Patents by Inventor Imran Ahmed Bhutta

Imran Ahmed Bhutta has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12272522
    Abstract: In one embodiment, an RF impedance matching circuit includes at least one electronically variable capacitor (EVC) comprising discrete fixed capacitors. Each fixed capacitor has a corresponding switching circuit for switching in and out the fixed capacitor to alter a total capacitance of the EVC. Each switching circuit includes a diode operably coupled to the fixed capacitor to cause the switching in and out of the fixed capacitor, the diode being a PIN diode or an NIP diode. Each switching circuit further includes a driver circuit operably coupled to the diode, and a resonant filter positioned between the driver circuit and the diode. The resonant filter includes an inductor and a capacitor coupled in parallel.
    Type: Grant
    Filed: April 19, 2022
    Date of Patent: April 8, 2025
    Assignee: ASM America, Inc.
    Inventor: Imran Ahmed Bhutta
  • Publication number: 20240404791
    Abstract: In one embodiment, the present disclosure is directed to a system for controlling microwave power delivered to a distributed electrode to improve the uniformity of an electric field on the distributed electrode. The system includes an RF source circuit comprising at least one RF generator and multiple RF source circuit outputs, each RF source circuit output outputting an RF source signal having a frequency of at least 300 MHz. For each of the RF source circuit outputs, a solid-state impedance matching circuit is operably coupled to the RF source circuit output and configured to receive the RF source signal output by the RF source circuit output. For each of the matching circuits, a system output is operably coupled to the matching circuit and configured to output the RF source signal to a distributed electrode of the load.
    Type: Application
    Filed: May 24, 2024
    Publication date: December 5, 2024
    Inventor: Imran Ahmed BHUTTA
  • Publication number: 20240234095
    Abstract: In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit includes at least one electronically variable capacitor (EVC). Each EVC includes fixed capacitors, each of the fixed capacitors having a corresponding switching circuit for switching in and out the fixed capacitor to alter a total capacitance of the EVC. Each switching circuit includes a switch operably coupled to the fixed capacitor to cause the switching in and out of the fixed capacitor. The switch includes at least one string of series-connected PIN or NIP diodes. For each string, at least one of the diodes of the string has a balancing capacitor parallel to the diode.
    Type: Application
    Filed: May 25, 2022
    Publication date: July 11, 2024
    Inventors: Ronald Anthony DECKER, Imran Ahmed BHUTTA
  • Publication number: 20240194449
    Abstract: In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit includes a series electronically variable capacitor (EVC) having first fixed capacitors. Each of the first fixed capacitors has a corresponding switch for switching in and out the fixed capacitor to alter the series variable capacitance. Each switch includes one or more diodes. A first inductor has a first terminal electrically coupled to the common ground and a second terminal electrically coupled between the RF input and the RF output. A control circuit determines a first parameter related to the plasma chamber while the RF source is providing the RF signal to the RF input. While the RF signal continues to be provided to the RF input, the control circuit alter the series variable capacitance based on the determined first parameter. The alteration causes RF power reflected back to the RF source to decrease.
    Type: Application
    Filed: April 5, 2022
    Publication date: June 13, 2024
    Inventor: Imran Ahmed BHUTTA
  • Publication number: 20240177970
    Abstract: In one embodiment, a system for determining a characteristic of the plasma chamber is disclosed. The system includes an impedance matching network, a sensor, and a control circuit. The control circuit stores one or more reference values for a parameter related to a semiconductor processing tool. A current value for the parameter is determined based on a signal received from the sensor. The control circuit then determines a characteristic of the plasma chamber based on a comparison of the current value for the parameter and the one or more reference values for the parameter.
    Type: Application
    Filed: February 6, 2024
    Publication date: May 30, 2024
    Inventor: Imran Ahmed BHUTTA
  • Publication number: 20240145216
    Abstract: In one embodiment, a system for semiconductor fabrication includes a continuous wave (CW) radio frequency (RF) source and a pulsing RF source. The system further includes a matching network positioned between the CW RF source and the load and a control circuit. The control circuit receives one or more signals indicative of the pulsing RF signal, and selects a portion of the pulsing RF signal. The control circuit then samples at least one parameter during the selected portion of the pulsing RF signal. Based on the at least one parameter, the control circuit causes an alteration of the at least one variable reactance element, which causes the matching network to impedance match between the CW RF source and the load.
