Vaisala K-PATENTS® Semicon Refractometer PR-23-MS

A compact refractometer with an ultra-pure modified PTFE flow cell body for semiconductor liquid chemical processes. Connected to the process by a ¼ — 1 inch pillar or flare fitting.

Vaisala K-PATENTS® Semicon Refractometer PR-23-MS has a built-in, ultra-pure, modified PTFE flow cell designed to keep all metal and corroding parts from coming into contact with the process liquid. All the wetted parts are made of ultra-pure, modified PTFE. The prism material is sapphire.

The PR-23-MS is mounted directly in-line with a pillar or flare fitting. The compact design allows integration to a wet bench or to a cabinet, where the need for foot print area is very low.

The dissolved solids concentration is determined by making an optical measurement of the solution’s Refractive Index. The advantage of this principle is that the same instrument can be used to measure any chemical.

The PR-23-MS provides a continuous 4-20 mA or digital measurement signal and immediate feedback to the control system, if the chemical is not within specifications. The PR-23-MS is physically a small device and easy to install in the bulk chemicals dispense, and in point of use chemical blending, spiking and monitoring applications.

With Vaisala K-PATENTS® PR-23-MS you can:

  • Prevent wrong chemicals from entering the fabrication process.
  • Optimize etch process and increase the bath life of the etch solution (e.g. heated KOH).
  • Increase wafer throughput typically by +25%, and reduce cleaning chemical consumption (e.g. SC-1 or EKC-265) in FEOL and BEOL cleaning.
  • Achieve tight control of CMP slurries and better uniformity of the planarization process.

Key Features:

  • Typical accuracy of 0.1% by weight, e.g. for HCl in water. For multi-component solutions, the measurement signal works as a check-sum.
  • Patented CORE-optics (US Patent No. US6067151). 
  • Dual connectivity: one transmitter can operate two sensors. A second sensor can be easily integrated later.
  • Process temperature range: -20°C – 150°C (-4°F – 300°F)
  • Fast process temperature measurement by built-in Pt1000 and automatic temperature compensation.
  • ATEX approved for Zone II, area classification EX II 3 G EEx nA II T4.
  • FM approved for Class I, Div. 2, Groups A, B, C and D, T6.
  • CSA certified for Class I, Div. 2, Groups A, B, C and D, T4.
  • cCSAus certified for Electrical Safety, Sensor: Class I, Pollution Deg. 3; Transmitter: Class I, Pollution Deg. 2; Installation Cat. II.
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Key Benefits

Completely digital device
Vaisala K‑PATENTS® Semicon Refractometer PR-33-S is used for process control and monitoring, and it provides a continuous Ethernet output signal. Compact design, and device is mounted directly in-line.
Accurate and stable measurements over the full range
Full measurement range of Refractive Index nD 1.3200–1.5300, which corresponds to 0-100 % by weight. Optional range nD 1.2600–1.4700 for strong HF. Typical accuracy R.I.+ 0.0002, which typically corresponds to 0.1% by weight, e.g. for HCl in water.

Measurement is not influenced by particles, bubbles, turbulent flow or impurities in the PPM range.
Easy maintenance
No drift. No re-calibration. No mechanical adjustments.