Rheed monitoring of rotating samples during large-area homogeneous deposition of oxides

摘要

We have successfully implemented RHEED monitoring of growth of complex oxides in a reactive evaporation process with substrate rotation and an oxygen environment. A rotating substrate heater is used with a partial enclosure kept at a 10 mTorr oxygen pressure. This heater allows for simultaneous and uniform deposition of multiple 2-inch wafers. The RHEED beam diffracts from samples as they pass through the high-vacuum zone of the heater. A CCD camera is used for RHEED data acquisition and image capture is synchronized to sample position. In order to achieve good quality diffracted images, rotation of the sample is required to be less than 1 degree for the duration of data capture. With our relatively inexpensive setup images can be acquired for sample rotation speeds up to 1500 RPM. We use this RHEED diagnostic system for study of in-situ growth of high-temperature superconducting thin films.