Plasma processing and surface treatments in LAPPS

Abstract

Summary form only given. Photoresist ashing tests have demonstrated anisotropic pattern transfer in our modulated 'Large Area Plasma Processing System' with moderate RF bias voltages. The system consists of a planar plasma distribution generated by a magnetically collimated (10-300 Gauss) sheet of electrons (2-5 kV, 10 mA/cm/sup 2/) injected into a neutral gas background (20-200 mtorr) producing ion densities of 10/sup 9/-10/sup 12/ cm/sup -3/ in noble and molecular gases. Test samples are exposed to the plasma on a simple, electrically isolated chuck. Because beam ionization is independent of the reactor chamber or geometry, stage or chuck effects are only coupled through the plasma species and collisions with background gas. Surface and electronic diagnostics have been used to investigate the flux to the surface composition and the associated electromagnetics of the stage. Processing results are correlated to relative plasma specie composition (and energies) from through-the-platen sampling mass spectrometry and [RF and DC] current sensor information. With the appropriate time resolved diagnostics, effects of pulsed vs DC operation can be studied as well. Our progress on these issues and how they impact real processing applications of photoresist ashing and ion milling will be presented.