Identification of Rogue Tools and Process State Drift by Using JMP Software Visualization and Analytical Techniques
Jim Nelson, Engineering Data Specialist – Freescale Semiconductor
The making of integrated circuits (computer chips) takes hundreds of very exacting series of steps. Hundreds of different pieces of equipment are used within those steps. Process drift and yield drops are a feared fact of life in the semiconductor industry. Identification of which process steps and/or tool or combination of tools contributed to the process drift or yield drop is a time-consuming and complex process, taking up a considerable amount of the engineers’ time within Freescale. A combination of JMP software-delivered analytical tools, Freescale-developed statistical methodologies and Freescale-developed analytical and visualization JMP scripts are being used to solve these issues. This paper describes the use of partitioning, a Freescale-developed methodology, Step Origin of a Drift Analysis (SODA), and two Freescale-developed JMP software scripts. The scripts allow for ordering of the charts and graphs based upon statistical evaluation along with the ability to move from chart to chart very quickly. This methodology allows for a very positive combination of analytical guidance, coupled with tools that provide the engineers with visual evidence to match their knowledge and experience in making decisions on what needs to be done to bring the processes back into alignment.