Application Scenarios
A solar-panel manufacturer running a PECVD tool for silicon-nitride passivation layers was seeing wafer-to-wafer non-uniformity that traced back to flow instability during recipe transitions. The chamber recipe called for a 70 slm argon purge step followed by a 40 slm argon dilution step, and the existing MFC took several seconds to settle after each change. During that unsettled interval the chamber composition drifted, producing a measurable variation in deposition rate across the batch.The tool was rebuilt around the 1579A-00412-LM1BV as the argon-delivery MFC. Because the controller is calibrated for argon at 100 slm full scale, the 70 slm and 40 slm recipe steps sit comfortably inside the 2–100% control range where the instrument is specified, rather than being run near the bottom of a larger-range device. The PID control loop reaches setpoint in under one second, which is the parameter that actually mattered: the recipe-transition idle time is now governed by the MFC rather than by the chamber waiting for the gas to stabilise. The plant reported tighter film-uniformity distribution and fewer edge-wafer rejects after the change.The technical point is worth stating plainly. Flow accuracy is often quoted as a percentage of full scale, so a 100 slm MFC reading 40 slm has a smaller absolute tolerance band than a 300 slm MFC reading the same flow. For a process that spends most of its time in the middle of the range, matching the calibration range to the normal operating point is a more effective way to improve repeatability than changing the controller at all.
Parameter
| Parameter | Value / Description |
|---|---|
| Product Model | 1579A-00412-LM1BV |
| Manufacturer | MKS Instruments |
| Product Category | Digital mass flow controller (elastomer-sealed) |
| Decoded Configuration | Argon-calibrated, 100 slm FS (12L), 8 VCR male (R), normally closed valve (1), analog 15-pin D (B), Buna-N seals (B), Viton option (V) |
| Calibration Gas | Argon (Ar), SEMI Gas Code 004 |
| Full-Scale Flow Range | 100 slm (N₂ equivalent) — selected from 50 / 100 / 200 / 300 slm family range |
| Control Range | 2 to 100% of full scale |
| Typical Accuracy | ±1% of full scale |
| Repeatability | ±0.2% of full scale |
| Resolution | 16 bit — the digital core divides the full-scale range into 65,536 steps |
| Settling Time | < 1 second — the time to reach setpoint after a step change |
| Warm-up Time | 30 minutes typical |
| Setpoint Command | 0 to 5 VDC from a source of < 20 kΩ |
| Flow Output Signal | 0 to 5 VDC into a load of > 10 kΩ |
| Connector | 15-pin Type D male (analog I/O) |
| Valve | Normally closed solenoid valve at the outlet of the meter section |
| Fitting | Swagelok 8 VCR male |
| Seal Material | Buna-N standard (Viton option); valve seat selectable |
| Wetted Materials | 316L stainless steel, nickel, Viton |
| Power Requirement | 20.5 to 30 VDC at 300 mA |
| Maximum Inlet Pressure | 100 psig |
| Normal Operating Differential | 15 to 60 psid (for the 50 and 100 slm range) |
| Zero Temperature Coefficient | < 0.05% of full scale per °C |
| Span Temperature Coefficient | < 0.10% of full scale per °C |
| Pressure Coefficient | ±0.02% of reading per psi |
| External Leak Integrity | < 1 × 10⁻⁹ scc/sec He |
| Leak Through Closed Valve | < 0.1% of full scale |
| Operating Temperature | 15° to 40°C |
| Compliance | CE |
Reviews
There are no reviews yet.