Crystal defects analysis using nano-probe technologies
With the device size shrinking to deep sub-micron region, silicon crystal defects become critical to device parameters. It also brings FA (Failure Analysis) great challenges on timely and exactly identifying the defect by EFA (Electrical Failure Analysis) and PFA (Physical Failure Analysis) methods. In this paper, we report the FA's on the single bit failure of a 6T-SRAM using nano-probe technologies for electrical localization. PFA methods, such as SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), and chemical etching were performed for failure visualization.
Case study on asymmetric Id measured on MOSFET
With the development of technological process, many Front End Of Line (FEOL) defects are found, and many studies focus on abnormal Id behavior of MOSFETs on SRAM cells. But in this paper a method of how to analyze asymmetric Id measured on a single MOSFET to locate the FEOL defect based on real case analysis is introduced. With studies on cases with asymmetric Id, we have built the corresponding failure mechanism and summarized a decision tree in order to analyze that kind of cases. The decision tree and thinking method are also applied in other cases analysis and shown to be effective.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.