Laser Signal Injection
| Locate shorts, junction defects, problem VIAs and other integrated circuit defects with Laser Signal Injection Microscopy (LSIM). An LSIM works by scanning a laser beam through a microscope lens, over an integrated circuit while monitoring the circuit input and output for laser induced changes. By choosing the laser wavelength, different effects can be produced. Short wavelength lasers produce electron & hole pairs, (photo-carriers) in the semiconductor. These photo-generated carriers reveal failure sites in transistors and PN junctions. Longer wavelength lasers induce heating and that reveals resistive and ohmic problems. Both photo-carrier generation and microthermal heating may be performed from the front or backside of the wafer, so the LSIM is a powerful backside inspection tool . |  |
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The LSIM is available on a dedicated optical head as pictured at right, or on QFI’s Multi Sensor Platform as seen at left. The Multi Sensor Platform combines the LSIM with Emission Microscopy and IR Thermal Hot Spot Detection. |
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Specifications |
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Laser Capacity |
May be fitted with one or dual lasers |
| Wavelength Options | 532 nm (diode laser) for high resolution front side thermal XIVA and photo-carrier XIVA |
| 1064 nm (ND:YAG) for backside photo-carrier XIVA fault detection. |
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| 1340 nm (Nd:YVO4) for backside thermal XIVA shorts and defect detection. | |
| User Selectable Full Field Sampling | Interchangeable X and Y scan directions |
| Region of interest scanning, | |
| Scan Based Zoom (same number of pixel samples for a smaller scan sweep). |
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| User Selectable Scan Capabilities | 256 x 256 (fast for focusing, navigating) |
| 512 x 512 (normal speed and resolution) | |
| 1024 x 1024 (fine, sampling) | |
| Field of View |
14 mm x 14 mm divided by selected magnification e.g., 2.8 mm @ 5x, 280 um @ 50x, 140 um @ 100x |
| Frame Rate | > 2Hz at 256 x 256 sampling |
| Resolution (diffraction) | Resolution is calculated from (0.4∗wavelength) / (Lens N.A.) |
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0.42 microns |
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0.85 microns |
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1.1 microns |
| A/D Resolution |
12 bits imaging and XIVA |
XIVA Electronics |
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| Maximum Bias Output |
10 VDC & 2 Amps |
| Input Coupling | AC/DC |
| User Selectable Input Filters | 100 KHz, 10 KHz, 1 KHz |
| User Selectable Amplifier Gain | 1, 10, 100 |