Define Pump-Down Curve The pump-down curve is the fundamental performance signature of any vacuum system. It plots chamber pressure (typically in Torr or Pa) against time, starting at atmosphere (760 Torr) and descending toward the system’s ultimate base pressure. In practice, the curve reveals three distinct regimes: viscous flow (high pressure, rapid gas removal), transitional

Plasma Chamber Pressure Stages In plasma processing equipment—whether for reactive ion etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD)—the vacuum system progresses through distinct pressure stages. Each stage demands accurate, real-time monitoring to ensure process stability, repeatability, and equipment protection. The first stage is rough vacuum pump-down, from atmosphere