Controlling your tool better

Semiconductor industry has seen and explosive growth in terms of its market capitalization and its sales volume. The progress of the technology development has been spurred by the ever increasing consumer market trend.  As more consumer electronics has been designed for the ease and benefit of humankind, technology trend has so seen an aggressive push towards more circuit density per a single chip which has been predicted by Gordon Moore which been recapitulate in his Moore's law.

The shrink in the circuit density has also prompt in a more sensitive devices which requires a more stringent control on its semiconductor process. If for an older technology a defect of the size of 0.2um will not cause and detrimental effects on the overall processing circuit, now with a technology node of 65nm and beyond this defect size has catastrophic effect on the chip which translate to yield loss on the wafer.

Hence ushered the world of FDC or Fault Diagnostic and Control. FDC has provided the semiconductor player with a tool of controlling the processing tool by monitoring the processing parameter. This will help process engineer or the equipment engineer to stop the tool in the event that that the tool detected a drift before more wafers are exposed to the process. Previously control of the wafers was done based on a post processing data such as thickness drift or based on the qual wafer monitoring. This creates a big potential impact in the event that a major excursion happened in between the qualification wafers.

FDC has evolved from merely a tool to detect simplistic drift to conducting multivariate analysis to see correlation between multiple variables. By having multivariate analysis capability we are able to monitor multiple parameters at once and reduce any false alarm that might be triggered due to false alarm in the condition of a single parameter drift. There has been extensive study conducted on the modelling of tool parameters in order to determine the health of the tool and detecting abnormal drift and stopping the tool before excursion even occurs.

FDC is a wonderful tool only if a process engineer or equipment engineers utilizes it well by ensuring proper parameter are been monitored and specific rule are been generated.