Industrial Microscopes

Microelectronics and semiconductor wafer manufacturing are believed to be among the fastest evolving technology industries in the world today. Wafer sizes typically are 200 mm to 300 mm while critical dimensions are shrinking to 0.09 um and smaller in size. As the size of discrete devices continues to be reduced while device density increases, the need for fast, accurate, and very flexible metrology and inspection tools in the microelectronics industry increases. Back in the early 1980s, semiconductor inspection was performed primarily by brightfield optical microscopes and with automated detection tools. The adaptation of automated detection tools led to the systematic control of increasingly smaller defects. The smallest detectable defect using these automated tools fell to below the 0.30-micron mark during the 1990s. As semiconductor design rules decreased, it then pushed the requirements for defect inspection into the domain of the Scanning Electron Microscope or the SEM. These instruments were able to easily resolved defects of 0.25 um and smaller. However, the increase in resolution came at a price in speed and flexibility. Likewise, SEM inspection took longer due to time consuming manual sample preparation. The delay in the manufacturing environment was often too long and as a result, a bridge tool was developed that was based on confocal imaging. (more…)

The three methods in the initial phase sample preparation thinning are the manual pre thinning, FIB Lift out and the Automated Pre thinning. All these three create a thick section that is ready for final thinning to electron transparency. The first method is the manual pre thinning technique. Manual preparation is relatively slow, typically requiring 4 hours to prepare a FIB-ready sample. It is said to require a very little capital investment, but this cost savings is offset somewhat by the expense for a skilled technician. (more…)

The semiconductor industry is said to have unquestionably entered the realm of nanotechnology. Critical dimensions of many features are specified in terms of nanometers. Gate oxides are only a few nanometers thick. Barrier and seed layers for copper processes are not much more. Gate lengths are forecast at less than 20 nm by the end of the decade. More over, the drive to increase device density is leading to the adoption of FinFET and other new transistor designs that include complex three-dimensional structure. Even conventional planar CMOS designs now incorporate processes such as damascene interconnects that are inherently three dimensional. The need for higher spatial resolution combined with the need for cross-sectional imaging of complex structures has led to a significant increase in the demand for scanning transmission electron microscopy or STEM and transmission electron microscopy or TEM in operations of semiconductor manufacturing. Both TEM and STEM require very thin samples, typically less than 100 nm thick. This however can be hard, time consuming, and expensive to prepare. As they say, sample preparation can become a process bottleneck. Manual sample preparation is relatively very slow and it requires a skilled technician to do such job. Focused ion beam or FIB preparation provides an alternative that is fast but expensive. A method called automated pre-thinning systems, such as the EM2, perform the preliminary stages of the thinning quickly, reliably, and at a fraction of the cost of using FIB for the entire sample extraction and thinning process. (more…)

The Atomic Force Microscopy or AFM has always been a key technique for the measurement and analysis of samples when nanoscale topography is involved. It offers a number of complementary probing modes that extend an AFMs measurement capability to a wide range of material and transport properties of surfaces, including hardness, friction, conductivity and adhesion. Sample temperature controlled AFM extends the study of surface morphology and properties to include changes in the material phases. Recently, silicon microfabricated AFM cantilevers that have integrated heaters. They have likewise become commercially available. These cantilevers were initially developed for probe based data storage by researchers at IBM Zurich. With the availability of these cantilevers, AFM measurements can be performed where the tip is heated as opposed to the sample. Heated Tip AFM , or the HT-AFM, refers to AFM operation where a heated tip is utilized instead of a normal tip. This is done in order to locally heat the sample surface. A number of AFM modes can accommodate a heated tip to yield new information tied to the thermal properties of the sample. The HT-AFM mode was used to improve the discrimination of the two components in the phase image, which occurs when the tip is heated near the transition temperature of one of the components. The three micrometer scan size images show the high resolution capabilities of the heated tips as well as the ability to locally modify the sample surface. (more…)

Fluorescence microscopy has experienced tremendous growth over the past four decades of the century. It also has facilitated major advancements in the fields of science. The classic fluorescent techniques, including epi-fluorescence and confocal, has allowed researchers to selectively observe labeled structures with great clarity and consistency. Historically, biological scientists have been the most prolific users of fluorescence imaging. However, the increasing numbers of nano-materials research initiatives are now incorporating quantum dots and other fluorescent labels into their imaging protocols. This is especially true in areas where nano-materials and biological research is overlapping. Example, in cases like drug delivery. This nano-bio convergence, along with other advancements, has generated the need to observe highly dynamic events involving labeled and unlabeled structures in real time. For many researchers, observing the sample portion that is fluorescently labeled is often not sufficient. (more…)

Aside from just their concerns about the appearance of the art display in their galleries, curators of art galleries are also very much concerned about the conservation of the artwork and the art works authenticity. Microscopes have played a role in these latter activities since the about the time of the 1930s. Various imaging techniques, including X-radiography, reflectography, macrophotography, UV-fluorescence and raking light source at a low angle to the surface imaging have all their advantages and share of disadvantages. Confocal microscopy is most often useful compared to the other methods for the purpose of examination of subsurface structure. However, the close working distance of just a few mm involved when using the confocal microscope makes it precarious to use on liable masterpieces. More recently, Haida Liang, Marta Cid, Radu Cucu, George Dobre, Adrian Podoleanu, Justin Pedro, and David Sauders have demonstrated the usefulness of the optical coherence tomography or OCT for the nondestructive examination of the artworks in galleries. (more…)