The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 08, 1989
Filed:
Sep. 02, 1987
Kimihiro Ohta, Kashiwa, JP;
Tadashi Nakagawa, Sakura, JP;
Takeshi Kojima, Kashiwa, JP;
Tsunenori Sakamoto, Yatabe, JP;
Naoyuki Kawai, Yatabe, JP;
Agency of Industrial Science and Technology, Tokyo, JP;
Abstract
A method for controlling the thickness of a thin crystal film which is grown in a vacuum atmosphere, comprising the steps of: generating an electron beam in the vacuum atmosphere; directing the electron beam thus generated to a crystal being grown to obtain a diffraction pattern of the crystal; detecting the variations in time of the intensity of the diffraction pattern thus obtained; obtaining the number of oscillations from the variations thus detected; and interrupting the growth of the crystal in synchronism with the oscillations of the intensity when the number reaches a predetermined number. The composition ratio of a mixed crystal can be also determined by the ratio among the frequency of oscillations of each crystal which constitutes the mixed crystal. The oscillations of the intensity of the RHEED pattern can be observed more than 400 times so that the thickness of the grown thin crystal film can be measured with the accuracy higher than 1000 .ANG. in terms of the mono-layer.