Patent ID: 9721854
Date: 2017-08-01
CPC Classifications: G01R,H01L

Claim:
1. A method comprising: forming a first spiral test structure in a wiring layer of a semiconductor wafer, the first spiral test structure comprising a first capacitor connected to two ends of a first test spiral, the first capacitor comprises a first conductive plate and a second conductive plate separated by an insulator, the first conductive plate is electrically connected to one end of the first test spiral and the second conductive plate is electrically connected to the other end of the first test spiral such that the first spiral test structure comprises a first predetermined resonant frequency dependent on physical dimensions of the first test spiral and a capacitance of the first capacitor; forming a second spiral test structure in the wiring layer of the semiconductor wafer, the second spiral test structure comprising a second capacitor connected to two ends of a second test spiral, the second capacitor comprises a first conductive plate and a second conductive plate separated by an insulator, the first conductive plate is electrically connected to one end of the second test spiral and the second conductive plate is electrically connected to the other end of the second test spiral such that the second spiral test structure comprises a second predetermined resonant frequency dependent on physical dimensions of the second test spiral and a capacitance of the second capacitor, a wire width of the first test spiral is smaller than a wire width of the second test spiral, and a wire spacing of the first test spiral is greater than a wire spacing of the second test spiral; providing a first range of frequencies to the first spiral test structure from a test apparatus causing the first spiral test structure to resonate at a first reflected resonant frequency; monitoring the first reflected resonant frequency of the first spiral test structure; determining if an open circuit exist in the first spiral test structure based on a change in the first resonant frequency as compared to the first predetermined resonant frequency; providing a second range of frequencies to the second spiral test structure from the test apparatus causing the second spiral test structure to resonate at a second reflected resonant frequency; monitoring the second reflected resonant frequency of the second spiral test structure; and determining if a short exist in the second spiral test structure based on a change in the second resonant frequency as compared to the second predetermined resonant frequency.