: Gases used for purging or welding must meet specific criteria. For example, welding argon should have oxygen and moisture levels below 50 ppb (parts per billion).
Historically, the industry used SEMI E49.4. However, as wafer sizes grew (300mm to 450mm) and process nodes shrank (to 3nm and below), legacy formats became inadequate. modernizes the standard by: semi e49.6 pdf
Here is a useful story illustrating why this standard matters, wrapped in a narrative about a high-stakes chip manufacturing crisis. : Gases used for purging or welding must