Configuration Options

delta iii 3-zone flow ratio controller with ethercat DLT3B Flow Ratio Controller, 3-zone, EtherCAT
delta iii 3-zone flow ratio controller with devicenet DLTNA3 Flow Ratio Controller, 3-zone, DeviceNet


  • Full Scale Flow Range
    500, 1000, 2000, and 10000 sccm (each channel) (nitrogen equivalent-Q)
  • Maximum Operating Outlet Pressure
    200 Torr
  • Maximum Allowable Outlet Pressure Differential
    50 Torr
  • Normal Operating Pressure Differential
    <150 Torr; Except, <450 Torr for 10K/10K
  • Ratio Control Range
    0, 5 to 100% Full Scale
  • Ratio Accuracy
    ±2% set point (for percent set points above 10%)
  • Repeatability
    ±0.3% of set point
  • Resolution
    0.02% of channel Full Scale
  • Zero Temperature Coefficient
    <0.05% Full Scale/°C (500 ppm)
  • Span Temperature Coefficient
    <0.08% of Reading/°C (800 ppm)
  • Typical Settling Time
    <3 seconds
  • Warm-up Time
    60 minutes
  • Operating Temperature
  • Storage Temperature
  • Storage Humidity
    0 to 95% relative humidity, non-condensing
  • Temperature Display
  • Temperature Accuracy
  • Temperature Resolution
  • Fitting Type
    4 VCR male, non-rotatable
  • Display
    4 digits for value, 4 characters for unit
  • External Leak Integrity
    <1x10-10 (scc/sec He)
  • Leak Integrity Through Closed Valve
    <2% of channel Full Scale at 500 Torr differential to <10 Torr
  • Wetted Materials
    316 Stainless Steel VAR, 316 Stainless Steel nickel, Inconel, KM-45, PTFE
  • Surface Finish
    5 microinch average Ra
  • Set Point Command Signal
  • Maximum Inlet Pressure
    150 psig
  • Communication
    DeviceNet or EtherCAT
  • Compliance


Control Flow to Three Zones

The DELTA III, three channel ratio controller provides a needed “knob” to tune process gas flows over the substrate surface or gas dispersion head to help achieve these uniformities. The DELTA III ratio controller provides closed loop control over the flow proportion that is not available with typical metering valve or flow orifice setups that have often been used. The DELTA ratio controllers provide the added advantage of tuning the process from the tool controller as opposed to manual valve adjustment necessary with metering valve and manual changeout which is impractical with fixed flow orifices.

The above schematic shows how the DELTA III Flow Ratio Controller can be used to control flow to three zones (Center (C), Middle (M) & Outer (O) within a chamber to optimize process uniformity.

Wide Dynamic Ratio Control Range

The DELTA III has a wide dynamic ratio control range and fast development of chamber flow while being adaptive to different tool and process conditions. MKS has developed a unique patent pending ratio control logic enabling rapid ratio and flow response times. This control logic enables the total input flow to be split with channel flows ranging from 2 to 100% of the channel Full Scale for measurement and control purposes. The total of all channel flows shall be split in such a way that their sum equals 100%. For example the flows may be split to 10, 20, 30 and 50% of total flow input going to channels Q1, Q2, and Q3, respectively. The dynamic control also allows for individual channels to be given 0% set points which closes the valve, effectively closing off flow to this output.

Above the device starts with flows of 25, 25 and 50% in channels Q1, Q2, and Q3, respectively. The flow then transitions to 33.3% in each channel followed by a transition to 10, 50 and 40% in each channel, respectively.

In-Situ Embedded Diagnostics

The DELTA’s diagnostic feature allows the user to check the DELTA’s performance in-situ, lowering costs through reduced removal of No Problem Found devices. This feature is enabled through a web browser utility accessed through the device’s Ethernet port. This utility uses a standard web browser and requires no special software. The diagnostic input includes the ability to control the device locally, operate the device, open and close valves along with collecting and saving data for later analysis.

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