across the primary winding 104A and the secondary winding 104B.

[0133] After receiving the capacitance control signal, the driver 3 generates a current signal, which is transmitted to the motor 3. The motor 3 rotates to rotate the plates of the variable capacitor 602 relative to the relatively positioned plates of the variable capacitor 602 via the connection mechanism 604 to achieve the capacitance within the capacitance control signal, and further achieve the voltage across the primary winding 104A and the voltage across the secondary winding 104B. The voltage across the secondary winding 104B is achieved to generate the RF signal 122.

[0134] FIG6B is a schematic diagram of an embodiment of a system 620 that illustrates the use of a variable capacitor 622 instead of capacitor 130 ( FIG1B ). The structure and function of system 620 are the same as system 184 ( FIG1B ), except that system 620 has a variable capacitor 622 instead of capacitor 130. For example, system 620 includes a transformer-based system 621 that is the same as transformer-based system 184 ( FIG1B ), except that transformer-based system 621 includes a variable capacitor 622 instead of capacitor 130 (which is fixed).

[0135] The system 620 also includes a driver 4, a motor 4, and a connection mechanism 624. The host computer is coupled to the driver 4, and the driver 4 is coupled to the motor 4. The motor 4 is coupled to the variable capacitor 622 via the connection mechanism 624.

[0136] During operation of the system 620, the host computer transmits a capacitance control signal to the driver 4. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 622, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 124A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 124B. The capacitance of the variable capacitor 622 and the voltage amount to be achieved across the primary winding 124A and the secondary winding 124B are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 622 based on the corresponding relationship between the capacitance of the variable capacitor 622 and the voltage amount achieved across the primary winding 124A and the secondary winding 124B.

[0137] After receiving the capacitance control signal, the driver 4 generates a current signal to transmit to the motor 4. The motor 4 rotates to rotate the plates of the variable capacitor 622 relative to the relatively positioned plates of the variable capacitor 622 via the connection mechanism 624 to achieve the capacitance within the capacitance control signal and further achieve the voltage across the primary winding 124A and the voltage across the secondary winding 124B. The voltage across the secondary winding 124B is achieved to generate the RF signal 196.

[0138] FIG7 is a schematic diagram of an embodiment of a system 700 for illustrating the use of a variable capacitor 602 instead of capacitor 112 (FIG. 2), and the use of a variable capacitor 622 instead of capacitor 130 (FIG. 2). The structure and function of the system 700 are the same as the system 200 (FIG. 2), except that the system 700 has a variable capacitor 602 instead of capacitor 112, and a variable capacitor 622 instead of capacitor 130. For example, the system 700 includes a transformer-based system 701, and the structure and function of the transformer-based system 701 are the same as the transformer-based system 202 (FIG. 2), except that the transformer-based system 701 includes a variable capacitor 602 instead of capacitor 112, and includes a variable capacitor 622 instead of capacitor 130.

[0139] Likewise, system 700 includes driver 3, driver 4, and motor 3, motor 4. The operation of driver 3 and motor 3 is described above with reference to FIG6A, while the operation of driver 4 and motor 4 is described above with reference to FIG6B. A voltage across secondary winding 104B is implemented to produce RF signal 174, and a voltage across secondary winding 124B is implemented to produce RF signal 196.

[0140] FIG8 is a schematic diagram of an embodiment of a system 800 for illustrating the use of a variable capacitor 602 instead of capacitor 112 (FIG. 3), and the use of a variable capacitor 622 instead of capacitor 130 (FIG. 3). The structure and function of the system 800 are the same as those of the system 300 (FIG. 3), except that the system 800 has a variable capacitor 602 instead of capacitor 112, and a variable capacitor 622 instead of capacitor 130. For example, the system 800 includes a transformer-based system 801, and the structure and function of the transformer-based system 801 are the same as those of the transformer-based system 302 (FIG. 3), except that the transformer-based system 801 includes a variable capacitor 602 instead of capacitor 112, and includes a variable capacitor 622 instead of capacitor 130. Similarly, the system 800 includes a driver 3, a driver 4, and a motor 3, a motor 4.

