摘要 |
<p>A formation (3) in a first surface of a substrate is machined by an ultraviolet or visible radiation laser, to a predetermined depth that is less than a full depth of the substrate; and material (5) is removed from a second surface of the substrate opposed to the first surface to the predetermined depth from the first surface to communicate with the formation. Material may be removed by, for example, lapping and polishing, chemical etching, plasma etching or laser ablation. The invention has application in, for example, dicing semiconductor wafers or forming metallised vias in wafers.</p> |