UFC-9660 High-Temperature Analog MFC by UNIT Instruments 9660 Series

UFC-9660 | High-Temperature Metal-Seal Mass Flow Controller

The UFC-9660 from UNIT Instruments is a high-temperature analog mass flow controller in the 9660 Series. It is designed for semiconductor processes requiring heated gas delivery and stable flow regulation.

Its heated construction supports operating temperatures up to 150°C. This design helps prevent condensation when handling process gases that may condense inside conventional gas delivery lines.

The controller combines a metal-sealed gas path, proportional electromagnetic solenoid valve, and remote electronics architecture. It uses a 0–5 VDC analog command and monitor interface.

Typical applications include CVD, epitaxial deposition, and heated delivery systems for condensable source materials.

01 | Thermal Control: Keeping Process Gas in the Required State

Temperature management is a key consideration when selecting the UFC-9660. Certain semiconductor precursor gases can condense when their temperature falls below the required process condition.

• Operating temperature: 0–150°C (32–302°F), high-temperature model.
• Heated configuration: Heated enclosure.
• Process suitability: Heated delivery of condensable gases.
• Typical processes: CVD, epitaxial deposition, and liquid or solid source vapor delivery.

For heated gas systems, the temperature profile must remain consistent across the source, delivery line, valve, and flow controller. A cold section can become a condensation point even when the controller itself is heated.

During system design, verify the required temperature for the specific process gas. Also confirm the heating configuration and temperature limits of the installed remote electronics.

02 | Metal-Seal Gas Path and Wetted Materials

The 9660 Series uses a metal-sealed construction for demanding semiconductor gas delivery applications. A W-seal configuration is specified for downported versions.

• Wetted materials: 316L stainless steel, K-M45, 304 stainless steel, and 7Mo+.
• Sealing: Metal seal.
• Downported configuration: W-seal.
• Standard surface finish: 10 micro-inch Ra.
• Optional surface finish: 4 micro-inch Ra.
• Leak integrity: 1 × 10^-10 atm-cc/sec He.

Surface finish and wetted material selection influence gas cleanliness and process compatibility. For sensitive precursor applications, verify the actual material combination and surface finish before ordering.

The listed leak integrity is a helium leak specification. It should not be interpreted as a guarantee of compatibility with every process gas or installation condition.

03 | Pressure Envelope and Flow Regulation

Pressure capability must be evaluated alongside the required differential pressure. Maximum inlet pressure, proof pressure, and operating differential pressure describe different operating conditions.

• Maximum pressure: 3,500 kPa (500 psi).
• Proof pressure: 10,500 kPa (1,500 psi).
• Typical differential pressure: 1.33–350 kPa (10 torr–50 psid).
• Control range: 2–100% of full scale.
• Pressure coefficient: 0.007% of reading per psi (N₂).

Do not use the proof pressure as a normal operating set point. Confirm the pressure limits of the complete gas delivery assembly, including fittings, regulators, valves, and downstream equipment.

04 | Analog Control and Remote Electronics

The UFC-9660 analog configuration uses a 0–5 VDC interface for setpoint and monitor signals. Its remote electronics arrangement separates the electronic module from the flow body.

• Setpoint signal: 0–5 VDC.
• Monitor signal: 0–5 VDC.
• Electrical connection: Card-edge connector.
• Remote electronics width: 1-1/8 inches.
• Analog family power: ±15 VDC.

Verify the connector pin assignment and signal reference before integrating the controller with a process tool. The 0–5 VDC signal range alone does not establish connector or pinout compatibility.

The 9561 and 9565 digital variants use different electrical specifications. Their power requirements and digital performance figures should not be applied to this analog model.

05 | Flow Performance and Dynamic Response

The following performance values include both analog 9660 specifications and family-level data. Confirm the exact flow range and performance limits against the UFC-9660 configuration supplied.

• Family-level flow range: 10 sccm–30 slm, N₂ equivalent.
• Analog 9660 accuracy: ±1% FS.
• Family-level repeatability: ±0.15% FS.
• Family-level linearity: ±0.5% FS.
• Family-level zero stability: Less than 0.6% FS per year.
• Control range: 2–100% FS.
• Fast-start response: Less than 2 seconds, per SEMI E17-91.
• Soft-start rate: Linear ramp at 20% per second.