[0141] During operation of the system 800, the host computer transmits a capacitance control signal to the driver 3. The capacitance control signal is generated by the host computer to achieve a capacitance of the variable capacitor 602, and the capacitance corresponds to a voltage amount to be achieved across the primary winding 104A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 104B. Similarly, the voltage amount to be achieved across the primary winding 104A corresponds to another voltage amount to be achieved across the secondary winding 304. The capacitance of the variable capacitor 602, and the voltage amounts to be achieved across the primary winding 104A, the secondary winding 104B, and the secondary winding 304 are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 602 based on the corresponding relationship between the capacitance of the variable capacitor 602 and the voltage amounts to be achieved across the primary winding 104A, the secondary winding 104B, and the secondary winding 304.

[0142] After receiving the capacitance control signal, the driver 3 generates a current signal, which is transmitted to the motor 3. The motor 3 rotates to rotate the plates of the variable capacitor 602 relative to the relatively positioned plates of the variable capacitor 602 to achieve the capacitance within the capacitance control signal and further achieve the voltage across the primary winding 104A, the voltage across the secondary winding 104B, and the voltage across the secondary winding 304. The voltage across the secondary winding 104B is achieved to generate the RF signal 122, and the voltage across the secondary winding 304 is achieved to generate the RF signal 312.

[0143] In addition, during operation of the system 800, the host computer transmits a capacitance control signal to the driver 4. The capacitance control signal is generated by the host computer to achieve the capacitance of the variable capacitor 622, and the capacitance corresponds to the voltage amount to be achieved across the primary winding 124A, and the voltage amount corresponds to another voltage amount to be achieved across the secondary winding 124B. Similarly, the voltage amount to be achieved across the primary winding 124A corresponds to another voltage amount to be achieved across the secondary winding 314. The capacitance of the variable capacitor 622, and the voltage amounts to be achieved across the primary winding 124A, the secondary winding 124B, and the secondary winding 314 are stored in a memory device of the host computer. The processor of the host computer identifies the capacitance of the variable capacitor 622 based on the corresponding relationship between the capacitance of the variable capacitor 622 and the voltage amounts to be achieved across the primary winding 124A, the secondary winding 124B, and the secondary winding 314.

[0144] After receiving the capacitance control signal, the driver 4 generates a current signal, which is transmitted to the motor 4. The motor 4 rotates to rotate the plates of the variable capacitor 622 relative to the relatively positioned plates of the variable capacitor 622 to achieve the capacitance within the capacitance control signal and further achieve the voltage across the primary winding 124A, the voltage across the secondary winding 124B, and the voltage across the secondary winding 314. The voltage across the secondary winding 124B is achieved to produce the RF signal 138, and the voltage across the secondary winding 314 is achieved to produce the RF signal 320.

[0145] 9 is a schematic diagram of an embodiment of a system 900 for illustrating a plasma tool in which a transformer-based system 902 is used. The system 900 includes a host computer, an RF generator, an IMC 110, a transformer-based system 902, a plasma chamber 904, a process gas supply 906, and a gas supply manifold 908.

[0146] The plasma chamber 904 includes a TCP coil system 912 and a substrate holder 910. The substrate holder 910 is coupled to a ground connection. The TCP coil system 912 is located above the substrate holder 910. Examples of the TCP coil system 912 include the TCP coil system 150 (FIG. 1A), the TCP coil system 186 (FIG. 1B), the TCP coil system 206 (FIG. 2), and the TCP coil system 330 (FIG. 3).

[0147] An example of the process gas supply source 906 includes one or more gas containers storing one or more process gases, wherein the process gases are used to process the substrate S on the substrate holder 910, such as a semiconductor wafer. An example of the substrate holder 910 includes a chuck. The chuck includes a lower electrode coupled to the ground connection. Examples of the one or more process gases include oxygen-containing gas and fluorine-containing gas. The gas supply manifold 908 includes one or more valves for controlling (e.g., allowing or prohibiting) the flow of the one or more process gases received from the process gas supply source 906 to the plasma chamber 904 via the gas supply manifold 908 to achieve a preset mixture of the process gases.

