Method of and apparatus for manufacturing a semiconductor substrate

A method of manufacturing a substrate including a plurality of semiconductor islands formed on a supporting substrate member with an insulation layer intervening therebetween, the semiconductor islands each having a selected size and a selected thickness, said method comprising the steps of:

• forming a semiconductor layer on the supporting substrate member with the insulation layer intervening therebetween, the semiconductor layer having a thickness larger than the selected thickness;
• forming grooves in a surface of the semiconductor layer so as to divide the semiconductor layer into a plurality of regions each corresponding to each of the semiconductor islands and having a size equal to the selected size of a corresponding semiconductor island;
• selectively forming a stopper layer in the grooves, the stopper layer being formed from an insulating material harder to be polished than the semiconductor layer and having a thickness allowing the stopper layer to have a surface level higher than that of the insulation layer by a difference provided therebetween substantially equal to the selected thickness of each of the semiconductor islands;
• selecting a polishing cloth so as to have a size which is larger in comparison with each of the regions in the semiconductor layer and is smaller than the semiconductor layer;
• polishing the entire surface of the semiconductor layer by moving the polishing cloth along the surface of the semiconductor layer, while the polishing cloth is pressed down to the surface of the semiconductor layer by a force applied thereto and rotates at a rotational speed, until the semiconductor layer at each of the regions has a thickness which provides the semiconductor layer with a surface level substantially equal to that of the stopper layer.