Uniformity measurements in a helicon plasma etcher

Summary form only given. Recent research efforts on the UW helicon etcher have focused on the plasma density profile variation along the axis of the etching chamber. The goal of this research is to find ways to maintain a high plasma density while creating a radially uniform plasma. This study is unique because high magnetic fields (425-625 G) are used in the source region. The UW helicon etcher consists of 21 magnetic field coils surrounding a 1 meter long, 10 cm diameter quartz tube. At one end of the tube is a Negoya Type III RF antenna which is run at 13.56 MHz. At the opposite end is the etching chamber containing a 20 cm diameter magnetic multidipole bucket. The purpose of the bucket is to both maintain a high plasma density and improve the radial uniformity in the etching chamber. This experiment was conducted using 20 seem of argon at a pressure of 5 mT with an RF power of 900 W. The magnetic field was varied between 425 and 625 Gauss. The density was measured using a Langmuir probe fitted with 3 filters to filter out the RF perturbations at 13.56, 27.12, and 40.68 MHz.