An industrial risk-based indicator for dynamic sampling in semiconductor manufacturing

Uniform rate sampling is the easiest and most common sampling strategy used in the semiconductor industry. It consists of measuring every N products and is used for both regulated and unregulated steps. However, it is well-know that the sampling frequency has a direct impact on regulator performances making uniform rate sampling ineffective with the regulated steps. This paper proposes an indicator allowing the adaptation of the sampling frequencies taking into account the performances of the regulator and the industrial risk. The developed method offers better regulation performances, less measured products and leads to yield improvement and cycle time reduction. The approach is tested with real data provided by STMicroelectronics.