[0148] Examples of transformer-based systems 902 include transformer-based systems 102 (FIG. 1A), transformer-based systems 184 (FIG. 1B), transformer-based systems 202 (FIG. 2), transformer-based systems 302 (FIG. 3), transformer-based systems 603 (FIG. 6A), transformer-based systems 621 (FIG. 6B), transformer-based systems 701 (FIG. 7), and transformer-based systems 801 (FIG. 8). Examples of TCP coil systems 912 include TCP coil systems 150 (FIG. 1A), TCP coil systems 186 (FIG. 1B), TCP coil systems 206 (FIG. 2), and TCP coil systems 330 (FIG. 3).

[0149] The host computer is coupled to an RF generator, which is coupled to an IMC 110. The IMC 110 is coupled to an RF transmission line 158. The host computer is coupled to a process gas supply 906, which is coupled to a gas supply manifold 908, which is coupled to a plasma chamber 904. The IMC 110 is coupled to a transformer-based system 902 via the RF transmission line 158. The variable capacitor 108 is coupled to the RF transmission line 158, and the variable capacitor 128 is coupled to the RF transmission line 158. The transformer-based system 902 is coupled to the variable capacitors 108 and 128, and to a TCP coil system 912.

[0150] During operation, the modified RF signals 120 and 172 are generated in the same manner as described above with reference to FIG. 1A. The transformer-based system 902 receives the modified RF signals 120 and 172 to output a group of RF signals 914 and 916. Examples of the group of RF signals 914 include the RF signal 122 (FIGS. 1A and 2), or the group of RF signals 194A and 194B (FIG. 1B), or the group of RF signals 122 and 304 (FIG. 3). Examples of the group of RF signals 916 include the group of RF signals 172A and 172B (FIG. 1A), or the RF signal 138 (FIGS. 1B and 2), or the group of RF signals 320 and 138 (FIG. 3).

[0151] Furthermore, during operation, the host computer transmits control signals to the process gas supply source 906 to supply one or more process gases, and transmits control signals to the gas supply manifold 908 to control the amount of the one or more process gases reaching the plasma chamber 904. When the one or more process gases are supplied to the plasma chamber 904, and the RF signals 914 and 916 are supplied to the TCP coil system 912, a plasma is ignited or contained within the plasma chamber 904 to process the substrate S. Examples of processing the substrate S include etching the substrate S, depositing a material on the substrate S, sputtering the substrate S, and cleaning the substrate S.

[0152] In one embodiment, the substrate holder 910 is coupled to one or more RF generators via an impedance matching circuit, rather than being coupled to a ground connection. The one or more RF generators are coupled to the impedance matching circuit via respective one or more RF cables, and the impedance matching circuit is coupled to the substrate holder 910 via an RF transmission line. The one or more RF generators generate respective one or more RF signals, which are supplied to the impedance matching circuit via respective one or more RF cables. The impedance matching circuit outputs a modified RF signal generated based on the one or more RF signals, and transmits the modified RF signal to the substrate holder 910 for processing the substrate S.

[0153] In one embodiment, a dielectric window is disposed between the TCP coil system 912 and the substrate holder 910 .

[0154] Fig.10 1 is a schematic diagram of an embodiment of a transformer 1000 for illustrating the principle of the transformer 1000. The transformer 1000 is an example of the transformer 104 (FIG. 1A) or the transformer 124 (FIG. 1B). The transformer 1000 has a primary winding 1002 and a secondary winding 1004.

[0155] For a given amount of power across the secondary winding 1004, the transformer 1000 can be used to change the ratio of voltage to current across the secondary winding 1004. The ratio of voltage to current can be changed by changing the coil ratio Np / Ns between the primary winding 1002 and the secondary winding 1004. Np is the number of turns of the primary winding 1002, and Ns is the number of turns of the secondary winding 1004. The voltage across the primary winding 1002 is Vp, and the voltage across the secondary winding 1004 is Vs. The current flowing through the primary winding is Ip, and the current flowing through the secondary winding is Is. The transformer formula is provided as follows:

[0156] Vp / Vs=Is / Ip=Np / Ns……(1)

[0157] The mutual inductance M between the primary winding 1002 and the secondary winding 1004 is expressed as:

[0158] M=k√(LpLs)……(2)

[0159] Wherein k is the coupling coefficient between the primary winding 1002 and the secondary winding 1004 , √ represents the square root, Lp is the inductance of the primary winding 1002 , and Ls is the inductance of the secondary winding 1004 .

