Vacuum Technology Considerations For Mass Metrology
نویسندگان
چکیده
Vacuum weighing of mass artifacts eliminates the necessity of air buoyancy correction and its contribution to the measurement uncertainty. Vacuum weighing is also an important process in the experiments currently underway for the redefinition of the SI mass unit, the kilogram. Creating the optimum vacuum environment for mass metrology requires careful design and selection of construction materials, plumbing components, pumping, and pressure gauging technologies. We review the vacuum technology(1) required for mass metrology and suggest procedures and hardware for successful and reproducible operation.
منابع مشابه
Thickness metrology and end point control in W chemical vapor deposition process from SiH4 ÕWF6 using in situ mass spectrometry
Real-time, in situ chemical sensing has been applied to achieve reaction metrology and advanced process control in a low pressure tungsten chemical vapor deposition process based on WF6 and SiH4 reactants ~silane reduction process!. Using mass spectrometry as the sensor to detect both product generation (H2) and reactant depletion (SiH4) at wafer temperature of 200–250 °C, these signals provide...
متن کاملIn situ mass spectrometry in a 10 Torr W chemical vapor deposition process for film thickness metrology and real-time advanced process control
In situ mass spectrometric sensing has been implemented in a 10 Torr H2 /WF6 W chemical vapor deposition process as a real-time process and wafer state metrology tool. Dynamic sensing through the process cycle reveals HF byproduct generation as well as H2 and WF6 reactant depletion as real-time quantitative indicators of deposition on the wafer. Thickness metrology is achieved by integrating th...
متن کاملThermal Desorption Mass Spectrometry (tds) Application on Mass Metrology
A new device has been developed for the study of physisorbed elements on polished and large surface used in mass metrology. This technique, based on the analysis by mass spectrometry of desorbed molecules caused by heating under vacuum from the analyzed surface, is presented. The first application of this device is the study of the current and future mass standards to understand the reactivity ...
متن کاملProcess diagnostics and thickness metrology using in situ mass spectrometry for the chemical vapor deposition of W from H2/WF6
Quadrupole mass spectrometry has been used to monitor reactant and product partial pressures in a selective W chemical vapor deposition process. A 4/1H2 /WF6 molar reactant ratio was used to produce W films on Si wafers, at 67 Pa ~0.5 Torr! total pressure, and for wafer temperatures around 400 °C. A relatively fast response time ~;4 s! sensor system sampled gas directly from a commercial Ulvac ...
متن کاملA squeezed light source operated under high vacuum.
Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sour...
متن کامل