Optimized wavelength photon emission microscope for vlsi devices
AssigneeDCG Systems, Inc.
InventorHerve Deslandes
Life of this patent
Estimating the term…
Abstract
A method for emission testing of a semiconductor device (DUT), by mounting the DUT onto an test bench of an emission tester, the emission tester having an optical detector; electrically connecting the DUT to an electrical tester; applying electrical test signals to the DUT while keeping test parameters constant; serially inserting one of a plurality of shortpass filters into an optical path of the emission tester and collecting emission test signal from the optical detector until all available shortpass filters have been inserted into the optical path; determining appropriate shortpass filter providing highest signal to noise ratio of the emission signal; inserting the appropriate shortpass filter into the optical path; and, performing emission testing on the DUT.
Claims20
An optical system for imaging a semiconductor device, said system comprising:
- a bench for mounting the semiconductor device;
- an optical arrangement defining optical path;
- a detector sensitive to electromagnetic radiation having wavelengths of at least from 1000 nm to 2200 nm;
- a plurality of shortpass optical filters with high blocking capabilities beyond their cut-off wavelength;
- a selector for selectively placing one of said filters within said optical path;
- and,
- a controller connected to said detector and to said selector, the controller configured to selectively operate in a calibration mode and in a test mode, and wherein:
- during calibration mode the controller operates the selector to successively insert one of said filters within said optical path as the controller records emission signal received by the detector, and once all of said filters have been placed within said optical path the controller operates to compare the signal-to-noise ratio of the output of said detector for each of said filter;
- and,
- during test mode the controller operates said selector to insert one of the filter having the best signal-to-noise ratio for a selected test voltage, Vdd, into the optical path while the controller records emission signal received by the detector.
A method for emission testing of a semiconductor device (DUT), comprising the steps of:
- mounting the DUT onto an test bench of an emission tester, the emission tester having an optical detector;
- electrically connecting the DUT to an electrical tester;
- applying electrical test signals to the DUT while keeping test parameters constant;
- serially inserting one of a plurality of shortpass filters into an optical path of the emission tester and collecting emission test signal from the optical detector until all available shortpass filters have been inserted into the optical path;
- determining appropriate shortpass filter providing highest signal to noise ratio of the emission signal;
- inserting the appropriate shortpass filter into the optical path;
- performing emission testing on the DUT.
A method for emission testing of a semiconductor device (DUT), comprising:
- providing an electrical tester capable of inducing state changes in gates of said DUT;
- providing an emission tester having an optical system to image emissions from the DUT onto a photodetector;
- providing a plurality of shortpass filters serially insertable into optical path of the optical system;
- stimulating the DUT using said electrical tester;
- serially collecting optical emissions from said DUT through each of the filters, while keeping all test parameters constant;
- measuring signal to noise ratio (SNR) of the optical emission collected through each filter;
- selecting one filter that maximizes the SNR;
- stimulating said DUT using the electrical tester;
- collecting optical emissions from said DUT through the one filter.
Dependencies are inferred from the claim text.