[0160] The twisted wire transformer improves the coupling coefficient between the primary winding 1002 and the secondary winding 1004. In the twisted wire transformer, the primary winding 1002 is twisted with the secondary winding 1004. The coupling coefficient k depends on the pitch of the primary winding 1002 of the twisted wire transformer and the pitch of the secondary winding 1004. For example, the pitch of each of the primary winding 1002 and the secondary winding 1004 can be defined so that the coupling coefficient k is equal to 1 or approximately equal to 1, for example, different from 1 within a predetermined range. The coupling coefficient also depends on the parameters of the wire used to manufacture the primary winding 1002 and the secondary winding 1004, such as resistance loss. The twisting of the primary winding 1002 and the secondary winding 1004 with each other reduces the difference in the coupling coefficient k caused by the different wires of the primary winding 1002 and the secondary winding 1004.

[0161] The embodiments described herein may be implemented by various computer system configurations including handheld hardware units, microprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, etc. The embodiments described herein may also be implemented in distributed computing environments where work is performed via remote processing hardware units that are linked through a computer network.

[0162] In some embodiments, the controller is part of a system, which may be part of the above examples. The system includes a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more processing platforms and / or specific processing components (wafer pedestals, gas flow systems, etc.). The system is integrated with electronic equipment to control its operation before, during, and after the processing of semiconductor wafers or substrates. The electronic equipment is called a controller, which can control various components or sub-components of one or more systems. Depending on the processing requirements and / or system type, the controller is programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, RF generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out of tools connected or engaged with the system and other transfer tools and / or load locks.

[0163] Broadly speaking, in many embodiments, a controller is defined as an electronic device having a number of integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, initiates cleaning operations, initiates endpoint measurements, etc. Integrated circuits include: a chip in the form of hardware that stores program instructions, a digital signal processor (DSP), a chip defined as an ASIC, a PLD, one or more microprocessors, or a microcontroller that executes program instructions (e.g., software). Program instructions are instructions sent to a controller or system in the form of different individual settings (or program files) that define operating parameters for performing a specific process (on or for a semiconductor wafer). In some embodiments, the operating parameters are part of a recipe defined by a process engineer to achieve one or more processing steps during the manufacture of one or more (kinds of) layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0164] In some embodiments, the controller is part of or coupled to a computer that is integrated with the system, coupled to the system, or connected to the system via a network, or a combination thereof. For example, the controller is in all or part of a "cloud" or fab host computer system that allows remote access to wafer processing. The controller enables remote access to the system to monitor the current progress of a manufacturing operation, check the history of past manufacturing operations, check trends or performance indicators from multiple manufacturing operations, change parameters of a current process, set a processing step after the current process, or start a new process.

[0165] In some embodiments, a remote computer (e.g., a server) provides a processing recipe to the system via a computer network, which includes a local area network or the Internet. The remote computer includes a user interface that can implement the input of parameters and / or settings, or program parameters and / or settings, which are then communicated to the system by the remote computer. In some examples, the controller receives instructions in the form of settings for processing wafers. It should be understood that the settings are specifically for the type of processing to be performed on the wafer and the type of tool that the controller engages or controls. Therefore, as described above, the controller is distributed, such as by including one or more separate controllers that are connected to each other in a network manner and operate toward a common purpose (e.g., completion processing as described herein). An example of a distributed controller for this purpose includes one or more integrated circuits that communicate with one or more integrated circuits located remotely (e.g., at the platform level, or as part of a remote computer) on the chamber, and the two are combined to control the processing in the chamber.

[0166] In various embodiments, the plasma system includes, but is not limited to, a plasma etching chamber, a deposition chamber, a spin rinse chamber, a metal plating chamber, a cleaning chamber, an edge etching chamber, a physical vapor deposition (PVD) chamber, a chemical vapor deposition (CVD) chamber, an atomic layer deposition (ALD) chamber, an atomic layer etching (ALE) chamber, an ion implantation chamber, a track chamber, and any other semiconductor processing chamber related to and / or used for the manufacture of semiconductor wafers.

[0167] It should also be noted that although the above operations are described with reference to an inductively coupled plasma (ICP) reactor, in some embodiments, the above operations are applicable to other types of plasma chambers, such as plasma chambers including parallel plate plasma chambers, capacitively coupled plasma chambers, conductor tools, dielectric tools, plasma chambers including electron cyclotron resonance (ECR) reactors, and the like.

