PROCESS FOR FILLING A TROUGH-SHAPED DEPRESSION EXACTLY

摘要

In the process, a layer of a preliminary product (22) of the layer to be formed is deposited on the substrate (3) provided with the depression (12), forming a cavity (25) corresponding to the depression (12) in the substrate. The cavity (25) of the preliminary product (22) is then almost filled with an auxiliary layer (26), leaving narrow, groove-like trenches (29). This structure is then provided with a levelling layer (30) thick enough to fill the trenches (29). Finally, the levelling layer (30) and the auxiliary layer (26) are completely removed by etching, and the part of the preliminary product (22) projecting above the depression (12) in the substrate is removed by etching to the level of the upper edge of the depression (12) in the substrate.