Accuracy expressed as a percentage of full scale differs from accuracy expressed as a percentage of setpoint. This distinction is important when evaluating low-flow operation.

The digital 9561/9565 accuracy figures are separate specifications. They are not interchangeable with the analog 9660 accuracy rating.

06 | Mechanical Configuration and Mounting

The UFC-9660 uses a remote electronics design. Flow body dimensions depend on the selected mounting and port configuration.

• Remote electronics dimensions: 3.50 × 4.00 × 1.47 inches (89 × 102 × 37 mm).
• Downported flow body overall length: 105.2 mm.
• Weight: 1.2 kg (2.65 lb).
• Mounting configurations: Horizontal mounting, including HOV/HOS configurations.

Check the port orientation and mounting arrangement against the existing process tool. The overall length listed above applies to the downported C/W configuration, not necessarily every flow body option.

07 | Semiconductor Process Applications

The high-temperature architecture is intended for gas delivery systems where temperature control is part of process reliability.

• CVD: Heated delivery of compatible precursor gases to deposition chambers.
• Epitaxial deposition: Flow regulation in heated process gas systems.
• Condensable gas delivery: Maintaining gas temperature to reduce condensation risk.
• Liquid source vapor delivery: Supporting heated delivery systems for vaporized source materials.
• Solid source vapor delivery: Regulating compatible gases in heated source delivery arrangements.

Gas compatibility, material selection, and operating temperature must be confirmed for each process. The UFC-9660 should be selected according to the actual gas composition and tool configuration.

08 | Technical Specifications

09 | Field Engineering FAQ

Q1: Why can a heated MFC still experience unstable flow when the gas source temperature is correct?

A correct source temperature does not guarantee a uniform temperature throughout the delivery path. Check for cold spots around fittings, valves, adapters, and chamber connections. Review temperature sensor locations and insulation. Confirm that the controller and connecting lines reach their required operating temperatures before evaluating flow stability.

Q2: What should engineers investigate when a process chamber shows deposition variation despite a stable analog command?

Check actual gas delivery conditions rather than relying only on the command signal. Review upstream pressure fluctuations, downstream backpressure, gas temperature, and calibration gas settings. Also compare the monitor signal with an independent process measurement where available. A stable command does not prove that the delivered mass flow remains constant.

Q3: Can the UFC-9660 be mounted in the same orientation as an existing standard-temperature MFC?

Not without checking the mechanical configuration. Confirm whether the replacement uses HOV or HOS mounting, and verify the port direction and flow body dimensions. Downported and other port arrangements may have different mechanical requirements. Check the equipment drawing before modifying the gas panel.

Q4: What commissioning sequence helps reduce problems after replacing a high-temperature controller?

First, verify the gas path and electrical connections. Perform the required leak test before introducing process gas. Bring the heated assembly to its specified operating temperature, then establish the required pressure differential. Check zero, analog scaling, and several stable flow points. Follow the equipment manufacturer's approved startup and purge procedures.

Q5: What information is needed to identify the correct UFC-9660 replacement configuration?

Provide the complete nameplate information, full-scale flow range, process gas, port orientation, mounting arrangement, and electrical connector details. Include the required operating temperature and pressure conditions. For condensable gases, identify the source and delivery temperature requirements. These details help prevent a mechanically similar but functionally unsuitable replacement.

10 | Configuration Verification Before Ordering

The 9660 Series includes different configurations and related digital models. Specifications can vary by electronics type, flow range, port arrangement, and temperature option.

Before ordering, confirm the following details:

• Exact model: UFC-9660.
• Analog electronics configuration.
• Required N₂-equivalent full-scale flow range.
• Gas type and calibration requirements.
• Heated operating temperature.
• Metal seal and port configuration.
• Horizontal mounting arrangement, including HOV/HOS where applicable.
• Card-edge connector and electrical requirements.

Do not use the digital 9561/9565 specifications or the 9500 remote-electronics flow range as substitutes for UFC-9660 configuration data.

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