US 2008/0188012 A1 · MANUFACTURING METHOD OF DISPLAY DEVICE

Abstract

In crystallization of a silicon film by annealing with a linear-shaped laser beam having an ununiform width of the short axis of the beam, the profile (intensity distribution) of the laser beam is evaluated, and the result is fed back to an oscillating condition of the laser beam or an optical condition which projects this onto the silicon film, whereby a display device comprising a high-quality crystalline silicon film is produced. In the present invention, (1) the energy distribution of the linear-shaped laser beam is measured by a detector type CCD camera moved stepwise in the directions that its long axis and short axis extend, respectively, (2) a value obtained by dividing an accumulated intensity E in the long axis direction obtained by accumulating the detected signals in a direction parallel to the short axis by the square root of the width W of the short axis of the linear-shaped laser beam in each position in the long axis: E/√{square root over ( )}(W), is determined in all the positions of a cross section of the linear-shaped laser beam. Since a laser power which is suitable for lateral crystal growth of the silicon film has a close correlation with E/√{square root over ( )}(W), this value is used as an evaluation result mentioned above in the present invention.

Claims11

Dependent claims

A manufacturing method of a display device for obtaining an active matrix substrate for a display device by scanning and irradiating a plurality of regions in an amorphous semiconductor film or a granular poly-crystalline semiconductor film on an insulating substrate with a laser beam shaped linearly in the direction which crosses the long axis direction to carry out annealing to reform said amorphous semiconductor film or said granular poly-crystalline semiconductor film into a strip-shaped poly-crystalline semiconductor film extending in said scanning direction, wherein the method is characterized by comprising:

a process of moving an area detector type CCD camera or a linear array sensor stepwise in said long axis direction or short axis direction of said linear-shaped laser beam laser beam to thereby detect the entire energy distribution as a counter number;
accumulating detected signals of said energy distribution in a direction parallel to said short axis of said laser beam;
calculating the accumulated intensity in said long axis direction of said laser beam;
dividing said calculated accumulated intensity by the square root of said width of the short axis of the laser beam to thereby obtain an intensity distribution;
and
a process of feeding a maximum value and a minimum value of said intensity distribution in a region which controls the profile of said laser beam back to an oscillation source of said laser beam or an optical system of the device to thereby control the profile of the laser beam.

3 more elements

a process of moving an area detector type CCD camera or a linear array sensor stepwise in said long axis direction or short axis direction of said linear-shaped laser beam to thereby detect the entire energy distribution as a counter number;
and
a process of
accumulating detected signals of said energy distribution in a direction parallel to said short axis of said laser beam,
calculating the accumulated intensity in said long axis direction of said laser beam,
dividing said calculated accumulated intensity by the square root of said width of the short axis of the laser beam to thereby obtain an intensity distribution, and
a process of calculating a maximum value, a minimum value and a means value of said intensity distribution in a region which controls the profile of said laser beam, and feeding a value “(maximum value+minimum value)/mean value” back to an oscillation source of said laser beam or an optical system of the device to thereby control the profile of the laser beam.

4 more elements

Dependencies are inferred from the claim text.

Manufacturing method of display device

Life of this patent

Manufacturing method of display device

Life of this patent

Abstract

Claims11