Publication: Optical 3-d inspection and defect detection in silicon wafers using phase-measuring deflectometry
| datacite.subject.fos | oecd::Engineering and technology::Mechanical engineering::Mechanical engineering | |
| dc.contributor.author | Lim Meng Lip | |
| dc.date.accessioned | 2025-05-19T02:47:33Z | |
| dc.date.available | 2025-05-19T02:47:33Z | |
| dc.date.issued | 2023-05-01 | |
| dc.description.abstract | Accurate three-dimensional (3-D) surface profiling on silicon wafers is becoming significant because 3-D defects on silicon wafers can ruin the product. Thus, the study aims to develop an optical 3-D inspection and defect detection system for silicon wafers using phase-measuring deflectometry (PMD). The measurement setup consists of a projector, a camera, and an acrylic projection screen. Sinusoidal fringe patterns were projected onto the screen, and images of specimens encoded with the reflections of the sinusoidal fringe patterns were captured by the camera. Phase demodulation, phase unwrapping, slope calculation, and height reconstruction algorithms were developed to compute the surface profiles of the specimens from the captured images. The algorithms were tested on spherical concave and convex mirrors before being applied to measure light-emitting diode (LED) silicon wafers. Studies were also conducted to correct perspective distortion, intensity errors of the fringe patterns, and color intensity errors of color-coded fringe patterns. The results show that the PMD system can measure the surface profiles of the concave and convex mirrors with micrometer-level accuracy. Sub-micrometer level height differences were achieved for verification using stylus profilometry. Reductions in phase error and height error were demonstrated when perspective distortion and intensity errors in the projected fringe patterns, and color-intensity errors in the color-coded fringe patterns, were mitigated. The capability of the developed PMD system in detecting and measuring 3-D surface defects on silicon wafers are demonstrated. | |
| dc.identifier.uri | https://erepo.usm.my/handle/123456789/21685 | |
| dc.language.iso | en | |
| dc.title | Optical 3-d inspection and defect detection in silicon wafers using phase-measuring deflectometry | |
| dc.type | Resource Types::text::thesis::master thesis | |
| dspace.entity.type | Publication | |
| oairecerif.author.affiliation | Universiti Sains Malaysia |