In order to maintain an effective and competitive manufacturing environment in the microelectronic industry, continual improvement to the fabrication tools is mandated. One of the myriad of measurement philosophies available is the concept of overall equipment effectiveness (OEE), which is a part of total productive maintenance (TPM). Results of an 18 month study on improving the OEE of single wafer aluminum plasma etchers are presented. At the start of the project, several designed experiments were performed to optimize the plasma etch process. A detailed logging procedure was implemented that accounted for the various equipment operating states as well as the number of wafers processed. The OEE for the initial 6 months of the program was determined to have an average value of 42%. Improvements to the etchers, their operation and maintenance were implemented as a result of the TPM program. During the last 4 months of the study, the average value for OEE was 67%, an increase of 60%.