Diode Laser Measurements in High Density Fluorocarbon Plasmas
Abstract
Inductively coupled, high-density plasma reactors are expected to play a key role in next generation 0.25 μm semiconductor manufacturing. This work focuses on diode laser diagnostics of two such reactors: a non-commercial GEC Cell inductively coupled plasma and a commercial AMAT 5300 HDP oxide etcher. In this study, we employ diode lasers in the mid-IR regime (3-11 μm) to detect radicals important to oxide etching. The experiments in this study focused on radical concentrations found in the reactor under typical high-density plasma etching conditions. Gas phase measurements of etchant species (CF and CF_2) formed from dissociation of a C_2F6 plasma, and etch-product species formed from plasma surface interactions are described. The technique is crucial to plasma model development since it is one of the few techniques that can reliably measure the absolute density of ground state radical species formed by electron impact dissociation in the discharge. A database of neutral radical species concentrations at various reactor power, bias and pressure settings is presented. This database is essential for theoretical plasma model calibration and validation. (This work has been supported by SEMATECH)
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 1998
- Bibcode:
- 1998APS..GEC.AM304A