There are four main objectives to this work. The first is to provide a better understanding of a new negative ion diagnostic procedure for radio-frequency processing discharges. This technique is based upon direct ion mass spectrometry. The second objective is to use this diagnostic to probe technologically important discharges and determine the negative ions identities and dependencies on externally controlled parameters. This information will be used to provide a more complete understanding of negative ion kinetics and transport in the discharge. Negative ions are being studied to determine whether or not they help to produce gas-phase particulates (microcontamination) in the discharge. This contamination can increase the failure rate of semiconductor devices. The fourth objective is to begin to investigate whether or not negative ions etch or deposit materials better than their positive counterparts. Mass spectrometric measurements of the neutrals and ions in the discharge in conjunction with microwave measurements of the electron density and optical measurements of radiating species will be combined to achieve the goals for this research.