CROWNE: Current Ratio Outliers with Neighbor Estimator
نویسندگان
چکیده
Increased leakage and process variations make distinction between fault-free and faulty chips by IDDQ test difficult. Earlier the concept of Current Ratios (CR) was proposed to screen defective (outlier) chips. However, it is not capable of catching certain defects. Neighboring chips on a wafer have similar fault-free parameters that are correlated through the underlying fabrication process. Based on this observation, an alternative test metric called Neighbor Current Ratio (NCR) was proposed. NCR screens outlier chips based on their nonconformance to local variation in IDDQ. In this paper, we explore the correlation between different vectors that yield CR and NCR values. The effectiveness of NCR along with additional test parameters to screen outlier chips is evaluated using industrial test data.
منابع مشابه
A Two-Phase Robust Estimation of Process Dispersion Using M-estimator
Parameter estimation is the first step in constructing any control chart. Most estimators of mean and dispersion are sensitive to the presence of outliers. The data may be contaminated by outliers either locally or globally. The exciting robust estimators deal only with global contamination. In this paper a robust estimator for dispersion is proposed to reduce the effect of local contamination ...
متن کاملAsymptotic Behaviors of Nearest Neighbor Kernel Density Estimator in Left-truncated Data
Kernel density estimators are the basic tools for density estimation in non-parametric statistics. The k-nearest neighbor kernel estimators represent a special form of kernel density estimators, in which the bandwidth is varied depending on the location of the sample points. In this paper, we initially introduce the k-nearest neighbor kernel density estimator in the random left-truncatio...
متن کاملUse of Multiple IDDQ Test Metrics for Outlier Identification
With increasing circuit complexity and reliability requirements, screening outlier chips is an increasingly important test challenge. This is especially true for IDDQ test due to increased spread in the distribution. In this paper, the concept of current ratio is extended to exploit waferlevel spatial correlation. Two metrics – current ratio and neighbor current ratio – are combined to screen o...
متن کاملA robust wavelet based profile monitoring and change point detection using S-estimator and clustering
Some quality characteristics are well defined when treated as response variables and are related to some independent variables. This relationship is called a profile. Parametric models, such as linear models, may be used to model profiles. However, in practical applications due to the complexity of many processes it is not usually possible to model a process using parametric models.In these cas...
متن کاملApplication of robust multivariate control chart with Winsorized Mean: a case study
Water pH and active ingredient concentration are two of the most important variables to consider in the manufacturing process of fungicides. If these variables do not meet the required standards, the quality of the product may be compromised and lead to poor fungicide performance when water is used as the application carrier, which is in most cases. Given the correlation between the variable...
متن کامل