| Films of magnetic materials are used in a variety of electronic devices. They are currently used primarily in both the giant magnetoresistive (GMR) read/write heads of hard drives and in magnetoresistive memory (MRAM). Patterning of the metals in GMR heads is usually accomplished using ion-milling techniques, whereas non-selective metal etch techniques are used in the patterning of MRAM devices. As the size of devices continues to shrink, new selective etch chemistries will become more important. The composition of CO/NH3, CO/H2, CO2/NH3, and CO2/H 2 plasmas suitable for the etching of magnetic materials has been studied by supersonic pulse, plasma sampling mass spectrometry. The composition of the plasma's major components has been determined by a variety of approaches including isotopic labeling, and the identification of clusters formed by the sampling technique. All four of the different etch chemistries were investigated individually. The major components of the gas flows and the plasmas for each system were identified. The chemical mechanism of etching has been identified for all four etch recipes. |
