Onwafer

Onwafer is a term used in the semiconductor industry to refer to processes or measurements that occur while the integrated circuits are still on the silicon wafer. Before a wafer is cut into individual chips, known as dicing, it undergoes numerous fabrication steps. Onwafer processes include photolithography, etching, deposition, and doping, all performed on the entire wafer.

Onwafer measurements are crucial for quality control and process monitoring. These can include electrical tests to verify functionality and performance of the circuits, optical inspections to detect defects, and metrology to measure critical dimensions. These tests help identify issues early in the manufacturing process, allowing for adjustments before the entire wafer is compromised.

The term "onwafer" distinguishes these stages from "post-wafer" or "post-packaging" processes, which happen after the wafer has been diced and the individual chips have been encapsulated. Understanding the onwafer stage is vital for semiconductor engineers and manufacturers as it represents the core of integrated circuit production. The efficiency and yield of onwafer processes directly impact the cost and availability of microchips.