Plasma density, energy and etch rate measurements at bias power input and real time feedback control of plasma source and bias power

摘要

A plasma reactor process measurement instrument includes an input phase processor receiving wafer bias voltage, current and power and computing an input impedance, an input current and an input voltage to the transmission line; a transmission line processor for computing a junction admittance of a junction between the transmission line and the conductive grid from the input impedance, input current and input voltage and from parameters of the transmission line; a grid-to-ground transformation unit for providing shunt electrical quantities of a shunt capacitance between the grid and a ground plane; a grid-to-wafer transformation unit for providing load electrical quantities of a load capacitance between the grid and the wafer; and, a combined transformation processor for computing the at least one of the etch rate, plasma ion density and wafer voltage from the junction admittance, the shunt electrical quantities, the load electrical quantities and a frequency of the RF power generator.