Method for fabricating monocrystalline semiconductor layer on insulating layer by laser crystallization using a grid of anti-reflection coating disposed on poly/amorphous semiconductor

In a method for fabricating a monocrystalline semiconductor layer from a polycrystalline or amorphous semiconductor layer formed on a main face of a monocrystalline semiconductor substrate having on said main face a thick insulating layer formed with windows through which said polycrystalline or amorphous semiconductor layer is in contact with said monocrystalline semiconductor substrate, in which the polycrystalline or amorphous semiconductor layer is melted by a scanning thereof with a CW laser beam to monocrystallize said polycrystalline or amorphous semiconductor layer starting from portions of said monocrystalline semiconductor substrate extending through said windows, the monocrystallized semiconductor material having a common crystallographical axis to that of said monocrystalline semiconductor substrate, wherein the improvement comprises the step of:

• providing a thin antireflection layer of insulating material of silicon nitride on said polycrystalline or amorphous semiconductor layer including a first portion and a second portion, a portion of said polycrystalline or amorphous semiconductor layer above said windows being covered by said first portion of said thin antireflection layer, said second portion of said thin antireflection layer being disposed on remaining portions of said polycrystalline or amorphous semiconductor layer, said second portion having the form of a grid of parallel lines extending from said first portion in a direction of scanning of said laser beam, the power of said laser beam being constant.