A Method for Localization of Electrical Anomalies within IC Devices During Nano-probing
Publication Date: 2016-Dec-28
The IP.com Prior Art Database
Disclosed is a method for localization of electrical anomalies within Integrated Circuit (IC) devices during nano-probing.
A Method for Localization of Electrical Anomalies within IC Devices During Nano -probing
Disclosed is a method for localization of electrical anomalies within Integrated Circuit (IC) devices during nano-probing. Here, an electrical failure signature of the device is captured with nano-probing. The nano-probe may be an atomic force probe, a Scanning Electron Microscope (SEM) based nano-probe and the like, which are used without altering the device electrical characteristics. The nano-probing is also used to capture accurate anomalous behavior of the device.
In a scenario, failure of the device is electrically localized to a sub-element with Electron beam (E-beam) excitation. The E-beam is a method of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film. The E-beam excitation can be but need not be limited to Electron-beam-induced current (EBIC), (Electron Beam Absorbed Current) EBAC and the like. Here, EBAC is a technique, which offers a quick and effective method to identify interconnect opens, high resistance and shorts without direct probing techniques of lower level layers. Then, the device is biased through a plurality of probes to place the device in the most sensitive state for EBIC attenuation of defective behavior. A multiplicity of current or voltage sensors can be used to generate maps. The device may require E-beam energies and doses that can alter the device electrical characteristics. However, the E-beam alteration is an acceptable compromise for further localization because the electrical fail signature is previously captured. The beam energies can be adjusted for beam penetration depth to offer insight into depth of defect. The beam current can be adjusted to provide the best attenuation to any device’s electrical behavior established with biasing through probes. Further, the beam may be raster scanned, vector scanned, stepped in “spot mode”, spot size adjusted, or pulsed (beam blanking). In addition, the device utilizes spot mode beam while evaluating device characteristics.
In order to depart from the non-destructive device characterization paradigm, many nano-probers opt for Scanning Probe Microscopy (SPM) based probers due to E-beam alteration concerns. SEM based probers are also operated at low dose settings such as low accelerating potentials, limited exposure etc. Further, a new paradigm is to first capture “virgin” electrical behavior to follow known E-beam stimulation techniques. The simulation techniques can be used to alter the device by identifying a localized contributor (sub-element) to the degraded electrical behavior. Here, the new paradigm can be to use EBIC application for multi-sub elements. The device characteristics are evaluated by using “spot mode” EBIC. The device biasing for EBIC is performed using a plurality of stimuli and time varying stimuli or pulsed E-beam modulation.
The method utilizes several E-beam interactions to identify an anomaly...