A traveling wave driven, inductively coupled large area plasma source

Summary form only given. A large area inductive plasma source driven by a 13.56 MHz traveling wave has been investigated. Launching a traveling wave eliminates standing wave effects to obtain a uniformly excited processing plasma. The plasma source is rectangular in shape with a processing area of 71 cm-61 cm, and contains a substrate holder large enough to study processing of 300 mm diameter silicon wafers and 360 mm/spl times/465 mm glass substrates. The antenna coil consists of a series (serpentine) connection of eight parallel rods embedded in the plasma inside thin quartz tubes. The antenna coil configuration and the circuit used to launch a traveling wave are described. The plasma properties, including plasma potential, ion density profile, and electron temperature were measured as a function of discharge power (up to 2000 W) and gas pressure (1-100 mTorr), with a capacitive probe and a Langmuir probe. The Langmuir probe is driven by two stepper motors to provide a two-dimensional density profile. Both motor motion and data acquisition and processing are controlled by a computer in real time through a data acquisition board. We find that it is possible to tune the system to launch a traveling wave for a wide range of powers and pressures.