Abstract: Provided are novel methods of preventing deposition on an optical component in an absorption spectroscopy measurement cell. The methods involve performing an absorption spectroscopy measurement of a sample gas introduced into the cell, and introducing a flow of purge gas from a purge gas inlet pipe across a critical surface of the optical element at a velocity effective to prevent deposition on the critical surface. The gas inlet is disposed adjacent said critical surface. Also provided are devices for practicing the inventive method, measurement cells useful in absorption spectroscopy measurements, apparatuses for performing an absorption spectroscopy measurement and semiconductor processing apparatuses. The invention allows for the performance of accurate spectroscopic measurements. Because deposits are prevented from forming on the surface of an optical element, interference therefrom can effectively be avoided.

Abstract: Provided is a novel in-line cell useful in absorption spectroscopy. The cell includes a sample region, a light entry port and a light exit port being the same or separate ports. Each port is in communication with the sample region and contains a light transmissive window. A mirror having a light reflective surface faces the sample region, and a heater effective to heat the light reflective surface is provided. The cell can be used to determine the concentration of molecular gas impurities in a sample. Particular applicability is found in semiconductor processing.

Abstract: Provided is a novel in-line cell useful in absorption spectroscopy. The cell includes a sample region, a light entry port and a light exit port being the same or separate ports. Each port is in communication with the sample region and contains a light transmissive window. A mirror having a light reflective surface faces the sample region, and a heater effective to heat the light transmissive window in the light entry port and/or said light exit port is provided. The cell can be used to determine the concentration of molecular gas impurities in a sample. Particular applicability is found in semiconductor manufacturing in a semiconductor processing tool.

Abstract: Provided is a novel method for intelligent data acquisition in a measurement system.

Abstract: Provided is a novel in-line cell useful in absorption spectroscopy. The cell includes a sample region, a light entry port and a light exit port being the same or separate ports. Each port is in communication with the sample region and contains a light transmissive window. A mirror having a light reflective surface faces the sample region, and a heater effective to heat the light reflective surface is provided. The cell can be used to determine the concentration of molecular gas impurities in a sample. Particular applicability is found in semiconductor processing.

Abstract: A novel method for calibration of a spectroscopic sensor is provided. In the method, a spectroscopic system is provided. The system includes a measurement cell having one or more walls which at least partially enclose a sample region. The cell further includes a light entry port and a light exit port. The light entry port and the light exit port can be the same port or separate ports. Each of the ports contains a light transmissive window through which a light beam passes along an internal light path inside the measurement cell. The system further has an optical chamber which contains a light source for generating the light beam which passes through the light entry port into the cell, and a detector for measuring the light beam exiting the cell through the light exit port. The light beam passes along an external light path inside the optical chamber. In addition, a gas inlet is connected to the optical chamber. A calibration gas stream is introduced into the optical chamber.

Abstract: An apparatus and method are provided for preparing low concentration gas phase calibration standards. The flows of a standard mixture of impurity in a gas and a dilution gas are controlled by regulating the pressure upstream of respective calibrated orifices. The pressures of the gas flows are regulated such that a critical flow condition is maintained through the orifices. The two flows are then combined to obtain a known dilution of the impurity in the gas.