| AVS 63rd International Symposium & Exhibition | |
| In-Situ and Operando Spectroscopy and Microscopy for Catalysts, Surfaces, & Materials Focus Topic | Thursday Sessions |
| Session IS-ThP |
| Session: | In-Situ and Operando Spectroscopy and Microscopy for Catalysts, Surfaces, & Materials Poster Session |
| Presenter: | Tina Graber, Carl Zeiss SMT GmbH, Germany |
| Authors: | G. Fedosenko, Carl Zeiss SMT GmbH, Germany H.-Y. Chung, Carl Zeiss SMT GmbH, Germany M. Aliman, Carl Zeiss SMT GmbH, Germany A. Laue, Carl Zeiss SMT GmbH, Germany R. Reuter, Carl Zeiss SMT GmbH, Germany V. Derpmann, Carl Zeiss SMT GmbH, Germany M. Antoni, Carl Zeiss SMT GmbH, Germany L. Gorkhover, Carl Zeiss SMT GmbH, Germany T. Graber, Carl Zeiss SMT GmbH, Germany |
| Correspondent: | Click to Email |
Real-time inline control of process gas compositions with high sensitivity has been of particular importance in recent years in the semiconductor industry and beyond. Most of the real-time process gas analysis was carried out with differentially pumped Residual Gas Analyzer (RGA) which are based on a linear quadrupole mass filtering technique. To generate a complete mass spectrum, a RGA usually needs a few minutes which is often too slow for real-time inline process control. A new process control mass spectrometer, based on Fourier-Transform 3D-Quadrupole Ion Trap technology, is more appropriate for real-time inline process and will be presented in this work.
The 3D-Quadrupole Ion Trap mass spectrometer (iTrap®) by ZEISS is installed in a vacuum chamber (120mm x 120mm x ~ 500mm) with an ALD valve for pulsed gas sample injection (pulse duration ~ 50ms). An electron gun is used for ionization of the gas pules. The Ion Trap achieves ion trapping and accumulation by means of a radio frequency applied to the ring electrode of the trap. With the aid of advanced electronic amplifiers and selective ion excitation technique the ion oscillations can be measured electrically without using any separate particle detector. The mass spectrum is finally obtained by a Fourier Transform of the recorded electrode current signal in less than one second.
Real-time measurements of the hydrogen plasma cleaning process of Sn contaminated samples were performed with the iTrap® mass spectrometer. The working pressure of the plasma cleaning process was 0.5 mbar. Decreasing signal of SnH4 and other contaminations from the samples which are directly correlated to the cleaning process were observed with iTrap®. This result is extremely useful for the process control of Plasma processes and inline real-time contaminations control for high-end applications such as the EUV Lithography manufacturing.
MOCVD process for GaN growth was also investigated with iTrap®. The result shows that gas species related to wafer holder contamination, gas phase reaction products and dopant memory effects due to Cp2Mg could be observed clearly. These information will help the user to recognize process drift and/or minimize chamber cleaning intervals.
The new mass spectrometer of ZEISS (iTrap®) has successfully detected real-time SnH4 signal in the hydrogen plasma cleaning process. Inline measurement at a MOCVD chamber showed that iTrap® is capable to detect reaction products, contaminations on the wafer holder and dopant memory in real-time. These results demonstrate that iTrap® is a very sensitive and fast process mass spectrometer suitable for real-time inline process monitoring.