[0168] As described above, depending on the operations to be performed by the tool, the controller communicates with one or more of the following in the semiconductor manufacturing facility: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools throughout the facility, a host computer, another controller, or tools used in material transport that transport wafer containers to and from tool locations and / or load ports.

[0169]

[0066] With the above embodiments in mind, it will be appreciated that some embodiments employ various computer-implemented operations involving data stored in computer systems. These computer-implemented operations are operations that manipulate physical quantities.

[0170] Some of the embodiments also relate to hardware units or devices that perform these operations. The device is particularly built for a special-purpose computer. When defined as a special-purpose computer, the computer performs other processing, program execution or non-special-purpose parts and can still operate routines for special purposes at the same time.

[0171] In some embodiments, the operations described herein are performed by a selectively activated computer, or are configured by one or more computer programs stored in a computer memory, or are obtained through a computer network. When data is obtained through a computer network, it can be processed by other computers on the computer network (e.g., a cloud of computing resources).

[0172] One or more embodiments described herein may also be manufactured as computer readable code on a non-transient computer readable medium. A non-transient computer readable medium is any data storage hardware unit (e.g., a memory device, etc.) that stores data, which is then read by a computer system. Examples of non-transient computer readable media include hard disks, network attached storage (NAS), ROM, RAM, compact disk read-only (CD-ROM), recordable compact disk (CD-R), rewritable compact disk (CD-RW), magnetic tapes, and other optical and non-optical data storage hardware units. In some embodiments, a non-transient computer readable medium includes a computer readable tangible medium distributed within a network coupled computer system, such that the computer readable code is stored and executed in a decentralized manner.

[0173] Although some of the method operations described above are presented in a particular order, it should be understood that in many embodiments, other housekeeping operations are performed between multiple operations, or the method operations are adjusted so that these method operations occur at slightly different times, or these method operations are distributed in a system that allows multiple method operations to occur at various intervals, or these method operations are performed in an order different from that described above.

[0174] It should be further noted that in an embodiment, one or more features from any of the above-described embodiments can be combined with one or more features of any other embodiment without departing from the scope described in the various embodiments described in this disclosure.

[0175] Although the foregoing embodiments have been described in considerable detail for the purpose of clear understanding, it should be understood that some changes and modifications may be implemented within the scope of the appended claims. Therefore, the embodiments of the present invention should be considered illustrative rather than restrictive, and these embodiments should not be limited to the details provided herein, but may be modified within the scope and equivalent scope of the appended claims.

Claims

1. A transformer device, comprising: a primary winding having a first end and a second end, wherein the first end of the primary winding is coupled to an output of an impedance matching circuit and the second end of the primary winding is coupled to a capacitor; a secondary winding associated with the primary winding, and wherein the secondary winding is coupled to a first end of a transformer coupled plasma TCP coil of a plasma chamber and to a second end of the TCP coil, The primary winding is configured to receive a modified radio frequency (RF) signal from the impedance matching circuit to generate magnetic flux, thereby inducing a voltage in the secondary winding, wherein the RF signal generated by the voltage is transmitted from the secondary winding to the TCP coil.

2. The transformer device according to claim 1, wherein the TCP coil is connected in series with the secondary winding.

3. The transformer device according to claim 1, further comprising: an additional primary winding having a first end and a second end, wherein the first end of the additional primary winding is coupled to the output of the impedance matching circuit and the second end of the additional primary winding is coupled to an additional capacitor; an additional secondary winding associated with the additional primary winding and coupled to a first end and a second end of an additional TCP coil of the plasma chamber, The additional primary winding is configured to receive a modified RF signal from the impedance matching circuit to generate magnetic flux, thereby inducing a voltage in the additional secondary winding, wherein an RF signal generated by the voltage induced in the additional secondary winding is transmitted from the additional secondary winding to the additional TCP coil. The transformer arrangement of claim 1 , wherein the capacitor is coupled to a ground connection.

5. The transformer device according to claim 1, wherein the secondary winding is twisted with the primary winding to be associated with the primary winding.

