Manufacturing requirements for a single-wafer develop process

The validity of a photolithographic develop process in a manufacturing environment is measured by critical-dimension control, photo defects, chemical usage, cycle time, functional test yield, and rework. Due to the rapid pace of change in the semiconductor industry and the trend toward ever tighter ground rules, the demands that these parameters place on the develop process are never constant. A process that worked in the past may suddenly become inadequate for a new product design with specific performance, throughput and cost requirements. This paper details the techniques used for engineering support of the photocluster single-wafer develop processes in the IBM Microelectronics Division's semiconductor production facility near Burlington, Vermont. Unique analysis procedures have been established for baselining spray- and puddle-develop processes and for identifying the sources of sudden process deviations or defect occurrences. Effective engineering support can maintain the required process performance while also ensuring that all other production considerations are met.