    Type: Application
    Filed: October 27, 2023
    Publication date: May 2, 2024
    Inventors: Imran Ahmed BHUTTA, Tomislav Lozic
  • Patent number: 11948775
    Abstract: In one embodiment, a method of matching an impedance is disclosed. An impedance matching network is coupled between a radio frequency (RF) source and a plasma chamber. The matching network includes a variable reactance element (VRE) having different positions for providing different reactances. The RF source is subject to a power control scheme to control a power delivered to the matching network. Based on a determined parameter, a new position for the VRE is determined to reduce a reflected power at the RF input of the matching network. The VRE is altered to the new position while the power control scheme is altered.
    Type: Grant
    Filed: November 2, 2022
    Date of Patent: April 2, 2024
    Inventor: Imran Ahmed Bhutta
  • Publication number: 20230215696
    Abstract: In one embodiment, a system includes an RF source and an RF impedance matching circuit receiving RF power from the RF source. The matching circuit includes at least one variable reactance element, a sensor operably coupled to a component of the matching circuit, and a control circuit. The control circuit receives a signal from the sensor indicative of a parameter value. Upon determining the parameter value meets a first predetermined condition, the control circuit transmits a control signal to the RF source causing the RF source to carry out a power control scheme. The power control scheme causes the RF source to reduce or maintain the RF power without turning off the RF power.
    Type: Application
    Filed: March 13, 2023
    Publication date: July 6, 2023
    Inventors: Ronald Anthony DECKER, Imran Ahmed BHUTTA
  • Publication number: 20230082359
    Abstract: In one embodiment, a method of matching an impedance is disclosed. An impedance matching network is coupled between a radio frequency (RF) source and a plasma chamber. The matching network includes a variable reactance element (VRE) having different positions for providing different reactances. The RF source is subject to a power control scheme to control a power delivered to the matching network. Based on a determined parameter, a new position for the VRE is determined to reduce a reflected power at the RF input of the matching network. The VRE is altered to the new position while the power control scheme is altered.
    Type: Application
    Filed: November 2, 2022
    Publication date: March 16, 2023
    Inventor: Imran Ahmed BHUTTA
  • Patent number: 11557461
    Abstract: In one embodiment, an RF impedance matching network is disclosed. The matching network is coupled between an RF source having a variable frequency and a plasma chamber having a variable chamber impedance. The matching network includes a variable reactance element (VRE), and a control circuit coupled to the VRE and a sensor, the sensor configured to detect an RF parameter. To cause an impedance match between the RF source and the plasma chamber, the control circuit determines, based on the detected RF parameter and a VRE configuration, a new source frequency for the RF source. The impedance match then causes the variable frequency of the RF source to alter to the new source frequency.
    Type: Grant
    Filed: June 10, 2021
    Date of Patent: January 17, 2023
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11521833
    Abstract: In one embodiment, a method of matching an impedance is disclosed. An impedance matching network is coupled between a radio frequency (RF) source and a plasma chamber. The matching network includes a variable reactance element (VRE) having different positions for providing different reactances. The RF source has an RF source control circuit carrying out a power control scheme to control a power delivered to the matching network. Based on a determined parameter, a new position for the VRE is determined to reduce a reflected power at the RF input of the matching network. The matching network provides a notice signal to the RF source indicating the VRE will be altered. In response to the notice signal, the RF source control circuit alters the power control scheme. While the power control scheme is altered, the VRE is altered to the new position.
    Type: Grant
    Filed: June 30, 2021
    Date of Patent: December 6, 2022
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11476091
    Abstract: In one embodiment, a method of using an impedance matching network to determine a plasma chamber characteristic is disclosed. An impedance matching network is coupled between a radio frequency (RF) source and a plasma chamber. The matching network includes a variable reactance element (VRE) having different positions for providing different reactances. A characteristic of the plasma chamber is determined based on reference values for a parameter of the matching network and a current value. Based thereon, either a visual or audible indication of the determined characteristic of the plasma chamber is provided, or an action is taken to address the determined characteristic.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: October 18, 2022
    Inventor: Imran Ahmed Bhutta
  • Publication number: 20220254610
    Abstract: In one embodiment, an RF impedance matching circuit includes at least one electronically variable capacitor (EVC) comprising discrete fixed capacitors. Each fixed capacitor has a corresponding switching circuit for switching in and out the fixed capacitor to alter a total capacitance of the EVC. Each switching circuit includes a diode operably coupled to the fixed capacitor to cause the switching in and out of the fixed capacitor, the diode being a PIN diode or an NIP diode. Each switching circuit further includes a driver circuit operably coupled to the diode, and a resonant filter positioned between the driver circuit and the diode. The resonant filter includes an inductor and a capacitor coupled in parallel.
