A silicon substrate has a protective film formed on each side. A semiconductor surface opening not smaller than a given region is formed by removing the protective film. A through-hole having an inner size smaller than the given region is formed in the opening by laser machining. Thereafter, the inner...http://www.google.de/patents/US7821105?utm_source=gb-gplus-sharePatent US7821105 - Method of manufacturing semiconductor device and semiconductor device
