Method for fabricating bragg reflector using in situ laser reflectometry
AssigneeElectronics and Telecommunications Research Institute
InventorsJong-Hyeob Baek, Bun Lee
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Abstract
A Bragg reflector with a uniform thickness is fabricated by means of an in-situ laser reflectometer. In order to fabricate the Bragg reflector, a plurality of buffer layers are formed on a semiconductor substrate. Then, first and second epitaxial layers are alternatively grown on the buffer layers. While growing the epitaxial layers, the thickness of the first and second epitaxial layers are continuously measured by using a laser beam having the same wavelength as a reflective wavelength of the Bragg reflector. In this way, the thickness of the Bragg reflector is precisely controlled according to the measurements, so that the Bragg reflector may be fabricated uniformly with a predetermined thickness.
Claims4
A method for fabricating a Bragg reflector having a reflective wavelength using an in-situ laser reflectometer, comprising the steps of:
- providing a laser beam having a wavelength substantially equal to the reflective wavelength of the Bragg reflector to be fabricated;
- forming a plurality of buffer layers on a semiconductor substrate;
- irradiating the semiconductor substrate with the laser beam while the plurality of buffer layers are being formed thereon so as to generate a reflected beam having at least one cycle period;
- growing first and second epitaxial layers alternatively on said buffer layers ;
- and
- measuring a thickness of the first and second epitaxial layers by comparing a growth interval of the first and second epitaxial layers with one half of the at least one cycle period of the reflected beam, so as to grow the Bragg reflector uniformly to a predetermined thickness.
Dependencies are inferred from the claim text.