Case study

Improve Dissolved Oxygen Measurement in Semiconductor Production

Case study

Case Study on Rapidly Responding Optical Sensors

Dissolved oxygen measurement
Dissolved oxygen measurement

One of Asia's largest semiconductor producers was struggling with their dissolved oxygen measurements. They were using an expensive system, which after maintenance needed three to four days before the DO readings were sufficiently stable to use.

The foundry evaluated METTLER TOLEDO Thornton's optical DO sensor and M800 transmitter as a solution for their dissolved oxygen measurement in their ultra-pure water system.

Dissolved oxygen measurement has been a high priority at this semiconductor foundry facility. Their expectations were high including very rapid speed of response, low detection levels and reduced maintenance. METTLER TOLEDO was able to not only meet but exceed their expectations with a solution including an optical DO sensor and an M800 transmitter. DO sensors with optical technology do not require polarization, so measurement system availability is very high. The M800 transmitter offers multi-channel, multi-parameter capabilities, which enable the DO measurement to be paired with the measurement of other parameters.

Download the case study to read the full details including the following topics:

  • Why measure dissolved oxygen in a semiconductor foundry?
  • Precision and response advantages
  • Long-term savings with optical measurements
     

Dissolved oxygen is measured after degasification of ultra-pure water (UPW) to confirm oxygen removal from the water. Reducing dissolved oxygen maintains the low conductivity of the water, which is critical for subsequent treatment steps, particularly continuous electrodeionization. Concentrations of dissolved oxygen in the point-of-use (POU) water during wafer processing are maintained at less than 5 ppb to prevent loss of control of gate oxide thickness. A higher level of dissolved oxygen at the POU can result in unexpected etching by the oxygenated water, resulting in failures and low yields – at great financial cost.