Abstract: Methods for integrated circuit diagnosis, characterization or modification using a charged particle beam. In one implementation, the bulk silicon substrate of an integrated circuit is thinned to about 1 to 3 ?m from the deepest well, a voltage is applied to a circuit element that is beneath the outer surface of the thinned substrate. The applied voltage induces an electrical potential on the outer surface, which is detected as a surface feature on the outer surface by its interaction with the charged particle beam.

Abstract: Methods for using measured time resolved photon emission data and simulated time resolved photon emission data for fault localization are provided and described. In one embodiment, a method of localizing a fault in a circuit includes generating simulation photon emission data for the circuit. Moreover, measured photon emission data for the circuit is generated. The simulation photon emission data is compared with the measured photon emission data to generate a comparison result. Further, the comparison result is classified according to predetermined criteria. The classified comparison result is used in a fault localization technique to determine next action in localizing the fault.

Abstract: A plurality of images, including a first image and a second image having a higher resolution than the first image, are aligned by generating an oversampled cross correlation image that corresponds to relative displacements of the first and second images, and, based on the oversampled cross correlation image, determining an offset value that corresponds to a misalignment of the first and second images. The first and second images are aligned to a precision greater than the resolution of the first image, based on the determined offset value. Enhanced results are achieved by performing another iteration of generating an oversampled cross correlation image and determining an offset value for the first and second images. Generating the oversampled cross correlation image may involve generating a cross correlation image that corresponds to relative displacements of the first and second images, and oversampling the cross correlation image to generate the oversampled cross correlation image.

Abstract: A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves processing of integrated circuit computer aided design data to identify transistors within the CAD data. The analysis may further involve the use of Boolean operators to process the CAD data to particularly identify, such as through a channel, the location of the NMOS and PMOS gates, the location of the drain and source, or some combination of the location of the gate and drain or source to particularly identify the pinch-off region.

Abstract: A method for surface preparation of a polycrystalline material prior to etching. The material surface is amorphized by two particle beam bombardments s on the material surface. These energized particles break the crystal structure of the crystalline material and convert it into amorphous material. The two particle beams are oriented to each other at an angle of at least twice of the critical angle of channeling for the most open crystal structure in the material. This ensures amorphization of the material surface regardless of the different grain orientations on the surface. The amorphous surface has isotropic surface properties and thus allows uniform etching. The uniformity in surface properties allows better control over etching process and reduces damage to underlying and adjacent material.

Abstract: A method for surface preparation of a polycrystalline material prior to etching. The material surface is effectively amorphized by two particle beam bombardments on the material surface. These energized particles break the crystal structure of the crystalline material and convert it effectively into an amorphous material. The two particle beams are oriented to each other at an angle of at least twice of the critical angle of channeling for the most open crystal structure in the material. This ensures effective amorphization of the material surface regardless of the different grain orientations on the surface. The amorphized surface has isotropic surface properties and thus allows uniform etching at the second angle. The uniformity in surface properties allows better control over etching process and reduces damage to underlying and adjacent material.

Abstract: A reliable, inexpensive “back side” thinning process, capable of globally as well as locally thinning an integrated circuit die to a target thickness of 10 microns, and maintaining a yield of at least 80%, for chip repair and/or failure analysis of the packaged die. The flip-chip or wire-bond packaged die is mounted on a thinning/polishing tool with the backside accessible. The thinning/polishing tool can be a lapping machine used for global thinning, or a mini milling machine, laser, FIB, or E-beam machine for local thinning. The thickness of the die is measured at at least five locations on the die before thinning. The thinning tool removes silicon on the exposed surface of the die to a thickness somewhat greater than the target thickness. The exposed surface of the die is polished. The thickness of the die is again measured optically with high accuracy.

Abstract: A system and method for determining precisely in-situ the endpoint of halogen-assisted charged particle beam milling of a hole or trench in the backside of the substrate of a flipchip packaged IC. The backside of the IC is mechanically thinned. Optionally, a coarse trench is then milled in the thinned backside of the IC using either laser chemical etching or halogen-assisted charged particle beam milling. A further small trench is milled using a halogen-assisted charged-particle beam (electron or ion beam). The endpoint for milling this small trench is determined precisely by monitoring the power supply leakage current of the IC induced by electron-hole pairs created by the milling process. A precise in-situ endpoint detection signal is generated by modulating the beam at a reference frequency and then amplifying that frequency component in the power supply leakage current with an amplifier, narrow-band amplifier or lock-in amplifier.

Abstract: A plurality of images, including a first image and a second image having a higher resolution than the first image, are aligned by generating an oversampled cross correlation image that corresponds to relative displacements of the first and second images, and, based on the oversampled cross correlation image, determining an offset value that corresponds to a misalignment of the first and second images. The first and second images are aligned to a precision greater than the resolution of the first image, based on the determined offset value. Enhanced results are achieved by performing another iteration of generating an oversampled cross correlation image and determining an offset value for the first and second images. Generating the oversampled cross correlation image may involve generating a cross correlation image that corresponds to relative displacements of the first and second images, and oversampling the cross correlation image to generate the oversampled cross correlation image.

Abstract: Methods for integrated circuit diagnosis, characterization or modification using a charged particle beam. In one implementation, the bulk silicon substrate of an integrated circuit is thinned to about 1 to 3 &mgr;m from the deepest well, a voltage is applied to a circuit element that is beneath the outer surface of the thinned substrate. The applied voltage induces an electrical potential on the outer surface, which is detected as a surface feature on the outer surface by its interaction with the charged particle beam.

Abstract: A system and process for determining precisely in-situ the endpoint of halogen-assisted charged particle beam milling of a hole or trench in the backside of the substrate of a flipchip packaged IC. The backside of the IC is mechanically thinned. Optionally, a coarse trench is then milled in the thinned backside of the IC using either laser chemical etching or halogen-assisted charged particle beam milling. A further small trench is milled using a halogen-assisted charged-particle beam (electron or ion beam). The endpoint for milling this small trench is determined precisely by monitoring the power supply leakage current of the IC induced by electron-hole pairs created by the milling process. A precise in-situ endpoint detection signal is generated by pulsing the beam at a reference frequency and then amplifying that frequency component in the power supply leakage current with an amplifier, narrow-band amplifier or lock-in amplifier.

Abstract: A charged particle beam system such as a focused ion beam system includes a vacuum chamber; an optical microscope located so as to have a filed of view within a first region of the chamber; a laser aligned with the optical microscope so as to project a laser beam into the first region; a charged particle beam column located within the chamber and arranged so as to focus a charged particle beam into a second region of the chamber; and specimen support located in the chamber and moveable between a first position in the first region and a second position in the second region. The laser is used to mark a DUT with a registration mark which is visible in the images from the optical microscope and the charged particle beam. The position of the registration mark can be accurately determined in the optical image and the position of features which would otherwise be invisible in the charged particle beam image inferred.