Circuit Edit

Circuit edit (CE) is a common technique used in the design-debug phase of integrated circuits. Most CE activities are performed by means of FIB systems equipped with a Gas Injection System (GIS). Such systems allow site-specific and precise material etching as well as the deposition of conductive contacts or insulation.
Typical GIS chemistry used in CE includes XeF2 for selective Si-based materials etching, water for copper etching, SiOx for providing insulation and Tungsten for metal contacts. However, the task of circuit editing becomes extremely challenging in modern 3D IC devices because of their small size and high density. Full depth control and precise end-point detection are crucial in order to navigate along the z-direction and accurately reach only the layers of interest.
Any TESCAN FIB-SEM system can be equipped with a GIS for enhancing and optimising a wide range of FIB applications including circuit edit. Two options for GIS configuration are available: a 5-nozzle motorised GIS or multiple MonoGIS units. In either option the following precursors are available: Pt and W for metal deposition, SiOx for insulator deposition, H2O for enhanced etching Cu and XeF2 for selective etching of Si, SiOx, and Si3N4.
  • TESCAN LYRA and GAIA FIB-SEM systems are equipped with the DrawBeam lithography module, dedicated, user-friendly and effective software for precise etching, deposition and end-point detection required for advanced circuit editing applications.
  • Precise end-point detection is achieved by means of the FIB-SE signal, i.e. secondary electrons emitted during milling which are used to identify transitions between layers. The detection accuracy is better than 20 nm in the Z-direction on ICs.
  • In addition, Synopsys Avalon™ (Camelot™) software  as a well established CAD navigation standard in combination with the X-Positioner Module allows live overlay of the SEM or FIB image with CAD design data, optical, IR, X-ray, etc. images for precise navigation over the IC for frontside and backside circuit editing.
Circuit Edit
SEM image of a chip with a coloured overlay from optical microscope

Related Application Notes

Integrated circuit device modification using Camelot
As the complexity of Integrated Circuit (IC) design modifications increase, the time to perform these modifications also increases. As a result, the turn-around-time for bug fixes becomes critical to a product’s success. The Focused Ion Beam (FIB) is powerful tool for circuit edit because it can remove and deposit materials with high precision. These capabilities can be used to cut and connect circuitry within a device, as well as to create probe points for electrical test. To execute circuit edits, the FIB tool is coupled to a CAD navigation system that makes it possible to locate the area of interest.
pdf – 2.2 MB
Live overlay of FIB image with CAD design data for precise navigation over the IC
Live overlay of FIB image with CAD design data for precise navigation over the IC
Multi-scale Electron Beam Lithography using DrawBeam Batch Processing
DrawBeam Advanced is a versatile lithographic software allowing advanced electron- and ion-beam lithography. A CAD-like software interface allows the user to define a multi-layered project along with the processing parameters for each layer independently. It also allows combination of layers with electron- and ion-beam exposure/ milling and possibly also gas‑injection assisted processing. The new feature of Batch Processing allows automation of selected layers as one batch. This allows better optimization of the lithographic process e.g. by combination of high currents for large patterns and high resolution for fine-details.
pdf – 484 kB
Image of developed contact pad acquired using a light microscope
Image of developed contact pad acquired using a light microscope