    Type: Application
    Filed: April 19, 2022
    Publication date: August 11, 2022
    Inventor: Imran Ahmed BHUTTA
  • Patent number: 11398370
    Abstract: In one embodiment, a method, a method of manufacturing a semiconductor is disclosed. A monitored semiconductor manufacturing system (monitored system) is operated over a period of time, the monitored system comprising an impedance matching network coupled between a radio frequency (RF) source and a plasma chamber. First values for a parameter of the monitored system are received, the first values comprising different values for the parameter over the time period of operation of the monitored system, and a learning model is trained using the first values for the parameter. A substrate is then placed in a plasma chamber of a controlled semiconductor manufacturing system (controlled system). A characteristic of the controlled system is determined using a current value of the parameter and the trained learning model. An action is then taken upon the controlled system to address the determined characteristic.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: July 26, 2022
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11393659
    Abstract: In one embodiment, a method of impedance matching and controlling the power delivered to a plasma chamber is disclosed. A matching network includes a variable reactance element (VRE), the VRE having different positions for providing different reactances. Based on a determined parameter, the method determines potential new positions for the VRE that would have a threshold effectiveness in providing an impedance match between the RF source and the plasma chamber. A preferred position for the VRE is determined by determining the one of the potential new positions meeting the threshold effectiveness whose efficiency in delivering RF power from the RF input to the RF output would cause an RF power at the RF output to be closest to a desired RF power.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: July 19, 2022
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11315758
    Abstract: In one embodiment, the present disclosure is directed to an RF impedance matching network that includes an electronically variable capacitor (EVC) and a control circuit. The control circuit is coupled to a sensor configured to detecting an RF parameter. To cause an impedance match between an RF source and a plasma chamber, the control circuit determines, using a match lookup table with a value based on the detected RF parameter, a match combination of a new EVC configuration for providing a new EVC capacitance, and a new source frequency for the RF source. The control circuit then alters the EVC to the new EVC configuration, and alters the variable frequency of the RF source to the new source frequency.
    Type: Grant
    Filed: July 3, 2019
    Date of Patent: April 26, 2022
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11289307
    Abstract: In one embodiment, a method of matching an impedance is disclosed. A matching network includes an electronically variable reactance element (EVRE) comprising discrete reactance elements and corresponding switches. For a determined parameter, potential new positions for the EVRE are determined, the potential new positions having differing effectiveness in causing an impedance match between an RF source and a plasma chamber. The discrete reactance elements of the EVRE that are currently restricted from switching are determined. A preferred position for the EVRE is determined as being the one of the potential new positions that provides greatest effectiveness in providing an impedance match while also not requiring switching in or out of any of the discrete reactance elements that are currently restricted from switching.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: March 29, 2022
    Inventor: Imran Ahmed Bhutta
  • Publication number: 20220084791
    Abstract: In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit is coupled between a plasma chamber and an RF source. The matching circuit includes a first electronically variable capacitor (EVC) having a first variable capacitance, a terminal of the first EVC being operably coupled to the RF input, and a second EVC having a second variable capacitance, a terminal of the second EVC being operably coupled to the RF output. A control circuit determines, based on a first parameter, a first capacitance value for the first EVC and a second capacitance value for the second EVC. The control circuit then generates a control signal to alter the first and second variable capacitances accordingly. The alteration of the capacitances, while the frequency of the RF source is not altered, causes RF power reflected back to the RF source to decrease.
    Type: Application
    Filed: November 24, 2021
    Publication date: March 17, 2022
    Inventor: Imran Ahmed Bhutta
  • Patent number: 11195698
    Abstract: In one embodiment, an RF impedance matching network utilizing at least one electronically variable capacitors (EVC) is disclosed. Each EVC includes discrete capacitors operably coupled in parallel, the discrete capacitors including fine capacitors and coarse capacitors. A control circuit determines a parameter related to the plasma chamber and, based on the parameter, determines which of the coarse capacitors and which of the fine capacitors to have switched in to cause an impedance match. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.
    Type: Grant
    Filed: July 7, 2020
    Date of Patent: December 7, 2021
    Inventors: Imran Ahmed Bhutta, Michael Gilliam Ulrich
  • Patent number: 11189466
    Abstract: In one embodiment, a switching circuit includes an electronic switch comprising one or more diodes for switching a reactance element within an electronically variable reactance element. A first power switch receives an input signal and a first voltage, and switchably connects the first voltage to a common output in response to the received input signal. A second power switch receives an input signal and a second voltage, and switchably connects the second voltage to the common output in response to the received input signal. The second voltage is opposite in polarity to the first voltage. The first power switch and the second power switch asynchronously connect the first voltage and the second voltage, respectively, to the common output, the one or more diodes of the electronic switch being switched according to the first voltage or the second voltage being connected to the common output.
    Type: Grant
    Filed: February 23, 2021
    Date of Patent: November 30, 2021
    Inventor: Imran Ahmed Bhutta