New R&R Methodology in Semiconductor Manufacturing Electrical Testing

Abstract

In a measurement process, Quality is achieved only if “good measurements” are performed. Values must remain unchanged within the same gauging set (repeatability) and in time (reproducibility). In semiconductor testing manufacturing, R&R (Repeatability and Reproducibility) methodology is based on the well-known ANalysis Of VAriance (ANOVA) statistical technique. It is applied to the entire measurement system, where the first element is Automatic Test Equipment (ATE) and the last is the Device Under Test (DUT) or a sample representing it. In this paper, a new patented method, based again on ANOV A, is presented, where ATE is addressed separately from the rest of the measurement chain and aligned independently from the DUT and related systems. It was achieved through a platform-oriented tool able to stimulate each critical ATE resource in a relatively short time. All DUT -dependent systems, such as load boards, probe cards, etc., are aligned separately through standard correlation methodologies. Consequently, each new product can be easily released to production through a very fast correlation procedure. Benefits of this new approach vs the previous one are demonstrated in terms of quality, reliability, efficiency and reduced impact on manufacturing environment. This practice has been used for some years at worldwide level in STMicroelectronics to demonstrate, beyond any reasonable doubt, its added value through all manufacturing supply chains and departments, and moreover from final customers appreciation.