Browse Prior Art Database

Two-Dimensional Spectral Imaging of Devices Using Long Pass Filters for Non-Destructive Device Analysis

IP.com Disclosure Number: IPCOM000042248D
Publication Date: 2005-Feb-03
Document File: 4 page(s) / 446K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a two-dimensional (2D) spectral imaging technique that uses four infrared (IR) long pass filters (LPF), an IR camera, a spectra library of emissions, and software to reconstruct and convert 2D images into spectra. Benefits include a solution that enables higher resolution imaging and eliminates spectral overlapping.

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Two-Dimensional Spectral Imaging of Devices Using

Long

Pass

Filters for Non-Destructive Device Analysis

Disclosed is a method for a two-dimensional (2D) spectral imaging technique that uses four infrared (IR) long pass filters (LPF), an IR camera, a spectra library of emissions, and software to reconstruct and convert 2D images into spectra. Benefits include a solution that enables higher resolution imaging and eliminates spectral overlapping.

Background

There is currently a need for a nondestructive, simple, and global spectral analysis and defect localization, as well as an inexpensive way of performing device analysis. There are many technical road blocks associated with device characterization and defect localization, including:

§         The inability to analyze non-visible defects

§         The inability to conduct non-destructive failure analysis (FA)

§         A lengthy FA throughput time

§         Overlapped spectra for multiple emissions

§         Dispersion images that vary by number of pixels and extend beyond the capture frame

Currently, systems with sufficient sensitivity for spectral analysis are used to address the above problems (see Figure 1). These systems often consist of cooled CCD arrays with a wavelength range of 300nm–1700nm, and transmission gratings to disperse the emitted light into its spectrum. Figure 2 shows the schematic of a grating-based spectral imaging. Failure mechanisms (e.g. gate oxide breakdowns, hot carrier effects, leaky junctions, and CMOS latch-ups) have their own unique spectrum which can be used for “defect finger-printing” analysis. With spectral imaging, two existing technologies—imaging and spectrometry—are combined so that there is no separation between the image and the spectral information about the device.

General Description

The disclosed method adds a 2D spectral imaging capability to the existing Infrared Emission Microscope (IREM). It uses four IR long pass filters (IRLPF), a database of known spectra, and an algorithm to reconstruct and convert each pixel of the 2D image into its corresponding spectrum. This enables one to determine the spectrum from each pixel in the whole image frame; this not only captures the emission image, but also the spectral information of the emission. Figure 2 shows the schematic of the existing IREM system. The four LPF are mounted in a computer controlled filter wheel fixture and inserted in between the objective lens and IREM camera. Figure 3 shows the schematic diagram of t...