Reflection high‐energy electron diffraction intensity oscillations during molecular‐beam epitaxy on rotating substrates
作者:
Jan P. A. van der Wagt,
James S. Harris,
期刊:
Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena
(AIP Available online 1994)
卷期:
Volume 12,
issue 2
页码: 1236-1238
ISSN:1071-1023
年代: 1994
DOI:10.1116/1.587053
出版商: American Vacuum Society
关键词: WAFERS;ROTATION;MOLECULAR BEAM EPITAXY;RHEED;OSCILLATIONS;DETECTION;MEASURING METHODS;MONITORING;THICKNESS;CHEMICAL COMPOSITION
数据来源: AIP
摘要:
We report the gated detection of reflection high‐energy electron diffraction (RHEED) signal intensity oscillations during molecular‐beam epitaxy (MBE) while the wafer is being rotated at high speed (≳100 rpm). In general, a larger number of oscillation periods are observed with this technique than during stationary measurement because of the very high growth rate uniformity across the sample. We found that the average over all azimuths of the RHEED specular spot intensity shows the same growth induced oscillations. This allowed us to replace the gated detection by an averaging detection method: a low‐pass filter suppresses fast variations due to rapid changes in azimuth, while passing low‐frequency (<1 Hz) growth related oscillations. This simplifies the detection system and at the same time reduces noise related to wafer motion, 60 Hz, etc. These techniques have potential use forinsitumonitoring of thickness and composition of device wafers.
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