Patent ID: 7674719

Claim:
A method for forming a semiconductor device on a substrate, the substrate having a via, the method comprising the steps of: a) providing the substrate including an electrically insulating material having a first surface and a second surface; b) forming an ablation buffer layer on at least a portion of the second surface of the substrate; c) forming a semiconductor layer on the exposed portions of the second surface of the substrate and; d) substantially focusing pulses of laser light of an ultrafast pulsed laser source to a beam spot on the first surface of the substrate such that each focused pulse of laser light ablates a volume of the substrate; e) scanning the beam spot of the focused pulses of laser light over a via portion of the first surface of the substrate until the via is formed extending from the first surface of the substrate to the ablation buffer layer, thereby exposing a portion of the ablation buffer layer; f) etching the exposed portion of the ablation buffer layer to expose a contact portion of the semiconductor layer; and g) forming an electrode on the first surface of the substrate such that the electrode is electrically coupled through the via to the contact portion of the semiconductor layer.