There are many different tools for semiconnductor metrology. One of such tools is Atomic Force Microsocpy (AFM), which is an important form of nanoscale scanning probe microscopy. A high resolution, repeatable AFM is valuable to semiconductor metrology in many ways.
AFM is the most accurate and data rich tool for step height measurements. Trench and VIA depths are also important for semiconductor engineers in the development and production process. A repeatable, and precise AFM is necessary to make the nanoscale and angstrom level measurements for micro-planarity, surface flatness analysis, and for 3D representations of wafers and chipsets.
Epitaxial layers are common in semiconductor fabrication. AFM is an easy to use, high resolution tool for taking wafer surface roughness measurements. Learn more in our white paper "Measuring Surface Roughness with the Asylum Research Jupiter XR Atomic Force Microscope".
Failure Analysis (FA) and defect characterization in the semiconductor industry has evolved. No longer is it enough to simply analyze returned product. FA processes are being developed to proactively analyze device failure over their lifetime. Additionally, defects and failures that occur post-production need to be addressed and looped back into the manufacturing process faster than ever before. A high-resolution, repeatable AFM provides the most detailed and reliable look possible at your components. AFM provides feedback for both electrical failure analysis and physical failure analysis, as well as tribological, mechanical, and interfacial analysis of devices. We'll look at some FA techniques for semiconductors below that involve AFM.
Nanoprobing, is a method by which nanoscale tungsten wires and probe tips measure the electrical characteristics and localize defects of integrated components. This type of measurement-- typically performed with AFM or SEM -- helps semiconductor researchers and engineers test integrated circuits (IC) and other materials during the the production and FA process. On AFM this is refered to as Atomic Force nanoProbing (AFP). We'll take a look at a couple of AFP techniques below:
Dopant density profiling with Scanning Capacitance Microscopy (SCM), allows for detailed non-destructive analysis of the doping variations and errors within extrinsic semiconductors, such as those used in Transistors, Diodes, Integrated Circuits, FETs, Lasers, Solar Cells, Photodetectors, LEDs, and Thryristors.
Current-Voltage (I-V) Characterization, can be done with extreme precision with the nanoprobing tools on a good AFM. Conductive AFM can be used to measure electrical properties such as IV curves, while simultaneously measuring topography. The benefit to using AFM here over say, SEM, is the ability to localize defects and electrical failures at high resolution without introducing electrical bias from electron beams.
To learn more about using Conductive AFM for failure analysis, our webinar "More Than Just Roughness: AFM Technique for Thin Film Analysis" is an excellent resource.