## Semiconductor Manufacturers Increasingly Employ Guardbanding for Enhanced Reliability
Semiconductor manufacturers are prioritizing the identification and removal of partially defective die, often referred to as “marginal” die, to bolster product reliability. These die may initially pass final electrical tests but can exhibit failures under ongoing stress, a critical concern for sectors like automotive and medical device manufacturing. To address this, the industry is increasingly adopting a process called guardbanding.
### What is Guardbanding and Why is it Shifting In-Line?
Guardbanding involves updating wafer map coordinates to mark suspect die as unusable and expanding this exclusion to surrounding die as a safety buffer. Traditionally implemented at the end-of-line, guardbanding is now being integrated with in-line macro defect inspection. Earlier detection is vital, as some in-line issues can be obscured by subsequent processing steps. Microtronic’s EagleView system, for example, allows fabs to inspect every wafer, not just samples, facilitating more frequent inspections and quicker identification of process and equipment issues.
### EagleView System Automates and Improves Precision
EagleView enables direct guardbanding on high-resolution wafer images, offering greater precision and efficiency compared to manual, paper-based methods. The digital platform automates guardbanding for specific defects – such as scratches – while allowing operators to selectively exclude other issues. The system also creates a comprehensive database of permanent, high-resolution wafer images that supports defect analysis and root cause investigations, while integrating seamlessly with existing workflows and supporting standard wafer map formats.
### Early Defect Detection Bolsters Confidence
While final testing remains an important step, incorporating in-line macro defect inspection and guardbanding represents a significant effort to identify and mitigate potential chip failures earlier in the manufacturing process. This proactive approach aims to improve chip reliability, reduce returns, and ultimately, enhance customer satisfaction.
