Case study

Resistivity Measurement with Digital Sensors

Case study

Case Study on North American Semiconductor Fabrication Plant

Measure resistivity
Measure resistivity

Resistivity measurement, the inverse of conductivity, is the most critical parameter to monitor in the microelectronics industry in order to maintain ultrapure water quality. Highly stable resistivity measurement is necessary for semiconductor fabricators to produce high quality products.

To improve their processes and final product, a major North American semiconductor fabrication plant was looking for a resistivity measurement system to meet their high expectations. In partnership with METTLER TOLEDO, the fabricator tested the UPW UniCond® system for resistivity measurement in their ultrapure water system for several weeks. After analyzing the results of the test in their water loop, the fabrication plant observed a dramatic enhancement in resistivity measurement performance compared to their previous product solution. They opted to update their strategy and specify the UPW UniCond sensor in new plants and facility upgrades. The resistivity measurements obtained exceeded all expectations, with stability and accuracy beyond the capabilities of any other resistivity sensor on the market.

This case study covers the following:

  • The background of the customer situation
  • Evaluation of the test setup for resistivity measurement
  • Assessment of the results
     

The UPW UniCond sensor from METTLER TOLEDO offers highly repeatable measurement accuracy. Enhanced digital signal processing reduces noise and provides an order of magnitude of improvement in measurement stability. The UPW UniCond sensor is equipped with Intelligent Sensor Management (ISM). ISM conductivity sensors offer improved performance over analog probes due to an on-board microprocessor that converts the analog signal from the sensor into the actual conductivity measurement.

UPW UniCond sensors provide high measurement accuracy as their integral cell constant, temperature sensor, and measuring circuits are all calibrated as a unit. There are no negative influences due to variable cable length, connections, or change of transmitters because the measurement circuits are self-contained and sealed. The sensors output a highly robust digital signal that is immune to interference or degradation from the surrounding equipment and environment.