Using Modeling to Determine Ion Energy Associated with A Plasma System

摘要

Systems and methods for determining ion energy are described. One of the methods includes detecting output of a generator to identify a generator output complex voltage and current (V&I). The generator is coupled to an impedance matching circuit and the impedance matching circuit is coupled to an electrostatic chuck (ESC). The method further includes determining from the generator output complex V&I a projected complex V&I at a point along a path between an output of a model of the impedance matching circuit and a model of the ESC. The operation of determining of the projected complex V&I is performed using a model for at least part of the path. The method includes applying the projected complex V&I as an input to a function to map the projected complex V&I to a wafer bias value at the ESC model and determining an ion energy from the wafer bias value.

主权项

1. A method for determining ion energy, the method comprising:
identifying a first complex voltage and current measured at an output of a radio frequency (RF) generator when the RF generator is coupled to a plasma chamber via an impedance matching circuit, the impedance matching circuit having an input coupled to the output of the RF generator and an output coupled to an RF transmission line; generating an impedance matching model based on electrical components defined in the impedance matching circuit, the impedance matching model having an input and an output, the input of the impedance matching model receiving the first complex voltage and current, the impedance matching model having one or more elements; propagating the first complex voltage and current through the elements of the impedance matching model to determine a second complex voltage and current; obtaining a peak voltage; determining a wafer bias based on the second complex voltage and current; and determining the ion energy based on the wafer bias and the peak voltage.