Laser Scanning Microscopy (LSM’s)

Checkpoint Technologies’ proprietary con-focal laser scanning microscopes (LSM) have been in use in the semiconductor failure analysis field for over 20 years. These custom designed and configurable microscopes are capable of supporting near IR (NIR) and visible (Vis) wavelengths. Each microscope is capable of up to three wavelengths that produce industry leading imaging.

Coupled with the LSM’s is Checkpoint Technologies ASP-2000 for use in passive laser scanning techniques such as TIVA, LIVA, OBIRCH, OBIC and SEI. The ASP-2000 contains a 4 quadrant source that can deliver both positive and negative voltages and currents to the device under test (DUT). The standard ASP-2000 can deliver up to+/-60V or +/-3 A. Included, in the ASP-2000 are user selectable band pass filter that are used to help reduce the noise in the measurements. The high voltage version of the ASP-2000 HV can provide up to 2kV to the DUT in OBIRCH mode.

Checkpoint’s LSM’s are also capable of dynamic laser scanning techniques such as, SDL, RIL and LADA. The LSM’s pixel clock has external trigger to synchronize the pixels with the DUT’s test loop. Checkpoint’s custom 16 bit digitizer allows its customers to average data and precisely locates SDL and LADA hits.

Laser Scanning Microscopy
Figure 1The LTM also allows the user to park the laser on a specific transistor while the DUT is in a continuous test loop. Using a trigger in the test loop, the user can average the reflected light with a high-speed digital sample oscilloscope and generate an electronic waveform that represents the voltage on the transistor with respect to time. Figure 2 has a sample of such a waveform.

Photon Emission (PEM’s)

Checkpoint Technologies’ Photon Emission Microscopes (PEM) are the industry leader in sensitivity and resolution. The InfraScan product family can be equipped with a variety of cameras to suit its customers’ needs. The camera selection include variations of the following types of cameras; Si CCD, InGaAs and MCT.

The SI CCD cameras available are deep depletion SI CCD to extend their responsivity further into the NIR region of the spectrum. This allows for basic backside PEM functionality while keeping the ease and responsivity of the visible spectrum for front side IC FA work too.

The specialized InGaAs cameras that are available in the InfraScan product family, come in either liquid nitrogen cooled (LN2) or thermo-electrically cooled (TEC) versions. The TEC cool version is an easy to use low maintenance camera that is quickly cooled to -60C. At this temperature, the blackbody radiation is reduced to the point where the camera is capable of integrating for several minutes. This is cost effect solution for customers who need to perform backside PEM consistently but are not pushing the edges of IC technologies.

Checkpoint has a custom built LN2 cooled InGaAs camera that further reduces the blackbody radiation and allows for customers to integrate for 10’s of minutes. The responsivity of the InGaAs array is 900-1650 nm. The low noise in this camera leads the industry in sensitivity and resolution. This camera is designed for customers that are looking a low leakage parts and need to see sub-nA issues.

Lastly, Checkpoint has designed an extremely low noise, LN2 cooled, MCT camera. The responsivity of the MCT array is 400-2500 nm. This camera comes equipped with an integrated optical filter wheel that allows users to select the wavelength regime in which they want to work. The design of the optics and camera gives the users long integration times >10 minutes and great resolution for the new <10 nm IC technologies and low voltages < 500 mV.

InfraScan™ LTM

Checkpoint’s InfraScan LTM option can be installed on either InfraScan 400TDM or InfraScan ES400 system chassis. The LTM option is a laser probe that uses the reflected light from the LSM to create both signal mapped images (SMI’s) and electrical waveforms from the DUT.

Collecting the reflected light from the DUT while it’s being tested in a continuous loop, allows LTM user’s the opportunity to measure its change in reflected power. By using a spectrum analyzer the user can isolate a specific electrical frequency that is propagating through the DUT. This isolated frequency can be imaged, simultaneously while imaging with the LSM. This imaged frequency is the SMI, shown below in false color in figure 1 is overlaid on top of the corresponding optical image.

Optical Wavelengths
Figure 2The InfraScan LTM is available in various optical wavelengths, 1319 nm, 1154 nm, 1064 nm and visible.

Solid Immersion Lens Objectives (SIL’s)

Solid Immersion Lens (SIL) objectives are used to increase the numerical aperture (NA) of an optical system to increase the resolution; therefore, enabling the user to see smaller IC geometries. Additionally, the higher the NA derived from a SIL improves the collection efficiency of the system.

Checkpoint has designed and built SIL’s for the FA and debugging market for 10+ years. By using its proprietary backing object designs, Checkpoint has been able to lead the market in SIL development. The design of all of Checkpoint’s SIL’s is that of a hemispherical SIL tip. This design allows the user to use the same SIL objective for multiple wavelengths and a range of DUT thicknesses. Also, since Checkpoint assembles and polishes its own SIL tips, SIL objectives are available in both Si and GaAs and are customizable for almost any Si IC thickness.

Checkpoint’s latest SIL with an NA of 3.3 and using a 1064 laser is capable of resolving structures below 220 nm. Figure 1 is an image of a SIL imaging a resolution structure of 240 nm pitch.

SIL Objectives
Figure 1SIL objectives are available with either InfraScan 400TDM or InfraScan ES400 system chassis. Automated tip/tilt stages are included when SIL objectives are used on an InfraScan system.


Our InfraScan™ Product lines provide the groundbreaking combination of Checkpoint Technologies, world leading laser scanning microscope and its best in class emission system into a single tool. Discover why our systems set the bar in the industry. Browse the products, systems and technologies below to learn more.

InfraScan™ 400TDM

The InfraScan 400TDM is the newest evolution of Checkpoint’s pioneering top-down laser scanning an...

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InfraScan™ ES400

The InfraScanTM ES400 family provides the groundbreaking combination of Checkpoint Technologies, wor...

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InfraScan™ LTM

Checkpoint Technologies’ laser probing tool, the InfraScan™ LTM (Laser Timing Module), employs a...

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