6. The transformer device according to claim 1, wherein the secondary winding is wound in an interleaved manner with the primary winding so as to be associated with the primary winding.

7. The transformer device according to claim 1, wherein the capacitor is a variable capacitor or a fixed capacitor.

8. The transformer device of claim 1, wherein the capacitor is a variable capacitor, the variable capacitor being coupled to a motor to vary a capacitance of the variable capacitor.

9. The transformer device according to claim 1, wherein a plurality of taps are provided on the secondary winding to change the voltage applied to the TCP coil by the secondary winding.

10. The transformer device of claim 1, wherein the first end of the primary winding is coupled to the impedance matching circuit via another capacitor, wherein the other capacitor is a fixed capacitor or a variable capacitor.

11. A transformer device, comprising: a primary winding having a first end and a second end, wherein the first end of the primary winding is coupled to an output of an impedance matching circuit and the second end of the primary winding is coupled to a capacitor; a first secondary winding associated with the primary winding and coupled to a first end of a first transformer coupled plasma TCP coil of the plasma chamber and to a second end of the TCP coil, wherein the primary winding is configured to receive a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux, thereby inducing a voltage in the first secondary winding, wherein an RF signal generated by the voltage induced in the first secondary winding is transmitted to the first TCP coil via the first secondary winding, a second secondary winding associated with the primary winding and coupled to a first end and a second end of a second TCP coil of the plasma chamber, wherein the magnetic flux is configured to induce a voltage in the second secondary winding, wherein an RF signal generated by the voltage induced in the second secondary winding is transmitted from the second secondary winding to the second TCP coil. 12 . The transformer device of claim 11 , wherein the first TCP coil is connected in series with the first secondary winding, and the second TCP coil is connected in series with the second secondary winding.

13. The transformer device according to claim 11, further comprising: an additional primary winding having a first end and a second end, wherein the first end of the additional primary winding is coupled to the output of the impedance matching circuit and the second end of the additional primary winding is coupled to an additional capacitor; an additional first secondary winding associated with the additional primary winding and coupled to a first end and a second end of a third TCP coil of the plasma chamber, wherein the additional primary winding is configured to receive a modified RF signal from the impedance matching circuit to generate a magnetic flux, thereby inducing a voltage in the additional first secondary winding, wherein an RF signal generated by the voltage induced in the additional first secondary winding is transmitted from the additional first secondary winding to the third TCP coil; an additional second secondary winding associated with the additional primary winding and coupled to a first end and a second end of a fourth TCP coil of the plasma chamber, wherein the magnetic flux generated by the additional primary winding induces a voltage in the additional second secondary winding, wherein an RF signal generated by the voltage induced in the additional second secondary winding is transmitted from the additional second secondary winding to the fourth TCP coil.

14. The transformer arrangement of claim 11, wherein the capacitor is coupled to a ground connection.

15. The transformer device of claim 11, wherein the capacitor is a variable capacitor or a fixed capacitor, wherein the variable capacitor is coupled to a motor to change the capacitance of the variable capacitor.

16. The transformer device of claim 11, wherein the first secondary winding is twisted around the primary winding to be associated with the primary winding, and the second secondary winding is twisted around the primary winding to be associated with the primary winding.

17. The transformer device according to claim 11, wherein the first secondary winding is wound in an interleaved manner with the primary winding to be associated with the primary winding, and the second secondary winding is wound in an interleaved manner with the primary winding to be associated with the primary winding.

18. The transformer device of claim 11, wherein the first end of the primary winding is coupled to the impedance matching circuit via another capacitor, wherein the other capacitor is a fixed capacitor or a variable capacitor.

19. A method for achieving uniformity in substrate processing, comprising: receiving a modified radio frequency (RF) signal from an output of the impedance matching circuit through a primary winding of a transformer, wherein the primary winding is coupled to a capacitor; upon receiving the modified RF signal, generating magnetic flux through the primary winding to induce a voltage across a secondary winding of the transformer; as well as An RF signal generated by the voltage is transmitted from the secondary winding to a transformer coupled plasma TCP coil of a plasma chamber, wherein the secondary winding is coupled to a first end of the TCP coil and a second end of the TCP coil.

20. The method of claim 19, wherein the TCP coil is connected in series with the secondary winding.

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