Valery Ray Particle Beam Systems & Technology, Methuen, USA CAD – less Blind Navigation in Focused Ion Beam System PBS&T Chris Gerlinsky Titus Consulting, Saskatoon, Canada

1/5/2016 ISTFA Purpose  Develop methodology for blind coordinate navigation on undocumented devices.  Improve accuracy of navigation in standard FIB equipment.  Ensure successful FIB contacting of small buried nodes.

1/5/2016 ISTFA Outline  Methodology for acquisition of the device layout information.  FIB coordinate navigation by acquired layout.  Enhancements of navigational accuracy.

1/5/2016 ISTFA Study of the Device Layout  Acquire high-resolution image  Identify functional blocks  Identify reference points  Locate nodes of interest Layout of random off-the-shelf device

1/5/2016 ISTFA Identification of Reference Objects Stepper alignment mark reference identified using optical microscope. The same alignment mark is easily recognizable using FIB.

1/5/2016 ISTFA Enhanced Accuracy “Lock” in FIB  Outline reference object by repair boxes;  Mark center of the object with a cross;  Make a precision lock on the center, even if the object is damaged by de-packaging or FIB milling;

1/5/2016 ISTFA Identification of Nodes and Acquisition of Preliminary Coordinates Analyze layout and identify nodes targeted for contacting; Trace nodes to locations convenient for FIB access; Acquire bitmap X/Y coordinates of the access locations and use as FIB coordinates; Layout of random off-the-shelf device

1/5/2016 ISTFA Acquisition of Precision Coordinates De-process location of the targeted node in a FIB and acquire precision coordinates of the node.

1/5/2016 ISTFA Enhanced Reliability of Contacting Contacting of buried node (green) by rectangular 0.2μm X 0.4μm access via provides safety margin to avoid shorting to the above- located nodes (yellow).

1/5/2016 ISTFA Enhanced Reliability of Contacting Monitoring of sample absorbed current provides reliable endpoint detection with high S/N ratio.

1/5/2016 ISTFA Summary  Developed methodology for identification of IC node coordinates without manufacturer’s CAD data.  Developed and used improved techniques of coordinate – based navigation in FIB system.  Achieved reliable FIB contacting of deeply buried nodes by multiple 0.2µm X 0.4µm vias.