초록 ▼

Laser radiation can be directed through an aperture to a target surface without causing the expected diffraction groove effect by moving the target relative to the stage to which the aperture is attached in such a fashion as to interrupt the diffraction pattern and minimize the production of diffrac

Laser radiation can be directed through an aperture to a target surface without causing the expected diffraction groove effect by moving the target relative to the stage to which the aperture is attached in such a fashion as to interrupt the diffraction pattern and minimize the production of diffraction grooves.

대표청구항 ▼

A method of forming an etching of predetermined configuration on a target surface with a laser beam directed through an opening of an aperture, said opening being of predetermined outline, said aperture being positioned between a source of said laser beam and said target surface such that said laser

A method of forming an etching of predetermined configuration on a target surface with a laser beam directed through an opening of an aperture, said opening being of predetermined outline, said aperture being positioned between a source of said laser beam and said target surface such that said laser beam is directed to impinge upon said target surface to form said etching, and wherein a portion of said laser beam passing immediately adjacent the perimeter of said opening experiences a diffractive effect which causes an initial formation of a plurality of diffractive grooves having alternating peaks and troughs about the perimeter of said etching on said target surface, the method comprising: during formation of said etching, changing the positional relationship between said laser beam and said target surface in a first direction substantially transverse to said alternating peaks and troughs, said change in positional relationship being such as to satisfy the condition: Atarget≥D wherein Atarget is the range over which said diffraction pattern is shifted, and D is the distance between the first peak, and the first trough on the groove pattern produced by a single pulse, whereby said formation of diffractive grooves is minimized.