scholarly journals Optical 3-D Profilometry for Measuring Semiconductor Wafer Surfaces with Extremely Variant Reflectivities

2019 ◽  
Vol 9 (10) ◽  
pp. 2060 ◽  
Author(s):  
Liang-Chia Chen ◽  
Duc-Hieu Duong ◽  
Chin-Sheng Chen
Keyword(s):  
Optical Sensors ◽  
Wafer Surface ◽  
Semiconductor Wafer ◽  
Full Field ◽  
Specular Surface ◽  
Surface Profilometry ◽  
Optical Inspection ◽  
Reflected Light ◽  
Automated Optical Inspection ◽  
Light Beams

A new surface profilometry technique is proposed for profiling a wafer surface with both diffuse and specular reflective properties. Most moiré projection scanning techniques using triangulation principle work effectively on diffuse reflective surfaces, on which the reflected light beams are assumed to be well captured by optical sensors. In reality, this assumption is no longer valid when measuring a semiconductor wafer surface having both diffuse and specular reflectivities. To resolve the above problem, the proposed technique uses a dual optical sensing configuration by engaging two optical sensors at two different viewing angles, with one acquiring diffuse reflective light and the other detecting at the same time specular surface light for achieving simultaneous full-field surface profilometry. The deformed fringes measured by both sensors could be further transformed into a 3-D profile and merged seamlessly for full-field surface reconstruction. Several calibration targets and industrial parts were measured to evaluate the feasibility and accuracy of the developed technique. Experimental results showed that the technique can effectively detect diffuse and specular light with repeatability of one standard deviation below 0.3 µm on a specular surface and 2.0 µm on a diffuse wafer surface when the vertical measuring range reaches 1.0 mm. The present findings indicate that the proposed technique is effective for 3-D microscale surface profilometry in in-situ semiconductor automated optical inspection (AOI).

Modelling Light Transmission in a Fiber-Optical Reflection System

2004 ◽  
Vol 9 (1) ◽  
pp. 55-63
Author(s):  
V. Kleiza
Keyword(s):  
Optical Sensors ◽  
Light Transmission ◽  
External Cavity ◽  
Linear Displacement ◽  
Fiber System ◽  
Light Emitting ◽  
Optical Media ◽  
Reflected Light ◽  
Fiber Optical ◽  
Fiber Optical Sensors

Light transmission in the reflection fiber system, located in external optical media, has been investigated for application as sensors. The system was simulated by different models, including external cavity parameters such as the distance between light emitting and receiving fibers and mirror positioning distance. The sensitivity to a linear displacement of the sensors was studied as a function of the distance between the tips of the light emitting fiber and the center of the pair reflected light collecting fibers, by positioning a mirror. Physical fundamentals and operating principles of the advanced fiber optical sensors were revealed.

Measuring Surface Uniformity in Chemical Mechanical Polishing

2009 ◽  
Vol 76-78 ◽  
pp. 459-464
Author(s):  
Jae Won Baik ◽  
Chang Wook Kang
Keyword(s):  
Chemical Mechanical Polishing ◽  
Geometric Mean ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Semiconductor Wafer ◽  
Statistical Process ◽  
Significant Step ◽  
The Difference ◽  
Thickness Variations ◽  
The Stability

Chemical mechanical polishing (CMP) is a technique used in semiconductor fabrication for planarizing the top surface of an in-process semiconductor wafer. Especially, Post-CMP thickness variations are known to have a severe impact on the stability of downstream processes and ultimately on device yield. Hence understanding how to quantify and characterize this non-uniformity is significant step towards statistical process control to achieve higher quality and enhanced productivity. The main reason is that the non-uniformed interface between the wafer and the machine-pad adversely affects the polishing performance and ultimate surface uniformity. The purpose of this paper is to suggest a new measure that estimates the uniformity of wafer surface considering the difference of the amount of abrasion between the center and the edge. This new measure which is called the Coefficient of Uniformity is defined as the following ratio: Geometric Mean (GM) / Arithmetic Mean (AM). This metric can be evaluated regionally to quantify the non-uniformity on the wafer surface from the center to the edge. Further simulations show that this new measure is insensitive to shift of the wafer center and sensitive to shift of the wafer edge. This trend indicates that this new measure is a very useful to test the non-uniformity of wafer after CMP polishing.

