×

Systems and methods for reverse pulsing

  • US 9,761,459 B2
  • Filed: 09/23/2015
  • Issued: 09/12/2017
  • Est. Priority Date: 08/05/2015
  • Status: Active Grant
First Claim
Patent Images

1. A method for operating a plasma chamber during plasma processing, the method comprising:

  • receiving a digital signal, the digital signal having a first state and a second state;

    generating a transformer coupled plasma (TCP) radio frequency (RF) pulsed signal having a high state when the digital signal is in the first state and having a low state when the digital signal is in the second state, wherein the high state of the TCP RF pulsed signal has a higher amount of power than an amount of power of the low state of the TCP RF pulsed signal;

    providing the TCP RF pulsed signal to one or more coils of the plasma chamber;

    generating a bias RF pulsed signal having a low state when the digital signal is in the first state and having a high state when the digital signal is in the second state, wherein the high state of the bias RF pulsed signal has a higher amount of power than an amount of power of the low state of the bias RF pulsed signal, wherein generating the bias RF pulsed signal includes;

    transitioning the bias RF pulsed signal from the high state to the low state at a time of transition of the TCP RF pulsed signal from the low state to the high state; and

    transitioning the bias RF pulsed signal from the low state to the high state at a time of transition of the TCP RF pulsed signal from the high state to the low state; and

    providing the bias RF pulsed signal to a chuck of the plasma chamber, wherein providing the TCP RF pulsed signal occurs while providing the bias RF pulsed signal, wherein said transitioning of the bias RF signal from the low state to the high state at the time of transition of the TCP RF pulsed signal from the high state to the low state is performed to increase vertical directionality of ions generated in the plasma chamber towards the chuck to process an etch operation of high aspect ratio features.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×