NEAR REAL-TIME EXTRACTION OF DEPOSITION AND PRE-DEPOSITION CHARACTERISTICS FROM ROTATING SUBSTRATES AND CONTROL OF A DEPOSITION APPARATUS IN NEAR REAL-TIME

Methods and apparatus are provided for monitoring deposition and pre-deposition characteristics such as the growth rates, oxide desorption, surface reconstruction, anion surface exchange reaction and smoothness of the surface of rotating substrates in near real-time during molecular beam epitaxy by processing the data in the time domain and for controlling a deposition apparatus in near real-time. An apparatus for extracting the characteristics and controlling the deposition apparatus in near real-time includes the following: (a) the deposition apparatus having a rotating substrate, (b) an energy pattern generator for subjecting the substrate to a beam of energy and for producing energy patterns, (c) an imaging unit for obtaining video images of the energy patterns, video images each having pixels, (d) a data processing unit for monitoring a selected set of the pixels on each of the video images, generating time-domain data for each video image and generating deposition parameters in near real-time, and (e) a deposition control unit for controlling the deposition apparatus in response to receiving the deposition parameters in near real-time. The method of extracting the characteristics and controlling the deposition apparatus in near real-time includes the following steps: obtaining video images of energy patterns coming from the substrate, monitoring a selected set of the pixels on each video image to generate time-domain data, filtering the time-domain data in near real-time, and controlling the deposition apparatus in near real-time.