Front-side/back-side IC Editing with Coaxial Photon and Ion Optics
Sage Analytical Lab’s 45-nm editing is state-of-the art, and the OptiFIB-IV focused ion-beam instrument offers a proven circuit edit solution for 45 nm and beyond.
Advanced circuit edit capability with outstanding edit throughput and unparalleled edit success rates significantly reduce time-to-market and time-to-yield for our customers in the semiconductor industry. We are able to provide simultaneous imaging and ion editing with the OptiFIB’s unique coaxial ion-photon column, thus providing actual real-time verification of edit end-pointing.The coaxial ion and photon optics enable you to see through silicon or passivation, allowing precise and accurate alignment of the FIB and CAD layout.
Photon optics enable fast access to Metal-1 by viewing through silicon (photons enable non-invasive, through-SOI imaging) resulting in real-time optical imaging that can be used for accurate navigation. OptiFIB accesses the lowest buried metal layers though the back-side bulk silicon, allowing direct and accurate edits to be performed at every level of the circuit.
The FIB, Optical and CAD images always remain aligned with one another throughout the edit process. There is no need to remove the device or shuttle it back and forth between a FIB and a separate imaging system: OptiFIB-IV performs the entire operation with the device in place. Edits may be defined within the FIB, Optical or CAD windows. OptiFIB technology enables navigation across your device without having to turn on the ion beam, thus limiting ion exposure to fragile circuitry.
The OptiFIB-IV offers best copper edit chemistry solution in the industry. The challenge of copper edit becomes a predictable routine when using the OptiFIB-IV. Sophisticated and well-proven edit recipes take the guesswork out of dealing with uneven etching of copper grain structures. OptiFIB has the only true copper etch chemistry in the circuit edit business. This also enhances device edit success rate by enabling clean cutting during circuit edit modifications. Sage’s unique “CU2″ chemistry solution for editing copper over SiO2 and Low-k provides true and reliable results for the most complex edit challenges. The copper etch chemistry minimizes over-etching of underlying low-k dielectric material down to less than 20 nm. By avoiding over-etching, OptiFIB-IV enables a precise recipe for a successful edit. The OptiFIB-IV utilizes 2nd generation enhanced copper etch solution CU2, which has been proven to etch 4-5 times faster than previous solutions.
High aspect ratio edits of up to 25-to-1 are OptiFIB’s specialty, with the ability to access the lowest level metal through eight or more metal layers. OptiFIB-IV is capable of placing the ion beam to within an accuracy of 10 nm, allowing plenty of capability to accommodate future technology nodes.
Removal of bulk silicon, commonly called “trenching,” is a critical step in the back-side editing process. This process uses the ion beam to excavate a trench through the silicon substrate in order to get close to the active regions and access the necessary metal layers for rewiring. Through the use of its unique optical capabilities, the OptiFIB-IV provides critical information on trench floor flatness by detecting optical interference fringes.
The highly sensitive end-pointing tool detects a transition between materials, prompting termination of the ion milling process. Through its patent pending Material Contrast/Voltage Contrast (MC/VC) and Shallow Trench Isolation (STI) alignment techniques, OptiFIB-IV provides alignment to an accuracy of 10 nm, exceeding the 45 nm technology node requirements.
PC-based FUSION system control software incorporates proprietary FIB Assist™ technology acquired from Fibics Incorporated. FUSION enhances visualization with high definition imaging for FIB and Optical as well as numerous real-time image processing tools. FIB Assist provides a valuable set of features that increase speed and accuracy in circuit editing, as well as capability to track and review edits.
- Co-axial photon imaging through passivation and silicon (US patent 7,297,948)
- Precision copper etching over SiO2 and low-k dielectrics
- Sub-pA beam current imaging and end-pointing
- Backside trenching and editing
- FUSION PC-based control software
- Integrated FIB Assist™s
- On system support of ten different chemistries
- Laser interferometer stage
- CMP Navigator: Patented precision electronic beam deflection in combination with CAD overlay (US patent 5,401,972)
- Optional Dual micro-jet chemistry injector
- Optional Manual joystick and knobs panel
- Optional Load lock
FIB circuit edit is a crucial technique in the semiconductor field for reasons including:
- Circuit debugging
- Probe-point deposition
- Engineering evaluation
- In-depth analysis of customer return samples
Due to the highly localized sub-micron processes needed for advanced circuit edit, procedures performed at Sage Analytical Lab utilize CAD overlay techniques to pinpoint exact locations. This improved accuracy allows our engineers to navigate directly to the targeted location enhancing yield and precision. Coupled with 2nm beam resolution, multiple gas injection systems, and huge aperture and beam current ranges, Sage Analytical is equipped to provide you the best service in the industry.
The addition of backside circuit edit techniques expands our capabilities to the cutting edge of the industry. The new DCG OptiFIB-IV handles all backside trenching and editing of the most complex circuit where front-side techniques cannot compare. This technique is imperative in high technology nodes to work through the dense topside metallization on these devices.
Using different chemistries throughout the editing procedure ensures robust connections and cut. IEE gas etch is a special mix selective to dielectric that is capable of producing a high aspect ratio hole through dielectric layers in a timely manner. By applying a targeted platinum or tungsten gas into this hole, a uniform via and conductive lines can be established. If there is the chance of corrosion or damage to the edit site, the region may be passivated with oxide. Post-circuit modification, glob topping allows the modified ICs to be mounted onto PCBs, reducing the possibility of damage to the circuit and wire bonds.
We understand that these types of modifications are crucial to the design and debugging life-cycle. Due to the highly time sensitive nature, immediate turnaround at Sage Analytical Lab is standard procedure. We try our best to meet your timelines and target dates in every case. With a nominal charge, circuit edit modifications can also be performed on weekends and holidays in rushed circumstances.