scholarly journals Ceramic Cracks Segmentation with Deep Learning

2021 ◽  
Vol 11 (13) ◽  
pp. 6017
Author(s):  
Gerivan Santos Junior ◽  
Janderson Ferreira ◽  
Cristian Millán-Arias ◽  
Ramiro Daniel ◽  
Alberto Casado Junior ◽  
...  
Keyword(s):  
Deep Learning ◽  
Ceramic Plate ◽  
Ceramic Tiles ◽  
Entire Area ◽  
Manual Inspection ◽  
Optical Inspection ◽  
Proposed Model ◽  
Processing Step ◽  
Long Time ◽  
Automated Optical Inspection

Cracks are pathologies whose appearance in ceramic tiles can cause various damages due to the coating system losing water tightness and impermeability functions. Besides, the detachment of a ceramic plate, exposing the building structure, can still reach people who move around the building. Manual inspection is the most common method for addressing this problem. However, it depends on the knowledge and experience of those who perform the analysis and demands a long time and a high cost to map the entire area. This work focuses on automated optical inspection to find faults in ceramic tiles performing the segmentation of cracks in ceramic images using deep learning to segment these defects. We propose an architecture for segmenting cracks in facades with Deep Learning that includes an image pre-processing step. We also propose the Ceramic Crack Database, a set of images to segment defects in ceramic tiles. The proposed model can adequately identify the crack even when it is close to or within the grout.

scholarly journals Novel Boundary Edge Detection for Accurate 3D Surface Profilometry Using Digital Image Correlation

2018 ◽  
Vol 8 (12) ◽  
pp. 2541 ◽  
Author(s):  
Liang-Chia Chen ◽  
Ching-Wen Liang
Keyword(s):  
Digital Image Correlation ◽  
Edge Detection ◽  
Digital Image ◽  
Optical Diffraction ◽  
Image Correlation ◽  
Detection Accuracy ◽  
Boundary Edge ◽  
Discontinuous Surface ◽  
Full Field ◽  
Surface Profilometry

Digital image correlation (DIC) has emerged as a popular full-field surface profiling technique for analyzing both in-plane and out-of-plane dynamic structures. However, conventional DIC-based surface 3D profilometry often yields erroneous contours along surface edges. Boundary edge detection remains one of the key issues in DIC because a discontinuous surface edge cannot be detected due to optical diffraction and height ambiguity. To resolve the ambiguity of edge measurement in optical surface profilometry, this study develops a novel edge detection approach that incorporates a new algorithm using both the boundary subset and corner subset for accurate edge reconstruction. A pre-calibrated gauge block and a circle target were reconstructed to prove the feasibility of the proposed approach. Experiments on industrial objects with various surface reflective characteristics were also conducted. The results showed that the developed method achieved a 15-fold improvement in detection accuracy, with measurement error controlled within 1%.

In-line advanced process control solution for the fabrication of micro-bumps

2017 ◽  
Vol 2017 (1) ◽  
pp. 000087-000092
Author(s):  
Dario Alliata ◽  
Stephane Godny ◽  
Cleonisse Serrecchia ◽  
Tristan Combier ◽  
Astrid Sippel ◽  
...  
Keyword(s):  
Process Control ◽  
Fabrication Process ◽  
Wafer Surface ◽  
Control Solution ◽  
Advanced Process Control ◽  
Line Scan ◽  
Advanced Packaging ◽  
3D Information ◽  
Light Beams ◽  
2D And 3D

Abstract In this paper, Confocal Chromatic Microscopy was investigated to characterize the micro-bump fabrication process. We designed and fabricated in house a new detector that integrates through the same optical chromatic lens two light beams that are reflected into a 2D line scan camera and a spectrometer to obtain on the fly 2D and 3D information while scanning the wafer surface. We inspected 300 mm round wafers hosting arrays of copper micro-bumps down to 10 μm in width and 5 μm in height at post Cu growing and etching step. The 2D inspection revealed the presence of partial μbumps, shifted and missing μbumps. The 3D inspection could recognize shorter and taller bumps and determine the coplanarity of each bump population at die level. This information could be used to classify GOOD and BAD dies over the wafer, so that after dicing only known good dies would be used in the following advanced packaging step. In this way, the risk of shorts and / or missing contact is minimized when stacking dies either on a wafer or on a die.

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