MKS Announces New Pressure/Vacuum Transducer

MKS Instruments, Inc. - HPS Products is introducing the new HPS® Series 901 Loadlock Transducer (LLT) at Semicon West booth 1616. The CE marked Series 901 is a combination Piezo and Pirani sensor with an integrated electronic control circuit, analog output and two setpoints as standard features for process control.

Semiconductor tools often use a loadlock as an interface to the continuously pumped main chamber. These loadlocks are often pumped to high vacuum levels very rapidly, which can overwhelm the traditional Pirani gauges due to their slower response time. When the loadlock is brought up to atmosphere, a separate switch is used to indicate when the door can be opened. The HPS Series 901 Loadlock Transducer (LLT) combines a vacuum gauge (MicroPirani™) and an atmosphere switch (Piezo) into an integrated, compact package. The Piezo is a differential pressure sensor, which will operate properly under varying outside environmental pressures like weather and elevation, ensuring that the loadlock door will open at the optimal time.

Unlike traditional Pirani gauges, the element in the MicroPirani™ portion of the Series 901 is made of a one millimeter square silicon chip, allowing the measurements to be made in a very small volume. A traditional Pirani sensor has a measuring range from 10-3 to about 100 Torr, rapidly losing sensitivity above 10 Torr. Because the size of the sensing portion of the MicroPirani™ is so small, it has a range from 1,000 down to 10-5 Torr. Since the MicroPirani™ is gas-type sensitive, it can be used to find medium to fine leaks in a vacuum system.

MKS Instruments, HPS® Products, 5330 Sterling Drive, Boulder, CO 80301. Tel: 303-449-9861; Fax: 303-442-6880.