Transmission Electron Microscopy for Imaging of Biological Molecules
Transmission Electron Microscopy for Imaging of Biological Molecules Customer Case The customer is improving their customized Transmission Electron Microscope (TEM) that is optimized for imaging unstained biological molecules with minimal radiation damage. Diffraction-limited resolution of 0.25 nm is routinely obtained with a cold field-emission electron-gun operating at 40 keV. The sample is maintained at about 123 K (i.e. -150°C), both to eliminate contamination and to reduce mass-loss. The scan raster is 512 x 512 points with a dwell time of 30 microseconds per pixel (over 8.5 seconds per raster-scan). For most mass measurements, the pixels are separated by 1 [...]
Advantages of Measuring Semiconductor Thin Film Thickness with Capacitance
Thin Film Thickness Measurement Using Capacitance in the Semiconductor Industry In the semiconductor industry, the precise measurement of thin film thickness is crucial for ensuring the quality and functionality of wafer coatings. Thin films are deposited onto silicon and other wafer materials one atomic layer at a time, and the thickness of these coatings significantly impacts the wafer’s electrical, optical, and mechanical properties. Thin film thickness measurement is particularly important for semiconductor wafers, which may have either conductive metallic films or non-conductive metal oxide films deposited onto them. Common deposition methods include chemical vapor deposition (CVD) and physical vapor [...]
Treadmill Power Glitch Monitoring
Treadmill Power Glitch Monitoring Customer Case A customer develops gym equipment such as treadmills. The requirement is for an inexpensive way to monitor voltage signals for long periods of time. The treadmills are controlled by microprocessors that drive the LED displays. The customer has observed that some units intermittently fail during testing, a condition known as a "glitch" or a "brown-out". A glitch can have many causes, one of which is a weak power supply. The customer needs to capture certain key signals when a glitch occurs. At that stage, based on the captured data, it can be determined [...]
How Often Should Vibration Analysis Be Performed?
How Often Should Vibration Analysis Be Performed? Once a customer takes delivery of a PBS system and learns how to use it, the next logical question is: “How often should we use it?” At a minimum, your approved maintenance program (whether it’s a program developed by your operation, or the maintenance procedures outlined by the engine/airframe manufacturer) will tell you about the intervals at which to perform a vibration analysis. Usually, there is a procedure to specify how an engine vibration analysis and balance need be only completed when squawked by a pilot or after the completion of maintenance [...]
Contact vs. Non-Contact Measurement and Linear Displacement Sensors
Contact vs. Non-Contact Measurements Choosing between a contact measurement system and a non-contact measurement system requires careful evaluation of your application’s performance needs, material properties, environmental conditions, and measurement goals. Each system type offers unique advantages- and understanding these distinctions can help you make a more informed decision. Let's explores how contact and non-contact measurement techniques work, their strengths and limitations, and where they’re best applied. What Are Contact Measurement Systems? Contact measurement systems involve tools and sensors that physically touch the object to determine various physical characteristics. These systems are widely used in dimensional metrology, offering high precision, [...]
Capacitance Sensors vs. Eddy Current Sensors Application Note
Capacitance Sensors vs. Eddy Current Sensors Application Note Capacitance sensors and Eddy current sensors are both used for non-contact measurements. Capacitive probes use electric fields to measure the distance from the sensor face to the surface of a target that is typically conductive and grounded. Eddy current probes use an alternating AC current to induce a magnetic field in a conductive target instead. In turn, the induced magnetic field produces a back magnetic field that is proportional to the gap between the probe face and the target. In a recent application note, MTI Instruments examines the differences between capacitance [...]
Using Capacitance Sensors for Non-Conductive Material Measurement
Non-Conductive Material Measurement with Capacitance Sensors Capacitance sensors are non-contact devices that can be used to obtain position, thickness, and dynamic measurements with a high degree of precision, accuracy, and resolution. Capacitive measurement is used with electrically-conductive materials such as metals but can also be used to measure non-conductive materials such as glass, sapphire, and many plastics. Even if a non-conductive material is relatively inexpensive (such as closed cell foam), manufacturers want to avoid errors that can result in significant waste across high volumes. Importantly, capacitance measurement is also used with semi-insulating materials such as gallium arsenide (GaAs) and [...]
Semiconductor Wafer Lapping and Displacement Measurement
Semiconductor Wafer Lapping and Displacement Measurement Semiconductor Semiconductor Wafer Manufacturing Displacement Description Semiconductor Wafer Lapping and Displacement Measurement This application note explains how MTI’s Accumeasure technology was used with a lapping machine to measure displacement (wafer material removal) and determine the new semiconductor wafer thickness. Changes in electrical capacitance (displacement) were measured and then directly converted into a 24-bit digital reading to obtain precise digital thickness measurements. During lapping, a wafer of known start thickness is placed on a rotary lapping table. The backside of the wafer faces downward and toward [...]
Wafer Stress Analysis Using the 300iSA
Wafer Stress Analysis Using MTI Instruments Proforma 300iSA Wafer processing involves several stages that can lead to mechanical changes in the wafer structure. These changes, or stresses, may result in deformities, making the wafer either unusable or only marginally usable. To evaluate these stresses and determine the wafer's quality, wafer stress measurement is essential. The Proforma 300iSA wafer characterization tool offers a powerful solution for wafer stress analysis. It allows for the analysis of a wafer both before and after processing. By comparing these two states, the Proforma 300iSA effectively evaluates the wafer's stress levels and mechanical alterations, providing [...]
Capacitance Probes vs. Strain Gauges in Piezo Flexure Stages
Capacitance probes with pico-positioning sensors can be embedded in piezo flexure stages. With minor mounting modifications, these non-contact probes provide significantly greater accuracy than strain gauges. Piezo flexure stages are positioning devices with a high degree of resolution. These motion stages contain a piezoelectric actuator that converts an electrical signal into displacement based on the reverse piezoelectric effect, which is the ability of a piezo electric material to elongate when a voltage is applied. When a voltage (e.g., 0-150 VDC) is applied to the actuator, the stage moves in proportion to the applied voltage. Yet, the exact position remains [...]






