Defect Detection and Thickness Mapping of the Passivation Layer(s) of Integrated Circuits.
Abstract
A narrow, high energy, electron beam is caused to impinge upon an integrated circuit. The accelerating voltage of the electron beam is increased until the electrons have just enough energy to penetrate through the thickness of the passivation layer (SiO2). The accelerating voltage is then increased a predetermined amount (3-5 KeV) above the voltage required for passivation layer penetration. The transmitted electrons interact with the sublayer or film material (Al) to generate distinct X-rays. The increased-intensity electron beam is x/y or raster scanned over the area of interest of the IC chip. The X-ray intensities generated during the raster scan are detected and stored (e.g., in a RAM). After a complete scan of the area of interest, the X-ray intensities are read out of store and visually displayed on a CRT. Through correlation of measured and predicted X-ray intensities, a scanning thickness mapping is available for display/quantitative analysis of the thickness profile of a passivation layer. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1987
- Accession Number
- ADD012906
Entities
People
- Richard G. Sartore
Organizations
- United States Army