Patent ID: 7622930
Filing Date: 2009-11-24
Classification: G01R

Abstract:
1. A method for inspecting a semiconductor device, wherein said semiconductor device includes a primary connection port, which includes a signal pad and a ground pad, a transmission line, comprising connection ports, which are symmetrically arranged with respect to said primary transmission line portion and the straight line extension of said primary transmission line portion, each connection port being connected to a respective one of said branch transmission line portions and said straight branch transmission line portion, and including at least one signal pad, and active elements, wherein each active element is connected to a respective one of said branch transmission line portions and said straight branch transmission line portion and for establishing and preventing electrical conduction through said respective one of said branch transmission line portions and said straight branch transmission line portion, the method comprising: establishing a first circuit state in which electrical conduction through at least a first of said plurality of branch transmission line portions is established, electrical conduction through at least a second of said branch transmission line portions is prevented, and electrical conduction is established from said primary connection port through said primary transmission line portion and said straight branch transmission line and measuring electrical signal reflection characteristics of said transmission line at said primary connection port to obtain a first measured value; establishing a second circuit state in which electrical conduction through at least a third of said branch transmission line portions is prevented, electrical conduction through said at least the second of said branch transmission line portions is established, and electrical conduction is established from said primary connection port through said primary transmission line portion and said straight branch transmission line, and measuring said electrical signal reflection characteristics of said transmission line at said primary connection port to obtain a second measured value, wherein the second circuit state is a mirror image of the first circuit state with respect to said primary transmission line portion and the straight line extension of said primary transmission line portion; and after obtaining only the first and second measured values, comparing the first and second measured values to determine characteristics of said transmission line.